How exact should "Step 10" (Geometry check) be ❓
Got my sought for MK3 today and set the table for a full concentration assembly...
Although i did not get far.
After putting together the frame with the extrusions - step 10 is to check the geometry. It "rocked", so I followed the instructions and loosened all the screws and finally it had all four paws on the bench. Parhaps I should mention that the bench is a 200kg polished stone-counter - so I count that as very flat and stern.
So, I removed and tuirned some extrusions to see if it went better... it did still not have all four corners on the counter once tightened - ever so slightly.
So, I disessembled the whole thing and put all the extrusions on the bench - checking each and every one of them. And violá - one of the longer extrusions "rocked" slightly and the other long extrusion also felt like rocking - ever so slightly. The front-plate is also a hair off the counter of hold on one side.
So, is this acceptable? Once assembled one corner is always about 1-1,5mm up from the bench 😯
Bought my first (used) MK2 in december 2017... and still learning...
Re: How exact should "Step 10" (Geometry check) be ❓
During the assembly on a banquet table, I also had the frame rocking a bit. Loosen the screws and tighten it again. I used an electric chuckless screw driver on lowest setting.
But even after tightening it for the second time had the same problem so I put it down on my mosaic 50x50cm flat tiles and the printer didn't rock. It printed okay though I still haven't fully calibrated it using the 9point prints yet.
Re: How exact should "Step 10" (Geometry check) be ❓
Make a video.
Contact support.
Get a flat extrusion.
You don't want to fight this forever.
Re: How exact should "Step 10" (Geometry check) be ❓
I'm having the same problem. I haven't checked each individual extrusion yet. I loosen a couple screws and put it on a flat surface. As soon as I tighten a screw, it becomes uneven. And yes, I'm using the diagonal method as described in the manual.
Re: How exact should "Step 10" (Geometry check) be ❓
See the comments on the wiki version of the manual for this step. Someone there had a _great_ fix, which was to put the smallest allen wrench under the corner that is low, then set a few heavy objects on the other three corners (I used 10lb weights). Then tighten all the screws. Then I removed the allen key/weights and there was no rocking everything was perfect.
Re: How exact should "Step 10" (Geometry check) be ❓
+ 1
Same problem here.
Tightened all screws correctly with torque wrench.
Tried fix in manual, didn´t work at all.
Turned one extrusion around to see if it´s any better: no.
I think the problem maybe the front and/or back plate. I will try to turn them around this evening.
my whiggle is, I guess, 0,5mm diagonal.
Re: How exact should "Step 10" (Geometry check) be ❓
I looked at this the other way and assumed it was my table that was not perfect, so i used a laser level to ensure each extrusion was exactly 90 degrees from the frame. After doing so it did rock slightly on the table but i know it was square. The setup agreed with me and says my axis are perpendicular during the pre print wizard.
Re: How exact should "Step 10" (Geometry check) be ❓
Turning around front plate solved my problem 🙂
Before I did this, I measured the gap with a feeler gauge, it was 0.20 mm.
Re: How exact should "Step 10" (Geometry check) be ❓
Make sure you check and clean off the ends of the extrusions where they were cut off. Some may have a small burr. I used a file and removed any burrs that were there. This will help make the extrusions perpendicular to the frames when screwed together.
MK3 Kit, Designed, built 4x4 CNC Plasma Cutting Table, Motorcycles Bigdogbro's Adventures
http://www.youtube.com/channel/UC5djrxBeeOKB9_6rHnn6G8A
Re: How exact should "Step 10" (Geometry check) be ❓
Keep in mind that the bed will be almost as skewed as the frame.
It is very difficult to calibrate the skew when the printer is mounted.
A skew bed will cause major quality problems with your prints so be extremely careful when building your printer.
Bear MK3 with Bondtech extruder