@btmclain I see you have standstill current at 0% (M917 X0), have you tried commenting out this line, or increasing the standstill current value?

on my system when I add the M917 X0 I also get this clunk. Removing it and I have no clunk when tuning.

some background. I recently started playing with Duet, so I could be considered complete noob (though I have plenty of 3d printer and CNC experience)

I picked up a Duet mini5+, a 1HCL board (ver 1.0a), and a magnetic encoder (v0.3).
Upgraded the firmwares to 3.5.1
I've got it setup very minimally on the desk just getting used to the software/setup.

I'm trying to follow the guide, (still can't post links) but the Plugin never allows me to select a driver. "No data available"

I can move the motor in open and closed loop.
and even do a manual M569.5, then open the subsequent file in the plugin.
I just can't get the plugin to cause the recording/tuning moves.

I thought maybe it was my version, Started with RRF Version 3.5.1 on all, Updated to 3.5.4 on Mini 5+ 1HCL and DWC. uninstalled and reinstalled the ClosedLoop plugin 3.5.1. Same situation. Can move, can record, cannot get the plugin to cause the move.

is there something obvious i'm just missing?

Config.g

; Configuration file for RepRapFirmware on Duet 3 Mini 5+ Ethernet
; executed by the firmware on start-up

; General
G91 ; Relative coordinates
M83 ; relative extruder moves
M550 P"TestSaw" ; set hostname

; Network
M552 P192.168.1.14 S1 ; configure Ethernet adapter
M553 P255.255.255.0 ; set netmask
M554 P0.0.0.0 ; set gateway
M586 P0 S1 ; configure HTTP

; Wait a moment for the CAN expansion boards to become available
G4 S2

; Closed Loop Drivers
M569.1 P50.0 T3 E0.0:0.0 S200 R40 I0 D0 ; only magnetic shaft encoder

M569 P50.0 S1 D4 ; driver 123.0 goes forwards (extruder 0) FEED

; Axes
M584 E50.0 ; set axis mapping
M350 E16 ; configure microstepping 
M906 E800 ; set axis driver currents

; (micro)Steps/mm Calculation:
; E: Driver 16 microsteps
; E: Motor 400steps/rev (89080.1598:1) {6400}
; E: Belt Reduction 1/2 (0.5)(222.7003995:1) {12800}
; E: Harmonic Reduction 1/100 (0.01)(111.35019977:1) {12800000}
; E: Pinch Roller Radius 7.212148 mm (circ 45.3153) (1.1135:1) {28246.530421/mm}
; E: Encoder Roller Diameter 12.954 mm (circ 40.6962)(1,610.371484 ticks/mm)
M92 E28246.530421 ; configure microsteps per mm 
M566 E0 P1 ; set maximum instantaneous speed changes (mm/min)
M203 E17.7 I0.1 ; set maximum speeds (mm/min)
M201 E5462.962963 ; set accelerations (mm/s^2) 

; Kinematics
M669 K0 ; configure Cartesian kinematics

; Spindles
M950 R0 C"nil + io1.out" Q500 L60:10000 ; configure spindle #0 ;P"io1.out" 

; Tools
M563 P0 S"Blade" D0 F0 R0 ; create tool #0

; Miscellaneous
M453 ; select CNC mode
T0 ; select first tool

; Remove Requirement for homing
G92 E0 ;

@dc42 Sorry, been out the last 4 days on holiday. I'll test that build today and let you know asap.

@btmclain to do the tuning it needs to be in closed loop.

Generally you home the axis in open loop, move it to a "safe" location (not crashing the machine), set it to closed loop, then do the calibration.

I suggest you read the tuning documentation here

This would also help me,
With BiSS-C I would be able to select an appropriate encoder for my desired setup (17+ bit resolution required)

There's a post I found where someone was supposedly able to "read" a BiSS-C encoder with SPI in the "SimpleFOCproject" community forum. (can't post links yet, but search for SPI BiSS-C SimpleFoc and it'll likely come up. )

@btmclain By "manually" i mean not in a homing macro, but by sending the gcode manually either in the DWC console or connected SBC.
But after rereading your first post, I assume that's what you've done.

I think your issue may lie in the initial configuration of the encoder. the C parameter should be the number of cycles from the quadrature encoder per motor revolution.
I don't see anywhere you specify the motion relationship between motor and linear encoder, the linear encoder you specify has a 5um/pulse output, (20um/cycle)
With your C value of 1000 that works out to a movement of 20mm/motor rotation. is that correct?

