Retraction issues

Stealthy_TT

Thanks will do when I get off work.

Any ideas as to why when I get my nozzle offset corect after a first couple layers print the nozzle starts to scrape over the top of the print?

I calibrated the extruder steps and when I extrude 100mm of filament 100mm is indeed what is taken up. So I dont think it can be that. I was thinking maybe the z axis steps, but thats the same as I had in Marlin. Is there like an offset per layer or something?

Stealthy_TT

May have figured out my issue with the nozzle dragging on the print after the first layer or so. Searching around i found that a M8 rod 1.25 pitch at x16 should have a value of 2560 steps/mm i have mine set to 400 steps/mm ill have to try when i get home

Phaedrux

@stealthy_tt Are you maybe skipping steps on the Z axis?

Stealthy_TT

@phaedrux
Not skipping that i am sure of, see my reply above you, i think i figured it out but wont know till later

Stealthy_TT

Okay, So just messed with my Z steps/mm 400 is infact correct with my printer afaik. I homed z and took a measurement and then moved z up 10mm and it was exactly 10mm. so thats not my dragging issue.

Stealthy_TT

https://youtu.be/IFxbb1yQTXU

Heres the video of what it is doing. The hums you hear are it retracting and re extruding

Phaedrux

Did increasing jerk and acceleration help at all?
What do the retraction settings look like in Cura?

Stealthy_TT

@phaedrux

current settings in Config.g
; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes forwards
M569 P2 S0 ; Drive 2 goes backwards
M569 P3 S0 ; Drive 3 goes backwards
M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation
M92 X100 Y99 Z400 E470 ; Set steps per mm
M566 X500 Y500 Z60 E800 ; Set maximum instantaneous speed changes (mm/min)
M203 X15000 Y15000 Z800 E1800 ; Set maximum speeds (mm/min)
M201 X1000 Y1000 Z800 E8000 ; Set accelerations (mm/s^2)
M906 X800 Y1500 Z800 E800 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S0 ; Set idle timeout

Cura settings
retract distance: 6.5mm
retract and prime speed: 80mm/s
retract extra prime amount: 0

dc42

Try reducing the Z acceleration in the M201 command.

Stealthy_TT

@dc42

Thanks dc I’ll try that.

Another thing, sometimes i have to home all twice in order to get all axis homed. It usually happens when I move an axis by hand or with the web gui past roughly the center point.

For example

I home all and it works correctly, my config is set to put the hotend in the center of heat bed after it homes. So after homing the hotend will be at 185 for x and y. So if I move X with the web gui +100 and do another home all command it will usually fail to home X and I’ll have to home all again for it to make it to the limit switch. Is there a fail safe setting for homing distance somewhere?

peter247

@stealthy_tt I`m having the same problem of it rubbing over the print .,so much that it wears out a cheap Chinese nozzle half way through the print and a titan aero which stop half way through the print for no reason .

Stealthy_TT

@peter247

If you’re rubbing that much I’d assume that the reason the extruder is stopping is because your nozzle is so close that the filament can’t flow though.

Is your nozzle offset correctly from the bed?

I’m not rubbing too bad, just enough to cause a little extra stringing and mine only shows up after layer 1 or two

dc42

@stealthy_tt said in Retraction issues:

@dc42

Thanks dc I’ll try that.

Another thing, sometimes i have to home all twice in order to get all axis homed. It usually happens when I move an axis by hand or with the web gui past roughly the center point.

For example

I home all and it works correctly, my config is set to put the hotend in the center of heat bed after it homes. So after homing the hotend will be at 185 for x and y. So if I move X with the web gui +100 and do another home all command it will usually fail to home X and I’ll have to home all again for it to make it to the limit switch. Is there a fail safe setting for homing distance somewhere?

The maximum homing distance is defined in the G1 S1 commands in the homing file(s) for that axis.

Stealthy_TT

@dc42 haha Thanks I knew it had to be something like that.