CFP (Call For Pen holders!)

call-for-pen-holders.md

Open call for pen holders 📣

Design a pen holder for the drawing machine and send it in the #development-of-things-and-stuff channel on Slack. 3D-modeling it using CAD would be very cool (we’ve been using OnShape; feel free to use your CAD tool of choice), but a 2D illustration (on paper or digital) would also be acceptable. If you design a pen holder and make a post in #development-of-things-and-stuff on Slack detailing your design with images/drawings/3D models, I will mail you a physical artifact from Hack Club HQ. Perhaps, I will even fabricate your design and mail it to you, depending on how many there are.

Design constraints:

• Able to move up and down, using a servo probably
• Would be ideal if it used a compliant mechanism and mostly 3D printed
• Attaches to the belt tensioner (probably with two M5 screws). Can use existing belt tensioner design, or if you feel inclined to design a new one, that’s also cool.
• Optimize for low cost

Here are some past iterations of pen holders and some notes:

- Takes up too much horizontal space, so it limits the movement of the y-axis
- Used many different screw sizes (M5 to attach to axis, M2.5 for servo, M3 for securing pen)

Some half-baked ideas:

CAD files

+ Is more vertical so it doesn’t limit the range of the y-axis as much
- Pen holder part was too high above the paper, so the pen wasn’t very stable
- No tension mechanism to put pressure on the pen part

+ The pen seems secure. The notch in the pen holder hole thing works well.
+ It moves up and down.
- It requires too many extra things (nails, spring)
- The nail sticks out and looks threatening. (Idea: make the nail fit nicely into a slot/hole at the bottom of the pen holder)

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Compliant mechanism ideas:

• look into planar mechanism
• https://all3dp.com/2/compliant-mechanisms-3d-print/