Drastic improvements with BL Touch disabled

[RyanP]

@Phaedrux @deckingman

I have now disassembled the bed platform, turned it over, and re-secured it. removed and rotated the build plate, re-secured it.

Its amazing how much time you can lose on a mechanical issue.

@Phaedrux regarding the G92 Z0 / G30 S-1, I did this earlier today and started an excel spreadsheet to track the issues. I didn't finish it as it was immediately apparent that the bed was sloping downward at the front (Yaxis), just like the mesh shows. X Axis was relatively stable down to 0.015mm.

Still working on things.

[RyanP]

Its a start.

[zapta]

"Drastic improvements with BL Touch disabled"

I should get one for my printer and disable it.

[RyanP]

@zapta

Thanks for your input.

[o_lampe]

@ryanp said in Drastic improvements with BL Touch disabled:

What I can't wrap my head around is how the nozzle, which is a relatively fixed distance from the BL Touch pin, can be squared up and safely touching in each corner, and then the mesh turn out so slanted.

The only difference I see is the Z-offset. You align the bed manually with the nozzle touching the bed, but the mesh routine stops around 2.6mm above the bed. You already replaced the Z-nuts, but something (had) happen during the last 2.6mm.
Maybe Z-acceleration is too high? The same value applies for deceleration. That would get worse when you use multiple small moves to lower the nozzle.

Another thing I noticed is the 'bellows' like up and down along X-axis of your last heightmap. Why is every other probe point lower or higher?

[engikeneer]

@ryanp asking the silly questions, but was mesh compensation disabled when you did the nozzle height test? I ended going round and round in circles when I first started using auto bed levelling because I had mesh compensation enabled at the same time (so it was trying to level a compensated bed and the two things just fought each other).

[Hornetrider]

Hi @RyanP

I have had similar issues with my printer concerning the bed leveling.
Have you tried to mechanically align all axis to the bed?

What helped me was the following procedure:

1. Check with a digital Bevel box if the frame of printer is leveled (x, Y and Z Frame)
   -> If not, get it leveled
2. Check if the bed is leveled with digital Bevel Box
   -> use X & Y Frame as reference (zero bevel box to that reference)
   -> Level it out as good as possible
3. Check X and Y axis are leveled to the bed with a caliper and get this down to 0.1..0.2 mm
   -> It might be that axis are out of level to the frame

Funny thing though, even after mechanically aligning my printer I had a weird effect on the height map.
My finding is, that if the height map shows a clear deviation to one side (mostly X-axis) then the mechanical alignment to the bed might be poor.

[RyanP]

Still Working on it

Corner One Probe
4.309 mm
4.307 mm
4.306 mm

Corner 2 Probe
3.981 mm
3.983 mm
3.983 mm

Corner 3 Probe
3.380 mm
3.388 mm
3.385 mm

Corner 4 Probe
3.933 mm
3.929 mm
3.931 mm

[RyanP]

Im taking a break from it. I have other working machines and need to take a break from it. Get back to it tomorrow.

[Phaedrux]

Your probe results look consistent in one spot, which is good, but they also seem to vary with XY position a bit still. Dipping off to the back side by the looks of the map?

The fact that your adjustments and re-alignments are making a difference is a good sign though.

[RyanP]

@phaedrux

Well, I don't even know where to begin. As I previously posted on Saturday, I had gotten close to fixing my issue with my bed and probing, but was going to walk away for a few days (canadian long weekend).

I've come back to this machine now with a clear mind and a few ideas.

I turn the machine on and warm it up. This machine is using the Duet 2 Maestro, and 2.05 firmware.

I hit the home button:

Print head moves X and Y to their endstops, then to the center of the bed. The BL Touch probe is deployed properly, touches the glass surface twice and reports back the correct z-offset and moves the head up to the expected position:

But as soon as it stops its motion the head position for the Z-axis turns from 11.77 to this:

Now the machine is locked up and I cannot move the head with the DWC controls or macros.

I'm starting to think that the Maestro board is pooched, but I really have no idea. I have a backup Duet 2 Wifi board here that I can replace the Maestro with, but I would rather know for sure.

[droftarts]

@ryanp post your homeall.g file?

Ian

[RyanP]

@droftarts

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Tue Feb 18 2020 18:08:45 GMT-0500 (Eastern Standard Time)
G91                     ; relative positioning
G1 H2 Z5 F9000        ; lift Z relative to current position
G1 H1 X-240 Y-240 F3000 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X20 Y20 F3000      ; go back a few mm
G1 H1 X-240 Y-240 F1000  ; move slowly to X and Y axis endstops once more (second pass)
G90                     ; absolute positioning
G1 X110 Y80 F9000 	; go to center of bed  ; go to first bed probe point and home Z
G30                     ; home Z by probing the bed

; Uncomment the following lines to lift Z after probing
G91                   ; relative positioning
G1 Z5 F9000            ; lift Z relative to current position
G90                   ; absolute positioning
G29 S1                  ; absolute positioning

[Phaedrux]

I wonder if it's a problem from loading the heightmap. Can you try deleting the heightmap.csv file and recreating it fresh?

[RyanP]

@phaedrux
Will do.

[o_lampe]

@ryanp said in Drastic improvements with BL Touch disabled:

This machine is using the Duet 2 Maestro, and 2.05 firmware.

Did you go through 'known bugs' related to RRF 2.0x? Maybe there were unsolved issues with BLtouch?

I have checked an old SD-card image from RRF2.05 and there are retractprobe.g and unretractprobe.g in the /sys folder. I remember, they messed up my homing routine, because they contained some BS....
I didn't know, that 'G30' always calls them, if present...

[RyanP]

@Phaedrux @o_lampe

deleting the text in the height map did solve the latest issue.

But now I am having problems with the Maestro board connecting to the network. If I turn the unit off, then back on, many times now it won't connect. I have to turn it off, unplug it, plug it back in and turn it on...and even thats 50/50.

All my wifi units work. So Im going to swap the cable, as well as review the access point it is connected to. But I have a pretty extensive knowledge of home networking from my home audio and automation days, and am confident regarding my network.

Like I mentioned, I have a backup Duet 2 Wifi board that I can use if I think something has

[RyanP]

@Phaedrux @o_lampe @droftarts @Hornetrider @engikeneer @deckingman

I have fixed my problem. I took apart the printer last weekend and re-assembled it. Moving some of the extrusions around (like rotating your tires) and re-squared everything up. Found one spot that seemed a but off so I positioned it with a small gap and tightened things up with a metal 90 degree corner.

I also noticed that my bed.g file looked like this

M561 				; clear any bed transform
G29 S2				; Clear bed height map
; Probe 2-points
M401 				; Deploy probe - deployprobe.g
G30 P0 X90 Y115 Z-9999 		; Center Left
G30 P1 X125 Y115 Z-9999 S2 	; Center Right
M402 

But there is only one 7 axis on this printer. So I deleted everything expect the M561 command.

Between those two things, my printing is back to normal. I wanted to thank everyone for their suggestions.

[DonStauffer]

@ryanp Check the reliability of the wiring from your BLTouch. I found 2 only occasionally intermittent wiring problems that caused me no end of problems. The intermittent nature of the problems had me confused for a very long time. What clued me in was that for a while, the probe started failing to probe at one corner of the bed, every time. That said to me it was the wiring being moved. Sure enough, that was the big problem.