Cat 777D Mining Truck

[modelman]

I have decided not to build the Marion dragline for several reasons but I am going back to the Cat 777D mining truck. From what I have heard this is the perfect size truck to be loaded by the Marion shovel like I have built. I am spending some time to see if I can make some tires which will be the deciding factor on this build. If I can make an acceptable tire then I will go forward with the truck. I am also making a rough wood mock-up of the truck to see if all the components will fit inside. I think my scale (1/30) will cause some problems because the truck is small and the way these trucks are designed there is not much room for motors, batteries, ESC's, etc. but I have to stay with this scale to match my shovel. I have started the master part for the tire and I am waiting on some small end mills to cut the tread pattern. Here is what I have so far -
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1133.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1134.jpg

[modelman]

I will post more pictures as I go. Making the master will be the hard part for me. I don't think the molds and tires will be to hard to build. Time will tell.

[9W Monighan]

Great idea Tom, We don't have enough rigid frame rock trucks. Hope you can fit all the components in. Maybe hide some parts in the bottom of the dump body like the batteries and have a removable cover to access them.

[Lil Giants]

3 3/8's = 85mm, tam trk tires are 83mm.

To propel the haul trk and to save on space you could use gearhead motors directly on the wheels, just like my Stahl Volvo adt. That truck has plenty of power & good speed too... though I don't know exactly the rpm.

[tc1cat]

Looks like a good start for the build. Gearhead motors would save lots of space. If you need any ideas for what to use for the electronics, you might want to get with rc farm guy. Not sure if this is his name on this forum but he has r/c'ed lots of diecast vehicles. He has helped lots of people with their vehicles.

[modelman]

Lilgiantsjoe-the tires are actually 3-1/2" dia.x1-5/8" i.d. I could not find any this size so I thought I would see if I could make them. I am thinking about dual g.m.'s in the wheels but not sure if it will turn. I have no experience with mixing in the radios but thought that may have to be used for turning. May need some help on this when I get there. tc1cat-I am just starting and not sure about anything yet. I am not to good at engineering and design I just start building and go from there and sometimes that gets me in trouble but I hope it will all work out. I may ask for help as I go.

[9W Monighan]

What did Sargent Gunny Highway say in Heartbreak Ridge? "Improvise Adapt and Overcome"

[modelman]

I got the tread pattern cut, now I have to slick it up and make the mold. I went with a simple design that I felt I could cut. I saw a tire similiar to this at 'machinery trader.com". Also some of the foreign sites that make tires have one close to this.-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1138.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1140.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1141.jpg
It will take me awhile to get a good finish on this.

[9W Monighan]

WoW that's really nice. How did you mill the slots? Do you have a small CNC mill Tom?

[pugs]

Looks great. Are you doing a silicone overmold of the master or something different?

[modelman]

Thanks steve and pugs-steve, no I do not have a cnc mill.(wouldn't know how to use it if I did). Did it all manually on my ole smithy. Took lots of set-ups and lots of time but I have patience when messing with things like this.
Pugs-I hope to use a two-piece flexible mold. I don't think the parts would release from a rigid mold without having lots of mold segments which would take a long time to make.

[Snochaser]

Your "old smithy"....Shopsmith?

[pugs]

Done on a manual 3in1 machine? I'm impressed.

[modelman]

Snochaser-it's a "SMITHY" brand (chinese made) 3 in 1 machine. pugs-when you don't have money you figure out ways to do things.

[td9clyde]

Nice job!!!!!! if those were a 7 by 25/8 or 3 i would order 4 i have no paitents for makin my own tires nice job really

[dirtpusher9]

WOW, those tires look great, Tom. How did you do your set up on them, did you make a jig or what?

[modelman]

Thanks joe- no jig, just slow and easy, 1 set-up, then 30 cuts then on & on. The 1st. set-up was just a straight in cut. Then I had to bolt a plate to my rotary table so I could mount it on an angle on the mill table. Then I made the 2nd. cut at an angle toward the center of the tire. The side cut was an easy cut but a tough set-up. I had to mount the rotary table tilted up on an angle. I had an old adj. angle vice under my work bench gathering dust that I hadn't used in years. I dug it out and realized if I could mount it to the mill table it would work. So I put a plate on it and mounted it. Then I put the rotary table in the vice and raised it to a 40 deg. angle and made the side cut. Isn't it amazing what we will do to work on our toys!!

[rc_farmer]

Tom, thats an outstanding plug you made there. I have no idea what a smithy, a 3-n-1 or any of that technical talk.........but that looks good.

[JAMMER]

Rod a Smithy 3 in 1 is a lathe mill and drill all in one. Ed

[modelman]

Thanks a lot sand craft transport & rob-all this talk about machinery doesn't mean much though, all that matters is what the results are. I have seen some great builds that the only thing used were hand tools. I don't know what tools you use rob but those pieces you made are amazing!!

[Finster]

That's a great looking tire plug you made. Well done! I look forward to seeing the mold and tires it produces.

[td9clyde]

won't the lugs be stickin out ????or is that used to make the mold and then the casted tire??

[modelman]

TD9-this part will be used to make a two-piece flexible mold. Then the liquid rubber for the tire will be poured into the mold. Let it cure then hopefully I will have a tire.

[9W Monighan]

Do you have to coat the master with varnish like they do with sand casting? That would aid in releasing it from the rubber.

[td9clyde]

ahhhhh now i get it lol sorry i just didn't grasp the whole concept but now i do i wish i could make a solid mold so i can use it quite a few times like at a tire plant or something there is too much of a process for me to make tires i think unless i can buy solid rubber lol

[modelman]

Yes steve, This is the hard part. Varnish will not work but I have to finish it really smooth so it will release. I wanted to use glass filled delrin for the plug because it machines easy and you can mold directly from it but a 3-1/2" pc. cost over $200 with shipping and I only need a 1-1/4" slice and I probably would never use the rest of it so I went with the mdf but finishing it will take a while.

[modelman]

TD9-it is a long and time consuming process but I didn't think I had any other options. I e-mailed a couple of the foreign sites and although they did not have exactly what I needed I was going to buy their tires anyway but I never even got a response from them. Not sure how to deal with them maybe it has to be in their language, not sure?

[mog]

do you need some delrin i shere i got some liking around at the shop for you if all you need is a 1 1/2 pice think it 4" but that onlu take seconds to make it 3 1/2 lol let me know we got some scrap think there is some 6" around too

[modelman]

Mog-thanks-maybe I should have ask around before I started. I am too far along now to start over but if this doesn't work I may get back to you. I am waiting for the silicone & rubber to make the molds and tires so I should know something in a couple of weeks.

[D8R]

Great looking tyres, will follow progress closely. To find tyres that matches are a very hard part, Have had som thoughts of building a Pete with lowboy to transport my D8, but then it is the tyre problem again.
I you find a easy way of making those you will solve a lot of problems for us others.
Dan

[modelman]

D8R-thanks a lot-I agree tires can be a huge problem especially when you are not building by the common scales. I did not want to make my own tires but I felt like I had no other options. This is not an easy solution but there is not a lot of work involved just a lot of time. For me making the master part was the hardest job. The mold and tires just require some time & patience. A machinist would probably make the master part from aluminum and you could spray the release directly on that and make the molds. I spent several hours with the finish on the wood part I made so the silicone will release from it. Hopefully in a few days I can see the results of my work.

[tracksntreadslou]

Hi tom ..Not sure how far along you are with your tires but i did find this site with supplies and alot of free intresting how -to vids ..Any chance you could give us a bit of a tututial on how you are going about it...Cheers Lou

http://www.freemansupply.com/video.htm

[modelman]

T-n-T Lou-thanks for the link but I already have my supplies. I have the molds started and I am taking pictures as I go along so maybe I can do a how-to if everything works out okay.

[modelman]

Okay fellas, I have a tire! I will try to show how I did this. First step-I bedded the master part 1/2" deep in modeling clay. I put 4-3/8" steel balls in the corners and sprayed in the release wax.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1146.jpg
Then I poured the top half of the mold-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1156.jpg
After this cured for 16 hrs. I turned it over and removed the modeling clay and the steel balls and put the stems on for fill holes and air vents and sprayed the release wax on this surface.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1150.jpg
I then poured the other half of the mold.

