After I had a moving motor and arm, I now needed to use something to allow the dot to travel on the outside of the wood. I thought that a simple paper fastener would do the trick. It turns out: almost.
The paper fastener worked, but the dot needed more freedom. I ended up having to pinch the fastener to a round shape so that while it was being pushed around, the square sharp edges wouldn’t get caught. It was like working with clay – you push this way and that way but each time you can over-tweek and ruin it! After much tinkering, it finally worked. 🙂
It was all measured and set to go! My perfectly cut acrylic fit the motor’s holes. I was now ready to add one additional but crucial element: two switches to auto-calibrate the motor’s location. I placed the switches and marked the acrylic for drilling. After placing screwing them in I noticed my fatal flaw… the body of the switch was positioned in the way of the motor’s arm – making it impossible for the switch to be pressed!
Ok, so quick thinking… if I angle the switches a bit differently, I can keep one of the drilled holes and only drill one more. Alas! My angles were correct! Only one more big problem: The motor wasn’t powerful enough to push the switches anyway.
The good news is, the stepper is accurate enough to hold manual calibration for awhile, so I can hand calibrate it before my presentation. I will need to find a solution for this if I want to really use it!