Are you doing a small motor movement in open loop mode before attempting calibrations?

When playing with my setup I was able to somehow get the system to move in closed loop with only a magnetic encoder calibration, then I was able to confirm the linear encoder cycles/rotation value (i had to iterate a few times as the documentation says Pulses per revolution, I believe it should say cycles/revolution instead as that is what I ended up at to get the correct movement) Once I had the C value in the ballpark I was able to get the system to calibrate the Quadrature encoder (M569.6 V1) successfully.

@flopes
I am also trying to build a super accurate machine with the Duet.
At the moment i have yet to achieve my target, but it's hopeful.

far as I understand it you'll need 1HCL boards for each motor, and if you want to go closed loop then a magnetic encoder board for the motors.

If you don't go closed loop the only way to get the encoder ticks (at the moment) is to run a M122 B(can address) and parse the result for the encoder tick.

If you do go closed loop, you'll want to tune the values, and spend quite a bit of time tuning at the speeds/accelerations you plan to run.

Turns out, something in the system REALLY doesn't like 0.5mm/min probing speeds with closed loop and probe attached to the 1HCL.

The extra plunge on the probe happens almost constantly and the 4kprobe cycle was not able to complete due to the amount of skew going outside machine limits. Only 298 probes before going over my axis limit of 1.5mm

With that happening constantly I was able to get a few videos, one of "normal" expected operation,
and one when it was happening every, or every other probe.
Normal Probe
Extra Plunge Probe

eventlog6-9.01.txt
eventlog6-9.01.xlsx

5 More tests.
Not sure I gain anything more from these beyond the fact that the skew seems "consistent", every setup skews for some reason.
I added a two columns to my results, mathing how many steps of skew seen as dc42 mentioned a possibility of skipping 4 steps if the probe speed was too fast.

I'll test slower next and hope to see some better results.

G30, Mini5, ClosedLoop, 2mm/min, Coolant On

eventlog6-4.05.txt
eventlog6-4.05.xlsx

G38, Mini5, ClosedLoop, 2mm/min, Coolant On

eventlog6-5.06.txt
eventlog6-5.06.xlsx

G30, Mini5, OpenLoop, 2mm/min, Coolant On

eventlog6-5.07.txt
eventlog6-5.07.xlsx

G30, Mini5, OpenLoop, 2mm/min, Coolant Off

eventlog6-5.08.txt
eventlog6-5.08.xlsx

G38, Mini5, OpenLoop, 2mm/min, Coolant On

eventlog6-6.01.txt
eventlog6-6.01.xlsx

6 more tests.
Closed loop skew on 1HCL attached probe is quite a bit higher than open loop skew at 2mm/min probing speed.
at 2mm/min I didn't get any Tolerance warnings, but there is a section in both closed loop tests at 2mm/min where the encoder depth as well as the reported depth is shifted from immediately before/after (just as when the tolerance warnings were present at 1mm/min)
here's the breakdown of all the tests so far.

Coolant on and off seems to make a slight difference (I won't be able to run the system with coolant off, but at least it's another data point)

6-4.04 G30, 1HCL, Open Loop, 1mm/min, Coolant On
No Plunge on Probe
Encoder Slope: 1.162846E-3
Real Position Slope: -1.95309E-6
Error Slope: 4.01316E-5
Overall Skew: 0.153387381

eventlog6-4.04.txt
eventlog6-4.04.xlsx

6-4.05 G30, 1HCL, Open Loop, 1mm/min, Coolant Off
No Plunge on Probe
Encoder Slope: -3.33881E-4
Real Position Slope: 5.6078E-7
Error Slope: 3.4996E-5
Overall Skew: 0.134812968

eventlog6-4.05.txt
eventlog6-4.05.xlsx

6-5.01 G30, 1HCL, Open Loop, 2mm/min, Coolant On
No Plunge on Probe
Encoder Slope: 5.2123E-4
Real Position Slope: -8.75448E-7
Error Slope: 5.32046E-5
Overall Skew: 0.200704569

eventlog6-5.01.txt
eventlog6-5.01.xlsx

6-5.02 G38, 1HCL, Open Loop, 2mm/min, Coolant On
No Plunge on Probe
Encoder Slope: -2.73306E-4
Real Position Slope: 4.59039E-7
Error Slope: 5.0216E-5
Overall Skew: 0.195034134

