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[R] Worm gear for V axis?

A project log for SecSavr Sublime [gd0036]

An FDM 3D printer that I described as "The FULL Coverage, Extended X, Pro Max, Ultramatrix Solution".

kelvinakelvinA 06/30/2022 at 01:183 Comments

https://www.instructables.com/Strong-Worm-Gear-on-3d-Printer/

I just found this. I might not use it because it's a 20:1 and so could be quite slow (but if I can get 60rpm with decent acceleration, I wouldn't mind).

Currently, my plan is to have a curved GT2 rack and drive a closed belt.

While this method means that I may not have to worry about backlash, I am still worried about effective torque and elasticity in the axis. Using a large width of belt will mitigate the latter, but if I recall correctly, I'm using a 16T to 60T, meaning 3.75:1 reduction on a standard 40Ncm Nema17. I was planning to counterbalance it, but that currently sounds like it would add complexity to the design and the installed tools would likely have different weights.

Going cyclodial is probably the route out of this situation, but I thought the DIY worm gear looked cool so I wrote this log.

Discussions

Daniel Grace wrote 06/30/2022 at 02:18 point

That's an interesting gear design for sure. Similar to a rack and pinion, but on its side, and curved?

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kelvinA wrote 06/30/2022 at 02:22 point

This is where I got the idea from: https://www.youtube.com/watch?v=2YC-0C8oPUo
In looking for that video, I just found this other one: https://www.youtube.com/watch?v=bgQDu1jSufk

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Daniel Grace wrote 06/30/2022 at 02:35 point

I am surprised the belt stays engaged with the outer circle in that first video. I'm not sure why it doesn't take the shorter direct path. It looks really cool, though!

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