Assembling the Printer was fine - great work all the documentation!
I discovered an issue with the bed. In the center is about 2,5 to 3mm higher than the sides. Any ideas how to fix this? Is it possible to get a new bed?
I tried to bend the bed to correct the issue. By doing this i broke the thermo sensor. I’ve already ordered a replacement. I have 10 now so if somebody needs one as well pls let me know…
I will try using a mirror on top of the bed. Let’s see how that works. I would prefer to fix the bed issue if there is a way to do this.
[quote=“huebsch”]Assembling the Printer was fine - great work all the documentation!
I discovered an issue with the bed. In the center is about 2,5 to 3mm higher than the sides. Any ideas how to fix this? Is it possible to get a new bed?
I tried to bend the bed to correct the issue. By doing this i broke the thermo sensor. I’ve already ordered a replacement. I have 10 now so if somebody needs one as well pls let me know…
I will try using a mirror on top of the bed. Let’s see how that works. I would prefer to fix the bed issue if there is a way to do this.
-AH-[/quote]
I broke mine this way too. Maybe the screws are too tight. I will try to use something to make a bigger distance between paper sheet and heat bed.
Uuups,
2,5 to 3 mm higher in the middle … thats quite a lot!
On the “first try” I had about 1,5mm.
Trying to bend the whole assembled bed is not a good idea, 'cause you have to apply to much force and even get the single components not in a flat state.
After “rethinking” this whole assembly, I’ve done the following :
disassembling the whole bed
the underlaying aluminium-part isn’t as flat as it should be
so tried to get it as flat as possible
and at least decided to use it with the bulge showing to the bottom of the machine
so there is no counterforce to the heating-bed
drilled the holes for fixing the heading bed to a 4mm diameter
also give the holes in the insulating cardboard a little bit more in the diameter
so the screws have litte bit more clearance
also I noticed that the 4 countersinks in the heat-bed have not the same depth
so I decided to refinish them
!Attention! not to go to deep and damage the copper on the oposite of the heating-bed!
after all of that I reassembled the whole thing with a little trick:
when mounting the heat-bed i put a heavy plain burden on top of it
and than tightened the screws
Now I have about 0,5 mm difference between the edges and the middle, a difference I think I could live with.
Tested it, whith the first layer a little bit thicker than the others, and have now problems so far.
In my opinion an additional mounting screw in the middle of the heating-bed could defuse this behavior, but unfortunatly this can’t be done without destroying the tracks of the heating bed
Folks!
I forgot to mention, that I already increased the size of the holes. During assembly I recogniced the tight but correct alignment. I widened up the holes to avoid any force. The screws not extremly tightned. So from this side I do not expect an issue. I guess the copper side with the meander shape causes the bending. The Aluminium Support is quite straight on our machine.
-AH-
[quote=“VEL327”]Hi all,
[…]
3.5mm or 4mm should be good and get rid of all bulging of the heated bed.
[/quote]
Thanks for the quick Response!
From my Point of view the PCB is not flat. The issue is not caused by a force through mounting. Even when it is not mounted, so no force is on it, mybed is bent.
-AH-
I’ve increased the holes to 4 mm, and also countersinked the holes in the bed PCB (the screwes were higher then the PCB so the nozzle could colide with them on the first layer. Also I countersinked the holes in the mounting plate, shown above, so that the cardboard would lie flat on the carriage. But non of these fixes fixed the problems since the PCB it self seems unflat. Now I have a glass mirror on small distances on the bed PCB and that makes the bed flat but the temperature is harder to control.
Folks!
Dear Velleman Team!
I have now a widened hole in the bed and as well the holes in the Support alu are now 4mm.
You can see the opening angle between the ruler and the mirrored Image of the ruler. I placed a green plastic behind to increase the contrast for the photo.
Unfortunately it’s not so easy to take a picure but I jope it illustrates the issue.
I can assure you that this is no problem to print on. The printer can handle a small uneven surface. Make sure the surface is grease free.
We have not tested printing on a glass plate so I cannot say if this is better or worse.
I can confirm that prints with even my completly bumpy bed are possible. Currently about 2mm difference between middle and ands. I decided to calibrate the Printer nozle to the highest point in the middle.
I also can confirm that a little uneven surface of the bed won’t cause problems.
The more imortant thing is: keep it grease and dust free!
Just printed a little spare-part (about 15 x 15 x 12 mm) I need for an other project.
The first try failed: I noticed it too late that there is a little bit dust on the bed and the piece wobbled around, after cleaning the bed and restarting the job all went fine.
Just a side note: some lightning arround the nozzle would be a nice addon