eventlog6-5.02.txt
eventlog6-5.02.xlsx

6-5.03 G30, 1HCL, Closed Loop, 2mm/min, Coolant On
No Tolerance Errors, One noticeable extra deep plunge on probe
Encoder Slope: 1.916218E-3
Real Position Slope: -3.21844E-6
Error Slope: 1.07788E-4
Overall Skew: 0.423135282

eventlog6-5.03.txt
eventlog6-5.03.xlsx

6.5.04 G38, 1HCL, Closed Loop, 2mm/min, Coolant On
No Tolerance Errors, Two noticeable extra deep plunge on probe
Encoder Slope: -4.98784E-4
Real Position Slope: 8.37747E-7
Error Slope: 1.03858E-4
Overall Skew: 0.414567662

eventlog6-5.04.txt
eventlog6-5.04.xlsx

Five more tests, Still not really seeing a pattern to what could cause the skew.
The Position Error/overPlunge on probing doesn't happen in Open Loop, so it's something in how the closed loop works when probing cycle returns.

currently the run with the least skew at 0.1374mm was using G38, 1HCL attached probe, in Open Loop, at 1mm/min probe speeds with coolant on.
Followed closely at 0.1863mm which was using G30, Mini5+ attached probe, in Closed loop, at 1mm/min probe speeds with coolant on.
I've edited the first post to include the overall skew values with the results.

6-3.04 G30, Mini5, Closed Loop, 1MM/min, Coolant On
10 Tolerance Errors
Encoder Slope: -2.40482E-4
Real Position Slope: 4.03909E-7
Error Slope: 3.84349E-5
Overall Skew: 0.186260065

eventlog6-3.04.txt
eventlog6-3.04.xlsx

6-3.05 G30, Mini5, Closed Loop, 1mm/min, Coolant Off
10 Tolerance Errors
Encoder Slope: -1.440915E-3
Real Position Slope: 2.42013E-6
Error Slope: 1.02157E-4
Overall Skew: 0.39720354

eventlog6-3.05.txt
eventlog6-3.05.xlsx

6-4.01 G30, Mini5, Open Loop, 1mm/min, Coolant On
No Probe Plunge outliers
Encoder Slope: -7.49232E-4
Real Position Slope: 1.25839E-6
Error Slope: 1.00412E-4
Overall Skew: 0.397692421

eventlog6-4.01.txt
eventlog6-4.01.xlsx

6-4.02 G38, Mini5, Open Loop, 1mm/min, Coolant On
No Probe Plunge outliers
Encoder Slope: -1.493907E-3
Real Position Slope: 2.50913E-6
Error Slope: 9.97285E-5
Overall Skew: 0.405980298

eventlog6-4.02.txt
eventlog6-4.02.xlsx

6-4.03 G38, 1HCL, Open Loop, 1mm/min, Coolant On
No Probe Plunge outliers
Encoder Slope: -4.35522E-4
Real Position Slope: 7.31494E-7
Error Slope: 3.60884E-5
Overall Skew: 0.137387362

eventlog6-4.03.txt
eventlog6-4.03.xlsx

This is partially a continuation of this post I made earlier, here but since I'm now on the newer firmware I figured a new post was warranted.

I have been testing probing on the new 3.6.0 firmware, and have collected some interesting data.
First: the machine Z position skew compared to the linear encoder ticks.
Second: randomly while probing the system will probe normally, then plunge ~30um when reaching the probe trigger position.

This system is a tubing cutter, with the Z axis as the blade, Y axis as the tube feed, B axis as the tube rotation, and A axis as the tubing clamp.
The probe is setup between the blade and the tubing, The spindle of the blade is electrically isolated from the machine attached to the probe input. The probe ground is grounded to the machine. When the blade touches the tube, the Probe pin is pulled to ground.

Z axis is driven by the 1HCL board, with a linear enoder on the axis and the magnetic encoder on the motor.
The rest of the axis are driven by the mini5+eth board.

For testing I have a Gcode that moves the blade from the homed position close to the tubing (usually ~200um above) feeds the tube a small amount, then starts a repeating (4000x) cycle of:

• Probe,
• Call M122 B50,
• Call M118 to record current Z axis position,
• move blade up by a small amount,
• feed tubing a small amount to expose fresh tube that hasn't touched the blade.

in my startup gcode I run a macro where I probe the tube 4x around the tube and record to determine average position of the tube, then set the Z 0 position to that average tube position.

