Re: First build ,cat D11
 

The tracks are scale in width, I don't have any plans to measure from except the cat dimensions cats sites. Standard stuff like height, gauge, ect,,, I did get a die cast model 1:50 scale to " look " at and somewhat reference. I did break down last week and order a shop/parts manual for a cat d11r from eBay . Hopefully I will find some good info in them. As far as thick, they probably are. This is going to be somewhat scale in appearance (I hope to at least) but is intended to be put to work on our 1:16 scale trophy truck race track at a summertime Riverlot. Soil is pretty soft. Once disturbed (tilled) it will be like playing in a sandbox. Thanks for watching, and yes the tracks are a true test into self discipline and wanting to go beat my dog!!! (Lol, love animals, as in the one pic our 9month old Dane 150lb puppy has a pretty cushy life!!!)

Re: First build ,cat D11
 

Measuring the diecast is the only method I use to get dimensions for scaling. Measure what ever part you want to produce on the diecast, multiply by 50 to bring it full scale and then divide by 14.5 to bring it to the scale your building in. Building models this way keeps the proportions roughly the same and is what I call it. ( looks right scale)
Rob

Re: First build ,cat D11
 

Hey Cooper,

I am building a D11 as well, your tracks look awesome! I am doing a 1:14 scale, the standard track pad on the dozer is 36" scaled is 65 mm or 2.55" wide and appx 1.07" in cross section.

Re: First build ,cat D11
 

Thanks, I think my tracks are 2" wide, 1" long and 1/2" total height. Or slightly smaller, I used 1 x 1/2 stock to mill them. For these parts that come out in the thousands I just use a round number. For the most part I'm building scale but not going to be as detailed as a couple builds I've seen. Wow hats off to those guys! The one I saw could be passed off as the real thing just shrunk!!! And this is a first build for me so getting to understand the mechanics of working parts is more of the importance to me than exacting scale. But am trying to seep it real, close :)

Re: First build ,cat D11
 

Thanks for the input, I didn't know what others did in acquiring dimensions. So the measure, multiply and divide calipers will work just fine:)

Re: First build ,cat D11
 

Cooper-you are doing a great job on this build. Exact scale is not important to everyone. Most people do not have access to machinery to measure and photograph and the die-cast models are not 100% accurate. I always said I wanted a model that looked okay and work GREAT in the dirt. To me that is what matters. Keep up the great work!

Re: First build ,cat D11
 

Cooper I think you are doing a awsome job on these tracks so for ..Its alot of work and not just anybody can pull it off ...looking forward to up dates

Re: First build ,cat D11
 

Yes that is my goal, to look good but work great!!! Thank you for the encouragement and replies. Always like the input. As I don't really know what I'm doing I will try and post intentions and get feedback before I make the mistake !!! I am thinking of using acetal (plastic) for the rollers. Other choice was/is brass. I don't think the black acetal will look good but I could get yellow. Pros / cons anyone? I'm undecided on material for rollers. They are going to be straight shafts no bushings or bearings. So acetial or the brass will function on steel shafts well, right?

Re: First build ,cat D11
 

Just a close up of the material. This isn't final cuts, just eyeballed real quick to get an idea. Boy this stuff is fun to cut!! Like butter, actually softer than butter:)

Re: First build ,cat D11
 

Like your tracks. Do you have a cnc mill? Looking at a can router.

Re: First build ,cat D11
 

http://img.photobucket.com/albums/v1...202011/002.jpg

80lbs track hoe uses acetal rollers on steel shafts without any problems.

Your build thread is likely going to be filled with hundreds of pictures, you should look at linking your photos from a photo host site sooner than later. ;)

http://www.rctruckandconstruction.co...ead.php?t=4057
Photobucket is one option, there are other sites out there too, like Flikr or Image Shack. They're all free to use, just sign up & get started.

