Frame Slightly off Square on Ratrig VCore 3.1 400 Enclosed
Just finished the gantry and EVA and noticed that there is about 1mm of space ahead of the left Y bumper, while the right it flush. I tried to loosen the screws on both Y carriages and the pully screws for each side of the gantry, but this didn't fix the issue. I did try loosening the left rail and retightening after moving Y forward and back, and same result.
To keep checking, I measured the spacing in left and right, which seem fine. Diagonally, however, the spacings were 900mm and 902mm. Everything Else I've measured seems fine or is different by less than 0.5mm. One thing to note is that I have not tensioned the belts with any tuning, but they seem to be relatively tight and similar to each other. Additionally, I did not notice any change in the misalignment during tightening.
My main concern is that I notice an occasional (but consistent) judder when the left motor is spinning when I move the toolhead by hand. I have not tried moving the toolhead by the motors yet as my electronics are not set up yet and I still need to get some of the final wires. I'm not sure if the juddering is solely because I am moving it by hand, or if it is from something else. I also wasn't sure if the ~2mm difference would be an issue or not considering everything else seems to be ok. For all I know, it could just be the position of the corner plates being slightly off.
Any assistance or advice would be much appreciated!
Thanks,
Dan
6 Replies
complex-teal•14mo ago
You should tune the belts as well as you can, not similar, and after that measure that space
The belts need to be adjusted. Currently one side of your belts is tighter than the other and creating rotation. I had the same issue. In the build guide there is a section for x axis gantry alignment. If you follow that you should be good
rival-black•14mo ago
Did you build the frame upside down? Or did you upgrade from 3.0 to 3.1 and not rebuild the frame?
Was the frame perfectly square before adding the gantry?
fascinating-indigo•13mo ago
Sorry for the delay, I've been a bit busy with work and whatnot, but I wad finally able to work a bit more on the printer last night. After tightening the belts it seems that the gantry is more square, with the "gap" on both sides being the same. While belts might not be perfectly equal, they should be close. I'll tune it a bit more once electronics are all in.
Is there any worry with the aforementioned ~2mm difference in the diagonal measurements on the top of the frame? I think it's likely just from the plates themselves being slightly off, with the extrusions still square.
complex-teal•13mo ago
2mm is a problem
as close to 0 as possible with max 1mm, but what I have learned is that 0.5 can be achieved easily
fascinating-indigo•13mo ago
The 2mm is taken from the outside, touching the frame plates. All the interior distances taken from extrusion to extrusion seem to be within 0.5mm. Thats why I'm not sure if the 900/902mm is because of the plates or somthing else. Everywhere else I can measure seems to be within 0.5.
Also, I realize this is a bit unrelated to the main topic, but do you think I could use good quality stranded 18 AWG wire for the psu to Octopus and SSR rather than 16 AWG? Asking because I have a good length of "scrap" wire from work thats good quality.
Also, thanks for taking the time to answer, it's very appreciated!