The Project
To build a simple cheap method of testing small electric motor output torque.
Design Goals
- Cheap - I should be able to use the things I have lying around to make this
- Support many motor profiles - It should be able to test n20s, 16mm, 22mm, servos and more
- Easy to use - I don't want to have to assemble and disassemble a lot of things when changing motors during testing.
Things needed
- A Scale - the faster the scale the better. It turns out that if there is a delay in the reading registering you could burn out your motor or get an invalid result.
- A 3d printer - to make the the parts
- A few nuts and screws.
- A camera (smart phone will do) for capturing data since it can happen really fast.
- A current meter for measuring No Load and Stall current
- A visual tachometer for measuring No Load RPM.
- A spreadsheet for tracking results
The Story
I designed and printed up a PETG testing rig. It has different adapters for different motors sizes and a 100mm long arm (from pivot to contact point) that presses down on the scale. It works reasonably well, but the motor mount solution is dumb, takes a long time to print, and doesn't hold the motors as securly as I'd like.
Next Steps
- Design and print a motor mount that is fast to print and easily secures the motor.
- Design a built-in rack to hold all of the motor adapters.
- Share the cad files
The Results
I've managed to measure the torque of a quite a few of my motors lying around (I have a bucket of un labeled mystery n20s)
