Grub Screws - Loctite Yes or No

What is the general consensus?
I know I’ve read over and over to keep em tight but…

I’ve used it, don’t see how it could cause any harm.

1 Like

I think you’ll definitely be in the “for” camp after the first one comes loose…

2 Likes

My thought is that if you do have set screws that came loose, the first one that you tightened probably wasn’t tightened down perfectly perpendicular to the flat of the stepper motor shaft, or it just wasn’t tight tight. Since the set screws are so small they require what seems like an extreme amount of torque to get them to bite.

If you do decide to use Loctite, be sure that the first one you tighten is perfectly perpendicular to the flat of the shaft.

3 Likes

Yes. Blue stuff.

2 Likes

Yes I used the “blue” one – which for some inexplicable reason comes in a red tube.

1 Like

+1 for blue threadlocker.

1 Like

Ahhh… didn’t know that was called a “Grub” screw. And yes, mine do come loose. I have loctite like crazy, since I also work on old cars! :slight_smile:

If it’s helpful to anyone, me and one of my engineering team did a study on whether Loctite affects the nylon for nylocks (or prevailing-torque nuts). It doesn’t.

Feel free to Loctite AND Nylock your assemblies where appropriate. Not sure if this is the right place considering we’re talking set screws, but wanted to try and share the info as much as possible since it’s good to know.

Note: I was concerned that the loctite would dissolve or chemically degrade the nylon in the nut. Confirmed with Loctite Engineering reps (and other external sources) that it does not negatively affect the nylon; and actually helps prevent them from prematurely locking due to the lower friction coefficient when spinning the nuts on. Then, once in place the anerobic agent cures in the absence of air, and helps fill any gaps that may have occurred when spinning the locknut on.

Hopefully this helps someone. Feel free to reach out if you want more detail.

2 Likes