Unable to ABL (G29) when FT Motion is enabled.

[ahmetcemturan]

Did you test the latest bugfix-2.1.x code?

Yes, and the problem still exists.

Bug Description

Auto Bed Leveling fails when FT Motion is enabled (M493 S1). It works fine when I send M493 S0 before G29.
Also when I try to send e.g. M493 S1 A25 B25, I get: Wrong mode for [A] frequency. Wrong mode for [B] frequency.
I dont get that message when I set S to S11, 12 etc..
Also the K factor seems to be off by a factor of (felt) 10 (in reference to Marlin K-factor)

Bug Timeline

This is the bugfix of a few days ago.

Expected behavior

I expect it to be able to ABl without disabling FT motion and I want to be able to change the FT Motion settings..

Actual behavior

Doesnt work

Steps to Reproduce

No response

Version of Marlin Firmware

2.1.2 bugfix as of 17th July

Printer model

Prusa Clone

Electronics

SKR3 EZ

Add-ons

No response

Bed Leveling

ABL Bilinear mesh

Your Slicer

Prusa Slicer

Host Software

Pronterface

Don't forget to include

• A ZIP file containing your Configuration.h and Configuration_adv.h.

Additional information & file uploads

Marlin.zip

[narno2202]

@ahmetcemturan , i look at your config files , the config seems ok. My probe is a BLTouch and my motherboard a MKS Monster8 V1 with same stepper drivers. I test with the last Marlin bugfix-2.1.x (my actual firmware is from my FT_MOTION develop branch)

1. With or without FT_MOTION , G29 works fine (S0, S1 ...) for Bilinear bed levelling
2. With M493 S1, you can't set frequencies as only FT_MOTION is enabled without shaping. You need a ft_motion_mode > 1
3. In your config file, FT_MOTION linear advance is disabled, so no K factor is applied as standard lin_advance is bypassed with ft_motion_mode >0

I have a question. When i submit the #26083 PR, screenshots are from Marlin Simulator : same emulated LCD as your REPRAP_DISCOUNT_SMART_CONTROLLER. When i test the menu, the simulator crashes if i change Motion Mode before sending any serial command (i.e. works if i home then change FT Motion Mode). Do you notice the same behavior with your printer?

[ahmetcemturan]

@narno2202 ,
to 1: echo: M913 T0 E50
echo:; Driver stepping mode:
echo: M569 S1 X Y Z
echo: M569 S1 T0 E
echo:; Fixed-Time Motion:
echo: M493 S1 A45.00 B25.50 D0 F0.00 H0.00 P1 K0.00
echo:; Hotend Idle Timeout:
M86 B0 E0 S900 T180
echo:; Linear Advance:
echo: M900 K0.06
echo:; Filament load/unload:
echo: M603 L0.00 U100.00 ; (mm)
// HOMING HERE

G29
SENDING:G29
//action:notification Probing Point 1/25
//action:notification Probing Failed
Error:Probing Failed
[ERROR] Error:Probing Failed

//action:notification Hornet3D SKR3 Ready.

M493 S0
SENDING:M493 S0
Fixed-Time Motion disabled.
Linear Advance enabled. Gain: 0.00100
G29
SENDING:G29
//action:notification Probing Point 1/25
//action:notification Probing Failed
Error:Probing Failed //BECAUSE I DIDNT HOME (AGAIN)
[ERROR] Error:Probing Failed

//action:notification Hornet3D SKR3 Ready.
echo:busy: processing
echo:busy: processing
echo:busy: processing

G29
SENDING:G29
//action:notification Probing Point 1/25
//action:notification Probing Point 2/25
.
.
.
.
.
.
echo:busy: processing
//action:notification Probing Point 23/25
//action:notification Probing Point 24/25
echo:busy: processing
//action:notification Probing Point 25/25
//action:notification Hornet3D SKR3 Ready.
Bilinear Leveling Grid:
0 1 2 3 4
0 -0.705 -0.813 -0.858 -0.815 -0.698
1 -0.294 -0.313 -0.286 -0.226 -0.289
2 -0.128 -0.046 +0.042 +0.122 +0.014
3 -0.030 +0.019 +0.161 +0.297 +0.064
4 +0.041 +0.100 +0.109 +0.245 +0.071
Subdivided with CATMULL ROM Leveling Grid:

to 2: don't understand: So what frequency does it correct when I don't enter any? (there would be the FW settings though)
Can You explain a little bit more?

