Question X Motor set screws vibrating loose during tuning.

Hi guys.

Just a quick note that might help others experiencing difficulties during the setup and mechanical tuning phase. I have been fastidious at getting the modules running freely on the lead screws, both at the sub-assembly phase and during final mechanical tuning. I was quite astonished when I watched the Stepcraft U.S. videos on adjusting the XZ module pre-load where they had to jerk the module in both X and Z extrusions to get it to move. Before I saw this, I spent ages adjusting mine ensuring that they ran free with just a light push from one finger or moved slowly and smoothly under gravity.

Anyway, I ended up with all lead screws moving freely with very light force applied between index finger and thumb.

Nevertheless, I was having difficulty getting the X axis sorted and already experienced one problem with the M4 x 4 mm set screws (part #45) working loose on the X axis connector (part #58) presumably as a result of the motor buzzing at the ends of the track.

I substituted the supplied self-colour set screws with stainless steel ones that I had filed the point flat to give a larger surface area to mate with the flat on the motor and screw. I note that they fitted the thread very precisely (neither loose nor stiff).

However, while loosening off the gantry uprights and tuning, I had two further issues with both set screws vibrating themselves loose very easily. I ended up dismounting the x axis motor, cleaning all parts with isopropyl alcohol (part of the issue might have been lubricant getting in to the thread helping it work loose easier) then putting a small dot of cyanoacrylate superglue on the set screw point only, not on the threads!.

On reassembly, there were no further problems.

Regards.

Doug

1 - Filing the points flat is a good idea.

2 - Isopropyl alcohol not a good idea, use a dab of malt whisky on a bit of kitchen paper towel and drink the bottle. You won't have to worry about grub screws for a while.

3 - Cyanoacrylte? No. Cyano is not adequate for this as it is an aerobic adhesive. To fix threads in place the proper adhesive is Loctite. Add some duct tape too for good measure. Perform this operation after you've drained the whisky bottle mentioned above, or you'll feel tempted to Loctite the stopper and then the whisky will stay inside the bottle with you outside. Frustrating.

www.loctite.com.au/your-solution-4041.htm

I like tip #2 ... fits very well to your avatar ... at least

Wow Doug. You're one persistent person. Well done.

In the meantime, I'm still stuck with a bad non working machine.

SC still try to find what is wrong. Maybe you can help them out?