Here is my attempt to document an assembly attempt. I was pretty happy with the way this much of it came together. The plastic assembly is supposed to be the easier part.

Assembled flex

Backside

Remove adhesive backing

Monday morning quarterbacking this, I see although sticking it down makes the assembly a little easier, I is causing way more issues. Next run I will not stick it  down until everything is together.

Mount on motor

I put a header under the board and came up through holes in the flex. The two pins on the right were great and it holds it to the flex because there are plated through holes to solder to before the board is put down. This is power to the circuit. The two pins on the left are for charging and are OK but  a little tight into the foot housing. The two in the middle should be removed and replaced with just wires. I soldered to the pin headers I bent over here but then had a hard time putting them in the foot and getting the battery in the foot. 

Stick down the flex

Mount in the foot

Check power.

Squeeze the battery in

All assembled

The one off button has almost no room. It is a momentary switch but it needs to be pressed to get power to the circuit. Need to make the window bigger again. The board is not sitting well because the bent header pins that connect to the wires that go to the battery are wedged under the housing.

Cut off the tops of the motor

The motors butt up top to top and the flex is in between. Cutting the tops give more room for the flex.

Add tibula

Screwing it together. Electric driver is a life saver.

Major Fail!!! Ripped the solder pads off the flex. Game over……

Once the pads come off the flex, it is game over. I think if I go with a double sided flex, they might be more robust. I also might try a thicker flex in general. Lastly, I seem to have the most trouble when I put down the adhesive. There is no longer any give and things start to tear. Also the adhesive backing makes it less likely to tear as well.

Another broken trace in the corner

Here is another example of a tear and you can see it cut through the trace. After this I turned on the battery and connected it to the head but no power went up so its back to the soldering iron.