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.