Started with 6mm hubs and drive sprockets for the tracks, using 2 sets of 3 inch tracks for each side. I made custom axels 6mm on ends and 1/4 inch in center. http://home.comcast.net/~ccook1289/tank1.JPG
For the support wheels i used OFNA Racing rims, these wheels have 3/8 inch hubs that came with them. Those motors i got from harbor frieght they are 14.4volt cordless drill motors. http://home.comcast.net/~ccook1289/tank2.JPG
I proto typed it out of wood to make sure everthing would work right before i bought aluminum. I plan to mount the motots in the center of the robot to keep it balanced, and use the drive chain and sprockets to transfer the motion. As you can see i have started the final process of mounting everything to aluminum plate i bought. The bearing for the lower wheels are standard skateboard bearings 3/8 inch bore. http://home.comcast.net/~ccook1289/tank3.JPG
This will give you a good idea of what the final track will look like. Still waiting on the 1/2 inch aluminum rods to make support between the halfs. The track doesn’t sag so much with the other side on. http://home.comcast.net/~ccook1289/tank4.JPG
Robot number 5
http://home.comcast.net/~ccook1289/tank6.JPG
Robot wars? http://home.comcast.net/~ccook1289/tank7.JPG
I got a sabertooth 2x5 motor controller its seemed to be working fine, could control both motors kinda. Then the sabertooth started to smoke did i burn it up and is there something i could do fix it. The blue light only comes on for a second when i turn off the power to it.
You might want to try the Sabertooth 2X10 that can handle 10 amps/side contiuous and around 15 amps peak.
I have a Sabertooth 2X5 running four GHM-04 motors without a problem. However, I have the Sabertooth 2X5 mounted on a 2"X3"X1/4" piece of aluminum for good heatsinking.
I suspect that your Sabertooth 2X5 is fried. If you do invest in a Sabertooth 2X10, I would heatsink it to a 1/4" thick piece of aluminum of a resonable size to help improve its thermal dissipation.
I’d expect you will need even more than 10 amps per channel with these motors. I tested some 12v cordless drill motors, and they would draw over 34Amps at stall, and they dropped my supply voltage from 14v to 4v.
Anyway, I was looking at this controller: VNH2SP30.
Which should do the trick if you put a heat-sink on it.
Also, you moght want to give John an email from dimension engineering as he was looking for some beta testers for the new sabertooth 2x25 not long ago. You might be able to get one for free if you are willing to push your robot to the limit. Check out this thread.
That is a great suggestion! Personally I felt bad none of us seemed to be doing anything high enough power to really take advantage of his generous offer. This project certainly seems like it would be right up their alley. Nice job on your mechanics by the way, really well done.
firegod819 don’t plan on making a suspension for the tank, was thinking about adding an arm could double as off set balance.
I recieved my 2x25 sabretooth motor controller . I tested if for 2 hours and had no problems with it at all. (Well the flower beds are my fault). Next test i will try to run 2 batteries on it to give it more amps. I will try to get video of the tank in action and post it here.
Thanks again kroony for pointing out johns topic and Special thanks to john for letting me beta test the 2x25 sabretooth motor controller.
No worries, you’ll have to really put it to the test and see how hot you can get it, or how much weight you can drag around(without wrecking anything of course).
Did more testing on the 2x25 gives the drill motors enough power to unthread the sprocket off the drill. No matter how hard i tighten them a couple back and forth moves and they unthread. I will have to shorten the screws that came with the drill to prevent this problem. (Reverse thread to hold drill head on)
I would like to say i thought the lynx motion sprockets are alot stonger then i thought they would be. I beleive the motor has warped one axel, but the plastic sprockets seems fine.
I will try to get it up and running in the morning and do some sort of a drag test. Maybe use the wagon and fill it with weights to test. How would i try to get the board hot, it don’t even act like its trying to push my motors. I still only have one 14.4v rechargeable battery that came with the drills hooked to the robot. I’m guessing if i hook to up it with 2 batteries it will double the amps. I have a tester for amp but only goes to 10ah. Battery gives 8.6 ah the 2x25 can handle 25 to 50 amps. So maybe 3 in row?
I have a similar problem! The hubs keep coming off my motor shafts no matter how hard a tighten them down. Im going to have to use some locktight on them. But im not sure if I will be a able to get them off after
If you can drill a small hole through the motor shaft, you could use a lock nut and split pin. A guy at uni was doing this with his drill motors because he had the same problem. It fixed them right up. It leave no where for the nut to go.
The weight of the robot is 20 pounds and the 2x25 saber tooth controller has no problem pulling it around provided the battery has the amps. Did find a weird thing, when it sits and i send 64 then 192 in simple serial (which is stop for both motors) about every 3 to 4 secods it pulses one of the motors. I guess i could code that out and only send if the value is different then last input.
Don’t know how to figure how much pull it has but the hill I tested it on was at least a 45 degree angle. Had no problem pulling it self up the hill so that has to add weight. Not saying it didn’t go slower but it did make it up the hill.
Might need to make a tentioner for the tracks they seem to have grown a tiny bit larger. And a couple more sprockets for the tracks can’t hurt.
Oh fixed the sprocket coming off the motor with the reverse thread screw as the sprocket trys to come off the motor it tightens the screw.
did i burn it up and is there something i could do fix it. The blue light only comes on for a second when i turn off the power to it.
