Bent Bed

[peggytracy 0]

Hello guys,

 

I need some help with my bed leveling problem. Please see attached pictures. I've adjusted it for few days but it still print like this: 3 corners seem ok but only one corner(left back corner) seems too close to the head. Because there is only one screw in the middle at the back so when I adjust it, if the left back corner becomes ok then the right back corner would become too far away from the head. I am not sure if the bed or the glass is bent?

 

Another problem is the material wraping, should I apply glue when I print PLA? I set the temperature as 60. Or should I replace a piece of glass?

 

Thank you very much for kind reply.

[Smithy 1,144]

I think you just have not leveled correctly and your nozzle is still too far away from the bed. Level it again an level it deeper. Take a piece of paper and turn the screws until you feel some resistance when you move the paper. 

 

Additionally use a thin layer of glue on the cleaned glass. Make some stripes of glue on the glass and then distribute it with a wet tissue to get a thin layer of glue. 

 

BTW. your front bed clips are mounted wrong, they should be at the front and not on the side. But this is not the reason for your issue.

[peggytracy 0]

Thanks a lot for the help. I'm new to the matchine so corrent me if I'm wrong... As I said I've tried to adjest it with paper as well. The problem is at ther back there is only onw screw in the middle which means when I adjust the screw according to the right back corner, the left back corner would be too close. So I'm wondering if the bed is not horizontal.

 

Thanks again.

[Smithy 1,144]

When you level the bed via the menu function, the head moves to the middle in the back, then front left and front right. So you do the leveling always near the screws. Ok, if your bed is really bent in some way, it will not help.

 

The screws should be somehow in the middle before you start leveling. So not too tight and not too loose. You want to have some movement with the springs. You can also search for some Youtube videos how to the level, there are a lot of them.

 

I don't want to say it is not the glass or bed, but in all cases I have seen or heard it was just the leveling. Often users think the friction is enough when moving the paper, but it was not. It needs some time and experience to get a feeling how much friction you need. Basically you can say, if the nozzle is too close nothing will be extruded, if it is too far away, the filament will not stick enough. 

[geert_2 558]

What if you rotate the glass 180° (=front right becomes left back)? If the cause would be uneven thickness of the glass, the problem should move too. If the aluminum plate is bent, or leveling is the problem, then the problem should stay in place.

 

[Smithy 1,144]

Good idea!

[peggytracy 0]

Hello, Thanks for suggestion. I've rotated the glass and the problem occurs at the same corner. Does it mean the problem is with the bed? 

[geert_2 558]

29 minutes ago, peggytracy said:

Hello, Thanks for suggestion. I've rotated the glass and the problem occurs at the same corner. Does it mean the problem is with the bed? 

 

I think so, otherwise the problem should have moved with the glass. So it must be or a bent bed, or incorrect leveling, or both?

 

If you would have a steel ruler or a steel bar that is totally straight, maybe you can put that on the bed, and see if it gives perfect contact everywhere? Or does light shine under it in certain areas?

[peggytracy 0]

Hello I've try to adjust the bedding level precisely and it still print like this. I try to push the corner with finger and it prints perfectly. So I guess it is the bent bedding or at least leaning bedding problem. I print the square as big as possible to see how big the area this problem would affect and it messed up. I’ve attached the video and pictures. I bought it as send hand. Should I return it? Because as I checked it would cost over 100 to get a new bedding.

Thanks

[johnse 31]

If you think about the three point leveling, the back screw is only going to adjust the owner all angle front-to-back.

 

if the back left corner is too high, that means the front right corner may be too low, causing the bed to pivot around the axis from the front left screw to the back center screw.

 

Another thing that could be happening is your gantry rods may not be parallel with the bed, and if the angle changes front to back, due to rods not firmly attached to the belts for example, that could make leveling nearly impossible.

 

Check for any play in any of the rods and confirm they are properly aligned.

[Smithy 1,144]

And check how tight you tightened the three thumbscrews.  The springs should only be slightly tensioned, the bed should still be able to move downwards. 

[peggytracy 0]

Hello guys. Great news! After loose the front right screw the problem is solved! Although it's still a bit close to the nozzle but it's totally acceptable. Thank you so much for all the help.

[Smithy 1,144]

Thanks for the feedback!
I'm glad it worked.
 

[LuisCRsousa 0]

I also have this problem with muy UM2+ extended for more than  a year.

The biggest culprit is the three point adjust system. This is by far the worst design for a bed leveling system.

If ultimaker had a 4 point system this problem would never exist.

 

It's a pain to level it with the ultimaker menu functions because it only moves your nozzel to back center and front sides. There's no way to know if the back sides are correct. You have to move the extruder manually to that points to set it correctly after trying and error.

Edited December 19, 2019 by LuisCRsousa

[Smithy 1,144]

2 hours ago, LuisCRsousa said:

The biggest culprit is the three point adjust system. This is by far the worst design for a bed leveling system.

If ultimaker had a 4 point system this problem would never exist.

Everyone has different perceptions, but I find the 3 points much easier than the 4 points in an ender, for example. There it is a horror to calibrate the bed correctly.

[Dim3nsioneer 557]

Imo, 4 point manual leveling only makes sense if the build plate has a certain flexibility. Which is hardly the case for a glass plate so best thing to do is to stick to mathematics and let those three points define a plane.

[LuisCRsousa 0]

3 points can define a plane but that does not mean that it is the best option for a 3d printer with manual bed leveling.

It's not easy when your back corners changes inversely proportional when you adjust the front corners. It  makes 0 sense for easy of use..

 

Just search in this website for similar people that can't get the bed leveled. All due to this 3 point non sense.

Edited December 19, 2019 by LuisCRsousa

[tinkergnome 927]

I can confirm that adding more leveling points is of no help at all, if the glass plate is not flat... 😏

(YMMV of course)

[LuisCRsousa 0]

Just now, tinkergnome said:

I can confirm that adding more leveling points is of no help at all, if the glass plate is not flat... 😏

(YMMV of course)

 

Neither 3 points