Sk3 6374 motor keeps brakeing from motor screws

My motor screws broke and I took my board home and the sk3 came with replacement screws so I fixed it but the first time ridding it last night they broke after a few blocks could someone drop a link to theses screws or some that won’t brake

@Quinlanbrown If the screws broke twice I’d look into why they keep breaking. How is your belt extremely tight? Are you getting adequate purchase between the screws and the motor? Are they long enough for your mount? Are you using thread locker?

It’s the screws inside the motor my motor mount screws are fine

Your going to have to post some pictures for us to better help you :wink:

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Which screws in particular? The hex screws on the face around the axle? Or the little phillips screws on the can? Or are they completely internal?

Side question: The outrunner on my SK3 can slide a few mm back and forth along the axle. Anyone remember which screw tightens this up? I believe its the black face screws, but I don’t have the correct metric wrench

Are you talking about the set screw on the non pulley side of the motor can?

check this thread out.

Ya it’s the hex on the inside and when they brake the motors like disconnected from the bace witch is bolted to the mount

Not this it’s the inside screws I’ll drop a pic when I get home

its these!! that happen to a couple sk3’s… one of them still has part of the threads stuck in the stator.

i replaced these with locktite and some stainless m3 screws from a set, but I haven’t riden with it because i’m pretty sure it will happen again. most other motors have a bearing on the outside to avoid this problem.

Yep these are the screws but how would you avoid this problem like why do they brake

Can anyone tell me the size of these screws?

most likely your belt is too tight.

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M3 just like @saul already said.

Yes, but what is the length? :stuck_out_tongue:

So I’ve had this same problem with my sk3 motors and I have found the solution!

After dickin’ around with helicoils (witch actually lasted a few months) the real forever* fix is to drill and tap it out to m4, get yourself some m4x10 socket cap screws and Red thread lock them in!

It would be best if you do this on a drill press and use an end mill but this can be done with a basic hand drill and drill bits

And don’t be afraid of the Red thread-locker. It can be removed with just a little heat!

Also note that you will be tapping a blind-hole so get yourself a bottoming tap if you wanna do it right :wink:

For screws better use hardened steel ones. Stainless steel is too soft. Stainless steel looks dope and it better been used for some art instalation, or some place where you need stylish finish look, where is no much strenght needed.

At first I also bought super duper good lookin stainless steel screws for motor attaching to mount also for my enclosure. They looked dope for sure, but already after one more opening and tightening some screws already had f***ed up heads so that allan key wont open them again. They soft and allan key is hard so it easy can ruin screw.

The guy in hardwere store also said to me that stainless steel is for blink blink not for strenght and opening them multiple times. If I remember he told me those stainless steel ones had 5 grade of hardeness and black ones wich are hardened steel are 9. So nearly twice as much strenght for hardened ones.

^^ Yep. Go with grade 8 (for inch) or 12.9 (which is the same as grade 8 but metric) steel screws. The only time to use stainless is for pretty or for very high temperature or sea water. Since no one will see these, and they aren’t going to get hot or go in the ocean, you don’t need stainless. Going up a size is also a possibility, but just going to proper high strength fasteners and loctite should solve the problem.

If his problem is SNAPPING screws then you definitely don’t want an even harder screw… That being said, i’m sure the hardware Hobby King uses is just melted down tin cans lol.