I then download the eventlog and parse it with a python script, pulling out the z position, the linear enoder tick value, and the line number in the file.

Relevant Config/macro files.
4kProbes.g
4kProbesG38.g
config.g
findContact.g
homez.g
setZeroDepth.g
start.g

I intend to test all combinations of the following
Tested Variables:

• G30/G38.2 probe commands
• 1HCL/Mini5+ Probe connection
• Closed Loop/Open Loop
• Probing Speeds (0.25-2.5mm/min)
• Coolant On/Coolant Off

For now I have results of 4 of these tests.
6-2.02 G30, 1HCL, Closed Loop, 1mm/min, Coolant Off
11 tolerance error events
Encoder Slope:-1.614729E-3 (this is using Excel's slope function)
Real Position Slope:2.71207E-6 (this is the position calculated from the encoder ticks)
Error Slope:1.35584E-4 (this is the difference between the Z position, and the "Real Position" calculated from encoder ticks)
Overall Skew: 0.545333006

eventlog6-2.02.txt
eventlog6-2.02.xlsx

6-3.01 G30, 1HCL, Closed Loop, 1mm/min, Coolant On
7 tolerance error events
Encoder Slope:-1.138511E-3
Real Position Slope: 1.91222E-6
Error Slope:1.2222E-4
Overall Skew: 0.490220687

eventlog6-3.01.txt
eventlog6-3.01.xlsx

6-3.02 G38, 1HCL, Closed Loop, 1mm/min, Coolant On
19 tolerance Error events
Encoder Slope: -5.80388E-4
Real Position Slope: 9.74808E-7
Error Slope:5.91329E-5
Overall Skew: 0.259642576

eventlog6-3.02.txt
eventlog6-3.02.xlsx

6-3.03 G38, Mainboard, Closed Loop, 1mm/min, Coolant On
12 Tolerance Error events
Encoder Slope: 1.145735E-3
Real Position Slope: -1.92435E-6
Error Slope: 9.73267E-5
Overall Skew: 0.368842908

eventlog6-3.03.txt
eventlog6-3.03.xlsx

I noticed after the first 2 runs that the tolerance errors always happened when the probe result was significantly lower than surrounding probes. and inspecting the tube after confirms that the blade actually traveled down further (notches in the tubing, in the same pattern as the graph shows)
I was luckily able to get 2 good logs of the plunge, when playing with the closed loop tuning plugin while running.
Here you can see the probes before/after the plunge are all very close to where the target motor steps jump.

50_2025-06-03_08.07.29.xlsx
eventlog2025-06-03_08.08.29.txt

50_2025-06-03_08.08.44.xlsx
eventlog2025-06-03_08.08.44.txt

From these 4 results I cannot say there's been any significant change in the skew/slope of the probe position.
The G38 seems to be a bit less skew, but not a huge amount.
It seems that when the probe plunges, the Z shift is more significant.

@dc42 Sorry for the delay, I've been out of town the last 4 days.

I have loaded the provided build and have ran over 10k probes without a sticky probe issue.

I'll continue to test(mostly because of skew i'm seeing), but it looks like you got the sticky probe issue whipped.

Thanks again!!

@dc42 Ran a full cycle of my test without a sticky probe.

on the start of the second cycle I had a weird thing happen, where the G30 did not return, I was watching the movement and it seemed to be due to my secondary attempt speeds being too slow and the debounce was ignoring the contact (blade moved down, contacted, blade moved up and started moving down slowly, but the probe never triggered again and the system hit the bottom stop)

I'm still calling this probe sticky issue no longer an issue. Again, thank you very much for your work in this.

While i have your attention though, would it be possible to get the encoder counts from 1HCL boards into the object model? or is that a huge change? (would make my tests of skew much easier)

@dc42 Sounds good, I'll load this last one in and start the test.

I am probing below 5mm/s, though would like to keep the overshoot less than 1um, so that's a good "limit" value for me as I try and increase the speed of the system.

Thanks again for your hard work in this. It really is amazing what the Duet team is doing.

@dc42 I'll gladly do more testing.

As for trigger latency, I have not had the chance to drag my scope in and connect it, so I don't have enough data to even guess at a range.
I will attempt to get it connected today and get some traces, but no promises there.

