Month: March 2021

This week JP and I modeled and fabricated the external housing for the robot in TechSpark. It took a little bit longer than we expected to get familiar with the laser cutter and we ended up making a few small mistakes but came out of it with all 6 sides cut, including the mount on the rear for the tablet. As far as electronics, the stepper motor and the drivers arrived on Thursday. I am still awaiting the DC motor delivery however. I was able to begin soldering the control board for the stepper motor and put together a test setup with my Arduino and the motor along with some example code to check everything is working. I did make a small mistake soldering though, and will have to correct it in TechSpark on Sunday because I don’t have a desoldering tool. The board works though: a small LED in the corner glows when I turn the motor.

Stepper Motor with control board:

I also made a lot of progress on the 3D model and assembly. After the DC motor gets here and I can get the dimensions on that I can add that to the upper mount and get it printed. The launcher is likely the only thing we will print, the outer circle we can just cut out of acrylic and the bottom we can do the same. Pictured is the main launcher assembly where the balls will roll in and be launched by the motor spinning at the bottom.

My biggest blocker right now is still not having the DC motor. I’ve been waiting over a week for that part now and I’m wondering if the best option would be to just drive to a hardware store to buy one temporarily or check if there is one in inventory I can use.

Last week:

Last week I spent a lot of time going through different launcher ideas with JP. As mentioned in our weekly report, we settled on a non-motorized version for our initial testing. Conveniently, ping pong balls fit perfectly in cardboard paper towel rolls so that will be a good way to rapidly get this prototype into being. I also found an online guide with some example code for driving a micro-stepping motor and ordered those parts as well as a DC motor and bridge to drive that.  I also did the design sketches for the launching mechanism we agreed to and of an initial idea for the final housing. Once I get the parts in hand, I can add those screw measurements and motor dimensions to the 3D model for the rotator mount and get that fabricated.

This week:

My tasks for this week are to build the stepper and DC motor circuits and to model the mounts for them. I also will mock up the launching mechanism with cardboard and finally get to test the exit velocity of the new DC motor.