Unable to home z axis

droftarts

@Kayjay I don’t see a problem fitting the RAMPS temporarily to check the steps per mm on X. It’s a shame you lost your old SD card; that would have answer on it! I still can’t fathom why the X moves further than it should. When it homes in X, is X=0 with the nozzle on the left edge of the bed? If it homes with the nozzle over the bed (say 20mm in from the edge) then moving it 150mm would put it at 170mm from the edge. The other way to check steps per mm is to measure (with ruler or tape measure) from a fixed point on the printer to the X carriage (in line with X movement), move X 100mm, and measure again.

Maybe post a picture of the printer, or even better a video of the homing.

The other thing that occurs to me is the homing direction. When standing in front of the printer, X0 Y0 should be front left of the bed. The X endstop should be on the left, and Y endstop on the front. Is that how yours is set up? I haven’t looked at the BigBox build manual to check myself.

Ian

Phaedrux

In addition to all those checks, please make sure that the files you are editing at in the /sys folder and not somewhere on the SD card. It does happen occasionally.

Testing with a RAMPS might be a good sanity check. Nothing wrong with that.

Kayjay

I have found an interesting anomaly regarding the x stop, in the diagram https://wiki.e3d-online.com/File:X-AXIS_IDLER_CARRIAGE.jpg part 10 which is a 25mm socket cap screw would appear to be too long and stops the x carriage 20 mm short of its correct stopping point, it wouldn't screw in enough to allow the x stop to reach 0, the minimum it reaches is 20mm, unless I'm wrong this would be the problem. I've removed this screw and replaced it with a shorter screw around 5mm giving it a little room for maneuver in either direction. This modification now gives the correct movement to meet the bed centre at the exact point.

I'm wondering if later iterations of the manual have modified this error so this problem no longer occurs although as the Bigbox is now obsolete perhaps the mods haven't been made.

Although this problem has been solved it still leave me with the Z homing using G30 ..... which unfortunately i have to solve.

Phaedrux

Can you post the results of M122 and M98 P"config.g" ?

Kayjay

@Phaedrux

Yes, I'll do that when I'm feeling better. I thought I was suffering with covid then after a day or two I was feeling better but now it's returned with a vengeance so I'll post those results when this disgusting disease passes and I feel better, sorry.

Keith

Kayjay

@droftarts Sorry, I don't feel like posting much more but yes, you are correct about the positions of the x and y stops

Phaedrux

@Kayjay Get well soon.

Kayjay

@Phaedrux
Thanks for the kind words. I'm busy watching snooker at the moment which is cheering me up at little

Kayjay

There is one point I'd like to make.

I find that reading through the Gcode page to try to give me some knowledge but I find that the more I read the more there are references to more Gcodes which basically make thing harder and harder to understand.

What I think would help me would be a working set of files for the Bigbox using Duet Ethernet with one hot end.

Could someone please supply me with these, I ask for this because all the explanations I get of different methods I should try simply confuse me more and more. Yes, I had A level in maths back in 1968 but that was so long ago now most of it has been forgotten.

I really would be grateful if someone could do this for me.

May I add that I an very, very grateful to everyone who has contributed in this post, you have all been amazing, I just struggle to understand the various commands, hence my request for a working set of files for Bigbox with Duet2

Thanks to all
Keith

Phaedrux

Doing some searching in the E3D Big box forum (https://forum.e3d-online.com/#bigbox-3d-printer.1) I was able to find this, but it's from 2016, which makes it rather old firmware at this point, but it does contain the basics. I also don't know if it matches your BigBox as there were a few different versions and revisions I think... So that complicates matters and makes directly porting a config between machines non-trivial.

; Movement section
M569 P0 S1                          ; Drive 0 goes forwards (change to S0 to reverse it)
M569 P1 S1                          ; Drive 1 goes forwards
M569 P2 S1                          ; Drive 2 goes forwards
M569 P3 S1                          ; Drive 3 goes forwards
M569 P4 S1                          ; Drive 4 goes forwards
M574 X1 Y1 Z1.2 S1                    ; set endstop configuration (X and Y endstops only, at low end, active high)
M906 X800 Y600 Z800 E1000           ; Set motor currents (mA)
M201 X800 Y800 Z15 E1000            ; Accelerations (mm/s^2)
M203 X15000 Y15000 Z100 E3600       ; Maximum speeds (mm/min)
M566 X600 Y600 Z30 E20              ; Minimum speeds mm/minute
M208 X300 Y200 Z200                    ; set axis maxima (adjust to suit your machine)
M208 X0 Y0 Z-0.2 S1                    ; set axis minimum (adjust to make X=0 and Y=0 the edge of the bed)
M92 X160 Y360 Z1600                    ; Set axis steps/mm
M92 E304:304                           ; Set extruder steps per mm
G21                                 ; Work in millimetres
G90                                 ; Send absolute coordinates...
M83                                 ; ...but relative extruder moves
M350 X16 Y16 E16 I1               ; Set 16x microstepping with interpolation

I found a couple others which all had different values for steps per mm and number of tools etc as each person has customized the machine.

