Thursday, July 13, 2017

Local 3D printing option

This is somewhat offtopic, but I have a few Palm foldable keyboards sitting around that I would like to make use of. First problem: the keyboard uses a proprietary 10-pin connector. Solution: download a cad file from and 3D print it. Second problem: I don't own a 3D printer, so how do I print it?

I found that our local library ( has a 3D printer, and will print things for 10 cents per gram. The cost of printer filament alone often runs 2-3 cents per gram, so that's a really good price. It's a TKI 3D printer, and they have a selection of PLA filament in various colors. To use it, I converted the cad file to .stl, and took it to the library on a USB stick, where Linda processed it and set up the printer. Library personnel do all the actual handling of the printer - no gefingerpoken by the lookenspeepers. This object was about 2 grams, so it cost me all of 20 cents to get it printed. It took about 25 minutes - could have been faster, but she decided to run the printer at low speed for something this small. It's a library, so there's plenty to look at while waiting.

First step was to download the appropriate cad file from cy384's github site. It's designed in openscad, which is in the Debian repository, so I installed that. Importing the *.scad file and exporting an .stl file took only a few seconds. The longest dimension is about 3 cm.

And here's the finished product, with a penny for size reference. The object is flipped in this photo: the front in the openscad screenshot is the back in this photo. The printer software automatically added the panel so it would stick to the base while printing, and it added the supports so the ears could be printed properly.

Here it is sitting on the keyboard connector after a little bit of trimming with a sharp knife.

And here it is fully plugged in. Fits snugly and perfectly, so the design was good, and the printer did its job well. Next step is to wrap wires in the slots to make contact with the pins, and then I can start working on the software.

So if you're within driving distance of the Hudson, NH library and have an occasional need for 3D printing, it's a great resource. They have a shelf full of PLA filament in various colors. Check the library website for days and times the printer is available. The librarian did say they only run the printer when the library is open, so make sure your print jobs take less than 12 hours.
There's only one machine and printing takes a long time, so there might be a queue. I went in on a Monday night and there was no wait - your mileage may vary.