HELP! New Cast Alum. Bed doesn't seem to AutoMeshLevel

Christockos

Help with new bed

Hello,

I have three machines, all with Duet 2 boards. A highly customized Ender 3 and Ender 5 Pro. Both with (most of) the EVO mods from Design Prototype Test. I have Volcano hot ends on all three machines, like to have uniformity. Both the Ender 3 EVO and Ender 5 Pro EVO work flawlessly.

My one machine that doesn’t seem to want to cooperate is my Mamorubot SX4. It’s a 420x420 Core XY printer. I’ve upgraded it quite a bit.
BondTech Direct Drive
Volcano Hot End
New Z Rods
Volcano Copper Block and X Nozzle
Spring Steel PEI Flex Plate
Dual Z
… a few more bits too

It worked fine with ABS for quite a while, until I saw the light and switched to PETG.
I couldn’t get anything to stick. My conclusion, the bed was too warped. I tried some things to remedy this, but alas, no luck.

So I did another major upgrade.
Aluminum cast tooling plate (10mm) with a silicone heater

I thought this would solve my problem(s), but it’s still a nightmare. First off, I thought this cast plate would be FLAT. Here’s my height map:

While flatter than the stock bed, it’s not perfect.
And I still can’t get PETG to stick.
I’ve tried printing at super slow speeds. 20mm/s
I’ve tried PVA Glue
Different bed temps 50°, 60°, 70°

No luck, nothing wants to stick.
After days of trying to figure out what I’m doing wrong, I’m reaching out to you guys in hopes you can tell me where I’m going wrong.

I suspect that my mesh bed leveling is not working properly. Here’s why:
My first line, not sure what it’s called, where you purge the nozzle and lay down the first line near the Y edge, sticks great at almost any height.
But when it begins to print, 200mm away, it doesn’t.
Here’s my config:
; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"XSX4U" ; set printer name

M667 S1 ; select CoreXY mode
M918 P1 E4 ; configure direct-connect display

; Network
M552 P0.0.0.0 S1 ; enable network and acquire dynamic address via DHCP
M586 P0 S1 ; enable HTTP
M586 P1 S0 ; disable FTP
M586 P2 S0 ; disable Telnet

; Drives
M584 X0 Y1 Z2:4 E3 ; set drive mapping, two Z motors connected to driver outputs Z and E1
M569 P0 S1 ; physical drive 0 goes forwards
M569 P1 S1 ; physical drive 1 goes forwards
M569 P2 S1 ; physical drive 2 goes forwards
M569 P3 S1 ; physical drive 3 goes forwards
M569 P4 S1 ; physical drive 4 goes forwards

M671 X-43:443 Y200:200 ; Set the Z motor relative locations NO S param (default 1mm)
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z1600.00 E432 ; set steps per mm E used to be 415
M566 X1200.00 Y1200.00 Z24.00 E300.00 ; set maximum instantaneous speed changes (mm/min) WAS M566 X600.00 Y600.00 Z18.00 E300.00 test
M203 X9000.00 Y9000.00 Z600.00 E6000.00 ; set maximum speeds (mm/min) WAS M203 X30000.00 Y30000.00 Z300.00 E1500.00 then WAS M203 X18000.00 Y18000.00 Z300.00 E1500.00
M201 X500.00 Y500.00 Z100.00 E5000.00 ; set accelerations (mm/s^2) WAS M201 X6000.00 Y6000.00 Z100.00 E2000.00 then WAS M201 X3000.00 Y3000.00 Z100.00 E10000.00
M906 X950 Y950 Z950 E950 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

M593 F40 ; cancel ringing at 40Hz

; Axis Limits
M208 X20:400 Y20:400 Z-2:600 ; set axis minima.maxima
;M208 X400 Y400 Z600 S0 ; set axis maxima

; Define the X and Y coordinates of the leadscrews.
; Must come after M584 (Set drive mapping), M667 (Select CoreXY Mode) and M669 (Choosing Kinematics type)
; Motor order: Back (1), Front (2).
; Snn Maximum correction in mm to apply to each leadscrew (optional, default 1.0)
//M671 X-45:445 Y200:200

; Endstops
M574 X1 Y2 S0 ; set active low and disabled endstops

; Z-Probe
M558 P9 H5 F120 T4000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X36 Y15 Z0.22 ; set Z probe trigger value, offset and trigger height
M557 X80:370 Y80:370 S48 ; define mesh grid WAS: M557 X75:380 Y75:380 S30

