Working on assembling my LR4 core and have found that 1 of the 4 holes for the stepper motor screws simply odes not align – the other 3 are a perfect fit and I’ve snugged them down, but number for (front left corner as you look at the core) is off by 3/32" or so.
I don’t see any mention of it here, so I’m wondering what the heck happened when I printed?
Opinions as to whether I should either enlarge the hole or just skip the 4th screw? (I really don’t want to print the core again…)
Oh wait - I see the problem; that corner didn’t adhere to the print bed. Dang it.
3 screws will have to suffice, I guess!
That would have been my guess, that‘s why I use a brim, even on the MK4S. 
If thats the worst issue you have you’re doing alright I think
I’d drill it a bit and use it anyway.
I like not using a brim. But brims do help in the cases where it is hard otherwise.
A clean bed and good Z calibration/bed leveling are the key to solid adhesion and avoiding warps (in my experience).
In my case, this was the first print I had run in several (like more than 6) months, and the printer had been moved around a few times, causing it to get out of calibration. But I was so impressed that a 40+ hour print completed “successfully” that I didn’t notice the warping.
I ended up having to re-calibrate the whole printer a few days later as I started trying to print other LR4 parts and coming out with spaghetti monsters.
As far as I can tell, this is the only issue with the LR4 core that I printed; I may re-print it one of these days if I run into any problems after assembly, but I’ll use it as-is for now. Still undecided on whether to try to drill out the support hole or just stick with 3 screws - they’re good and tight, and I use Locktite on them so maybe it’ll be fine.
