Soft bed

netzmark

Hi,

I got my JGaurora few days ago and started with improvements like everyone probably: drivers, bearings bed etc.

My machine came with bed equipped with glass cover. The glass is flat but aluminum hot plate is fatal, very soft. It changes the flatness while leveling with screws adjustment. When the corners are leveled properly the center of the glass is lowered some 0.2mm and additionally I can still put 0.15mm tester between glass and the aluminum heater. So the heating plate is still more lowered than the glass. When I take off the edge clipses - the glass gets flat.

Someone has the same?

I consider two options:

- to remove the clipses and glue the glass with thermal paste like for PC processors. Then maybe some delicate positioners on corners.

- to order some flat and hard aluminum or copper plate 3-4mm and put it between the heater and the glass.

Some suggestions or advises how to fix it easier?

Samuel Pinches

Hi @netzmark ,
I am sorry if this message sounds negative, since you have just received the printer a few days ago.

However, I think, that you are having an "open eyes" moment, where you are starting to see the limitations of the A5. You could go down the path of trying to improve this, but at what point will you have invested more time than this printer deserves? I think, that if you are unsatisfied with the accuracy of the printer bed, once you apply this same attention to detail to all other areas of the printer, you will end up rebuilding it completely.

One of the problems is that a plane can be defined by three points - a tripod has 3 legs, not 4. The bed is overconstrained, with 4 levelling screws. 

The heater will always be fragile and warp, unfortunately. Perhaps you could add a sheet of 4mm cast aluminium plate to the underside of the bed, which should not warp with temperature changes. However, the height of the bed may become too high, causing other issues. Also, adding more material between the heater and the glass will require more power to maintain the same bed temperature. There will be a difference in the power reading on the bottom of the bed and the top glass surface.

If you have access to a friend with a machine shop, perhaps you may want to think about re-engineering the heating plate and mounting system. But this is a substantial amount of work to invest in a budget printer.

Best regards,
Sam

netzmark

Hi Samuel,

Agree with every your word including that no sense to invest too much in it. Yes it's my first printer and it really opens my eyes on problems :-).

I see small disadvantages possible to be fixed within 50-70 euros, and it's worth I think. Drivers to make it more silent and fluent, x-bearing and the most important the bed.

I just was curious if my problem is common and wether someone solved it some simple way.

What the problem with rising the print surface up? There is 320mm in A5 so loosing even 10cm seems be not problem, isn't it?

br

Marek

Samuel Pinches

The problems is the limited range of bed height adjustment with the screws, and the limited range of adjustment of the z endstop.

netzmark

Ach understand, expected something realy worse :-).

So 4 new screws and 4 minutes on FreeCAD do the trick :-).