Guys, I need an answer on this one as it was suggested that my bed is too warped/bent/whatever.
Here are some measurements (taken many many times to make sure I can measure them consistently).
How do you find it? The bed seems to have a bow in the middle of the right side front to back (~0.20mm) and the whole left side seems to be winged upwards for ~0.10mm.
How do you take those?? I think I have the same problem with my printer…
I don’t know, a bowed/concave bed in the middle could be adjusted from the middle bolts but there is no way to re-adjust a bowed/concave bed on one of the sides where we only have the two end-supporting bolts that connect it to the undercarriage. I will wait some response from the experienced guys here. I also got no answer so far at Prusa Forums. I really don’t want the Z motors to be used to compensate a defect in the bed.
I am using a 0.3mm glas with siliconglue (protective glas for big ipad) this minimize small differences - but 0.3 is quite a lot. Depending on your layers (you can print the first layer with .3) and using rafts - but that is probably not what you want. You can also put a bit 2K epoxy on your bed and scrap it with a blade so this would fill that area - then putting the glas bed on top. - check your bed when all screws are loose. I have seen that bending when (too much) force is applied on the edges, and by thermal stress. ( in german a tool https://de.wikipedia.org/wiki/Haarlineal exist - the english lemma is not the same you use light shine through the slit to see where its curved. )
I haven’t heated this bed maybe a couple of times during the self test but it failed firat time so I decided to take all apart and redo the build. Now I have everything square but this bed leveling, which, if correctly setup in the software (Live Z Adjust, 9 point calibration, etc etc) can be made to work ok but that relies on software to compensate a hardware defect.
I’ll check the bed with loosened screws from the under-carriage, that is something that didn’t come to mind. Thanks.
I’d probably contact tje Prusa support folks. They may have a fix for you.
keep in mind that final calibration needs to be done while bed is hot (if you plan to use the hot bed).
@Ulrich_Baer
Ever heard of anyone using a granite surface plate as a bed?
You can pick them up pretty cheaply sometimes.
@mark_warlick too much mass to move it for most designs. Also takes time to heat up proper.