I have received the machined lid and chassis back from Descher Automation They did a fantastic job machining away the parts of the chassis I didn't want and putting the features in the lid for mounting the PC-104 and the SSD. They even made a drawing of the changes to the stock PB7220 chassis that I have posted in the supporting info. The machining had removed around .2 kg from the chassis. Next, the PP7220 parts were transferred to the modified chassis. Everything fit as it should and having the large holes in the bottom of the chassis made getting to the underside of the board easy!

While the parts were out for machining I figured out how I was going to mount the THz optics to the lid. Originally I was going to have a special mounting bracket made, but I realized that the off-axis parabolic mirror mounts could be mounted directly to the lid with little effort. This would save a little bit more weight. I would try and keep all the parts towards the center of the chassis so that the weight distribution would be good. I drilled the holes and mounted the THz optics with little trouble.

During the rebuild, I also realized that the stock 14.4 volt battery was likely a much greater capacity than it needed to be at 69 Wh. What is the point in operating the spectrometer for hours when the drone can only operate for 15 or 20 minutes. The Ultralife battery weighed in at .35 kg. They had a 14.4 volt battery that was half the size so I assume it would save us another .15 kg if we swapped it in. However, the battery would be an extra $100 bucks plus shipping. So, for now, we will stick with the stock battery.

In order to power the SBC and hard drive, it was necessary to create an adapter cable that would connect to the PB7220 motherboard and deliver switched 5 Volts. The parts were ordered and the cable was easily constructed. The parts are listed.