@dc42 Ran a second test through,
Finished without sticky probe making it now 11,656 probes without "Probe already triggered"

Though however in this run I did get a single instance of "failed to enable probe" directly after a Can Response timeout.
Below is the eventlog of that section.
luckily my macro calls M122 B50.0 just after probing, so it did just that and the result is logged

that said, still didn't have a problem, so... fixed, unless you feel the failed to enable probe could be indicative of a larger problem.

025-05-20 11:22:51 [warn] Error: CAN response timeout: board 50, req type 6061, RID 1051
2025-05-20 11:22:52 [warn] Error: G30: Failed to enable probe
2025-05-20 11:22:52 [warn] Warning: Discarded std reply src=50 RID=1051 exp=1052 ""
2025-05-20 11:22:52 [debug] Diagnostics for board 50:
2025-05-20 11:22:52 [debug] Duet EXP1HCL rev 1.0a or earlier firmware version 3.6.0-rc.3+1 (2025-05-16 09:23:09)
Bootloader ID: SAME5x bootloader version 2.4 (2021-12-10)
All averaging filters OK
2025-05-20 11:22:52 [debug] Never used RAM 51300, free system stack 154 words
Tasks: EncCal(1,nWait 6,0.0%,469) Move(3,nWait 7,0.0%,124) CLSend(3,nWait 6,3.0%,125) TMC(2,nWait 6,65.0%,313) HEAT(2,nWait 6,1.3%,105) CanAsync(5,nWait 4,0.0%,66) CanRecv(3,nWait 1,0.0%,31) CanClock(5,nWait 1,0.0%,63) MAIN(1,running,14.5%,249) IDLE(0,ready,15.3%,29) AIN(2,nWait 2,0.9%,255), total 100.0%
Owned mutexes:
Last reset 05:16:46 ago, cause: software
2025-05-20 11:22:52 [debug] Last software reset time unknown, reason: HardFault zeroDiv, available RAM 51444, slot 2
Software reset code 0x0060 HFSR 0x40000000 CFSR 0x02000000 ICSR 0x00000803 BFAR 0xe000ed38 SP 0x20002cc0 Task TMC Freestk 366 ok
2025-05-20 11:22:52 [debug] Stack: 00000000 20002d2f 00000000 00000000 00000000 00026359 00026368 41000000 0018a715 00024de3 20019948 20019948 00000001 00025d53 00025d3d 2001a874 001ceac9 00027c73 01601008 a0180030 08004d84 41c31e52 05c80021 3a341809 002ad181 2001a7c0 001ceac9
2025-05-20 11:22:52 [debug] Moves scheduled 37991, hiccups 0 (0.00/0.00ms), segs 3, step errors 0 (types 0x0), maxLate 0 maxPrep 12, ebfmin 0.00 max 0.00
Phase step loop runtime (us): min=6, max=102, frequency (Hz): min=5813, max=17857
Sync err accum 91, peak jitter 1/3, peak Rx delay 174, resyncs 0/0, next timer interrupt due in 7 ticks, enabled, next step interrupt due in 4293675087 ticks, disabled
VIN voltage: min 24.4, current 24.4, max 24.4
V12 voltage: min 12.2, current 12.2, max 12.2
MCU temperature: min 32.5C, curr
2025-05-20 11:22:52 [debug] Driver 0: pos -7187, 10060.2 steps/mm, standstill, SG min 0, mspos 888, reads 33820, writes 0 timeouts 0
2025-05-20 11:22:52 [debug] Last sensors broadcast 0x00000000 found 0 57 ticks ago, 0 ordering errs, loop time 0
CAN messages queued 3346, send timeouts 0, received 27, lost 0, ignored 0, errs 0, boc 0, free buffers 38, min 37, error reg 0
dup 0, oos 0/0/0/0, rxMotionDelay 288, adv 36164/37169
2025-05-20 11:22:52 [debug] Closed loop driver 0 mode: open loop, pre-error threshold: 7.50, error threshold: 50.00, encoder type linearComposite, position 1696
Shaft: Encoder reverse polarity: yes, full rotations 2, last angle 9974, minCorrection=-15.4, maxCorrection=10.9, agc 15, mag 4604, no error
Lin: Encoder reverse polarity: no, raw count 1693
Accelerometer: none
I2C bus errors 0, naks 0, contentions 0, other errors 0