Topics created by hsverre

@hsverre If you mean a webcam, see here.

@hsverre Are you concerned about the belt stretch? I can't say much about it in the X and Y axes, but there shouldn't be any problem with a belt lifted Z axis longer than 35cm. My printer has 69 cm belt lifted Z axis and I often make prints that are 600 mm tall without any issues. I have measured both steel and glass core belt stretch in the Z axis and found it small enough to be inconsequential.

I measured stretch under multiple loads at about the center of the Z axis](https://drmrehorst.blogspot.com/2018/12/comparing-steel-core-and-glass-core.html), and yes, the numbers probably vary a bit depending on the bed position- less stretch near the top and a little more when the bed is near the bottom, but we're talking about a few microns. The roughness of the print's top layer is probably going to be worse than the error caused by Z axis belt stretch for most prints.

The ultimate stretch of the Z axis belts should be easily predictable for any given print -the slicer tells you the print mass, and a simple test tells the amount of stretch to expect for a given mass, so simply scaling the Z axis in the slicer should be able to compensate for stretch of a super heavy print and/or a super long Z axis, if you're really worried about it.

If you're worried about belt stretch in the X and Y axes, you can select a mechanism that minimizes the belt length- maybe drive the Y axis with two belts and mount the X axis motor on the X axis to keep belts as short as possible. Corexy might not be ideal if you're worried about belt stretch in X and Y in a very large printer.

@hsverre thanks for information, I am glad that you found the reason. Happy printing 😉

You can source 5v from other points on the Duex for testing purposes.

https://duet3d.dozuki.com/Wiki/Duex_wiring_diagrams

Another possible test would be to disconnect the Duex Ribbon cable and connect the BLtouch wires as shown for a simple Duet connection. If the BLTouch works there, then we have isolated the problem to the Duex itself.

@hsverre said in True Bed Leveling G32:

@fcwilt Hm. It seems like its adjusting the bed correct. Could it be that i might have a faulty stepper motor thats not doing its job properly by a mm or two, thats difficult to measure by eye.

Did you verify Z movement as I asked about.

Have you run G32 many times to see if it ever gets better?

It's possible to setup a loop which runs a max number of times or until a certain result is obtained.

From my bed.g file:

while true ; run leveling pass ; --- probe near bed corners --- G30 P0 X-140 Y-90 Z-99999 ; LF G30 P1 X-140 Y90 Z-99999 ; LR G30 P2 X140 Y90 Z-99999 ; RR G30 P2 X140 Y-90 Z-99999 S3 ; RF ; check results - exit loop if results are good if move.calibration.initial.deviation < 0.02 break ; check pass limit - abort if pass limit reached if iterations = 5 M291 P"Bed Leveling Aborted" R"Pass Limit Reached" abort "Bed Leveling Aborted - Pass Limit Reached"

Test the trigger height of the probe at that point. It looks like it's triggering too early.

Are you able to reliably trigger the wipe of the SD card or is it more random?