[modelman]

Aftter 16 more hrs. of cure time I separated the mold halves and this is how it looked-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1151.jpg
This is the molds ready for pouring the tires-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1154.jpg
I sprayed release wax on the molds and poured the black rubber mixture in the molds. To speed up this process I filled the bottom half about 2/3 full before closing the molds-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1155.jpg
I had the molds on a perfectly level table to pour in the remaining rubber. I feel this is an important step to be sure the mold is full and to release all air. If air gets trapped in the mold the tire will be flawed.

[modelman]

After an overnight cure I separated the molds and this is the first tire right out of the mold-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1159.jpg
Another-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1161.jpg
I have these stems on the side of the tire from the pour holes and air vents but I can grind these off and turn this to the inside and I don't think it will be a problem.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1160.jpg
Using this process I don't see any way to avoid this and I have a few tiny air bubbles on the fill side but I believe I can rig a shaker on the table and possibly solve this. I am happy with the results but will try to improve on the remaining tires. If anyone has any questions I will be glad to answer them.

[kerst]

Interesting! Thanks for sharing!

kerst

[9W Monighan]

WOW that is really nice. I think if you had a small autoclave that remedy the air bubbles. Can you put a ruler next to it for size?

[Iron Art]

Modelman, Those tires are looking good, I use a vacuum pump from Harbor Frieght and a garage sale pressure cooker as a vacuum chamber for moisture removal from Powder Coating powder, my thought is that would remove the air bubbles from the rubber. So far I haven't seen any problem with this lash-up. Fred

[pugs]

The urethane stuff I mold in my shop has do be "degassed", once mixed I place it in a vaccum chamber (with clear top) and pull a vac with a AC vac pump until it boils out. Then when molded you minimize the air bubbles such as you have in a simple hand poured mold.

The vac chamber I have is just a piece of 8 or 10" pipe with a bottom welded on, top machined flat and a piece of 1/2" lexan for a top sheet. Port in side for vac line from pump.

The tires came out very nice.

[Espeefan]

I know it's just a tire, but wow, that is really cool. Something like this is so easy to look at and say, what's the big deal, but the average street going person just does not realize the machining and effort that goes into creating something like a tire. There is nothing better then the feeling of creating something from nothing, even if it is a tire. Great job. It looks perfect. I can't wait to see what's next. I can truly appreciate the work it takes to creat something from scratch. I'm not a master at maching parts, but I've made some things for my own truck that turned out well, and they were much simpler then this. :D

[SonoranWraith]

Modelman, Those tires are looking good, I use a vacuum pump from Harbor Frieght and a garage sale pressure cooker as a vacuum chamber for moisture removal from Powder Coating powder, my thought is that would remove the air bubbles from the rubber. So far I haven't seen any problem with this lash-up. Fred

I have watched a few of vids on you tube and they all use vacuum for best results. Cheap way is to pour from a high height, 3 or 4 feet, that elongates the material and removes someof the bubbles. You have to have no air movement for this. I will try to track down vid I saw on this.

Awesome results for first attempt!!

[D8R]

Very well described! Congrate to the finished product.
Maybee there should be a seperate forum called "how stuffs made"
You should be first. Is it possible to cast different material in pattern? Do you use flexibel rubber or is tire hard on surface?
Dan

[9W Monighan]

How much shrinkage was there?

[modelman]

Thanks everyone-here you go steve-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1163.jpg
I lost almost 1/16" in dia. nothing in width-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1164.jpg
Iron Art-I have a vaccum pump that was used when building boats but that was in open molds. I have no experience with closed mold vaccuming,not sure it will work but I may give it a try. Since the molds are flexible the pressure may distort the molds and of course the tire. I do have a bleeder valve and gauge on the pump so I might be able to just have a slight vaccum and not force the liquid out or distort the molds. I may pull a vaccum on the molds just to see how they react. Pugs-the rubber I am using does not have to be degassed. Espeefan-I agree with you. At first I didn't want to mess with this but since this is a scratch build there is a certain satisfaction in making my own tires for the truck.

[modelman]

Sonoranwraith-I may try the vaccum but if it doesn't work the air bubbles I have are not enough to be concerned about if the other tires turn out this good.D8R-there is many different hardness materials to use and also rigid products. Here is a link to the company I used and you can see for yourself-
http://www.smooth-on.com/index.html
I used the vyta-flex-30 urethane rubber for my tires and they are flexible. You can see the flex here. The wheel of course will stiffen it but I think it is about right-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1165.jpg

[dirtpusher9]

Tom, that came out looking Great. If you don't watch it we'll all be asking you to build tires for us and you won't have any time for your build. Very nice work.

[td9clyde]

yea very very nice work i like those tires , just a lil bigger would be great lol

[kerst]

really nice!
In the past I have considered to make my own tires, but it became clear to me early on that it is quite involved. Finding the right tires is difficult, sometimes impossible and it is good to know how it can be done!

Thanks,

kerst

[modelman]

Thanks a lot joe & clyde & kerst- Joe-as slow as I am I doubt if anyone would wait for me to build anything. Clyde-If they were twice as big in dia. and twice as wide you might be calling me huh! Kerst-as the old saying goes "it aint rocket science". Anybody can do this. It just takes time & patience and take care of all the little details. Also 9W-on the dia., I did not measure the tire after I took it off the lathe. It started out 3-1/2" but I sanded it some so I might have lost some there. It may not have as much shrinkage as I thought.

[jffhrvstr]

nice work on the tire!

[modelman]

jffhrvstr-thanks-I am pleased with it.

[BigZracingRC]

wow thats impressive! im going to try this!

thanks

zach

[Rogue]

That sir is quite impressive. And not just the final product, but the entire process. You have my respect.

[Finster]

Awesome job on that tire! Thanks for the mini picture tutorial on how you did it. Seeing your results makes me want to try it myself. Are the supplies very expensive?

[modelman]

Thanks Guys-BigZracingRC-you should try this. It's not that hard. The rubber comes with very good instructions. Just follow them exactly and you should get good results. Rogue-thanks a lot-I don't mind sharing what I do. Finster-thanks-the prices are not too bad. Look at the above post #47 and the link to "smooth on" and you can see prices and all kinds of good info.

[tracksntreadslou]

Good work Tom Ireally like the way they turned out ..did you have to add dye as well?
Its really great that you shared all that with us ...Thanks

[modelman]

TnTLou-thanks a bunch-yes I had to add the black color to the rubber. It only takes 4-tiny drops per tire.I have all the tires made so I am going forward with the build.-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1173.jpg
I think it is going to be a challenge to get all the components in the truck but I am giving it a try. While I am waiting for more material for the wheels and chassis I have started the front wheels. I am making the wheels in two pieces. They will be bolted together and clamp on the bead of the tire to prevent slippage-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1174.jpg
Here they are together-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1177.jpg
That's all for now.

[9W Monighan]

Keep it coming Tom

[td9clyde]

looks great!!! keep up the awsome work

[SmallHaul]

Great job on the tires.:cool:

[dirtpusher9]

Tom, those tires look like you just got a delivery from GoodYear. They look good on the rims also. Have you started on any of the rest of the truck yet?

[modelman]

Thanks a lot guys-joe-it is gonna be slow for awhile. I am trying to gather up a lot of the parts and pieces. I am having to use mail order for everything and it is TERRIBLE!!(slow,slow,slow). A few months ago I was ordering stuff online with a credit card and someone jacked my card info online and lightened my bank account by several hundred$$$ :eek: before I realized what was going on so I am thru with credit cards. Lesson learned. It's a sad old world we live in now but I guess the Internet and the thieves are here to stay.

[td9clyde]

thats sad when someone takes your info and drains your stuff there is a way to do this 2 accounts one for ordering things and make shure there is just enough to cover the charges and the other is a safe account that you don't use for purchasing items .................and i really like those tires you will have one nice truck very cool keep up the great work

[ihbuilder]

Tom , the tires look great same with the rims . ? , Did you order from smooth on directly or a independent dealer ?

