Articulated Arm System

This is a set of files that make up an articulating arm system that can be used to hold probes, PCBs, cameras, or any thing else. The nodes are fully position adjustable and locked with a screw or thumb screw. There are two sizes included (small and large) for different situations. For examples work well with the small system but a camera may require the large system. If needed, the large and small parts can be intermixed using the included adapters. Node shafts fit into holes in the next node, adapter, probe holder, camera mount, etc. The pictures should give you a better idea of how the parts are used.

Printing/Post Processing:
- Small nodes with short shaft have been printed successfully at 0.2, 0.16, and 0.12mm layer height with PLA and 30% fill. Print with the shaft facing up and turn off supports.
- Large nodes with short shaft have been printed successfully at 0.2mm layer height with PLA and 30% fill. Print with the shaft facing up and turn off supports.
- Large nodes with long shaft are a bit more temperamental. As such, I have found the best way to print them is with the shaft facing sideways. The shaft is then needs to be supported. I added a support and it is in the “.stl” itself (so print the file without supports). Both horizontal and vertical “.stl” files are included for the large node with long shaft.
- I occasionally had an issue where the portion of the bottom of the ball inside the node would detach during printing. The part was still functional but the missing part needed to be avoided when tightening. If you have this issue, you may want to increase the infill to, say, 60% or try a different infill type.
- Probe Holder prints standing upright with holes at the bottom. Print without supports. I used 0.12 layer and 30% fill and no supports.
- Gender Changers, Large F to Small M, Large F to Small M, and Alligator Clip Holders print standing upright. I used 0.12 layer and 30% fill…no supports needed.

- The Wyze Camera Holder was printed with the platform up (bottom hole facing down). I used 0.12 layer and 30% fill…with supports.

- Nodes with “integral supports” should be printed with supports off.
- Alligator Clip Holder: Alligator clip holders use a M4 screw to retain the alligator clip.
- The large weighted enclosure is assembly using four M4 x 10mm screws.
- The large weighted enclosure is assembly using four M3 x 8mm screws.
- The large nodes use a M4 x 10mm screw or thumbscrew for shaft locking.
- The large nodes use a M3 x 8mm screw or thumbscrew for shaft locking.

• I found some screws are slightly undersized. Regular cap screws seem to be truer to their dimensions…thumb screws, and set screws, seem to vary a lot, but are more convenient to adjust.
• If the shaft does not hold in well into the adjacent nodes hole, you can always glue it. On PLA you can use a cyanoacrylate glue (superglue).
• If you find you need to print the nodes horizontally, you can try the Cura plugin “Custom Supports”. You can use this to place a support under the shaft. (After setting up this support turn off the “support” selection.)

Usage:
- Probe Holder: This can be used for oscilloscope probes, DMM probes, etc. Lay probe in the trough and hold in place with rubber bands. (Rubber Bands I used: https://www.amazon.com/gp/product/B083R13FV3/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1 )
- Wyze Camera Holder: Attach the Wyze round metal plate and adhesive to the holder top.
- Wyze Camera Holder can also serve as a base when flipped over.
- The large and small bases should be filled with something to make it heavy enough to support the attached node assemblies. I filed them with some surplus screws I had laying around. You can also use pebbles, sand, scrap metal, etc.

Tips to Making New Adapters
- Large node: holes for shaft are 10mm diameter and 6mm deep
- Small node: holes for shaft are 7.5mm diameter and 4.5mm deep
- The nodes shafts have a slight taper at the far end. On the large nodes, the last 5mm is tapered down at 1.72 degrees. On the small nodes, the last 3.75mm is tapered down at 1.7 degrees. The gender changer shaft has this taper on both ends.

See this posted on Adafruit at:
https://blog.adafruit.com/2021/07/01/articulated-arm-system-3dprinting-3dthursday/

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