Perhaps this versions list would help identify exactly which one you have? https://wiki.e3d-online.com/BigBox_Version_Overview

At any rate, most of the important parts can be derived from the machine itself during commissioning. Comparing distance requested versus distance moved, etc to get steps per mm.

I think you're quite close though with what you have currently.

Kayjay

@Phaedrux
Thanks so much Phaedrux, I'll review the files you've given me.

I agree with being close with my current set up but what I'm worrying about is why I can't Z probe or Z home. I have thought before trying to swap Duet for RAMPS or to try the files you've given me is to put a switch on Z lower position plugging it into the normal z socket rather than the Z probe connector, of course doing this just as a trial to prove a point.

I'll keep copies, of course, of all my previous files (I learnt this hard way ) Other points are lifting the floorboards but being 68 and suffering with severe back problems from birth and no children to do the job for me this is the very last option.

Can I post a series of all the other relevant files, homeall, homex etc,etc for your perusal just so those are correct. I know you have said previously that they appear good but I think I may have made a small change or two so I'd just like to be sure.

There is one other thing of course, I gather that there are various settings that are different even though they're on the same machine, am I right? If I am right in this assumption could you direct me to which these commands are and I'll attempt to set them to suit.

Keith

droftarts

@Kayjay yes, please post your current files.

For the probe, just to confirm, it triggers when close to the bed, both the LED on the IR probe itself, and goes from 0 to 530ish in DWC,

Also, how exactly are you triggering the home all (or Z)? Using DWC buttons?

Ian

Kayjay

@droftarts

It would appear that I have the Bigbox Pro Hybrid Titan, it's the one with the Titan extruder on the back of the machine rather than above the hotend. The probe changes from 0 to 537 when activated by my finger or a piece of paper etc but the bed never rises to activate the probe, this is the whole problem I am suffering. X and Y home fine at 0 on the left front side of the bed but as you can see from homez and homeall the head moves to the centre of the bed and then just stops whatever height the bed is at, the bed just doesn't move

Here are my current files.

; bed.g
M561 ; clear any bed transform
G29  ; probe the bed and enable compensation

; General preferences
G90                                     ; send absolute coordinates...
M83                                     ; ...but relative extruder moves
M550 P"Bigbox1"                         ; set printer name

; 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
M569 P0 S1                              ; physical drive 0 goes forwards
M569 P1 S1                              ; physical drive 1 goes forwards
M569 P2 S0                              ; physical drive 2 goes backwards
M569 P3 S1                              ; physical drive 3 goes forwards
M584 X0 Y1 Z2 E3                        ; set drive mapping
M350 X16 Y16 Z16 E16 I1                 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 E420.00       ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00     ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X750.00 Y500.00 Z20.00 E250.00     ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800 I30            ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                 ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1                        ; set axis minima
M208 X300 Y200 Z200 S0                  ; set axis maxima

; Endstops
M574 X1 Y1 S1                           ; set active high endstops
M574 Z1 S2                              ; set endstops controlled by probe

; Z-Probe
M558 P1 H5 F120 T6000                   ; set Z probe type to unmodulated and the dive height + speeds
G31 P500 X0 Y0 Z2.5                     ; set Z probe trigger value, offset and trigger height
M557 X15:215 Y15:195 S20                ; define mesh grid

; Heaters
M305 P0 T100000 B4138 R4700             ; set thermistor + ADC parameters for heater 0
M143 H0 S120                            ; set temperature limit for heater 0 to 120C
M305 P1 X200                            ; configure PT100 for heater 1
M143 H1 S320                            ; set temperature limit for heater 1 to 320C

; Fans
M106 P0 S0 I0 F500 H-1                  ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T45               ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

; 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

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v3.1.4 on Thu Aug 06 2020 10:36:11 GMT+0100 (British Summer Time)
G91                     ; relative positioning
G1 H2 Z5 F6000          ; lift Z relative to current position
G1 H1 X-305 Y-205 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X5 Y5 F6000       ; go back a few mm
G1 H1 X-305 Y-205 F360  ; move slowly to X and Y axis endstops once more (second pass)
G90                     ; absolute positioning
G1 X150 Y100 F6000        ; 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 F100             ; lift Z relative to current position
;G90                    ; absolute positioning

; homex.g

G91               ; relative positioning
G1 H2 Z5 F6000    ; lift Z relative to current position
G1 H1 X-305 F1800 ; move quickly to X axis endstop and stop there (first pass)
G1 H2 X5 F6000    ; go back a few mm
G1 H1 X-305 F360  ; move slowly to X axis endstop once more (second pass)
G1 H2 Z-5 F6000   ; lower Z again
G90               ; absolute positioning