IHSteve

[modelman]

IHsteve-thanks a lot-I used this place because it was closer to me-
http://www.reynoldsam.com/

[ihbuilder]

IHsteve-thanks a lot-I used this place because it was closer to me-
http://www.reynoldsam.com/

thanks tom , I also got 1 close to me , I was just wondering I f you dealt directly with them . but I'll check around for the best $

IHSteve

[modelman]

Well, it seems like gearmotors to fit this truck are made from the rare material
"unobtainium". I only found one that would work and is a little to fast but I think it will do. It is to long so I had to get creative with the rear wheels but I have it worked out. This is the complete set-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1178.jpg
The gearmotor extends all the way thru the inner wheel-

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1179.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1183.jpg
Here is rear wheels assembled-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1181.jpg
I have more holes to drill and tap and I have to make a hub cover. I am using 2-56 screws. I tried the 0-80 screws but could not tap the holes. Broken taps,stripped holes, ruined wheel-disaster! But the 2-56 size is working good.

[9W Monighan]

Glad to see you're making some progress. What RPM are the motors?

[pugs]

For the small holes in aluminum you should be able to use forming taps, which are much stronger. Just remember that they require a slightly larger tap drill to work. I have hand tapped some 0-80's before with them and it is quite easy to get very nice threads.

[modelman]

Steve-I have had some problems working this out. Hard to get my brain in gear. The motors are rated at 65-RPM@12V so I will have to adjust voltage. I think I can use 45-50 RPM so maybe 7.2V? I haven't got that far yet. Rolling the wheel on the table works out to 50 RPM but I will have to get it actually running to tell for sure. I had-1-more picture but for some reason it will not load. Now that the width is worked out I can start the chassis.

[sparkycuda]

Your tires turned out just great! Wheels and wheel motor assemblies should save you a lot of space in place of a diff, driveshaft and single motor. This truck will look great next to your shovel.

Ken

[modelman]

sparkycuda-thanks and you are right. The motors in the wheels save a lot of space and that is very important on this build. Pugs-I don't know what a forming tap is:confused:. I used new hss taper-bottom taps. My chart does not go smaller than 2-56. What size drill bit do you use with 0-80 taps? I used a #60.

[pugs]

A form tap has no flutes or cutting edges. It creates the threads by displacing the metal into the shape (basically makes a thread that is strong like a forging). Because it displaces it requires a slightly larger tap drill. Since it has no flutes (some have a reliefe for fluid to escape blind holes), it is a much stronger body tap which is a great thing in the really small stuff.

Balax makes some great form taps
http://metalworking.mscdirect.com/CGI/NNSRIT?PMPXNO=1907339

PM me your addy and I'll send you a small tap drill chart that goes down to 0-80 and shows form tap drills. One of the tooling places I buy from sends a chart with every order, I have a few around the shop, could spare one.

Tap drill for a cut type tap 0-80 is listed as 3/64 which is .0469", the #60 is .0400" so you're right in there. If it were a forming tap it would need to be drilled with a #54 which is .0550" And form taps a a bit more particular about using the proper size tap drill due to the way they work.

[9W Monighan]

sparkycuda-thanks and you are right. The motors in the wheels save a lot of space and that is very important on this build. Pugs-I don't know what a forming tap is:confused:. I used new hss taper-bottom taps. My chart does not go smaller than 2-56. What size drill bit do you use with 0-80 taps? I used a #60.

Tom, On my 0-80 adventures I started using a #56 (.0465") drill but broke taps occasionally but when I got the correct size: 3/64" (.0469") that did the trick the extra .0004" made a difference in steel. I also took the Dewalt drill and ran the 3/64 drill into the holes to possibly remove a tiny bit of the burr or what ever was on the holes after drilling in the mill. On your aluminum it may be tricky to not get the tap stuck. I use Cool Tool on steel and Alumatap on Aluminum for fluid. Brass I tap dry. Are those holes blind? That makes a bigger challenge to be able to get the chips out. You'll have to turn some then back out several times to keep chips from packing in the bottom.

[pugs]

Are those holes blind? That makes a bigger challenge to be able to get the chips out. You'll have to turn some then back out several times to keep chips from packing in the bottom.
Yet another advantage of form taps.....no chips.

They work good in steel too, I just don't usually have steel to tap.

[modelman]

Thanks for all your help guys. Sounds like my small drill bit is one problem. 0-80 screws are new territory for me. Steve the holes go all the way thru and I am using "Anchorlube G-771" cutting fluid and it works great for drilling. Is it wrong for tapping? Also the tap I broke did get stuck. It wouldn't turn either way so I knew I was in trouble.

[tracksntreadslou]

Hey tom motors of choice look pretty good...What rpm are you going with and what kind of torqure ..Hey guys thanks for the tips on taps ...very usefull info

[RCTech9]

Looks Good!!!

[grumpygrady]

be very glad they did it with your credit card
you can get every penny back when you call your bank
can't do that with checks or cash
they got my wife and i last year for almost a grand and it was back in our bank in less than a week '
and if you don't want anything just cancel the payment no fighting to get your money back

Thanks a lot guys-joe-it is gonna be slow for awhile. I am trying to gather up a lot of the parts and pieces. I am having to use mail order for everything and it is TERRIBLE!!(slow,slow,slow). A few months ago I was ordering stuff online with a credit card and someone jacked my card info online and lightened my bank account by several hundred$$$ :eek: before I realized what was going on so I am thru with credit cards. Lesson learned. It's a sad old world we live in now but I guess the Internet and the thieves are here to stay.

[SmallHaul]

Very nice work Tom!

[modelman]

Thanks guys-TnTlou-the motors are rated 65RPM@12V and they only give stall torque which doesn't mean anything but it is 270 oz. in.. I think 7.2V may work but I don't know yet. grumpygrady-the bank has been good about this. SmallHaul-thanks-I am slow but it is coming along. Also-lou isn't it nice to have machinist on here to tell us what we are doing wrong!

[dirtpusher9]

Nice machine work, Tom. Do you think your going to have enough room for everything?

[Stuff]

they look very good! if i ever make such a truck ill hit ya up for some tires :D

[modelman]

Thanks a lot DP9&stuff-joe-I think it will work. Probably the biggest challenge will be the dump mechanism. It will have to be some type of screw drive. Even if I could afford hyds. there is no place to put it. I'm not much of a designer I just start building and when a problem comes up I try to solve it. It is the only way I know. I have some ideas on the dump but I have a lot of work to do before I have to jump on that.

[JAMMER]

Very nice work those tires look great and so do the rims keep it up. Ed

[modelman]

Thanks jammer-while I am waiting on more parts & pieces for the chassis I was able to get the rear wheels finished. Here is a picture of the back side I had problems loading the last time-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1190.jpg
Here is the outside finished-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1192.jpg
This is a mini tapping fixture a friend made for me. It holds everything nice and straight when tapping holes-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1187_00.jpg
The chassis is next and we will see what kind of challenges that brings up:eek:

[pumptech]

Hey modelman : The tires you made are perfect,great work.
That's a neat tapping rig,I like that, bet it works great.
Looking forward to seeing the chassis.Keep the pics coming.

[Lil Giants]

1st class craftsmanship with another fine build Tom. :cool:

[dirtpusher9]

Tom, they look factory made. Can't wait to see this a little futher along.

[Iron Art]

Like those Tires and Wheels! I need one of those Tapping fixtures, seems like evertime I get out a 0-80 tap I need 2 of them to get the job done, gets expensive. Fred

[tc1cat]

Tapping fixture can be gotten from Micro-mark. Get the arbor press and the drilling/tapping add-on. Have been using one for years. Much faster than trying to hold in your hands.

Lynn

[modelman]

Thanks a lot everyone-I hope to make some progress on the chassis now. The front steering blocks are going to be tough for me to make but hopefully in a couple of weeks I can have a rolling chassis. Iron Art-the tapping fixture works great for me. I have always had trouble trying to start a tap straight by hand but this takes care of that. I am still struggling with the 0-80 screws but have managed to get a few tapped. These are really small for my tired old eyes.

[modelman]

I have the chassis almost done. This truck is way overbuilt for a model this size but I scaled from a 1/50th scale norscot truck and this is how it came out. I have more to do but I thought I would share a few pictures. This is how I started-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1196.jpg
Start of the front axle-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1198.jpg
Bolted together to check fit-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1199.jpg
Motor carriers-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1200.jpg

[modelman]

Next I made the hardware to hold the carriers and installed all this-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1202.jpg
I then finished the front axle and all the front end pcs.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1206.jpg
Put all this together and the chassis is built-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1218.jpg
I have more milling to do but I may get the cab started so I can work on several pcs. at once. Next I added the wheels-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1210.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1211.jpg

[modelman]

When the truck is finished and I know how much it weighs I will try to find some springs to put in the rear cylinders to give it a little bounce. The holes are only .180" and I may not be able to find any springs heavy enough but then I will just braze the shafts solid-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1212.jpg
The steering arms will need to be cut off but that won't happen until the radio is installed-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1215.jpg
That's all for now-back to work.