; Heaters
M305 P0 T100000 B3950 R2200 ; set thermistor + ADC parameters for heater 0 BED
M143 H0 S120 ; set temperature limit for heater 0 to 120C
M305 P1 T100000 B3950 R2200 C7.06e-8 ; set thermistor + ADC parameters for heater 1 HOTEND
M143 H1 S305
M141 H2; heater 3 is the chamber heater
M143 H2 A2 C0 S50
//M143 P100 H2 X104 A2 C0 S50
M305 P2 T100000 B4725 R2200 C7.06e-8 ; set thermistor + ADC parameters for heater 2 CHAMBER
M301 H2 B1 ; use bang-bang control for the chamber heater

; Fans
M106 P0 S0 I0 F500 H-1 ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 T45:65 H100:101:102
M106 P2 S0

; Tools
M563 P0 D0 H1 F0 ; define tool 0
G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C

; Custom settings are not defined

; Miscellaneous

M501

And here’s my Bed.g:
; bed.g
; called to perform automatic bed compensation via G32
; called to perform True Autolevel using
; generated by RepRapFirmware Configuration Tool v2.1.8 on Thu Mar 12 2020 17:58:27 GMT-0500 (Central Daylight Time)
;M561 ; clear any bed transform
;G29 S2 ; Clear bed height map

G28 ; Home
;G30 P0 X60 Y200 Z-9999 ; probe near a leadscrew, half way along Y axis
;G30 P1 X380 Y200 Z-9999 S2 ; probe near a leadscrew and calibrate 2 motors

Here’s my homeall.g
; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Thu Mar 12 2020 18:50:55 GMT-0500 (Central Daylight Time)
G91 ; relative positioning
G1 H2 Z5 F6000 ; lift Z relative to current position
G1 H1 X-405 Y405 F1800 ; move quickly to X or Y endstop and stop there (first pass)
G1 H1 X-405 ; home X axis
G1 H1 Y405 ; home Y axis
G1 X5 Y-5 F6000 ; go back a few mm
G1 H1 X-405 F360 ; move slowly to X axis endstop once more (second pass)
G1 H1 Y405 ; then move slowly to Y axis endstop
G90 ; absolute positioning
G1 X200 Y200 F6000 ; go to first bed probe point and home Z
G29 S2
G30 ; home Z by probing the bed
G29 S1

and here’s my homez.g
; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Thu Mar 12 2020 18:50:55 GMT-0500 (Central Daylight Time)
G91 ; relative positioning
G1 H2 Z5 F6000 ; lift Z relative to current position
G90 ; absolute positioning
G1 X200 Y200 F6000 ; go to first probe point
G29 S2
G30 ; home Z by probing the bed
G29 S1

; Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning

I’m at a loss to what I’m doing wrong, and hope someone can clue me in. I’m more than willing to look stupid if I can get some insight. It’s frustrating and while it may be embarrassing, please shame me.

Thanks so much,
Chris

DIY-O-Sphere

You have to enable the compensation by setting the
M376 with tapered height in your config.
https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation#Section_Compensation_Taper

Phaedrux

M376 defaults to off, meaning that the compensation is active for the entire height of the print. If you set a taper height with M376 the compensation will start to taper off over that height. Setting it too low can be problematic, but not setting it at all doesn't matter.

Can you check M122 during a print and look for

=== Move ===
DMs created 83, maxWait 1353041ms, bed compensation in use: mesh, comp offset 0.000

If it says none instead of mesh, it means the compensation is being disabled during the print.

Another way to verify if the compensation is working is to try printing with PLA that you know will stick and print a test pattern like this one twice, once with it enabled and again disabled. You should be able to tell pretty quickly if it's working or not.

Also, try upping your bed temps even more. PETG likes a hot bed. Glue stick (to keep it from bonding to me PEI) and 80c work for me.

percar

Are you printing on bare aluminum?
If you are that may be a problem try covering with Kapton tape and using hair spray it works wonders
I too tried cast aluminum plate with the same result I ended up switching to Borosilicate glass and my problems with leveling went away

Christockos

@percar No, I'm printing on a spring steel sheet/magnet combo, like a WamBam, but TinyMachines version.

Christockos

@Phaedrux Hey Phaedrux!

This is what I get after a M122
Bed compensation in use: mesh, comp offset 0.000

That's the only Mesh related thing in the report, via typing M122 in console. I assume that's the only way to do it.

