UM3 Automatic Bed Leveling / Calibration and High Temperature

[machineherder 0]

I have our Ultimaker 3 setup to do automatic bed leveling as often as possible, and occasionally do a manual levelling, but for larger parts there seems to be a significant height difference in printing the first layer, especially from front to back. This is significant enough to create problems with bed adhesion.

I am mostly printing with ASA for outdoor applications, and it benefits from a high bed temperature. I am running at 105C for the bed, which is the highest I seem to be able to achieve reliably.

It appears to me that the automatic bed leveling happens after the nozzle has warmed up, but does not wait for the bed to warm up. I wonder if the bed shifts a little as it heats, especially at 105C. I've tried using preheat before starting the print- I think it is helping, but I haven't printed a large part since I started doing it.

Is there any good reason why the bed leveling is done before heating the bed? Is it a reasonable hypothesis that the bed temperature could affect the leveling? Anyone observe similar effects?

thanks!

[Digital-Ed 0]

I have wondered about this also. Interested in the answer.

Also I had a borosilicate glass plate for another printer that was warped. Not bad enough to replace because of that printer's usage.