Frame Alignment
Hi all,
I am just kicking off a build for my new mk3s.
i haven’t done this before so I am spending a bit of extra time to get it right.
i am not sure if I have the frame level and square enough. I followed the manual the install the extrusions and haven’t been tightening the screws too firmly. When I put it together I get one particular corner wobbling a bit. I have taken out the extrusion and rotated it and also flipped the front plate. The video attached hopefully demonstrates. This is the best I could get after a bit over an hour of carefully fiddling. I tried on both the kitchen bench and a desk in the study. The kitchen is more Flat.
opinions?
Attachment deleted as unknown format. please drag and drop attachments in text box, Joan
RE: Frame Alignment
Not good enough. It need to be as perfectly square as you can get it. No wobble at all.
You finger tighten the bolts and push down on the corners while it’s on a level surface and then tighten a bit all the way round, push down again on the corners and repeat until they are tight and it’s flat.
RE: Frame Alignment
Not sure how Neo saw anything, it's a blank audio file on my PC.
But if the noise is anything - the wobble is way too loud. I have about 0.025 INCH out of square wobble when I was done. Zero wobble isn't required, but it should be very small. With rubber feet on, and some use, my wobble is undetectable now.
RE: Frame Alignment
I was watching the video on my iPad and it did play after a couple of seconds.
I squared my kit on the glass cooker hob as it was the flattest surface I had and there is no wobble what so ever so it is possible to do. Then again I did spend about 30 minutes doing it as I figured the better I can do it the less trouble I would have later and after calibration the skew reported was something like 0.0012 degrees.
RE: Frame Alignment
I was watching the video on my iPad and it did play after a couple of seconds.
I squared my kit on the glass cooker hob as it was the flattest surface I had and there is no wobble what so ever so it is possible to do. Then again I did spend about 30 minutes doing it as I figured the better I can do it the less trouble I would have later and after calibration the skew reported was something like 0.0012 degrees.
I spent well over an hour trying to get my frame perfect - even tried the strong arm approach. Nothing got it square. One or more of my of the rails was cut just a fraction off on both ends. There are tolerances ... lol.
In the end, my skew numbers are pretty close to zero - and well below the test limits.
From the sound of the wobble in the "video" I'd be looking for machining burrs.
RE: Frame Alignment
The hob surface is a good idea, I will try that tonight.
Let me know if this video worked.
RE: Frame Alignment
spent well over an hour trying to get my frame perfect - even tried the strong arm approach. Nothing got it square. One or more of my of the rails was cut just a fraction off on both ends. There are tolerances ... lol.
Which is hilarious given the proudly shown Prusa machine for testing accuracy of every cut. That was featured in one of the factory tour videos.
RE: Frame Alignment
spent well over an hour trying to get my frame perfect - even tried the strong arm approach. Nothing got it square. One or more of my of the rails was cut just a fraction off on both ends. There are tolerances ... lol.
Which is hilarious given the proudly shown Prusa machine for testing accuracy of every cut. That was featured in one of the factory tour videos.
The degree of "error" in my frame could be a metal filing tangled in the saw blade; or an extra spatter of paint on the frame. I think I am skewed 0.013 degrees or some such. And my zeros are off by a whopping 0.6 and 0.8 mm. I am NOT complaining ... lol.
RE: Frame Alignment
I had a wobble as well when assembling the frame, less than the 2 mm that are still fine, but I wanted to correct it straight away.
I loosened all screws, took a piece of wood I had in the shop, put it across the frame, pushed lightly on the piece of wood to get the entire frame to be in contact with my work surface. Then I did proceed to tightened all screws to properly to join the frame pieces. Then I firmly tightened the screws while still applying light pressure on the piece of wood. I removed the piece of wood: wooble was gone.
A very basic way to proceed, but it worked.
RE: Frame Alignment
Ah-Ha! Figured it!
I tried another couple of times loosening and retightening. But no Dice. The same corner was consistently lifting ever so slightly after tightening the bolts. I Suspect on of the plates or one of the extrusions is ever so slightly bunged.
To solve this I had a couple of F-Clamps lying about in the garage. After loosening all the bolts between the vertical and the long extrusions to just over finger tight, I GENTLY clamped the frame to the bench. Then Tightened all the screws up. Then repeated for long extrusion to the front plates.
Works, its not 100% perfect but no is a fraction of a millimetre out of square rather that 1-3mm out.
Thanks for the input.
RE: Frame Alignment
I had the same problem - in the end I loosened the 16 screws holding the extrusions to the frame, got it settled level then did them back up (diagonally) for each extrusion until I found the one that caused the lift. I then put a piece of card ripped from one of the boxes under the leg on the 'lower' end (so if front right was knocking up and down I put the card under the front left) then tightened that one while putting weight across both extrusions. I went from about a 1-2mm wobble to a fraction of a mm... I was happy with that.
I used a sheet of thick glass as my kitchen top workbench wasn't perfectly true.