<actuators/>
Compact harmonic drive actuators you can print at home. Every one ships with its CAD files, a complete bill of materials, and the actual load-cell data behind the torque numbers, because a spec you can't check isn't a spec. All free under CC BY-SA 4.0.
Rinnegan drive
HDP30 · 30:1 pancake harmonic drive · NEMA 17 · v2.0 (RevC)
About 2 arcmin of measured backlash from a printed gearbox. Half again the reduction of the HD20, in a thinner stack, off the same motor face and the same $4 of hardware. v2.0 is all PLA and took nearly 10,000 flex cycles at 1.3 N·m without damage. Keep peaks under about 1.3 N·m.
- ~2 arcmin backlash
- 30:1 reduction
- 1.3 N·m working limit
- ~$3.96 hardware
cup-style harmonic drive
in the works
We're working on a cup-style harmonic drive, the classic layout where the flexspline is a thin-walled cup instead of a flat ring. No numbers yet, and we won't post any until it's been on the load cell. Follow @robrotics to hear when it lands.
more coming
bigger, smaller, and higher ratio
We're working on other sizes in the same family. Want to be told when they land, or have a size you'd actually use? Say hello on YouTube or email us.
Looking for the HD20 or HDP30 v1.0? They're in the archive, files and test data intact.
<archive/>
Superseded revisions don't get deleted. Their CAD stays downloadable, their bills of materials still load and their test data stays up, because a dead link is a worse outcome than an out-of-date page.
The HD20 and HDP30 v1.0 (RevB) live there now. It's worth knowing that the HD20 is still the stronger drive: tested to 3.3 N·m, against the Rinnegan drive's 1.3. If you need torque, build that one.
<design-your-own/>
Every one of these starts in our free harmonic maker, a parametric tooth profile generator that exports DXF. If you'd rather understand the mechanism before you build one, start with harmonic drives, plainly.