Step 3: Frame/Drivetrain

Picture of Frame/Drivetrain
Now that I had the flipper weapon designed I could work on the frame for the robot.

I first made part of the frame that would hold everything. My material of choice is the 1/2"X1/2" box steel they sell at Home Depot. After welding the basic shape I once again test fit the components and worked on re-arranging them to make everything fit.

The drivetrain for Phoenix, as described earlier was two Harbor Freight 18 volt drill motors with 4" wheels, kitbots.com's hubs/motor mounts and one drill battery to power it. I decided on this drivetrain because it offered both adequate speed and power for the robot and was cheap. The speed controller I used was a Sabertooth 2X25 that I had won at a previous competition.

I then did a test assembly of the robot and then test drive...

Which reviled a major design oversight on my part. There was no weight on the drive wheels which made the robot almost impossible to drive. I needed to change that... with more steel....

I ended up welding 4lbs of steel to the front of the frame to help counteract the weight distribution  issues. The added bonus was now it had 1/8" thick steel armor on the front.
tomtortoise3 years ago
Hey, im working on a tank drive robot (non combat) and have the whole thing built but my only problem is that the wheels are horribly attached to the motors which happen to be the same exact motors your using, I was just wondering if you could go into a little more detain on how you attached your wheels, thanks.

Also quick tip, Amazon carries almost every type of structural metal, all the aluminum I got for my robot was less then half the price at Home Depot, you also get free shipping on almost all of it.
AlexHrn (author)  tomtortoise3 years ago
Thanks for the info about Amazon.

I use Kitbots.com's drillmotor hubs and colson wheels.The wheels press fit onto the hubs which screw right onto the output shaft of the drill gearbox.