[sparkycuda]

Wow, the frame and axle setups are great! Ingenious method of mounting and suspending the drive motors - and really nice work on the steering pieces. I hope you can find suitable springs - the axle movement under load would look good and let the truck keep tires on ground over uneven road. Hard to imagine the smaller size of all that machinery you have in there. How 'bout a soda can or something in a future picture, for size comparison? Lookin' nice!

Ken

[Dreamweaver]

Very impressive Tom, and the most impressive part is that you made everything but the motors. Those wheels look great.

-Mike

[Jared]

My first reaction was "it's way to short!" but when the box and cab/hood is on it'll be just right I imagine. I like the suspension setup. I don't know about your part of the country, but around here Ace Hardware has a pretty extensive spring selection.

[modelman]

Sparkycuda-thanks,that's the only way I could figure out how to mount the motors and keep the wheelbase correct. Dreamweaver- thanks a lot- I do enjoy making all my own parts. That way I've got nobody else to blame if something goes wrong!:eek: Jared- yeah it is a short little "bugger" but it is correct according to scale. I think it will look different with the cab and dump bed on.

[Snochaser]

Once again your setting another high bar. Great work!

Ben

[Finster]

Wow, really nice progress so far. She will really complement your shovel when finished. I was wondering with the rims you built how does it attach to the motor, setscrew(s) or some other way? Thanks. Keep up the great work.

[pugs]

It's looking really good! I love the motor setup.

I have to ask, maybe I'm missing something. How will it steer? I mean it looks like the steering arms will hit the frame rails when it turns?

[lorenzo]

Hey Tom,

that's looking very nice. A very seldom seen model. Keep the good work coming along.
How did you mount the gear heads into the rims? Did you get some extra bearing on the end of the gear heads to avoid bending?

[Espeefan]

Wow. There is no shortage of talent these days on the forum! I am totally impressed by the chassis, wheels, and tires. You are building a heck of a model, Modelman! I like your machine work and the chassis is looking really good. I'm curious how your steering will work out. It looks like you might get a little interference with the knuckles and their arms hitting the chassis, but maybe you don't need that much angle, and I know you said you'd machine the arms down, once you got your radio gear.

I cannot wait to see this project finished! This is all just so neat to see come together. Looking forward to the updates, as they come.

[dirtpusher9]

Tom, are you sure you didn't find a factory kit somewhere and been holding out on us, lol because it sure does look factory made. You are one of the pro's at this model building. Can't wait to see more.

[modelman]

Snochaser-thanks for the kind words. Finster & lorenzo-thanks a bunch-without a lot of room, set screws are the only way I had of holding the motors to the wheels. I think it will hold okay with some good loc-tite. pugs & espeefan-thanks-the frame rails have to be milled down. I couldn't make the steering blocks any taller because the pins are already over 1" long. Since they are only .150" dia. I didn't think I could machine them any longer and keep them straight. DP9 joe-yeah you got me-it is factory made-but the factory is my "little ole workshop". Thanks a lot.

[td9clyde]

looking geat very nice work everything looks like it came from a factory build but you are a pro and very paicent looks great keep the pics comming

[modelman]

Thanks TD9-but factories are not supposed to make mistakes. I messed up on the angle of the front bumper and I really don't know how I am gonna fix it.:confused:

[td9clyde]

machine or cut a lil off or take a lil out of the bumper or off the rails then make a lil shim to shim it back outwhere you need it .....i had to cut the D7 front end off today and raise it all up a half inch cuz of the angle of the pic

[kamyoncu]

It seems pretty cool hand made truck

[modelman]

kamyoncu-thanks-I'm having fun building this. I fixed the problem with the front bumper-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1230.jpg
sparkycuda-here is a size comparison pic that you wanted-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1229.jpg
I started the sheet metal work on the cab and just have a little bit done. This is gonna take awhile. Here is how I started-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1219.jpg
That's all for now.

[pugs]

Looking good. I see the cutouts for the steering arms now as well, that clears it up. Can't wait to see more progress pics.

[Iron Art]

Modelman, I aways smile when I read the fact that the forum says you are a Green Horn. I can assure you that you are no Green Horn in the model making hobby, Like the new project that you have taken on! Fred

[modelman]

pugs-it's making a little more sense now but this is not a very good picture. I will show more when I get a little further along. Iron Art-I feel like a "greenhorn" when I am messin with this silly computer. Some of this stuff I just can't get into my head.:confused:

[rc_farmer]

Greenhorn you are not......with those maching skills. Gonna look nice with a load of coal on the back

[modelman]

rc farmer-thanks a lot. I will be glad to see a load of anything on it!! I won't be working on the truck for awhile. I have to go into the hospital tomorrow for some foot surgery and I will be doing some r & r in front of the tv for a couple of weeks and then I should be ready to get back on the sheet metal work.

[td9clyde]

thats some nice work on your truck .......sorry to hear about your foot i hope everything goes well for you

[modelman]

TD9-thanks a lot. The surgery went well and I am feeling okay and a few days in front of the tv is good but now I am bored out of my mind!!.I have to stay off of the foot for 2-weeks so I guess I have more tv to watch. I really like watching college football but when that is over I am not sure what I will do. I guess I can read all these build threads over for the 10th. time then maybe I can get back to work!!!

[Lil Giants]

I really feel for ya Tom, BTDT with a pelvis injury, time almost seemed to stand still... you probably didn't want to hear that last part, eh? :D

Wishing you well and a positive recovery. :)

[9W Monighan]

Get yourself a CAD program and sit there and design all the pieces you need to build on the Triple Seven!! This usually takes longer to do than actually building it.
What happened to your foot? My wife is having problems with her's from standing at work all day.

[modelman]

Joe-thanks, I understand. A few days are okay but then-WOW!! Boredom sets in but all we can do is wait. Steve-I wish I could afford a CAD program. I would like to know how to do that kind of work. All my problems are diabetes related. All my toes are curled under from nerve damage and I developed an ulcer on my 2nd. toe from it pressing so hard on my shoe when I walk. They put a steel pin in the toe and cut the ligaments so the bones can fuse together and keep the toe straight and in 3-4 weeks they will remove the pin. So I think I have quite a long road to recovery but I think I can work some before it completely heals up. I hope so!!

[pugs]

I think Google sketchup is free, and know a few people that have used it. It's not a high dollar program but it can get things further ahead than napkin sketches.

Good luck in your recovery, hope you get back to the model soon.

[Jared]

I downloaded Alibre for a free 30-day trial period and after that it switched over to a stripped-down version. I can't print out drawings now, but it's still fun to play with and when the day comes for me to cough up 100 bucks for the full version I'll have some cool stuff ready. Hope all goes well with the foot.

[modelman]

I finally got some work done on the Cat truck.I had the lower body almost finished but it was not level and was a warped and twisted mess and I could not correct it so I threw it in the trash and started over with thicker metal. I used .035" steel and some .050" brass and it is working well so far. Here is how I started. I made the rear of the front fenders and the rear of the lower cab first-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1285.jpg
Then I added the floor and cut the hole in the center.-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1287.jpg
This is the only space I have for radio gear-very small-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1293.jpg
Next I added the front pcs. of the front fenders-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1294.jpg

[9W Monighan]

I figured you were about due for an update. Hows the health?
On the dump body, you may have to build a fixture to eliminate the warpage. Too bad you don't have a TIG welder.
I'm just about ready to start up too on my boom point.

[modelman]

Next I added the tires to check clearances-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1295.jpg
Another-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1296.jpg
I had to make this small press to stamp the grille-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1300.jpg
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1301.jpg
I may change this later if I can find something better. I have never seen the radiator of these trucks so I don't know what they look like. I have a few pictures but not close enough to see details-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1298.jpg
Another-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1299.jpg
That's all for now.

