Overall it has been a success. I tried Kicad for the first time and the board is largely functional. The new 3D printed fastener concept is working well and the gears are held in better than they have ever been.. But as I mentioned before, it is all in the tenths of a mm and here are things that need to be changed for version 16.

PCB 

I have gotten the 1.25 pitch instead of 1.5 pitch for the connector. It kind of works but I have to bend the pins to force it.  I will fix it today.

However, the big success was the 7805/2 Li ion battery combination. The motors now have just the right speed. It is awesome.

It looks like i may need to put the resistor before the photodiode instead of after.  This will allow a higher voltage when the photodiode provides a high signal.

Acrylic Frame

Our laser cutter seems to be losing some steam. I cleaned the lens but could no longer cut at 10 mm/s. This means all of the dialed in parts get a little wonky.

1) Shafts were a little tight for the motor gear and spacer. Need to open it up by a tenth.

2) Encoder is a little loose on the shaft. Tighten it by a tenth.

3) Motor fit in the wall was awesome. 

4)  Board holder was too loose in the vertical direction. I had 0.3mm slop. Combined with 0.2 mm 

kerf it was sitting on a 10-20 degree angle and I had to glue it.  Will go back to line to line. 

Fasteners

This was my second round with the 3d printed gear axle/holders. 

The play in the axial direction is perfect.

The window in the 3D printed parts to fit in the clip is getting covered over in the print and I need to file it. I works pretty good after filing but that is not idea. Maybe I will make the window bigger in the radial direction by 0.4mm.

The shaft clips are breaking. There is not enough flex. Increase the radius at the root of the U by 0.2mm. Replaced it with a foot (tatoo grommet) and it seems to work well. Might be a permanent fix.

Here's to round 16!