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 -

[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.-





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!!