[Papy]

....
I may change this later if I can find something better. I have never seen the radiator of these trucks so I don't know what they look like. I have a few pictures but not close enough to see details-
....

I can get you as many pictures as you need....just tell me what detail you want to see :)

[Lil Giants]

Nice fab work Tom, good to see you mobile again. :)

Have you seen modelkran's 777D model? May give you some ideas.

http://www.youtube.com/watch?v=CM0n0wvvTIg&feature=uploademail

[modelman]

Steve-my foot has healed up okay but now I am faced with shoulder surgery to repair a rotator cuff. The doc says I cannot use my left arm for 3-4 wks so I'm not sure how that is going to work. I will put it off as long as possible. The silver solder I am using has to get really hot (1400deg. I think) to melt and warpage is a big problem. I plan to use brass on the dump box and I don't know if that will help the problem but I may have to build a fixture like you said I'm just not sure how to go about that. Papy-thanks a lot-I would like to see a close-up of the grille. I don't know what material to use for this. I am not going for exact scale. I don't have enough info for that. I just want it to look close but mostly I need it to operate really good as a dump truck. Lilgiantsjoe-thanks a bunch-that is a very nice model in the link. I don't think my skills are up to that. I just want a working truck.

[td9clyde]

looking great keep up the nice work

[pugs]

Starting to look like a truck! Looks great.

[SmallHaul]

Nice progress! Its going to be a nice heavy truck.

[Lil Giants]

I don't think my skills are up to that. I just want a working truck.

What do you mean? :confused: You casted your own tires for goodness sakes, your skills are every bit as good as his. ;)

[pugs]

I'd say your pretty close
http://svsm.org/albums/Cat777D/IMGP2509.jpg
Found this guys pic album which has a lot of closeups in it, hope it helps you
http://svsm.org/gallery/Cat777D/IMGP2508

[9W Monighan]

Tom,you should be able to get a finer mesh screen possibly stainless steel. I've been to Cleveland Wire Cloth Co. before and they make all sorts of mesh. Heck I was leaving one time and rummaged through their scrap bin out side and found some real nice pieces but larger opening.

[Dreamweaver]

Here ya go Tom... Grill screen..

Plano Model Co. (http://www.planomodelproducts.com/scratch_scq.html)

Use the Morton Pattern (http://www.planomodelproducts.com/203.html)

http://www.planomodelproducts.com/203zoom.jpg

They have in in brass too.

-Mike

[modelman]

Thanks to everyone!! Pugs-that is a GREAT picture! All the pics on that site are good. Thanks for finding that. Steve-the mesh I used has .060" squares and I found some at smallparts that has .040" squares but I think I like the round holes much better. I made the grille removable so I could change this later. I am not pleased with the mesh look and I will probably do something different. Dreanweaver-that looks like just what I need. I like the round holes but I knew there was no way I could drill all those holes accurately. I will try to find out the thickness of the wire to see if I can form it and the size of the holes. This is a small truck (1/30 scale) so the size is important. Thanks for the link.

[pugs]

Mcmaster Carr has some really small hole stuff (like down to 0.006" hole dia) and everything in between.

Just search for perforated sheet and then click on round hole. Something like #9360T14 with .020" holes maybe.

[modelman]

Pugs-your right, Mcmaster-carr has a good selection. I counted the holes in the grille of the picture and with my figures It looks like I need .023" holes with .024" spacing but the closest they have is .020" holes with .040" spacing but I think that will work great. The brass has the thickness I believe I need but I would have to paint it silver. The s.steel would probably look the best although it is a bit pricey but I will decide on this later. I have a lot more work to do and I can change the grille at any time. Thanks for the help.

[modelman]

I got a little more done by adding the cab-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1325.jpg
I made this part removable since I may have to use this space for R/C gear-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1320.jpg
Now back to work----well maybe monday.

[D8R]

Looking good, will be a one of a kind model for sure. Have had toughts about a 777 to but that will be years ahead. So many project to build, so little time.

impressed of those tires, best looking so far.
Dan

[RCLogger]

Looking real good, you are moving along very fast. What is the scale of the 777 ?
Also what are you going to use on the dump box for power

greg

[modelman]

D8R-thanks-I chose the 777D because it is an earlier model and it goes well with my Marion shovel model. I have found a better way to make the tires to get a smooth finish on both sides so if the truck turns out really good I may make new tires. RCLogger-thank you-the truck is an odd scale (1/30). When I built the Marion shovel model I knew the 1-1 machine was really big so I made a drawing the size I wanted the model to be and it came out to 1/30 scale so I went with that. Then I made the truck to go with the shovel model. I will use a screw drive to lift the box and even that will be a challenge because there is very little room to work with. "Freddygeardrive" is going to help me with that and I'm sure I will need his expert guidance. I have a lot more work to do but I am enjoying it a lot.

[modelman]

I have decided not to use brass on the dump bed. It cost about 8 times more than steel but the main problem is that I cannot get the sizes I need in the flats for the braces. I would have to buy bigger sizes and machine them down to the exact size I need and this would involve a LOT of labor. Plus I would have to buy a radius cutting mill which is quite expensive so all in all it would have been a costly and time consuming deal so I decided to go with steel. I have the bed cut out and ready to put together-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1328.jpg
I got a local sheet metal shop to shear me some pcs. for the bracing. The cuts are smooth and straight and all I have to do is cut them to size and bend them into the shapes I need and braze them on.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1329.jpg
I have hours of brazing to do but then hopefully I will have a dump bed. That's all for now.

[D8R]

Better way to make the tires, you´r kidding, the ones you have now looks real good. Was it not possible to get the shop to bend U profiles for the bracing? that have saved you a lot of time.
Following progress, keep pics coming.
Dan

[modelman]

D8R-the metal shop had problems cutting the small pcs. that I needed so I don't think they could have bent the shapes on their huge brakes. I have a small brake so I can bend the pcs. into the shapes I need.

[modelman]

Well I got the dump box together after a lot of problems. I had to give up on the brazing because the thin metal would not take the heat without warping and twisting. I used a low-temp silver solder and it seemed to stick okay. Not as good as brazing but I had no choice.-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1332.jpg
I brazed the braces on the sides with them clamped down on the table but I knew I couldn't clamp the box together-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1333.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1334.jpg
I made one pc. of hand railing and using the norscot model I have the railing should be made with .090" wire but it looks big to me. If anyone knows the O.D. of the rails on these trucks I need to know what it is-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1336.jpg
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1335.jpg
I also made some of the detail pcs. while I was working on the box-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1339.jpg
I still have a lot to do on the box but hopefully the hard part is done.

[D8R]

Nice looking 777. Don´t know if Cat has standard size of railings, but on the D8 all are 1" tubing.
Like those wheels too (:>)
Dan

[Dreamweaver]

Tom http://i587.photobucket.com/albums/ss316/MJDreamweaver/References/Smillies/kidding54.gif This thing is looking awesome. Nice job on the metal work. http://i587.photobucket.com/albums/ss316/MJDreamweaver/References/Smillies/cheers2.gif

[kerst]

Looks good!

Kerst

[tc1cat]

Great looking truck:D If you want the handrails closer to an inch, try some .035" tubing or wire. It scales out close to 1". Your .090" wire is way out of proportion to the truck.

Lynn

[9W Monighan]

You sure are working fast. I figured you would have to go to the solder.

[ihbuilder]

tom you sure are a master :eek:

[Jared]

That looks great! Wheelbase doesn't look so stubby now with a box on it.
I'd take a stab at 1" railings.

[lorenzo]

Hi Tom, it's looking really good and heavy. Awesome steel work. Keep up the good work.
How did you cut the holes for the headlights?

[modelman]

Thanks everyone for the comments and input. On the handrails if I use 1" tubing as a guide that makes the rails .033". That looks way to small to me. I think I will try .060" wire which I used on the shovel and it looks right. I may make a small pc. and post a picture. Lorenzo-I milled the headlight holes using an .062" cutter. I had to go really slow but it worked.

[RAIDERS]

wow nice fab work love it....

[Espeefan]

Woah, you made a ton of progress, fast! That dump box and the cab look great! Nice to see you stuck with metal. By far nothing looks as realistic, when painted up. Can't wait to see the next update!

[SmallHaul]

Really looking good there Tom. Nice metal work.

