Computerized Etch a Sketch

Step 8 Stiffen Everything up.

OK, well, there I was. My motors were pleasantly coupled to my shafts, but I had no way of keeping the motors from spinning. What I needed was some way of holding the motors still relative to the etch-a-sketch knobs.

Fortunately, I had used these motors for another project and I had made lots of nice waterjetted motor mounts(shown below). It's not a difficult part to make by hand--it's just a plate that goes on the front of the motor, with a hole for the motor shaft and three holes for mounting screws that screw into the motor. I can try to dig up my CAD file if anyone wants it, but the dimensions just took a few minutes with calipers to figure out. To make the mounting plate, I used 3/32" steel plate and there are four holes you have to drill.

I took a couple mounting plates and bolted them on to the motors. Then, I took the motors and put the couplings on them, coupling them to the etch-a-sketch. I grabbed a piece of 1" angle iron and measured out the distance between the two motor mounts, including the width of the mounts, and then cut my angle iron using a chopsaw.

Next, I rotated the motors and motor mounts so that the long parts of the motor mounts were both sticking off the etch-a-sketch, exactly parallel. I then put the angle iron over the overhanging part of the motor mounts, making sure that they were flush with the inside edge of the angle iron(the elucidating pictures below should illuminate your path through the darkness of confusion)

In retrospect, I didn't need to spend so much time making sure the motor mounts were parallel, but this made my finished product sexier.


Now that I had my angle iron lined up on my motor mounts, I grabbed a MIG welder and did a light tack weld on both motor mounts, where the mount overlapped with the angle iron. I didn't want to do a full weld with the motors still attached to the mounts for fear of heating up the motor too much and screwing up a bearing or winding.

Then, I valiantly uncoupled the motors from the etch-a-sketch and un-bolted the motors from the motor mounts, leaving me with the two motor mounts tacked onto the angle iron. I put some sturdier welds joining both mounts to the angle iron(see below) and casually slew a dragon that kept sticking its nose into the machine shop.

I sat atop the dragon carcass and admired my work(see below) while feasting on fresh dragonflesh--there's nothing like it!