Re: First build ,cat D11
 

No CNC, for me it's Crank, read Number, then Crank again, that's my CNC, :D

Re: First build ,cat D11
 

Thanks lil'giant, I appreciate all your feedback. Guess it's just up to me if I want brass or acetal. I will try and get up with the photobucket rout. One more pic, I'm not a machinist, just learn from mistakes and others. This was a big piece for me to use a parting too on, my little lathe was talking pretty loudly to me and I didn't have the guts to cut it the whole way so the last 1/2" I cut with hacksaw. I got some 3 3/4" round pieces from local machine shop cheep so a lot of passes to get down to size and I don't have a band saw.

Re: First build ,cat D11
 

Cooper-I am also a "backyard machinist" self taught. I had problems with the cut-off tool until I learned how to sharpen it. If the tool is right and sitting at the correct height you should be able to go right thru that big stuff. Maybe some of the real machinist on here can help you. I think the delrin (plastic) will work just fine. In some cases it will outlast aluminum. Keep cranking!!

Re: First build ,cat D11
 

Cooper, awsome build! I really the way you designed those tracks.
I'll keep following you build closely.

Re: First build ,cat D11
 

Wow lots of cranking I would like to pick up a small cnc router

Re: First build ,cat D11
 

Very impressive work, Cooper. All manually machined too. That's awesome. Love the garage. It looks like a great place to spend a day hanging out. Nicer then some people's houses, or basements, I think! Looking forward to the updates.

Re: First build ,cat D11
 

Had some time to make the sprocket drive. I'm not sure about getting the shaft from motors to sprocket. I have to get some bearings and don't know what sizes I'll get so I just left it solid for now. But messed up the hole pattern on the first one so have to get some more stock. :(

Re: First build ,cat D11
 

http://www.servocity.com/html/20_rpm...ear_motor.html
Hey guys, got a drivetrain question. The link above is what I'm thinking for drive. One per side that will have beveled gears attached to get a 90 degree drivetrain. Rpm is 20. Should I be in a higher rpm range? And do you think these motors will be powerful enough? 1:14 scale. This is going to be a working model pushing pretty sandy soil.

Re: First build ,cat D11
 

These are the one's that Greg used on his Cat D8, 28lbs if I remember correctly? http://www.servocity.com/html/25_rpm...gearmotor.html
I bought some for my Cat D4H project.
Cheer's, Neil.

Re: First build ,cat D11
 

Nice work so far ..big step haveing the tracks done ..speed is ok or even up to 30 rpm ..If you have the room I would go a bit bigger on the motors as your is a D11
door window motors or Princess auto has some pretty stong small ones available

Re: First build ,cat D11
 

Be careful of the difference between stall torque and rated torque. I got burned by this last year when I ordered new motors for my EC300. I was using motors with a rated torque of 277oz and thought that ones with a stall torque of 500oz would be better. It turned out that they had way less power and were pretty much a waste of $80. When I asked Robot Shop about the different ratings I was told that the motors measured at rated torque would stall at roughly 3 times that number...I'm not sure if that is correct though. These http://www.robotshop.com/ca/en/cytro...gearmotor.html are what I use in my EC300 and 955K. They are on the slow side at 17rpm @ 12v and I am sure your sprockets will be smaller than mine slowing it further. I would recommend something faster for sure and possibly more powerful as well unless you were to up the voltage. These motors have plenty of power in the 19lb 955K but are way under powered for the 50lb excavator.

Reg

Re: First build ,cat D11
 

Hey Reg? So do you think 400oz in. Is big enough.
They seem to work just fine in Greg's video.
Cheers, Neil.

Re: First build ,cat D11
 

Yes I would say Greg's works really well. I'm pretty sure they are 400oz rated torque which would make them around 1200oz stall torque.

Re: First build ,cat D11
 

Thanks! I'm working on blueprints, for next year.
Cheers, Neil.

Re: First build ,cat D11
 

Here is another place to find some gear motors...maybe they have something that will work....I would use the biggest and strongest motors you can fit in the model !! Nice job on the build...lookin good !!!


http://www.robotcombat.com/products/motors_geared.html

Re: First build ,cat D11
 

Finally broke down and had to measure and make a plan :(. I just couldn't do it in my head. But I have a good idea of how the build will work. Had a couple attempts at getting the right scale from the parts catalog drawlings. Not all to scale and from page to page the scale changes. It's more for reference as to where the parts go, not really made for copying to a build scale. I'll have to get in touch with cat engineers and tell them to make their parts catalog more scale rc build friendly:lol:
And haven't settled on choice of motors/ drivetrain but thank you all for the places to look, it really helps me a lot!!

