# Bedleveling

Posted by lehar
 Bedleveling January 29, 2014 06:10AM Registered: 9 years ago Posts: 24
I have a problem with my printer, it one of the red from RS.

I have a bed leveling problem.
I measure the bed z position at each 4 corners. and have only 0.2 mm diff.
But when I move x = 100 then z = 0.2 diff form first point.

See:
x=60 y=60 z=0
x=60 y=170 z=0
x=180 y=180 z = -0.1
x=180 y =60 z =-0.2

but
x=100 Y=60 z=0.2
x=100 y=100 z = 0.2
x=100 y) 170 z = 0.2

Anyone know whats wrong?
 Re: Bedleveling January 29, 2014 06:22AM Registered: 9 years ago Posts: 1,230
aluminum plade bend or dented?, see johneato's comment here (top):

[forums.reprap.org]

Erik
 Re: Bedleveling January 29, 2014 07:09AM Registered: 9 years ago Posts: 14,646
I'm not clear what you mean by "z=0.2" in the x=100 values. Do you mean that the bed is 0.2mm higher than it would be if it were flat? If so, then I too suggest you look at johneato's comments. I have a similar issue: clamping the glass in the corners gives it a slightly domed shape. I can't measure this accurately yet, but I estimate that for me the centre of the bed is about 0.1mm higher than the corners. I have some feeler gauges on order, and when they arrive I will measure it more accurately, and then repeat the measurements using 4mm glass.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
 Re: Bedleveling January 29, 2014 07:27AM Registered: 9 years ago Posts: 1,230
also make sure your x-axis-plate is without any curve, any difference along the x-axis will influence the print head though the bearing running on the side of the rib
This can happen because of forces between the x-axis-plate and x-rib and the smooth rod, make sure that the x-axis-plate and x-rib go together freely, and the x-axis when put together is "relaxed" when you mount the smooth rod
also notice that the PTFE tube put a downward force to the printer head and mostly in the middle of the bed (I take it that your measurements if from zeroing the nozzle)

Erik
 Re: Bedleveling January 29, 2014 09:29AM Registered: 9 years ago Posts: 2,472
It could be that your glass plate is domed, but it could also be that your laser-cut Perspex X-axis plate is bowed. This is causing your hotend to tilt from side to side as the X-axis bearing runs along the side of the plate, and that in turn changes your Z height slightly (it will also put a bow in your prints). Put a straightedge along the side of the Perspex where the bearing runs to check. Also ensure that the bearing bolt does not hit the extruder motor as it passed under it.

Dave
(#106)
 Re: Bedleveling January 29, 2014 09:30PM Registered: 9 years ago Posts: 176
Hi,
Not the glass my friend, my print head sag a little at X=100 position. I carefully re-assemble the X axis plexiglass, adjust / change ( 623) X run bearing etc , much better now. my problem here is, bottom MDF warped from time to time , I need to re-level it. Asia weather will warp the MDF faster. My X0 to X180 is 2.9mm !!! its time for me to look for a better solution. ( less than 1kg of total print volume ) Still searching for local supplier who can help me to make an aluminium version, but no luck yet. my mini cnc can only milling PCB. I stop printing anything now until I can solve this problem.
 Re: Bedleveling February 02, 2014 03:12AM Registered: 9 years ago Posts: 24
Thank you, there are several things I would try to work with.

And I see other has the same problem as me, and solved it

Per
 Re: Bedleveling February 02, 2014 03:38AM Registered: 9 years ago Posts: 314
Quote
tru168
... my problem here is, bottom MDF warped from time to time , I need to re-level it. Asia weather will warp the MDF faster. My X0 to X180 is 2.9mm !!! .... Still searching for local supplier who can help me to make an aluminium version, but no luck yet. my mini cnc can only milling PCB. I stop printing anything now until I can solve this problem.
Have a look at [forums.reprap.org] by dc42, this excellent solution is all done by hand tools, looks neat.

I aim to try this, but your environment will do a good moisture test! I'm assuming that the other mdf parts are not as much of an issue due their alignment and unlikely to distort in a problematical way, so worth a try?

Ormerod #007 (shaken but not stirred!)
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