[td9clyde]

looks great!!!!!!!!!!!!

[modelman]

Thanks fellas-lot's of finish work to be done but as you all know that's part of it.

[modelman]

I built the fuel tanks and attached them. I am not going for a highly detailed truck but as I look at pictures of these trucks a few things jump out at me such as big tires, dump box, fuel tanks and such. These are the things I am trying to add. The hand rails and front steps are probably the only things left that I will attempt-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1347.jpg
Papy is checking the size of the hand rails on the 1:1 trucks so I should know something on this in a couple of days.

[pugs]

Looking great

[pumptech]

Very nice job on the mining truck ,great work modelman:D

[CAT315C]

Very Good!!!

Congratulations

[9W Monighan]

You gotta have the hand rails and steps Tom. That will set any model off. Have you tried the perforated metal on the grill yet?

[modelman]

Thanks a lot everyone-steve you are right. The hand rails are important to the look of these trucks. And the steps make the front end complete. After I find out the size of the rails I am ordering some brass wire. I have built a couple of sets of steps out of .060" music wire just for practice and they are a complete disaster. The music wire will not bend without heating it up and I can't heat it and get it on my bending jig before it cools down so it's impossible for me to make 2 pcs. alike. I hope the brass will bend easy but making steps that small is going to be a huge challenge for me. I am going to use the wire mesh from McMaster-Carr for the grille but I haven't ordered it yet.

[Tamiya Cowboy]

Great looking truck Modelman you have done a great job.. Any idea of how much dirt it will hold yet..

[tracksntreadslou]

Exelent work Tom..Looks really good.Amazing outcome on those tires too..Really looking forward to seeing some paint on this brute...Can you post a few picks on size comparison next to you shovel...Cheers lou

[lorenzo]

Really nice work Tom. Did you already weight it?

For your handrails just a thought. Take a brass or cooper wire in the desired size, put one side in the vice and the other in the drill and twist it a few times. Now it will be smoothened and stiff enough to stay in the shape you bend it.

Just like this:

http://i28.photobucket.com/albums/c225/tacbob/Drahtversteifen.jpg

[modelman]

Tamiya cowboy-thanks a lot. The box holds 3-1/2-4lbs. of dirt. TnTlou-thanks for the nice words-I have the shovel stored away while I am building the truck but I will have it out soon and I will get some pics. Lorenzo-thanks to you also.Now that I know the size of the hand rails I will get solid brass rods for that. I don't have a weight on it yet but it is heavier than I thought it would be and there is more weight to be added.

[modelman]

While I am waiting on parts,(seems like that is a constant problem), I got the steering worked out. Very tight place to work but that has been the theme for this entire build. I had to make various parts to get it to work without binding but I finally got it right-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1351.jpg
The servo is hanging below the truck but I had no choice. Space is a big problem-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1348.jpg

http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1353.jpg
I still have a lot of parts to go into the small radio compartment but-1-step at a time and hopefully it will all work out.

[pugs]

Nice work, looks like the servo was made to fit there

[9W Monighan]

Tom, would one of those micro sized servos work? I'm not an expert on them but can somebody recommend one?

[Espeefan]

9W Monigham, you are making some great progress! I love how the 777D is coming along!

As for micro servos, I would stick to Hitec brand micro servos. They are the best bang for the buck, and the some of the strongest.

I'd say take a look at the Hitec HS-82MG, HS-5085MG, or HS-85MG. I believe they all have metal gears, hence the MG designation. They are around the 39 ounce to 59 ounce torque rating. I'm not sure how much power your truck will need, but these mirco servos put out the same power as the standard sized cheap servos.

[modelman]

Pugs-thanks it worked out good I felt. Steve-the micro servos don't have much torque in my experience with them. I felt I needed good power to turn the wheels with the truck loaded. The servo I used has 110 in. oz. of torque @ 6V. That may be overkill but better over powered than under powered I think. Espeefan-thanks for the comments but I don't agree with you on the hi-tec servos. They are very short lived in my opinion. I believe in Airtronics, but everyone has their own opinion. I ran Airtronics in my race boats for 10+ years and never had a problem with servos, recs. or transmitters and boats are killers on radio equipment.

[modelman]

I got the hand rails and ladders made.These pcs. did not turn out as good as I wanted but I knew this was going to be a problem for me. Some things I cannot do with bad eyesight. In my mind I am a perfectionist but with bad vision perfect is only a dream.:(.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1360.jpg
I scaled from the Norscot model to get the height of the hand rails so I don't know if this is correct or not-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1362.jpg
These ladders are only 2" tall X 3/4" wide.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1363.jpg
These parts will not be attached until all the body work is done since they would be too hard to work around. I will try to build the screw drive next so we will see how that goes.

[9W Monighan]

I'm having trouble seeing too Tom. I get really frustrated trying to see up close juggling between reading glasses and open eyes. I think part of the problem is the fluorescent lighting in my shop and the walls not painted white. I want to go to the eye doctor soon after taxes and some insurance payments.

[sparkycuda]

The truck is lookin' great. And, yes, the handrails and ladders add hughely to the overall look. This is really a cool build and looking forward to seeing how the screwdrive comes out. Are you going to put fake hydraulic cylinders on the truck or just go without any?

Ken

[Espeefan]

The handrails look great to me. I don't know the 1:1 777D inside or out, but from what I can tell, things look really good!

[modelman]

Steve-I know about frustration when it comes to eyesight. If I could go back 25 years when I had perfect vision and hands that didn't work like lobster claws I could build these parts easily, but it's a different deal now. I'm not complaining though, I just use what I have and go on. This stuff doesn't affect how the truck works and that is what matters to me. Sparkycuda-actually I haven't thought about cylinders until you mentioned it but they probably would look good. When I finish with everything else I will make that call. It all depends on the space I have. Espeefan-thanks a lot!

[dirtpusher9]

Tom, the truck looks good. It's going to be great watching it get loaded by your shovel.

[modelman]

Thanks joe-haven't heard from you in a while-how have you been doing? No work done on the truck.WHY? 2-weeks ago today-5 tornadoes ripped thru AL..At 6:00a.m. one took a N.E.path across Cullman Co. about 1-mile so. of my house destroying lots of homes and about 25% of the golf course. At 3:00p.m. another one went ripping thru downtown Cullman which is about 1-1/2 miles north of my house and it destroyed 6-churches,1-school, hundreds of houses,restuarants,factories,and everything in it's path. About the same time another one went thru about 45 miles north of Cullman and hit the Browns Ferry Nuclear plant which generates electricity for approx. half of Al. 39 towers that carry the high voltage power lines were destroyed and 50% of Al.was out of power. The city of Cullman was shut down completely for a week. People could not get gas for generators or there vehicles.No one could buy food,clothing or anything. It looked like a war zone with 25% of the city destroyed and will take years to recover. It is a miracle that no one was killed but there were a few serious injuries.Things are slowly getting back to normal but some peoples lives have changed forever. Seems these storms are getting more frequent across our great nation and it's amazing how much damage can be done in a couple of minutes. All our communication tools,(power,phones,internet) just came back on yesterday afternoon.

[ihbuilder]

dang Tom , I almost forgot you were in that area :o I've seen pics of the damage :eek: never thought wind could pickup a steel train bridge and throw it a good couple yards down stream . It's good to hear your alright and most the folks in your area .

[modelman]

Yes steve-that was a scary day for a lot of us!! Several other cities were hit hard also. Maybe things can get back to normal soon.:)

[modelman]

I have been working on the screw drive mechanism for the truck for awhile now and I must say it has been "kicking my butt". I cut and hacked and re-made parts until I thought there was no way this was going to work but I finally got it right. This may be the shortest screw drive ever! I only had-2-"of travel on the shaft to make it work and something was in the way with every move I made. Oh well nobody said it was easy. Here are the pieces it took to make it work-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1383.jpg
I had some alignment problems with all the parts fiting with the gearmotor so a friend told my how to make this self-aligning coupler. It's really simple but works great-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1388.jpg
Here is everything put together in the frame-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1389.jpg
Here is a short video of it dumping-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/th_100_1394.jpg (http://s305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/?action=view&current=100_1394.mp4)
I need to get some shoulder bolts for all the hinge points and this part will be finished. That's all for now.

