9 hours ago, gr5 said:I'd check that first. Does the printer sit flat on a table? Or does it rock? If the frame has banana then you need to loosen a lot of the frame screws and push it back into position and retighten. On extremely rare occasions back in the UMO days there were some "bad" frames where the wood shifted during cutting. Now all frames go through quality control. It's possible to order just one side of the frame.
The base plate that you show as bent shouldn't matter as it connects to the heated bed through 3 points. You can't transfer "banana" through 3 points. You can just adjust the 3 screws to make the bed "level" with the gantry.
Yes! it does rock! when I loosen the screws I should just tap it with a mallet to knock it into shape or do I need to remove the screws to do that?
The frame has tabs that click into each other so it looks like hitting them with a hammer might break them.
Thank you
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gr5 2,228
#3 could be split into:
1) gantry is bent
2) frame is bent causing gantry to be bent
3) plate is not perpendicular to vertical rods
4) vertical rods are not perpendicular to frame
So our friend neotko had an issue he called "banana". One might call it "saddle". Where you can get any 3 points of the print bed level but to get 4 points level you can't because the bed is shaped somewhat like a sadle or potato chip. We'll call that "banana" here.
The most common cause for severe banana is shipping - DHL and other's seem to manage to put an immense amount of weight onto opposite corners of the printer such that it is no longer a cube but trapezoidal.
A bent frame will give you a banana gantry.
I'd check that first. Does the printer sit flat on a table? Or does it rock? If the frame has banana then you need to loosen a lot of the frame screws and push it back into position and retighten. On extremely rare occasions back in the UMO days there were some "bad" frames where the wood shifted during cutting. Now all frames go through quality control. It's possible to order just one side of the frame.
The base plate that you show as bent shouldn't matter as it connects to the heated bed through 3 points. You can't transfer "banana" through 3 points. You can just adjust the 3 screws to make the bed "level" with the gantry.
The glass that comes with many UM2's (and even worse I think with UM3's) tends to be thicker in the center. But by only 1mm at the most and the amount of force to bend it flat is very small. Maybe an ounce. When I saw some banana in my glass - I "fixed" it by bending the rear 2 corners of the heated bed upwards firmly until a metal straight edge (a ruler) showed it to be level. Only after I was done did I realize that I could have damaged my heated bed - I had forgotten that the other side was a PCB heater. But it worked really well for me on my UM3.
You can probably get a flatter glass from fbrc8.com. Measure the error very carefully and ask fbrc8 if you can do better with one of their glass beds for UM2.
The process for making tempered glass makes it thicker in the center. You could buy ordinary window glass from your local glass place (any town that has buildings with windows has lots of glass places). You'd be amazed how cheaply you can get a piece of glass of the correct thickness and dimensions and ground smooth to remove sharp edges (probably $10). The only problem with non-tempered glass is that if it breaks the pieces are very sharp - tempered glass is designed to shatter into thousands of pieces if it breaks and it's not as dangerous.
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