Another possibility: Have you been cleaning the holes and screws before reapplying? Dirty surfaces make threadlocker not work.
Also, it’s possible that your issue isn’t with your screws - you may have some deeper underlying mechanical issue (vibration, resonance, impacts, etc) that is causing undue stress on the screws that they just can’t take, even when you have properly tightened and secured them with loctite.
How loose is the motor shaft in the can when the screws aren’t tightened down? It should still be at the very least a snug sliding fit with no play or wobble, or better yet a press/interference fit.
The majority of the strength of this joint comes from the fit of the shaft in the can, not from the screws - the screws are there solely to keep the shaft from spinning or moving laterally, not to support the weight of the can.
If your can is not a good fit on the shaft, then you need a new can and/or new shaft. Therre’s no way around that.
Yeah just a touch / drop is enough, and drying for long enough. I used too much on my first build when I installed my mounts and opposite of whaddys issue it glued the screws in, resulting in having to use a blowtorch to get them out lol
Hmm, yeah so I also set retaining compound around the shaft where it meets the can but when the screws come loose, the shaft inches itself out of the can (only by fractions of a mm) but it’s significant enough that the motors start making that sloshy sound when throttling and braking, and the braking and accelerating ability also is cut almost in half.
edit:
I also have not consistently been cleaning the holes out before reapplying threadlock. Half the time I do with alcohol very thuroughly and the other half I’m just fuck it and throw more in =/
I know. TB sent me one but the hole for the shaft was smaller than the ones on the versions of their motors that I have - waiting to hear back from them about that =/
make sure to clean everything as thoroughly as possible with isopropyl alcohol before adding the loctite. I used 638 and let it cure for 72 hours for full strength. shaft hasn’t moved since.
Buy a reamer (or set of reamers) to open up the hole in the can to an appropriate fit to the shaft - You can’t use a regular drill bit for this, they don’t make round accurately-enough sized holes.
If you’re only going through the aluminum that works fine but if you also are going through the shaft, I had to drill using carbide endmills because the shaft is case-hardened steel and the bell housing is aluminum and the drill bit would just walk off the shaft into the casing, bend, and then break.
Mine failed. M4 bolt replacement is temporary. Heading to find some grub screws. Managed to fling the snap ring across the room but overall seems fine now
You can see how enlarged and out of round the pin location indents are on the shaft. These sloppy holes definitely helped managle the bolt and eventually destroy the threads
Need to find someone to index with a pin because this obviously won’t last.
Replacement can is $35. This is pretty frustrating for 30 days in. Hopefully I can salvage this can
Yeah I’m not a fan of the design of these motors one bit. Wasn’t worth the finagling for me anymore—went with Maytechs and haven’t looked back. Fuck these things lol
Hmm very interesting, yeah the Maytechs I got have a different can/shaft design than your photo. Very interesting though. I wonder what the best design is?
All the current motors will do this. Imagine all the abuse we put through these motors.
They literally just sit all that force through 2 small tiny M3 bolts sometimes set screws (most motors).
If yours hasn’t messed up it’s typically just a matter of time or just luck but the design in itself doesn’t scream reliability
Ideally, the best option is to add some sort of keyway or something so the rotor is physically attached to the motor shaft rather than sitting on bolts.
Latest batch of motors I did 4 M4 bolts but I’d want to take the pressure off of the bolt holes and put it on the motor shaft/motor can.
