Since printing my AstroPi back in March (and then never actually posting pics of it...oops.) I've been thinking of designing a mount that would allow the AstroPi to be held in the air in a similar manner to those up on the ISS. Thinking didn't actually become action until a friend of mine wanted a way to display his AstroPi at the Recursion Computer Science Fair
so that visitors could get a close look at it without, presumably, accidentally unplugging or dropping it.
I dug an old magnifying lamp with spring loaded arm out of the attic, removed the lamp assembly (which was held on by a single bolt) and set out to design a printable part that would hold the AstroPi in place. Of course by design I mean launching Autodesk Fusion 360 and start creating and modifying objects. When this approach didn't work (unsurprisingly) I actually went and sketched out some ideas and started over.
|The original design.|
Whilst not going to win any prizes in technical drawing, the sketches were enough for me to better visualise the 3D object, create it in Fusion (Its basically a couple of rectangles with holes) and run off a test print, immediately followed by several more until I got the sizes correct and the mount functional (For example, the hole for the nut was large enough to fit the nut, but too small to fit the socket required to tighten it up). Once I was happy I swapped over to my silver filament, printed out the final version and attached it to the arm.
|The AstroPi mounted on the end of the arm.|
|Arm goes up.||Arm goes down.|
With the sprung arm and mount out of the way it was time to tweak the design to make it more generally useful. A fairly common type of mount is the standard camera tripod which, according to the internet, a 1/4" UNC nut would fit so I ordered several from eBay
Whilst waiting for those to arrive I found out Fusion supported creating screw threads as part of the design so I created two variants of the mount. One with a built in thread and one which takes a nut.
|Nut based model on the left, threaded on the right||Side view, not all the curves printed cleanly.|
I printed the 'threaded' variant with a 0.1mm layer height and, whilst a bit tight to screw on the first time, is working surprisingly well. Even after being attached and removed a dozen times it doesn't seem to be wearing out. The 'Nut' variant I printed at a 0.2mm layer height, which seemed to produce better rounded corners, and the nut fits in snugly. Both variants of the mount connect to two corners of the AstroPi itself, using some slightly longer bolts (35mm) to account for the extra thickness added by the arms.
With the mount attached to the AstroPi it can be connected to, and moved between, any camera tripod or similar that you have available so you can position it on your desk, hanging from a shelf or suspended looking out of a window, just like Izzy is doing on the ISS.
|Suspended in the air.|
|Standing on the desk.||Hanging from a shelf bracket.|
If you want to print out your own AstroPi tripod mounts then I've uploaded the .STL files to Thingiverse
) where you can download and print them out.