; homey.g

G91               ; relative positioning
G1 H2 Z5 F6000    ; lift Z relative to current position
G1 H1 Y-205 F1800 ; move quickly to Y axis endstop and stop there (first pass)
G1 H2 Y5 F6000    ; go back a few mm
G1 H1 Y-205 F360  ; move slowly to Y axis endstop once more (second pass)
G1 H2 Z-5 F6000   ; lower Z again
G90               ; absolute positioning

; homez.g

G91              ; relative positioning
G1 H2 Z5 F6000   ; lift Z relative to current position
G90              ; absolute positioning
G1 X150 Y100 F6000 ; go to first probe point
G30              ; home Z by probing the bed

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

Kayjay

@droftarts
Sorry, I forgot to mention how I activate the probe. I've tried Homeall and Homez using the buttons on DWC Machine Control, Head movement.

Is there any other method I can use which may help?

Phaedrux

@Kayjay said in Unable to home z axis:

X and Y home fine at 0 on the left front side of the bed but as you can see from homez and homeall the head moves to the centre of the bed and then just stops whatever height the bed is at, the bed just doesn't move

Your config looks correct and it sounds like it's trying to home correctly. Your probe seems to be registering because the LEDs light up. But your Z axis doesn't seem to be moving.

Does the Z axis ever move?

Can you send these commands to try and test the Z axis movement. Make sure there is enough travel available on the Z axis in either direction just to try and avoid a crash.

G92 Z10
G91
G1 Z5 F60

That should let us determine if the Z motor is actually working.

droftarts

@Kayjay said in Unable to home z axis:

M92 X80.00 Y80.00 Z400.00 E420.00 ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X750.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800 I30 ; set motor currents (mA) and motor idle factor in per cent

This can't be the config.g you're using. All your motor settings are back at the original values. I thought they were now:

M92 X160.00 Y360.00 Z400.00 E304.00 ; set steps per mm
M566 X480.00 Y480.00 Z24.00 E300.00 ; set maximum instantaneous speed changes (mm/min)
M203 X9000.00 Y9000.00 Z360.00 E1500.00 ; set maximum speeds (mm/min)
M201 X750.00 Y750.00 Z100.00 E5000.00 ; set accelerations (mm/s^2)
M906 X1300 Y1300 Z1300 E1300 I30 ; set motor currents (mA) and motor idle factor in per cent

Please copy the contents of config.g from DWC (as in, what's actually on your SD card) and paste them in your reply. I think you've just copied and pasted old config files from your PC.

Also, I think what @Phaedrux was trying to say is that you need to test the Z motors at low speed, and find the speed that they stall at. So type in each line of the following at the gcode console in DWC, and see what speed the Z axis stops being able to move at:

G92 Z10 ; Set Z axis position
G91 ; set to relative positioning
G1 Z5 F30 ; move bed down 5mm at F30
G1 Z-5 F30 ; move bed up 5mm at F30
G1 Z5 F60
G1 Z-5 F60
G1 Z5 F90
G1 Z-5 F90
G1 Z5 F120
G1 Z-5 F120
G90 ; set absolute positioning

F120 is what your probing move is set to. If the motor can't move at this speed, that'll be why it won't home.

Ian

Kayjay

@droftarts

Thanks for the info. I have gathered several sets of files and it appears I've installed the wrong ones, I do apologise. I'll sort that out in the morning (as you can see I'm awake in the middle of the night) and also delete all the out of date stuff or at least mark it as such so I don't make the same mistake again.

To clarify what I did was copy and paste from system editor in DWC not the card, I must have inadvertently loaded the wrong config files into DWC at some point in the last day or so simply trying different things to test situations but as I say I will rectify this in the morning and ensure I have the correct files installed.

I'll also follow your instructions to test for the stall speed of the Z motors. Just to clarify, Z motors do work at the speed set in homeall, homex, and homey, they move up and down 5mm as per the command settings in the various homing files but wherever the bed is set, at any distance from the head it never moves when it reaches the G30 command.
Your list of commands should help sort out what's happening and possibly where the fault lies.

Thanks again
Keith

Kayjay

@Phaedrux

droftarts spotted I was using an old set of config files so I'll correct that in the morning.

Regarding your questions, Z does move, in fact it moves whenever commanded to in homeall, homex and homey it just fails in homez, I'm assuming when it reaches G30 as it executes every command before that instruction.
I will though test your instructions in the morning, I will also try out M122 and M98 P"config.g" and post the results, my apologies for not doing this before when you asked.

Thanks again
Keith

Kayjay

Should I make and post a video of what's happening? Would that help? Should I use 'Upload File' to do this? I;m assuming 'Upload Image' is for stills

Keith

droftarts

@Kayjay there’s a limit on the size of file you can upload, and videos are usually too big. Better to upload a video to somewhere like YouTube and post a link to it.

Ian