Overengineered Stepper Motor Mounts, Filament Guides

If you’re just tuning in, I’m working towards overengineering a drawing robot.¹ Here’s my progress to date:

• PolagraphSD case – discussed here - done!
• Mounts for a paper roll – discussed here – waiting to upload…
• Filament spools – discussed here – waiting to upload…
• Stepper motor mounts – discussed in this post – waiting to upload…
• Filament guides - discussed in this post – waiting to upload…
• Pen holder/gondola – TBD

The most difficult part is definitely going to be the pen holder.  I’ve seen some good ones, but… well, that’s another blog post.  :)

• Motor Mounts.
  • I’ve designed these motor mounts using the same exact groove system that I used to mount the paper roll holder.  This means I’ll be able to adjust, mount, and dismount the motors by just adjusting a single bolt.  I’m a little concerned about whether the plate the motors are attached to is thick enough to prevent it from wobbling.²
  • I’ve also left space around the motor so that I can add some kind of insulating material.  I’ll try a few different materials, starting with the cheapest and most readily available – cardboard.  After that, I’ll try polar fleece, foam packing material, a sheet of rubber or silicone.
  • With some minor modifications to the design, I could use some zip ties hold down the motor.
  • Since I don’t have any really really short M3 bolts, the length which would be ideal for holding the motor to the mounting plate through a thin layer of material, I’ll use an M3x16 with several M3 nuts on it.
• Filament Guides.
  • In my earliest version of my drawing robot I tried to use a plastic filament guide which was incorporated into a motor mount.  While a cool idea, the original just didn’t work.  The filament squeaked and tended to bind on the filament guide.  This may have been due to the filament rubbing against the wood of the project box.  This new one is basically a plastic cylinder that will be insert into a hole in the wooden project box.

1. Photo courtesy of Casey Hussein Bisson [↩]
2. Wibbly wobbly, timey wimey [↩]