Im finishing my LR4 uprade and noticed that the min side is is further forward than the max side. The braces all seem to be fine and i ordered machined plates.
Im kind of at a loss as to what would be causing it to be so skewed. Any thoughts?
Thanks,
Steve
Check your heal/toe measurements and make sure you are straight. are you sure that your table edge is square?
Speaking of this, what are some recommended ways to correct the side assemblies and the gantry not being perpendicular? I guess shimming is an option?
The rail is perfecrly aligned to the spoilbard
Would shimming decrease the rigidity?
If everything is assembled correctly with nothing in between there shouldnât be anything to correct. But it can happen. I had the end of my belt get between on one of the betas and had to take it loose and get it out.
That may well be. I guess options include take it apart, and put it back together again, or loosen the screws and tap on the corner a little bit and then tighten it back down?
Is this a fairly common issue?
Ill try and loosen it up, line it up and then re-tighten it. Iâll let you know what i find.
No it isnât. But it is something that is possible. I know you said your rail is aligned with the spoil board but what I meant for square is across the front where you have your Y min belt holders mounted. If the table isnât square that way, and you mounted them the same distance, then it is possible that is where your off a little. It happens. We have had plenty of people buy brand new wood from the store and its not even close to square. And if they cut it, there is a REAL good chance its not square.
Its pretty square. When i notice the issue its when comparing to the spoilboard that is square. This why I aligned the rail to the spoilboard.
How could you measure to see if it could be the heel and toe on the max side?
I can acount fot this in my controller but i would perfer to have to just make minimal adjustments with the controlboard.
You should align the braces so that they are perpendicular to the X struts, not your table. Use your square as you tighten each brace, ensuring perpendicular to both rails. Donât trust your table to be flat, square or level
If one of the side plates is printed only a little crooked (I had one printed 4mm off because I was stupid), the whole CNC wonât be straight. Those 4mm translated into it being 3cm out of square. 
Yeah, that could be a problem. I printed those with a pretty large brim to not have that happen again.
The right one in your picture seems crooked, the left one seems okay. 
I printed a second one as well.
If you donât have a flat surface to check: I press mine against a window or a mirror. 
I could be mistaken, but it looks like the printed plate on the right suffered from âliftâ during printing, which is when shrinkage causes contraction, and the body curls as the lower layers contract more than higher layers during the print. The red area has a bulge highlighted in orange, and lift can cause bulges like that because the print body has lifted higher than it should be, and the print head stays the course, which causes extra squeeze out.
Something that can help with preventing that shrinkage is protecting the print from cold drafts of air. An enclosure with no top on it can help, because it keeps drafts away, and a more even temp inside, but lets some heat escape so the ambient temp is not so high that it becomes problematic for PLA. Also, good bed adhesion helps (clean bed, perhaps some hairspray or other light adhesive) and as @Tokoloshe mentioned, adding a brim.