[steamer]

Tom. The screw drive turned out fantastic. You showed some real patience there, for it to fit in such a small space. Have you tried it yet, to see how much it will lift?
Rob

[9W Monighan]

I wondered where you've been hiding out. Hopefully your shop has some AC. That looks like it should do the job Tom. How much weight can it handle? I want to make one of those when I get to it on a Tonka like Scott's .

[modelman]

steamer-thanks a lot. It had me talking to myself for awhile but it all worked out. And yes,I tried it, it will dump a full load. Steve, no I do not have AC, I wish. I have been getting up at 6;00 every morning and working a few hours before the heat gets me. I spent a few sleepless nights wondering if I had enough power to dump a load since the lift points are so close to the hinge but it dumped a full load with a half-charged battery pack and only drew less than 1-amp. The motor is rated for 2-amps so I think I am okay. I didn,t weigh it but it is a huge pile of dirt. Later I will weigh the load and let you know.

[rc_farmer]

Modelman, that is fantastic engineering there!

[dirtpusher9]

Tom, that is some nice machine work and engineering on the lift. This will be another incredible model when you finish.

[cbazq271]

nice! How much weight can you put in the box and still be able to dump?

[sparkycuda]

Very ingenious screwdrive! This model is quite mechanically innovative and your workmanship is excellent. Will be a real eye-catcher when in paint. Great work.

Ken

[modelman]

Thanks everyone-the main topic seems to be weight capacity so I decided to check it out. The dump box in this video contains 6-1/2 lbs. of dry dirt. It struggles just a bit at lift-off but handled it just fine-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/th_100_1398.jpg (http://s305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/?action=view&current=100_1398.mp4)
A normal load seems to be about 5-1/2 lbs. but I can heap it full and carry the 6-1/2 lb. load. The hinges just have 4-40 screws thru them now and are binding just a little. I think when I get pins installed in all the hinge points it will work better. I will know more later. Also everything is dry. I don't want to grease anything until it's painted.

[steamer]

Tom. she handles the load just fine. That's a good lift for such a short throw. After I painted mine I covered the screw with anti seize and it sure helped ease the drag on the thread.
Rob

[cbazq271]

Can't wait to see this in paint!!

[mazdaparts]

It looks great, I can't wait to see it finished.

[SmallHaul]

Your mining truck is looking good Tom. It will be cool to see it all painted up.

[cbazq271]

any updates

[modelman]

Thanks for the comments guys-I decided to make the hinge pins since I could not find shoulder bolts with long threads. Some of the pins are going into aluminum so I need lots of thread engagement. I am making these now and I have a few other small parts to make. Some of the small detail work I have been putting off has to be done before painting. I need to get a radio and ESC to check out the operation of all systems and I need to put limit switches on the dump bed and that is going to be a major pain because there is no room left. I have not decided what type of battery to use so I am open to suggestions.

[JensR]

I have used Tamiya shoulder bolts for their kingpins with some success.
Their thread is M4 and about 5mm long - maybe not enough for you?
If interested, check parts# Tamiya 50100 and 84175.

For the limit switches, maybe keep in mind that you can have the switch either actuated by the sliding "nut" or the dump box.

Battery: Sorry, cannot really help. I'm still using my old NiMH packs and have neither made the switch to LiPos nor bought new packs in ages.

Cheers
Jens

[modelman]

I had some small parts that needed to be made and I kept putting it off til later and now it had to be done so I can get this project finished. First I made this plate for the bottom of the radio box and it also serves as a shield to protect the steering servo linkages-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1404.jpg
Next I made the front wheel hub covers-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1408.jpg
I got the correct wire for the grille. This will have to be painted. They had this in stainless but the smallest pc. I could buy was $70+shipping and I only needed a pc. 2-1/4"X3" so I felt that was a bit high so I decided to paint the brass-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1406.jpg
Next I put the springs in the rear suspension and put these chains on to limit the travel-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1411.jpg
I put the limit switches on the dump mechanism-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1412.jpg
I won't route the wires until it's painted. I think that's about all the building on this model. It will be awhile before I paint it . I am waiting on the ESC now and I have a radio to test everything. I still have to decide which radio to get. I need a switch to run the dump box so I am open to suggestions on a radio. That's all for now.

[9W Monighan]

Maybe a DX3 is all you'll need for it? You know, Put it a box and send it up here so we can give it a endurance test at Brownsville in 2 weeks:D:D I would love to test it to see what grade the haul roads need to be in our miniature pit:p

[tc1cat]

Traxxas has a 4 channel pistol grip 2.4GHZ radio TQ 4 that has a 2 position switch and a 3 position switch for channels 3 & 4. This should work very well for your truck. I have 1 in one of my trucks that I am going to use with one of Izzy's bottom dump trailers. It runs the Firgelli with no problem. Tower Hobby has them for $103. Not a bad price for what you get.

Truck needs some paint!! Still looks nice as it is!

[modelman]

Steve-I wish it was finished-that would be a good test. While I am making a wish list I wish I wasn't 720 miles away. I would really like to go to some of these shows. tc1cat-thanks-that may be just the radio I need-I could use the on-off switch for lights and the 3-pos. switch for the dump box. I agree the truck needs some paint. I am sick of chasing rust!! But I have to get everything working with a radio before paint. There is probably holes to drill for wires and who knows what else. Maybe it won't be too much longer.

[td9clyde]

i would put a lil primer on it since your that close primer is easyer to fix :)

[Slick]

I can't wait to see it painted.

[modelman]

Just a small update-I got my esc and used my Airtronics M8 radio to test the truck. To my disappointment the truck is really slow:( and I mean crawl speed slow. It is running .385-MPH and the correct scale speed is 1.5-MPH. I guess I had brain-fade when I calculated the speed of the truck and ordered the motors and now I am limited to the motors I can use because they have to fit inside the rear wheels. I have located some motors that will work but they will be about 30-35 RPM slower than I need but that is as close as I can find so I guess they will have to work. That's it for now.

[9W Monighan]

Sorry to hear it's not working as planned. Luckily a quick motor change should do the trick. At least with a slower final drive it'll have power to pull hills.

[Smokin Joe]

I build 1/24 scale models for clients from pictures of "the one they
wish they still had" Right now I am building a Pro Street 2006 Camaro Station
Wagon! Chevy made one up to the clay stage and then dropped the prototype program for it. A engineer asked me if I could build him one. I found a resin s/w body on ebay. $9.99 My point is I have a guy who casts tires for me when I need. I would be more than happy to ask him for tires anyone needs. You have the buck built which is the most difficult part. He also can use different compounds to fit the application.
MicroMark sells a good rubber mold compound for use in silicone molds. You
would be able to make a 2 part mold using the correct mold release spray.
Any questions, please ask. Joe
Experience is what you get right after you needed it.

[Smokin Joe]

Very nice craftmanship!

[Smokin Joe]

Thanks TD9-but factories are not supposed to make mistakes. I messed up on the angle of the front bumper and I really don't know how I am gonna fix it.:confused:

If you don't make mistakes, it only means you are not doing anything! You a true artist.

[modelman]

Steve-the motors do not have as much power as I would like because of the size and speed but I filled the box and the motors I have worked just fine and the new faster motors have more torque so I think it will all work out okay. Smokin Joe-I'm not sure what your thought process is here but the tires were the first thing I made on this project and they are the correct size but thanks for the offer and for your comments.

[Smokin Joe]

Steve-the motors do not have as much power as I would like because of the size and speed but I filled the box and the motors I have worked just fine and the new faster motors have more torque so I think it will all work out okay. Smokin Joe-I'm not sure what your thought process is here but the tires were the first thing I made on this project and they are the correct size but thanks for the offer and for your comments.

I leaped before I looked. I was not aware you had cast your tires previous
to my post. An attempt to help. I admire your skills.
Joe

[Lil Giants]

Looking better with every update Tom... :cool:

[modelman]

Lil Giants joe-thanks a lot! I am slowly getting there!

[modelman]

UPDATE!! BAD NEWS-I got the truck painted and thought it turned out great:) But,that was a week ago and the paint is not dry:eek: So now I get to strip it down and start all over:mad: I think the idiot at the paint store gave me the wrong paint. Maybe I should just put it out in the drive-way and run over it a few dozen times with my truck!!! Then see if the paint is dry!! OH WELL!!