Re: First build ,cat D11
 

Merry Christmas everyone , happy holidays!! When I get back home I'll have to see what the usps, ups, and FedEx Santa Claus have left under my mailbox:)

Re: First build ,cat D11
 

Got the bogies milled out, working on track frame next.

Re: First build ,cat D11
 

Looks so cool in the unfinished state.

Re: First build ,cat D11
 

Wow! Beautiful job! Looks like it is "cat" approved too...

Re: First build ,cat D11
 

The bogies and rollers look great! Keep the updates coming.

Re: First build ,cat D11
 

Cooper-you are making good progress and it looks really good. I notice that the track pads are real close together and it looks good but are you worried that dirt may get in between the tracks and cause binding? Just curious.. Keep up the good work.

Re: First build ,cat D11
 

Model man, I hope not, well I really don't know as this is my first build and experience with construction equipment. There is some space I between pads. I wrestled with that for a while and realized the full size dozers have a similar overlap in the direction of forward projection, (when the cleats fowl with dirt the links and overlap help seal the gap by the direction of overlap). As the majority of time the cleats will be gripping while pushing a load forward, or pulling something. Not going in reverse, that's why tracks are directional. Guess it's just the better of the two. So I just went with the same idea but did try and keep the spaceing to a minimum, as my thought was to try and keep the larger stuff from not getting in. But like I said, I don't know, but boy will I be unhappy to make tracks again!!! Lol!!! They are a lot of time, more of a pain being the repetitive work.

Re: First build ,cat D11
 

Nicely done!!!
Looking forward to seeing more...keep up the great work!!!

Re: First build ,cat D11
 

Thank you guys, appreciate the feedback, so far I have made slight measurement changes just for ease of machining the parts. I don't think it will look out of place. I didn't realize that some of the cat specs are artists renditions and not always to scale, and I've been taking pictures of d9's. As the cat dealer just up the road from me hardly ever has any d11's sitting around. Too big and expensive for transport. With a price tag of 1.5-2 mill I'm sure they factor in some sort of site build cost. ? Anyway, I've started on rear wheel/bogie carrier. I know its a lot to mill out of one piece but I've got more time than $ and brains:). And then I don't have to line up bolt holes :).

Re: First build ,cat D11
 

The carrage and wheel suspension in making. The stock I had on hand was just about 1/4 " shy of the right height so if it looks not as tall that's why. I may bolt on something when it comes time for the top track carrier.

Re: First build ,cat D11
 

Got the main bulk of the suspension done for the wheels.

Re: First build ,cat D11
 

From the previous picture this is how much movement I'm planning. When the sharp edges are smoothed and final fit it will have a little more in the main wheel and a bit more for the bogies, to the best guesstimate of mine I figured this is enough movement. What do you all think? If too much I can install rubber blocks between parts and limit movement. As I planned on using a thin piece for shock suppression of metal on metal. Now that I said that out loud I kinda realize at this level (scale) I don't think aluminum hitting aluminum from 1/4" away is going to hurt anything :).

Re: First build ,cat D11
 

:) happy, happy, joy, joy!!! Got motors, sprockets, and chain today!!! These will definitely be strong enough, I think!?! The motors @ 12volts spin 116rpm, I'm planning on gearing down to 40rpm, at least that's where I'm going to be with the sprockets I got. I may change gearing to try and get down to 30rpm. I can also limit with radio too. It would have been nice to just have direct drive to the drive sprocket but running motors at that lower input voltage would be hard on em. Haven't found the best fit, configuration, of motors but just sitting there I may stager them like in the pic. I think I still will have enough room above them for hydraulics , battery (lipo) and controller (thinking saber tooth ) under the hood and drivers area. As I wasn't planning on detailed cab but lightly smoked glass so all that space can be utilized for electronics ect.