Following up on this: the M18 does work, of course. I had my Slicer calling G29 directly, not bed.g, so M18 never got run.

On the subject of the interference, I ordered some ribbon cable and JST connectors and crimped a new cable for the probe. I also made some stand-offs to separate the stepper cables from the others in the cable harness. (photo below.) The probe does not do the instantaneous false triggers it was occasionally doing before. Unfortunately, its still not performing well. Strangely, the number of repeat probe events does change that much between S0.01 and S0.03, so I feel certain it is some kind of pick-up rather than the noise floor of the system.

If I separate the probe wire from the harness completely and suspend it off to the side, I can get a really good mesh probe. For now I'm just reloading the saved mesh from file and only probing the center before each print.

I'm wondering whether this is just shoddy performance of the Trianglelab clone BLTouch, I haven't had the same problem with the genuine BLTouch on my other printer. I'm thinking of getting the differential IR probe instead, and giving that a try.

Thanks, I'll give that M558 change a try and double check on the extruder disable. Then re-evaluate the wiring if there are still issues.

I'm getting false triggering issues with my (clone) BL Touch sensor. I've tried twisting the extruder stepper wire pairs for each coil, and moving the touch sensor wires further away from all other cabling (except within the cable harness going to the extruder).

I thought a quick win might be to turn off the extruder motor current during bed probing, I tried adding M18 to the bed.g but it doesn't seem to work, and suggestions as to why?

M561 ; clear any bed transform
M18 E0 ; disable extruder stepper to reduce noise
G29  ; probe the bed and enable compensation

Also, for the probe connection, I am using a length of USB cable stripped from a mouse, and wired the screen wires as the ground connection. This seemed like a sensible approach, but I'm no expert. Any comments on that?

From the config.g:

M307 H3 A-1 C-1 D-1
M558 P9 X0 Y0 Z1 H5 F500 T3000 A6 S0.04 B1 ; Configure probe A=max 6 times, S0.04m = tol, B1 disables heaters for probe
G31 X-66 Y0 Z0.54 P25			;was z1.92 (larger value moves nozzle closer to bed)
M557 X1:182 Y4:156 S29                ; define mesh grid

Now that sounds cool, definitely a reason to dip back into Cura. Is it your own customization or someone else's?

Yep, temperature tower is certainly next on the list.
I find it such a pain dialing in PETG to give good overhang performance at the same time as good layer adhesion. If anyone has any magic bullet, I'd love to hear it.

Thanks for the input. I'll certainly try upping the extruder and z axis accel/jerk values. (The reprap defaults seem to be very low.)

In other news, I ran the same test on some PLA, and the best result was somewhere between 0.05 and 0.1, closer to 0.05. Perhaps I'm running this PETG too cold at 245C, and it's excessively viscous? I haven't calibrated my temperature sensor so the true temperature could be somewhat below that.

Luke

I've been trying to tune things in the get DRR working well, (worthy of a separate thread), this is what I am working with at the moment:

M203 X7200.00 Y7200.00 Z800.00 E1200.00  ; set maximum speeds (mm/min)
M566 X300.00 Y300.00 Z20.00 E900.00      ; set maximum instantaneous speed changes (mm/min)
M201 X1500.00 Y1500.00 Z50.00 E1500.00   ; set accelerations (mm/s^2)
M593 F31				 ; DRR ringing reduction at 31Hz

I'm trying to dial in my settings after performing Duet Wifi brain surgery on my Flash Forge Creator Pro. I'll have a more significant post on the tuning process as I get further into it, but first, just a Sanity check:

I'm driving a Mosquito (non-magnum) directly with a BMG-M, and doing a pressure advance sweep with PETG (50mm/s, 245C, 0.4mm nozzle, 0.2mm layers). The optimum value seems to be coming out as 0.2, which is significantly higher than I had been led to expect for a direct drive system. The attached image is a 2 wall tower sweeping from 0.3 to 0.025.

Does this result seem reasonable, or does it suggest some kind of mechanical/flow problem?