[Trucker47]

hey sorry to hear about the bad news,hopefully you can get rollin again soon.

Chris

[Lil Giants]

I'm no paint mixing expert by any means, but could it be as simple as no or not enough harder added to the mix?

Would it help to try and bake the parts in the oven at 100 to 200F degrees or more to quicken the drying time?

[td9clyde]

i usually mix things like that 4:1 :1 if it is three parts thinner and and hardner and the paint they sell mixing cups at the paint store those really help if you haven't done much mixin and i usuall add a lil more hardner and thin the last coat it will make it shine or if you let your truck set for a couple 2 or 3 weeks it will dry and be good paint

[9W Monighan]

If they gave him baking enamel,it will never dry unless it's baked at 325degF for a short time. I really doubt that would happen but you never know. We use baking enamel for steel beams and the over spray in the paint booth never dries.

[modelman]

Thanks fellas-but if it's not dry in a week it will never dry. I already have the sticky mess stripped off and have started over. All the bondo and primer have to be removed because it softened also. At the paint store I specified non-catalized Acrylic enamel. After all,I'm not painting a show car-it's a dump truck!! They mixed the color and said it would work just fine. After I painted it and it didn't dry I went back and they checked it out and realized it was the catalized type of paint. Did they care that I had-2-years work in this model-of course not. They offered to help out by selling me the catalyst. Oh well just another set back. Isn't model building fun!!

[ihbuilder]

Tom , I would've riped them a new 1 :eek: my paint always makes sure I have all I need when I order . sometimes a set back on my part I can deal with but when it's someone else and it cost me extra unnessary time , all heck breaks loose . All well can't wait to see it hualing dirt :)

IHSteve

[dirtpusher9]

That's a bummer Tom. I had this happen one time, because I painted in too high of humidity 98%. Hope everything goes well the next time.

[RCLogger]

Very Nice Tom

Hope you get the paint worked out and post some more pics

greg

[9W Monighan]

Any good news on the paint job Tom?

[modelman]

Yes steve-I have it painted and this time it turned out okay:)I am working on some small details and getting ready to put it back together. I will try to get some pictures up soon.

[modelman]

Well,I hate painting and I didn't want to paint this truck the first time and I really didn't want to paint it the 2nd time but I did and it came out pretty good. Not perfect but nothing I do is perfect anymore:(. Here is a few pictures-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1451.jpg
I had the 777D decals made and put on and I ask "Cat" for their approval and they said no so I had to cover them up.That really stinks because they added a lot to the look of the truck.
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1450.jpg
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1453.jpg
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1455.jpg
I had to put the radio switch and the dump box relay in the cab-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1446.jpg
I still have to get the radio and batteries but everything is wired so radio install will be quick and easy. Going by the space I have I only can use a 1300mah lipo pack and not sure about the run time with that. So ???

[FabOne]

Modelman-

I think you did a SUPER job on the paint. We always want to beat our selves up, but honestly, I think it looks GREAT.

-Terry

[pumptech]

Very awesome job on the mining truck ,looks perfect to me.:)Like the color choice,stickers as well.Lots of time and patience went into it.
Again, Awesome job Modelman :D

[Espeefan]

I think it looks good too! Just curious why you had to ask Caterpillar for their approval on the decals? I thought you only need approval or licensing for mass production models, for profit. Why can't the hobbiest build an exact replica and decal it, when it's a one off item? That really stinks, to say the least, that Cat doesn't approve. I am sure there are Caterpillar decals and stickers around that haven't been approved. Heck, I wouldn't have even asked. I don't think I'd let that stop you.

[JensR]

I'm pretty sure you could use the stickers - you may not sell it as a CAT model, but for personal use, I would be surprised if Caterpillar had any power over that?!
Still, they should be proud to fly their flag from this fine model, the paint came out really well.
(I might be tempted to black-out the radiator grill? And maybe paint the wheel motors CAT yellow or black?)

[sparkycuda]

Wow! It turned out just great. CAT hands out thousands of decals every year at career days and job fairs for kids to put on hard hats or any where the want, so I don't see a problem at all with adding them to your personal truck. They want people to put their logo on things to promote their products.

A first-class job on the build!

Ken

[9W Monighan]

Very nice Tom, Just print the decals the way they should. Like Nathen said; you only built this for your personal use.

[D8R]

Tom, had the same answer from a CAT (am I allowed to type the name?) official when asking about decals to mine D8.
As said by others, what´s the problem for a one of a kind model, not made for selling.
Some years ago when I built the 992 I got the decal maade by Cat at that time, guess it was better before!

Maybee we should start putting a DOG sign on our models.
Dan

[ihbuilder]

Tom , the triple 7 look great :eek: As for "CAT" decals put them on , if they give you a hard time tell them I'm renaming my 2 kittens :mad: won't take me long to pull the decal off ;)

[td9clyde]

looks great!!!! wouldn't have asked cat anything it is a one off

[fhhhstix]

The truck looks fantastic and I say put the decals on as well. Most on here know that I work for a CAT dealer and when I took my service truck to work they loved it. I asked for the prints to the decals for our service trucks to get some scale one's made for my truck and the smiles went away and I was politely told no. Cat has to approve the dealership logos and considers them an official CAT logo as well. I am having decals made and will have my name put in as the dealership name. The local sign shop said they had no problem making the decals and that they would make the text part of the decal separate and I could put the two together when I put them on that way they did not make the actual decal just parts to make it.

Travis

[modelman]

Thanks a lot everyone!! The decals are on the truck-I just covered the numbers for the pictures. Espeefan-I just thought it would be nice to ask. I didn't even think I would get a response, but I was really shocked when they said no:eek:. Their answer was "political mumbo-jumbo" and wasn't perfectly clear to me but I took the safe road. You can be sure that in my shop the decals will be displayed. I really like the way they look. JensR-according to the picture on page -7-of this thread the grilles start out stainless steel and I guess as they get dirty they look black. I may make a black one and see how it looks.

[Papy]

Anyone can spot the difference ? :D:D:D

http://i18.servimg.com/u/f18/12/58/20/29/p1000010.jpg (http://www.servimg.com/image_preview.php?i=67&u=12582029)

Great work, Joe !!!!

Ho ! and....about the front grill......it will look more dusty than dirty, so the color lying under makes no difference :p

[doodlebug]

Valid point papy! I've heard that Union Pacific railroad, are really big sob's when it come to modeling-no permission, and get caught, expect a lawsuit. That's really a dirty rotten low down shame on big business's part!
The truck look's super with the new paint!
Later, Neil#2 aka doodlebug.

[dirtpusher9]

Tom, the truck turned out great.

When I contacted Cat about building more dozers I talked with one of the wheels in Peoria, they said nothing about my decals and they were watching the videos so they seen the decals.

[JensR]

Those rules are just pathetic :(

I googled and I'm pretty sure the grille is black.
The photo on page 7 is dusty and hence might look like raw stainless steel.
But the black&yellow paint scheme is CAT's trademark, I guess they wouldn't put a silver grille on their machinery. ;)

[modelman]

JensR-I may be" old as dirt" but I think my eyes are better than yours:D.I don't see what you are seeing.

[Papy]

...
I googled and I'm pretty sure the grille is black...

I see (and sometimes even operate) a triple 7 everyday, and I can confirm it is originaly black on the real truck.

It's just that you only see the real color every 250h, when you wash it for a service :D:D:D:D

[modelman]

I see (and sometimes even operate) a triple 7 everyday, and I can confirm it is originaly black on the real truck.
That's good enough for me papy!

[JensR]

?
Google image source:
http://www.google.co.uk/search?q=cat+777d&tbm=isch

Or did I miss the joke about them being dusty?
Yes, they get dusty and then may look grey, but not like raw metal:
http://www.scpm-international-concassage.com/materiel-occasion.html
(I chose this one, because it shows part of the grille rather black and the other rather grey.)

[modelman]

I made a couple of changes. The original muffler was scaled off the 150th norscot model and I felt it was too short so I made the outlet pipe longer-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1463.jpg
I painted the grille black following "papys" comments-
http://i305.photobucket.com/albums/nn216/modelman/777D%20Mining%20Truck/100_1468.jpg
Just a few details while I am waiting on a radio.

[9W Monighan]

Now it looks better with proper identification. What radio are you going to use?