to 3: Yes in FW it was like that but I enabled it via M493 later and had the problem of overcompensation by about x10

[ahmetcemturan]

To the question:
The printer doesnt "crash" in the meaning that it needs a reset but makes a rather unpleasant sound (as if hit an object) and shifts about 10mm and continues.
Pausing, changing Motion mode, Homing X and Y works ((it still makes that sound when moving the first axis for homing) fine.
This problem happened when switching from S1 to S10. No problem switching from S10 to 11, 11 to 12 etc.

[ahmetcemturan]

Note: On my CoreXY with Robin Nano S 1.3, G29 works fine with FT motion enabled. I have not used FT motion there yet though. I would like to ask: I am not sure that it is the correct way to Calibrate by setting the object 45 degrees and then using same frequency for both steppers as in my understanding the compensation must be done for the movement and not for the motors (the moving X mass and the moving Y mass differ quite a lot). Can you explain?

[ahmetcemturan]

Done calibrating and printing a Benchy:
Settings: M493 S14 A36.50 B40.00 D0 F0.00 H0.00 P1 K0.0015
Print via USB - Pronterface
Observation: Extreme slowdown on tiny features (Screenshot attached, GCODE attached)
I will Retry printing from SD card,
3DBenchy_0.25mm_PLA_MK3S_25m.zip

[narno2202]

@ahmetcemturan

1. M569 is useless as stealthchop is enabled in your Configuration_ADV file, try disable HYBRID_TRESHOLD in your Configuration_ADV file as some people have problem with this setting (not enabled in my config)
2. To set a X and/or Y frequency with M493 in FT_MOTION you need a valid shaping mode : S10 and above. On the printer start, default values are loaded if there is no user defined frequency stored.
3. In your Gcode, FT_MOTION linear advance K factor is set to 0. M900 is only for lin-advance in Marlin's standard motion mode. You have to calibrate your FT_MOTION K factor (algorithms are not the same) before using it.
4. Thank's for your answer, i will try to fix the menu
5. For a simple explanation on object rotation with a corexy : https://marlinfw.org/docs/gcode/M593.html

I will have a look at your new post

[narno2202]

@ahmetcemturan , you choose the more time consuming calculation algorithm. As you see my start gcode is very simple

;TYPE:Custom
G28 ; home all axes
M190 S80 ; wait for bed temp
M109 S225 ; wait for nozzle temp
G29 ; Bed Levelling
G1 X0 Y20 Z0.2 F3000 ; get ready to prime
G92 E0 ; reset extrusion distance
G1 X100 E20 F600 ; prime nozzle
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0

No more idea to solve your G29 failure as i use the same leveling process without any failure, only the board differs.

[ahmetcemturan]

Update: Printing from SD is working as expected. Same GCODE, no slowing down on small details..

[ahmetcemturan]

S14 seems to work best for me and the SKR3 is apowerful board (I hope)

[jamespearson04]

I'm experiencing the same leveling issue with UBL G29. Probe retracts but Z movement continues until emergency stop triggers.
M493 S0 also "resolves" the issue. Homing the Z using the same probe works at least.

[narno2202]

@jamespearson04 . I test with current bugfix and latest FT_MOTION code from PR #26074, UBL works with FT_MOTION enabled. My printer is a standard motion XYZE printer. If you have a coreXY printer, for now this kinematic is buggy in FT_MOTION. In this case, your help will be appreciated if you could send feedback from this PR with the last fix proposals.

[jamespearson04]

I'll test that fork out now, also just running a standard cartesian printer, so shouldn't have any issues.

[thinkyhead]

We can move discussion of this issue over to #26074. This is one of the issues we should be aiming to repair in that PR. I did disable FT Motion for the duration of G28 in that PR but perhaps not yet for the duration of G29. Anyway, please test with the branch associated with that PR and we'll get this fixed over there ASAP.

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