I’ve developed a NEO, NEO550, and SparkMax tester. PM me if you want one of the first run to play with ($40). As part of this I would like to build a library of failures and what the tester will display. I can fake a couple of things, BUT not all of them.
So, does anyone have a fried NEO they are willing to share with me? I’ll pay shipping. A few fried SparkMax drives would be good too!
So, if I understand, you are testing the electrical circuits.
We have 2+ NEOs which we had to pull last week because they are mechanically bad, really hard to turn. Presumably we damaged the bearings, but I have not yet been able to fully disassemble one. I assume you have no way to test that?
Sorry, I laugh-reacted because as a small business owner I have absolutely, positively no idea how a manufacturer/distributor might end up with piles of less-than-perfect product they can’t sell for one reason or another.
looks at 97 bottles of hot sauce in my commercial kitchen whistles and walks away
If it’s useful… we have a SparkMAX that I’m pretty sure we killed when a piece of aluminum cut into a motor power lead and encoder wires at the same time, and sent 12V into the encoder input. It’s been sitting on the bench waiting to be assessed, but I’m 99% sure it’s a goner (at least for brushless motor use, haven’t tried it with a brushed motor yet).
Mechanically bad would be a useful case! I’m contemplating how to give a low vs high current indication that would tell you the difference between a normal motor running unloaded and a draggy/shorted motor (which would draw a LOT more idling current).
I would bet Greg has dead ones both from teams and from returns
Both my kids and I dissected all of our dead motors, which is why I don’t have any to test with!
And FYI, there’s only 3 differences on a fried/shorted winding NEO:
That smell
Runs slow because the current limit is tripped
Very draggy when spun with a drill
If you want to pre-check your old NEOs before the competition starts, the first test I would do is to DISCONNECT the SparkMax, hook a drill up to the shaft, and spin it. A good motor has almost no drag at all. A fried one has a LOT of drag. Its a chalk and cheese difference; trust me you will notice! You can also look at the AC Voltage coming out of it. You should get the same Voltage across all three phases and it will be proportional to speed. Measuring phase resistance is super difficult; you need a fancy meter. Phase impedance needs a special meter nobody (other than mad scientists like me) is likely to have.
Oh, in case y’all haven’t seen it before, if you take a brushless drill and remove the chuck, you can make something that acts exactly like the old-school brushed motor testing/running drill, but with a NEO or NEO550 motor!
OMG worth the work and sacrifice of a damaged hand drill to build it…
