Enclosed 400: Low corner to saddle to wave to low corner infinite loop.
Hey all, any advice is appreciated because I am very close to 150 bed mesh attempts now and starting to lose hope 😅 .
I recently finished my enclosed 400 build and am attempting to run through the final calculations, but my mesh seems to follow this endless pattern of rear corners (pillar C then sometimes D) to a saddle to a wave (high in the front) to a low corner again and then this loop repeats infinitely no matter how much adjusting I do. I had finally managed to get a .190 (cold) at one point today but the moment I heated the bed it went back to .251
Specs: VCore 3.1 400mm enclosed, Eva 3 toolhead, igus chainflex umbilical, Spannsysteme lightweight x-gantry from fabreeko.
I've included my debugging details/process in a a message below due to the character limit
14 Replies
Here is what I have I have tried/confirmed so far:
1) The frame is square. I have gone around the printer and readjusted, triple checked measurements, corners etc. My measurements diagonally, front to back and side to side are all equal. The printer was built on a quartz slab so a flat surface is not the issue either.
2) I have watched the pinned video many times and have been following it closely as my guide, unfortunately I haven't seen any. success. from this other than that one cold .190
3) I have readjusted the belt tension, checked the front gaps at the idlers and loosened the y-rails/done the x-gantry alignment procedure many times. I don't believe anything is overtightened in this area.
4) In my earlier meshes (1-50) I may have had the umbilical too tight to where it was pushing/pulling on the toolhead a bit, so I have added a bunch of slack and it no longer appears to be pushing the toolhead around at all and my numbers improved marginally.
5) I'm currently running these meshes hot with the bed at 80C and the pei sheet off. I have triple checked the magnetic sheet and I cannot see any bubbles. or bumps in the surface. I was extremely careful putting it on.
6) I have triple checked every single measurement on the electronics subframe and everything is exactly as it is supposed to be numbers wise.
7) I'm trying not to make big adjustments when moving the y-beams up and down. Usually a mechanical pencil line at most at a time. Despite this, I am still seeing wild swings from mesh to mesh.
At this point, my only though is perhaps the bed is warped? I did give it a very quick once over with my machinist squares but I'm now concerned that I should have looked more closely. Any help will be much appreciated, I'm happy to share as much additional info or photos/videos in an effort to diagnose this!
Forgot to add:
8) My X - Y printed parts and joiner plates appear to be flat and lined up. There is no binding when the gantry runs along the y axis. Printed parts are PC-CF from a member in the print-services channel and the joiner plates are carbon fiber from fabreeko.
frail-apricot•12mo ago
is your x gantry seated firmly in the connector pieces (whatever they're called)? the hump in the front - where the bed is supported on either end - makes me think the gantry is bowing upwards and not seated all the way in those pieces.
@aruizramon I took a look and it seems to be well seated. The holes in the lightweight gantry are pre-drilled and everything lines up well
frail-apricot•12mo ago
huh. i had a pretty extreme saddle (vc500) and i took the x gantry apart, made sure it all fit well, and it magically went away. i think there's a little bit of sag in the back corners, but the front is totally flat. i think if the front were flat instead of having the hump i'd lean towards 'sag' but the hump is pronounced there too.
if you take the plates off the front two corners, do they want to push out away from the frame? that'd indicate the x gantry is getting put into compression.
(not an expert, this is my first rr and i only recently completed it)
I appreciate the advice! I'll do a quick disassemble and reassemble of the gantry today and see if that improves anything. Interestingly enough, I originally noticed that when I would shift the y-rail extrusions up and down in an attempt to level the mesh, the top of my frame would get pushed put of perfect square (only diagonally) by roughly 1/16" - 2/16" depending on how much I moved the y rails. I though that might be a problem so I ended up taking the extra idler plates (for the non-enclosed version) and used them in the front corners to ensure the frame stayed square even while moving the y-extrusions. I wonder if that could be causing the x-gantry to be put into compression and maybe I should remove them and be OK with the slight out of square on the upper frame? I'll try removing those as well as the other plates on the front two corners and see what happens.
frail-apricot•12mo ago
i think that video has a good idea of 'matters' vs 'doesnt matter' as far as squareness, although it does not cover the enclosure.
good luck, hope it works out 🙂 lemme know how it works out!
@aruizramon I definitely owe you an update! So I ended up going back through everything, (gantry, belts, frame, etc.) and disassembled, reassembled and confirmed square several times. After assuring myself that everything was in fact square I did as much as I could to closely inspect the bed without removing the magnet and heater and have pretty much confirmed that is does have a slight warp (that little hump in the front of the mesh). The good news though is that all of that re-squaring/realignment did bring my mesh numbers down to the high .2 - low .3 range consistently which allowed me to finally get a .153 with the tape method! I reran it at one point and even managed to somehow get a .129! Number have been consistently around these values since then with most smaller meshes showing deviations in the .06 - .07 range.
Here are the results nearly 200 mesh attempts later 😅
Not all good news unfortunately as I'm still having a weird first layer issue where there are gaps in the front and right edges but few to none in the back and left edges. It's printing relatively well at this point, but I have some scraping issues + gapping in the top layer that mirror the mesh result despite all the additional calibrations performing well. It's almost like the printer is performing the mesh but then ignoring it since the areas of the print that have scraping & gapping issues follow the mesh so closely... I guess it's off to fix-my-print for me!
Thanks again for all your help thus far though! I really appreciate it!
frail-apricot•12mo ago
hey! well, i'm glad the mesh is sorted out!
for the mesh, i run one before each print with the adaptive mesh setting, and i haven't noticed any first layer problems (that aren't my fault for z-offset issues). are you running that?