Z axis zeroing issues [resolved]

Hello

I have been trying to set my Z axis manually and following the instructions found on the forums. I do not want to use the z probe as the measurements always keep varying to wildly due to the bad lighting I use. I have manually levelled the bed and have managed to get it nice and level even with the bed heated.

I have followed a few guides and no matter what I do I keep finding that when I start a print the nozzle always seems to decide that zero is now about ~1mm (don’t have my feeler gauges to hand to confirm exact hight) above the bed. I have done the following steps on my last attempt

M561
set the z height to ~0.1mm above bed using paper
G92 Z0
G1 Z10 to move z axis
G1 Z0 to confirm it returns to 0

But when I start to print ormaxis.g from the sd card my z homing effort is now completely ignored and the printer seems to choose a new z height.

Any ideas?

Thanks

Edited 1 time(s). Last edit at 01/30/2014 04:50PM by trilby.

I presume you are doing the Z=0 setting at or near X=100 Y=100 and that you are using up to date firmware e.g. version 0.57a

Have you checked that the version of ormaxis.g on your SD card doesn't contain any homing or G92 commands?

If you are using the web interface, you can see what height the Ormerod thinks it is at.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi DC42

Yes doing homing at the center of the bed and I am running firmware RepRapFirmware-057a-16-01-2014.

No G92 commands in the file, one homing command I have noticed is G28 should I drop this command from the file?

Thanks

Edited 1 time(s). Last edit at 01/30/2014 04:00PM by trilby.

Yes, definitely remove the G28, or replace it by G28 X0 Y0 so as to home only X and Y.

PS - I think RRP removed the homing commands from the .g files a while ago. Did you update the SD card files when you updated the firmware?

Edited 1 time(s). Last edit at 01/30/2014 04:05PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

The version of circle.g i downloaded re homed the z axis and then dropped 5mm (if i remember correctly). ripped up my bed many times till i worked it out!

Hi

I downloaded all the files at the same time on the 22nd and loaded them the same day.

Thanks for your help it has now resolved this issue, now to file down the now removed IR sensor's mounting as it is now pulling my work up as it overhangs a bit.

Cheers for all your help

PS. For people wondering the fix was to remove the G28 command

Edited 1 time(s). Last edit at 01/30/2014 04:51PM by trilby.

I don't use the IR either, basically when I switch on, manually move the head to center and the bed to center by hand, wind z down manually and use a piece of paper to set the gap. Then type G92 Z0, hit warm bed, hit the home x and y in pronterface and load the file and all works fine. It does lift the head while warming and drops it to print height moments before printing.

Dieter #257