So it says it's working. hmmm

Such weird symptoms, I'm baffled.

Thanks,
Chris

Veti

@Christockos said in HELP! New Cast Alum. Bed doesn't seem to AutoMeshLevel:

M305 P1 T100000 B3950 R2200 C7.06e-8 ; set thermistor + ADC parameters for heater 1 HOTEND

that is an incorrect setting. what thermistor are you using?

Phaedrux

bedlevel_nozzle_0.4_200x200-0.3-0.8.stl

Try a test print like this with PLA twice. Once with G29 S1 (mesh enabled) and again with G29 S2 (mesh disabled). It should be fairly obvious if it's actually taking effect.

Christockos

@Veti I'm using a Semitec104gt-2. I have a Volcano Hot End.

mendenmh

My experience with PETG is that it likes the bed quite hot, to get good adhesion. I have an Ultrabase, which has 3mm glass on the aluminum base. The temperature is measured at the aluminum layer. A rough estimate of the heat flux gives me about 10 degrees lower at the surface of the glass than at the thermistor. If I set the thermistor to 90C, so the glass is about 80C, PETG sticks quite nicely. Much lower than that, and its adhesion isn't too good. One characteristic of PETG is that you don't want the nozzle too close to the bed on the first layer. If the nozzle is close, the PETG pulls itself along off the bed. It likes a bit of a drop height, as opposed to most filaments which like a lot of squish.

Also, I print PETG at a fairly high nozzle temperature, 250C. I am using a PT1000 sensor, so I am fairly confident of this number. The viscosity is fairly low when it is this hot, so one can print fairly fast (240um layers at 90mm/sec with a Hemera extruder and 0.4mm nozzle).

Veti

@Christockos

that would be M305 P1 T100000 B4725 R2200 C7.06e-8 ;

theruttmeister

@Christockos said in HELP! New Cast Alum. Bed doesn't seem to AutoMeshLevel:

So I did another major upgrade.
Aluminum cast tooling plate (10mm) with a silicone heater

I thought this would solve my problem(s), but it’s still a nightmare. First off, I thought this cast plate would be FLAT. Here’s my height map:

That map looks good, although once you upgrade the bed to something like 10mm of I assume MIC6... don't forget that the rest of your machine might not be square or true. That curve in the bed could very easily be droop in the gantry. Or your bed has no support in the center.

But printing PET on PEI should be an absolute breeze. Those two polymers will quite happily weld together and be almost impossible to remove.

I normally run CF-PET on PEI at ~235C with the bed at ~110C. Sticks like crazy.
Assuming its not something silly like tiny extrusion widths or some other slicing problem... I'd suspect contamination of the bed. Its easy to get stuff on the bed that will form a film that prevents the polymer from sticking down.
I have a spray bottle of 100% ethanol (but any alcohol works) that I use to clean the bed any time I have an issue.
Windex actually prevents things sticking (at least with blue tape...) so be aware that 'cleaning' sprays might actually make things worse.

PET is actually very easy to get to stick. On bare glass you should be able to get it to permanently weld on so strongly you'll break the glass trying to get it off. PEI is very similar. I would only use glue to protect the print surface!

Christockos

@Veti said in HELP! New Cast Alum. Bed doesn't seem to AutoMeshLevel:

M305 P1 T100000 B4725 R2200 C7.06e-8

Much Thanks!

o_lampe

One thing not mentioned by anyone is the G31 probe offset. Are you sure it's OK?

Christockos

@theruttmeister Well, I'd become so accustomed to 24V DC heating my bed (88°C max, even in a heated enclosure) that cranking it for PETG had never occurred to me. Well, making my PETG prints stick is no longer a problem, thanks to the 110V AC silicone heater. Amazing! Thanks Ruttmeister and everyone else.

Christockos

@o_lampe It's fine. Thanks for asking. You rule!

Christockos

@mendenmh Thanks for sharing. I've tried 90C and even 100C. Both work swimmingly.

Christockos

So, turns out I had a faulty cooling fan (amongst a bunch of other things I went over, disassembling my hot end/extruder and cleaning, checking alignment, etc.). Turns out my bed is just fine and mesh leveling works as it should. Lots of other little adjustments, fixes and the aforementioned cooling fan and I'm back in business.

Thanks so much everybody! I love my machines with Duets running them. The great community of knowledgeable and generous geniuses make my love of the Duet even stronger and more enduring.

Rock on!
Chris