Meetup 2018-11-08

Last week:

I finally figured out a good rendering setting for my random-scorped vase so that it takes less than forever to produce a rendered stl file. I started heating up the printer, but then got busy discussing things.

Steph got a few mini drone boards from a friend. He wasn’t sure what condition they were in, apart from the motors being gone. He managed to solder some leads to the power input, and the board lit up. Progress!

Kolijn (first time visitor) worked a bit on a Lora board that was developed together with JP Meijers. This board transmits GPS location on a regular basis. If any TTN (The Things Network) access points pick up the transmissions, they store that in the cloud together with some signal strength stats etc. This then allows them to produce a coverage map of TTN coverage.

He was looking at light pipes to mount in the standard bought case, instead of having to wire up external LEDs. Looks like a good solution. The switch is still a problem, since they want something recessed that cannot be accidentally switched off.

Kim visited, and we talked through a few options for her silicone bioreactor stretching setup. The basic setup would involve having a silicone part with some Tyvek sheets molded in on each side. This would then be attached to an 8mm shaft that turns to give the stretch. An 8mm shaft gives about 24mm of movement per full rotation, and there will be one on each side. Even if rotation is limited to half a rotation, that provides about 24 mm of stretch, which is more than the 10% needed on a 100mm silicone surface.

This week:

The vase got printed! Due to the low-poly render, the edges are quite sharp, so there is a lot of ghosting on the surfaces. Not great, but at least it works.

I also started with a project to print parts containers, like little parts bins that I can arrange on a grid. Single wall for this is not great, and my printer seems to have a few problems with the bottom 5mm of the prints, so this was not a huge success. Yet.

Steph brought along a cardboard plane that he wants to put radio control onto. It might be too heavy for the motors he has, so we discussed some alternative materials and design. We went into propeller selection and gearing as well.

Kolijn worked on the layout for the TTN GPS board and chatted a bit about how it works with Jan, who helped set up the hi-sites for this and had some ideas around power saving for the GPS module.

The motors and motor drivers for the MaslowCNC arrived! Jan and Otto got the motors turning with PWM and reading the encoders. At the end of the evening, they got the motors to run 5000 encoder steps and then reverse for 5000 steps, so we now have some confidence that it all works together.

We also spent some time discussing the layout of the frame for the MaslowCNC, taking into account that we want to cut right to the edges of a 4X8 foot board.