Hi all,
This is during homing and it repeats until power cut off. Looks like stepper losing power for very short period of time, but my suspicion is it may be connected to connection between lead screw and stepper. I tried to move it by hand, but there was no obvious signs of failure there.
Have you guys seen something like this before?
Loose grub screw in the coupler?
Loose wire to the motor?
Did you put lube on the leadscrews?
This was my first guess. I will look into this then! Thanks!
yes I did!
We have a winner! Two winners actually!
They got thread lock as a prize!
Thank you Jeff and Jon! 
We need a “loose grub screw” badge 
I want a “have you checked your grub screws” shirt even though absolutely no one that would see me wearing it would have a clue.
That should be on the shirts for next year’s Open Sauce and RMRRF for sure.
I’d say make that what’s on the T-shirt, but somehow that seems inappropriate.
Edit - I posted this answer after reading only the first post, not noticing that the grub screws were the issue. You can ignore this post…
Are you using an SKR Pro v1.2 by chance?
I have had something like this happen on my LR3, which used an SKR board.
If the screw stub hits the top of the cutout in the YZ Plate, the motor temporarily loses power and drops under gravity, then tries to continue homing.
See the videos in this post… (read the first post in the thread as well)
Not sure what causes the motor to lose power, but the way to make it stop dropping is to adjust the endstop so that it fully asserts before the lead screw stub hits the top of it’s travel (it will still drop if it travels too far, but at least you can get it to home properly.
It might be a nice way to start a conversation about what forum members do. Something clever that says, “I tell people to check their grub screws at V1E.com”
And I’m really happy it was the grub screws… intermittent wiring is a pain
You might be surprised. We need a tee with a v1 logo on it, and like the first sunday of the month, we all wear it out to the mall or dinner and see who matches like Waldo 
There would be thousands of us old men totering around where we were least expected
You still have a mall?
I’m told we do. Personally I avoid it like the plague. Too peopley for me
A slight Z-axis drop during homing usually points to mechanical looseness or incorrect stepper settings. Tighten everything up and double-check your firmware values. It’s kind of like stacking custom shoe boxes if one isn’t aligned right, the whole thing shifts. Small adjustments can make a big difference in stability and precision. Hope that helps!
Bizarre AI spam aside, I’ve considered using my small mill to flatten a spot on my Z axis screws for the grub screw to seat. Maybe a flat file could do it? Probably overkill though, once I crank them down they seem ok. Stripping the grub screw isn’t fun though
Hello, Jessica. You joined about 2 hours ago, and posts here read like AI SPAM. Can you elaborate on what V1 machine you have or are thinking of building, and what your interests are in the community?
You’ll get a notification of this reply and you can respond as a result, but for the time being I’m going to flag your post as fitting the charactaristics of being a spambot.
I never know how to react to them?
nuke them from the orbit. just to be sure.