Bed plate with flatness tolerances <0.2mm

TechNi

Hey,

I am looking for a supplier for a bed plate with flatness tolerances of <0.2mm. The reason is because I am using an IDEX printer and when both heads are printing (e.g. in mirror or duplicate mode), auto leveling is not an option. Whether the plate is glass or aluminium does not matter for now.

The typical tolerance for borosilicate glass I can find is +-0.2mm, so in total 0.4mm which is too much (since first layer is usually 0.3mm).

For cast aluminium plate, I also typically find an advertised flatness of 0.35mm/m for plates below <20mm thickness and 0.15mm/m for plates of 20mm and above. Latter does not sound bad but it's not an option because it needs way too much energy to heat up and weighs a lot.

So far I have only found Filafarm.de who claim to be able to manufacture below 0.2mm flatness but so far they proved to be very unreliable (delivery delays of many weeks) and extremely unprofessional.

Another supplier I have found is a Turkish supplier aluminyumburada.com who offers precision milled cast plates with flatness tolerances of +-0.1mm/m. They can cut them to size but they won't drill any holes. So far the most promising supplier and I am definitely gonna give it a try.

Please feel free to add other suppliers of both glass and aluminium plates with such tight tolerances (global). Especially as private customer, imo it's hard to find a machine shop willing to make a single plate for you.

I also noticed that people often confuse thickness and flatness tolerance. So I am kinda curious how these two correlate and which one is important for 3D printer users?

ZipZap

@techni

Feel free to contact Clever3D.
They are from germany (my homeland) and specialize in Heatbeds. They could also arrange a suitable heating mat if desired.

/Julien

mrehorstdmd

@techni Cast plate flatness spec is based on an entire sheet which is usually very large (4' x 8' or more). A small piece of that typically has a much flatter surface than 0.2 mm. I have installed 300x300 mm cast plates (1/4" and 8mm thick) in 3 printers and all are flat enough to print edge to edge at 0.2mm first layer thickness with PEI sheet on top. I suspect there's more variation in the PEI and adhesive layer than there is in the aluminum.

Dougal1957

@techni you could try Mandela rose works his beds are extremely flat and are engraved individually with there flatness but there not exactly cheap and he is stateside.

see https://www.mandalaroseworks.com/shop/mrw-products/jubilee-magbed for an example.

TechNi

@zipzap My current plate is from Clever3D and they also offer only 0.4mm/m. As @mrehorstdmd said, this can of course be okay but it's a bit like playing lotto. Especially with larger beds >400mm, there is no guarantee it's actually gonna be <0.2mm.

ZipZap

@techni

Hmm...
I think 0.4mm (total tolerance) per meter is pretty good for a plate of about 5-8mm thickness. Adding up to this comes the tension in the plate due to heating up bottom to top and the tension due to thermal expansion while being fixed on standoffs. Depending on your standoff-positioning you could deform the bed if you use more than 3 screws. There is also the deformation due to its own weight...

Did you contact clever3D and ask for a thicker plate? For everything over 300mm per side i think the plate must be ticker than the usual 8mm - should be more like 10-12mm.
Have you measured your bed with a BL-Touch for example? How is the heightmap looking?

/Julien