Good post for a start
I am curious why you didn’t use an idler and a single long chain per side to drive the wheels.
I used two chains per side
I used two chains per side to maximize ground clearance between the wheels and chain wrap on the sprockets, as well as redundancy.
Thanks! Strong was the goal!
The motors are CIMs from andymark.com and have been the unstoppable workhorse in the FRC for years. They stall at over 130 amps but are never run past 40, per the rules.
.
I’m still figuring this site out 
Your response shows just how little I know.
Your reasons are so logical and simple. If I ever decide to build something following your current format, making use of your power transmission method makes great sense.
Wow, that’s a big one
Wow, that’s a big one indeed. We mostly see the little of mid sized robots which can not harm any cat but only a few bigger ones like yours. Are you planing of making him autonomous some day or will he always be relying on that XBox controller?
I agree with mogul, as more the better. You might post everything you have, even to failures, since we all learn the most of failed attempts.
Very Interesting
Very Interesting. We rarely see anything this big. I am trying to move up to a bigger robot on my second project and am discovering it can be challenging to find the right motors, controllers, etc.
This is very impressive. I would love to see more pictures of it as well.
Good luck with your project, thanks for sharing.
Big for this site, maybe.
I cut my teeth on robots close to 140 lbs in the FRC when I was in 8th grade, so I’m glad to raise the average weight of entries on this site by a little.
On the topic of autonomy, I enjoy driving these things too much to give them too much say in where they go.
alas, double post
Is there a way to delete comments?
Nicely Done.
Wow, that is a beautiful piece of machinery! Looks very rugged and sturdy. As everyone else has said, I am looking forward to more pics and a video. Those 10" wheels seem to be a favourite of many outdoor robot builders, if possible, could you post some pictures of the method you use to connect them to the sprockets? What kind of run time do you get with that SLA? Awesome work!
Thank you!
One of the goals for this thing was to make it tough enough so I wouldn’t be afraid of other people breaking it when they drive it. I regularly stand on it to demonstrate.
The wheels are great but I may make tire chains for snowy conditions. I’ll put a picture of the assembly up soon.
The run time is a bit of a letdown, but bigger/more batteries can be acquired.
I know a guy… Andy Baker…
Well, I know a site that has stuff, no, everything for bigger robots. I was a bit surprised not to see andymark.com in the list of stores on the “add component” page. That’s where you can get the motors, gearboxes, battery, motor controllers, and breakers I used, and I swear they’re not paying me to write this post, but maybe they should.
Yep, please do that average
Yep, please do that average weight raising, as we need some of the big guys here
Well, you could run that simultaniously, RC and autonomous, depending on the requirements. As soon as there is no RC signal it could switch to autonomous mode.
Wow, 140 lbs, that’s big
No, there is not such function to delete comments, but as long as nobody commented under your comment you are able to edit it.
Thanks for the more details
Thanks for the more details and the video. That’s a beast ;-)
RC vs ROBOT
I appreciate the sheer size. Its a welcomed change from the ‘desktop’ varieties. However, I would be hard pressed to call it a robot? A robot should have some level of autonomy; sensor(s) to probe and react to its environment and be capable of being programmed. I think its fair to say that what you got there is a RC4WD.
The age old debate
I completely understand where you’re coming from, and I have seen this subject discussed before a few times with but one consistent result: “robot” is a big grey area. I agree, right now this project is a glorified RC …thing. Then again, it could be called a “robotic platform” or similar. I’m far from done with this machine, some level of autonomy may be in its future. I really just wanted to get it driving before Christmas
I don’t want to take sides
I don’t want to take sides nor I want to discuss that much more because I have commented this kind of topic several times and I believe that RC and robot should be separated.
However, as long as it’s still in a developing state it’s fine for me to see it in the robot section. And most important, it’s cool :-))) And frankly, there are much more so called robot projects in the robot category with just one picture and two lines of text which bothers me more than this post.
Again, that’s my opinion, i do not want to judge nor disabuse anybody…ALABTU
It reminds me of the Parallax QuadRover!
This is a great build! I bet if you went with a “drop-in” LiFePo battery (meant as drop-in replacements for common size SLA batteries like the one you are using), you would get excellent run time; LiFePo batteries are really lightweight (but much more expensive than their equivalent SLA). Some may require a special charger, but it might be something to look into for this build. The chassis style reminds me of the Parallax QuadRover (minus the engine and hydraulics). Hmm - there’s a thought: take one of those small Honda gen-sets, rip out the inverter - and go hybrid!
that, my friend, is an idea
that, my friend, is an idea which we will apply to one which requires clearing the garage out enough to make room ;D
Nice
Wow, really nice
My son and I are in the process of building what seems to be very similar to your build. Almost same kind of wheels. We plan on using one or two batteries from a car, and will end up with a very heavy robot.
For control we are quite far down the line with an Arduino + Raspberry Pi setup, where the Rpi is setup as a LAMP and with 3G connectivity. Control is via a web page, but algorithms for autonomous actions is under way. The Arduino is handling motorcontrol and inputs from GPS, sensors, compass etc.
We are on a budget, so for motors we are using two wipermotors from a truck (24V), but they have quite a bit of tourqe at 12V too. Right now we are struggling with the connection of gears to the wheel hub, and your solutions gives inspiration - thanks. If it is possible I would love to see more pics of the whole drivetrain.
My question is. Have you tried yours with a heavier load. Would it be possible for you to make a video of how it would perform with the load of two ordinary 12V 60Ah batteries from a car (or similar). I am very curious.
/Niels