RRF 3 Z home not triggering.

joehsmash

ive noticed that when i home my Z axis, i am using my 0.20mm feeler gauge to make sure that my gantry is perfectly trammed with the bed plane.

if i set my carriage to the left most position and drop it down so that the nozzle height is just touching the gauge my z height is being reported at 1.45 how ever on the right side its being reported at 0.95.

when i manually adjust the stepper to make them even and than i rehome, it goes back to exactly the same place.

how do i force either the right side or the left side to stay in line?

edit:
So i just raised the z height to +50 and dropped it back down, the left side is still touching the feeler at 1.45 how ever now the right side is touching at 0.80. it lost 0.15 over 50mm clearly there is an issue with my second z motor and its speeds perhaps

homez.g
homeall.g
config.g
bed.g

fcwilt

I'm late to the game. It appears you have two Z end stop sensors.

How are you assuring that when the sensors are triggered the bed is parallel to the gantry?

Frederick

joehsmash

Currently trying to set this up

https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors#Section_Axis_levelling_using_endstops

joehsmash

@fcwilt

in my Config

M671 X-144:144 Y0:0 S0.5 ; leadscrews at left (connected to Z) and right (connected to E0) of X axis

and this is in my bed

G28 ; home
M561 ; clear any bed transform
G30 P0 X-110 Y0 Z-99999 ; probe near a leadscrew, half way along Y axis
G30 P1 X110 Y0 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors
G29 ; probe the bed and enable compensation

but its not working

joehsmash

also, the g30 is just calling me to manually adjust the zheight instead of using the nozzle as a probe.

fcwilt

@joehsmash said in RRF 3 Z home not triggering.:

also, the g30 is just calling me to manually adjust the zheight instead of using the nozzle as a probe.

Well in the last config.g file you posted I see this:

M558 P0 C"!zstop+!e0stop" B1 X0 Y0 Z0 H2 F60 T6000 ; Set Z probe type to switch

Unless something has changed in firmware v3, the parameter P0 specifies no Z probe.

This would be consistent with the behavior you are seeing.

Frederick

joehsmash

@fcwilt i agree with you there, so is there no way to use the Z axis endstops as a sudo probe? i know it wont be true leveling but its all i have for now seeing as my IR probe wont work.

i read another post a while back where a guy got it to work, i sent him a message but hes long gone. granted this was on 2. something

joehsmash

@fcwilt ive located the post

https://forum.duet3d.com/topic/4737/zprobe-robo3d-r1

fcwilt

@joehsmash said in RRF 3 Z home not triggering.:

@fcwilt i agree with you there, so is there no way to use the Z axis endstops as a sudo probe? i know it wont be true leveling but its all i have for now seeing as my IR probe wont work.

While many things are possible in v3 firmware that are not in v2 (which is what I am still using) I cannot imagine how you could do that.

Perhaps DC42 will jump in and address this question.

Just out of curiosity do you have bed leveling thumbscrews or something like them for manually adjusting the bed?

I built a printer not too long ago with three Z motors and a BLTouch Z probe to try automatic bed leveling. While it worked it was more complicated and noisy than my FT5 which used one Z motor and manual bed leveling and didn't work any better.

I re-built it with one Z motor belted to two lead screws on opposite sides of the bed, much like the FT5, and a BLTouch Z probe.

I'm much happier with that arrangement.

Something to consider.

Frederick

joehsmash

@fcwilt @dc42 has chimed in before to help.

i do not have levelling screws on my bed. its actually held to the y gantry with magnets that are epoxied to the bottom of the glass bed.

one of the future upgrades i have planned is to re design the y gantry supports to allow me to delete the magnets and add in a screw type adjustment.

but with that said, i have manually leveled and used metal shims that tto get all of the magnets to within 0.01 so the bed it self is level, just the zmotors arent and im not sure how to get the one driver for E0motor to come up or down.

i also just ordered a BLtouch, how ever with the design of my xcarriage its going to be a challenge getting that set up. but again i will likely need to reprint the carriage to get it to work as i want.

jay_s_uk

This applies to you
https://forum.duet3d.com/topic/16766/offset-for-dual-y-endstop/3
obviously you apply it to Z rather than Y. But you can adjust one of them (probably the one that reads 1.45) down by ~-0.65 so they are both at the same height.

fcwilt

For now can you couple the Z motors with a belt and use just one Z end stop switch?

With that you could manually adjust the relationship of the two Z lead screws using one of the motor pulleys but one adjusted they would stay in sync.

Frederick

joehsmash

@jay_s_uk thats great, i will most certainly try that out.

all though im not sure why the second motor is losing distance.

as i said before when i shoot the zheight up 50mm than back down the right one is off. so all though this would temporarily fix the problem (and i appreciate it) its not an ideal solution.

but it is a solution to one of my problems none the less

joehsmash

@fcwilt said in RRF 3 Z home not triggering.:

adjusted they would stay in sync.

i most certainly could rewire my printer to have both of the z axis work off the same stepper, i though it was ideal in RRF3 to have each z as an individual motor, (its easier on the board as well as easier on the parts)

jay_s_uk

@joehsmash It could be that your endstops aren't at exactly the same height. I know that doesn't explain the difference of 0.15 when backing off 50mm but it would explain the difference between 1.45mm and 0.95mm

JoergS5

@joehsmash To use one Z stepper only is a good idea. Additionally you may have a mechanical problem with one side. It is easier to discuss this by seeing images from your construction, especially the connection between stepper and spindle/belt/whatever and how the bed/gantry is moved.

joehsmash

@jay_s_uk this is a certain possibility. the way my gantry works is the lead screws are embeded into the x gantry, there is a clamp that holds the switches onto the underside of the gantry which is clamped onto the lead screws.

so to adjust them would put the entire weight of the gantry on one little screw which would move in the long run

joehsmash

@JoergS5

this is the construction of my printer

JoergS5

First I wonder why you have three cables at your endstops, because my are looking the same and two cables are sufficient: using left and right means closed when not active and they open when endstop is triggered.

I would expect some pressure between left and right, so if you change direction of one Z side, it will stuck at the trapezoid spindle. First test would be to let fixed the spindle and the linear guide on one side (let's say it is left), but loose the other (right) side a bit (trapezoid screw and linear guide) (like a fixed bearing and a loose bearing at CNC machines for installing ball bearings). So the right side can move a bit horizontally if necessary.

joehsmash

@JoergS5 i just soldered on ones for the no, nc and common because i didnt want to have to dissasemble them to solder them if i ever needed to in the future, both of the NO contacts are disconnected underneith