Delta z height AC Predator

Gary

Jay,
Probe not the problem. Turn machine on home and one day z height reads different on another day.
(As above my motors are MT-1704HSM168RE 0.9deg step 190102, 400 steps/rev 1.68A not stock).
On my other stock machine I've set v-ref to 0.61 working great.
Going to change my belts. I've got some GT ones.
Gary

jay_s_uk

@Gary
Missed that on the motors.

I never used to probe the machine every time. Couldn't be bothered to fit the probe every time.

I have had a belt snap that appears to have been stretching for a while that led to dodgy readings. If you're going to change the belts, also plan on changing the bottom pulleys as they are smooth and ideally you want toothed pulleys.

Other than that, I've not had an issue with any of the opto endstops etc.

Gary

@jay_s_uk
Thanks for your advice. Yeah when problems happen I clean the bed, check the carriages and if that does not work do the stock probe bit. Machine is second hand so who knows what it's been through! Do you have a link to toothed pulleys? I was thinking of getting them. The Gates belts are compatible with the stock belts.
Thanks again
Gary

jay_s_uk

@Gary

These are the type you'd need.

Gary

@jay_s_uk
Thanks for the link.

I still don't understand how config override has H456.513 as below
M665 L440.000:440.000:440.000 R224.891 H456.513 B185.0 X-0.442 Y-0.213 Z0.000

And doing a Homdelta, (with it being edited to just home), the web interface shows z 456.42. Am I missing something?

jay_s_uk

@Gary
Whats in your homedelta file?
Are you doing the home after any sort of probing or is this as soon as the machine is turned on?

Gary

@jay_s_uk
Soon as printer turned on. No probing. There's stuff edited out in there that needs deleting, but Homedelta below;

; homedelta.g
; called to home all towers on a delta printer
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Feb 26 2019 21:31:01 GMT+0000 (Greenwich Mean Time)

G91 ; relative positioning

G1 S1 X490 Y490 Z490 F1800 ; move all towers to the high end stopping at the endstops(S1 checks for endstops) (first pass)
;G92 X0 Y0 ;force this to read 0,0
;G92 Z456.747

;below 3 comment/uncomment
;G1 X-5 Y-5 Z-5 F1800 S2 ; go down a few mm GARYuncomment (S2 - Ignore endstops while moving. Also ignore if axis has not been homed.)
;G1 S1 X10 Y10 Z10 F360 ; move all towers up once more (second pass) GARYuncomment
;G1 Z-5 F6000 ; move down a few mm so that the nozzle can be centred GARYuncomment

;G1 Z-10 F1800 ;need to move down for x0 y0 to complete
;G92 Z456.747

G90 ; absolute positioning

;G1 X0 Y0 F1800 ;force to centre
;G92 Z456.747

Gary

Normal Homedelta below
Below obviously moves z height. It becomes 441.42

; homedelta.g
; called to home all towers on a delta printer
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Feb 26 2019 21:31:01 GMT+0000 (Greenwich Mean Time)

G91 ; relative positioning

G1 S1 X490 Y490 Z490 F1800 ; move all towers to the high end stopping at the endstops(S1 checks for endstops) (first pass)

;below 3 comment/uncomment
G1 X-5 Y-5 Z-5 F1800 S2 ; go down a few mm GARYuncomment (S2 - Ignore endstops while moving. Also ignore if axis has not been homed.)
G1 S1 X10 Y10 Z10 F360 ; move all towers up once more (second pass) GARYuncomment
G1 Z-5 F6000 ; move down a few mm so that the nozzle can be centred GARYuncomment

G1 Z-10 F1800 ;need to move down for x0 y0 to complete

G90 ; absolute positioning

G1 X0 Y0 F1800 ;force to centre
;G92 Z456.747

jay_s_uk

One thing I have noticed is your endstop adjustments in M666 are a lot larger than mine

M666 X0.081 Y0.238 Z-0.319 A0.00 B0.00

What 'S' value are you using at the end of your bed file?

Gary

@jay_s_uk
I'm sure it's your bed file with S6

jay_s_uk

Try overriding the M665 and M666 values and then reprobe.
I.e. resend whats in config and then probe

Gary

@jay_s_uk
Yeah I did that before. I deleted config override and re-probed, but I've noticed that re-probing overwrites the M665 and M666 values in the override file. Worth another try though. When you said your endstop adjustments were smaller than mine by how much?

jay_s_uk

@Gary

The code I included is my endstop M666.

As you can see, my X is 0.081. Yours is -6.790

jay_s_uk

I don't know how yours can be so different unless the original owner messed with the little metal flags on the top of the carriages.

Gary

@jay_s_uk
The flags look/feel the same as my other stock machine. I'll need to get to the endstops as that's a huge difference.

Just done another re-probe and similar results.
M665 L440.000:440.000:440.000 R224.513 H456.388 B185.0 X-0.646 Y-0.364 Z0.000
M666 X-6.930 Y3.322 Z3.607 A0.00 B0.00

jay_s_uk

I would investigate your X endstop then as its 10mm different to your Y and Z enstops

Gary

@jay_s_uk
Yes. Got my finger under all of them and one is maybe a 0.5/1mm higher, not 10. Disassembly required. Never seen an endstop could it be upside down?

Gary

@jay_s_uk
I got the error " Warning: the height map was loaded when the current Z=0 datum was not determined probing. This may result in a height offset." Just wondered if the problem could be anything like the link below?

https://forum.duet3d.com/topic/10835/z-0-datum-was-not-determined-probing/3

I can kind of see that having both a Z endstop switch and a Z probe could cause a problem, as the z tower is not the z height.
Mine Firmware is: RepRapFirmware for Duet 2 WiFi/Ethernet 2.04 (2019-11-01b1)

Have you got the same firmware version?

jay_s_uk

@Gary

I wouldn't worry about the message around the height map just yet.

If you're going to stick with RRF2 for the moment, I would be upgrading to 2.05.1
I'm on the latest RRF3.01 release and I use conditional gcode in my bed file.

You need both a Z stop and a Z probe. The Z stop is set at the maximum end to signify its at the top of the tower. The firmware knows that the Z stop is for the Z tower and will treat it accordingly.

Gary

@jay_s_uk
Will update the firmware. It was just a thought as X-6.790 and my probe offset of 5.52 gives 1.27mm which would correlate roughly to what I felt with my finger maybe.