rotary delta + mesh compensation | Strange Z-Lift

Egris

Hello dc42,

at the moment i have problems setting up mesh bed-compensation on my rotary delta.
I use a bed which is 300x300.
I defined the config.g as follows:

; Z-Probe
M558 P9 C"^zprobe.in" H5 F120 T3000 ; BLTouch connected to Z probe IN pin
M950 S0 C"exp.heater7" ; create servo/gpio 0 on heater 3 pin on expansion connector
M280 P0 S90 ; send control signal to BLTouch through servo/gpio 0
G31 X-20.7 Y3.8 Z7.0 P25 ; Z probe trigger value, offset in relation to nozzle. And trigger height adjustment
M557 X-140:140 Y-140:140 S20 ; define mesh grid

My Problem is, after the first Probe the machine does a strange movment to higher the Z Position. It looks like there is no kinematic-transform to lift Z up..
Could this make sense? Would it be possible to use kinematic-transform here?

best regards

PCR

@Egris @dc42 once said that Rotary delta ist more a proof of concept in RRF

dc42

@Egris, I can't think of any reason why mesh probing wouldn't work on a rotary delta. Can you post a link to a video?

Orang_

@dc42 said in rotary delta + mesh compensation | Strange Z-Lift:

mesh probing

My mesh probing does not work correctly either, I posted a video earlier in this post https://forum.duet3d.com/topic/20887/rotary-delta-calibration-not-implemented/13?_=1612725679699,
Also g30 does not work correctly

Egris

@dc42 yes i will record a short videoclip

Egris

@dc42 good evening, i uploaded a short Clip where you can see the Mesh Compensatzion Probing.

https://www.youtube.com/watch?v=zwc3E4wfodQ

The Z-Lift after the probe triggers did a strange movement.
I limited the Probing to X 0:145 & Y0:145

normally i use X -145:145 & Y-145:145 but after the first trigger the effector will move to about x-145 Y145 and crash into the bed.

maybe you have any idea. It's the last problem I'm trying to solve. Thank you in advance. Great firmware, thumps up

PCR

@Egris have you tried probing with the Radius Like a Delta?

Best

Egris

@PCR I haven't tested this yet, i will give it a try

Egris

@Egris 2 years ago i used firmware 2.x. There i managed to probe the bed with g29 in a rectangular grid

https://youtu.be/v46Gh64aN_o?t=65

Egris

@PCR With M557 R140 S15 got the same result for the Z-Lift as
M557 X-140:140 Y-140:140 S20..
Effector moves after first probe trigger to abaot X0 Y140.
Thanks for your help

dc42

@Egris, can you post a video showing the effect of doing a single G30 move using firmware 3.2 or 3.3beta?

Egris

@dc42 yes sure, here is a link for probing a single point

https://youtu.be/DCtipYQOzsc

-> Home Delta
-> G1 Z30
-> G1 X-130 Y-130
-> G30

Board: Duet 2 Ethernet (2Ethernet)
Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 3.2 (2021-01-05)
config.g

Egris

@dc42 After the G30 i did via Webcontrol button Y+5 5mm in Y-Direction. The Effector is moving in Y and Z direction. Could this matter?

https://youtu.be/W4afA7cdHNI

Testing it with 3.3 beta gives the same Result

dc42

It looks like the move to raise the probe after it triggers may be using one motor only. Is the Z motor on the left as seen in that video?

Please post your config.g file so that I can try to replicate it.

Egris

@dc42 thank you very much for looking into my problem!
Here is my config.g File

config.g

and i did a drawing of the actual wiring layout

; Rotary Delta Config
M669 K10 U190.0 L393.5 R45 A-90.0:46.50 H419.5 X60, Y60, Z60 B212.132
M666 X0.0 Y0.0 Z-0.28

I rotated the all 3 arm angles by 60° to line up the X/Y Axis

dc42

@Egris , @Orang_ , I am trying to work out exactly what the problem is. Can you tell me whether mesh bed calibration is working on your rotary delta printers?

Egris

@dc42 at the moment i cant confirm weather the mesh compensation is working or not. For me it was not possible to finish the grid probing. At the outskirts of the bed the Z-Lift is doing really fast moves to the other side of the bed. What i can confirm is that printing without the compensation is working really well.

Probing a single point changes / effects the the machine coordinate sytem. After a G30 when i whant to move lets say only in Y-Direction, the move is in Y and Z direction like in that last video.

Looking forward to solve this Problem together. Thanks alot for looking into it.

dc42

@Egris said in rotary delta + mesh compensation | Strange Z-Lift:

At the outskirts of the bed the Z-Lift is doing really fast moves to the other side of the bed.

Are you saying that when the machine has been calibrated manually so that good prints are possible, the Z-lift moves during mesh bed probing are not vertical?
What happens if you home the printer, command the nozzle to e.g. 5mm above the centre of the bed, and do G30 S-1 ? Does the Z lift move afterwards go straight up? If so, is it any different if you run G30 S-1 when the nozzle is away from the centre?

Egris

i looked into the Statemachine for bed-probing in Gcodes 4 but couldn find any hint.
before the Z-Lift there is called the Function SetMoveBufferDefaults(). Could there be somthing reset?

dc42

PS - one more test:

Move the nozzle to a point off-centre e.g. X0 Y50 Z10. Then command the nozzle up (e.g. to Z50) and check that the movement is vertical. Next, command the nozzle to X0 Y50 Z10 again, but after that send G91 Y50 Z10 (i.e. tell the machine where it is at, giving it the same coordinates that it thinks it is at). Then command the nozzle up to Z50 again and see if the movement is still vertical.