Maybe more of a “verifier” than a “tester” but little gizmos like this are great to have in your bag of tricks.
CAD model for the case is at Onshape and the schematic is at Utility/SparkMax-Tester.pdf at main · JolietCyborgs4241/Utility · GitHub (go directly to the OnShape model as I need to update the CAD files in GitHub to reflect some late breaking changes due to the hardware I used). I used 6-32 threaded inserts so if you’re using something else, you’ll want to change the holes on the bottom side of the case. Considering this thing is a screw it shut once and be done, threading directly into the plastic is a totally viable option - I just like threaded inserts.
With this, you’ll see each phase in the brushless control output and can see if a phase has failed or is weak. In operation, all the same color LEDs should light at similar intensities.
Terminate the connections using whatever connectors you typically use on your robot - we use PowerPoles so I made a pigtail that goes in series with the motor feed from a brushless controller - I made it relatively short to be able to plug it into a built robot without a bunch of extra wiring. It just tees into your existing wiring.
Quick one-day project with not a single part needing to be purchased (at least not specifically for this project) - I love making things out of stuff already on hand.
– Chris Herzog - Joliet Cyborgs #4241