nozzle suddenly destroying sheet
Last night the EVA front cage broke (one of my early ASA prints, bad layer adhesion I guess). I printed a new one, adjusted everything and did some print over the day which went fine. A few minutes ago I started another print and just came back to this - the brand new (installed two days ago) Phaetus tungsten Carbid nozzle is scraping the PEI from my even newer (installed today) sheet.
I turned off the printer, saved the klipper and moonraker logs (don't see much).
What happened here? How can I prevent it from happening again?
What happened here? How can I prevent it from happening again?
25 Replies
genetic-orange•2y ago
seems like you didn't redo Z-Offset calibration after replacing the Toolheadparts?
afraid-scarletOP•2y ago
I did, also did a few prints afterwards which were successful. Everything is properly fixed and adjusted
Probe mount is a prime suspect
afraid-scarletOP•2y ago
you might be right, but it's weird. I didn't do anything else yesterday anymore because I was so annoyed. I just checked the probe mount - it's fixed very well like before - but when I homed the Z axis it ran into the bed.
the new sheet I installed is another brand, but has the same thickness and is also steel. I can't imagine that, but could different PEI sheets lead to different measurements?
using the superpinda probe
optimistic-gold•2y ago
The exact some thing happened to me. I've been printing fine... now I have a scratched PEI sheet. So I adjusted the z-offset using the paper method - but what I noticed was major inconsistencies with the SuperPinda. Sometimes it would give negative numbers and other times positive? Perhaps I'm doing something wrong? Method: Home, nozzle to paper, Get Position (kinematic: X:150.000000 Y:150.000000 Z:0.900081) Then multiply 'Get_Position Z' by -1 and put this number into printer.config. I've been printing fine like this but now I sometimes get negative and positive Get_Position Z numbers and it's ripping apart my sheet.
genetic-orange•2y ago
just use the Safe Button from Mainsail, it converts automatically and saves the right value
optimistic-gold•2y ago
That's a feature I haven't used before - I'll have to find that button. Just out of interest - should the Get_Position Kinematic Z number be positive or negative? (This number is then multiplied by -1 and inserted into printer.config).
genetic-orange•2y ago
depends where you start, the offset in the Printer.cfg is always positive as this value describes the distance from the nozzle to the surface when the probe triggers, a negative Value here would mean that the Probe triggers after the nozzle hitting the bed already.
When you are doing the paper test just don't use the probe calibrate tool, simply command your Z to 0 and use the Z-Offset Buttons to touch the paper, then press the Save button there and do save_config in the console, Mainsail automatically calculates your new offset and saves it, then do a test print of a 1 Layer Square and live adjust it again with these buttons in babysteps until you are satisfied, press again save and do save_config and you are done.
optimistic-gold•2y ago
Apologies, what do you mean by 'Command your Z to 0' - do you mean insert a zero into the position absolute Z box? Also, I don't seem to have a 'clear' or 'save' button? Everything has been updated in the Update Manager.
Does it trigger when you hold some metal to it? Is it not mounted too high? If you hit the bed during homing, it is not triggering (too high or not working)
afraid-scarletOP•2y ago
This rings a bell for me. For a long time I just did the paper method, then "save_config", went to printer.cfg and added 0.08 to the distance - always perfect results for my 0.2 layer test print.
This method doesn't work for me anymore, right now I am in the 6th or 7th iteration trying to get the right value.
genetic-orange•2y ago
as soon as you alter the Z-Offset the save button magically appears 
yes just put in 0 in Z
yes just put in 0 in Zafraid-scarletOP•2y ago
afaik the trigger distance for the super pinda is around 2 mm. Therefore I always try to get between 0.8 and 1.5 offset in case the bed misleveled when homing
That's too large. You want 0.2
afraid-scarletOP•2y ago
good to know! is there a reason for this?
optimistic-gold•2y ago
I think I must be doing something wrong. If I input 0 to the Position Absolute Z box I would assume the nozzle will crash into the bed if it's not correct?
genetic-orange•2y ago
start carefully with 1-2mm if you are not sure if you are then touching before 0 you can already put in something like and then put the total to zero and adjust it, much easier than any calibration function and stuff
Because of what you are experiencing. These probes don't work well that far away from the bed
I have heard before from people you can use a credit card to properly adjust the distance
genetic-orange•2y ago
i always use the credit card, old one because the magnet will destroy the stripe 😉 a Creditcard is about 0.8 mm
afraid-scarletOP•2y ago
so what you mean is, set the nozzle onto the bed (z=0) and then but a CC under the pinda to adjust it's height?
genetic-orange•2y ago
yes
optimistic-gold•2y ago
I really appreciate your help - but I'm still confused.
If I insert 0 (and press enter) into the Z (position absolute box), the head will move to where it thinks zero is. If I insert a 0 without pressing enter - there is no save button appearing.
I have got the nozzle into the correct position on the bed (images show the absolute position).
Printer.config: z_offset: 0.00 (temp figure to allow calibration).
The SuperPINDA height above the bed has been set using a credit card.
I'm confused how I input this position as 0 and get that save button to appear - as this would be a great thing to know.
genetic-orange•2y ago
the absolut Z has to be zero, and now with the Z-Offset Buttons and a piece of paper or a feeling gauge or anything bring the nozzle as close to the bed as possible, as soon as you input a Z-Offset the Save Button will appear, then when the physical the nozzle is touching the bed and your Z value shows zero and you have an Z-Offset of XXXX press Save and the Firmware will automatically calculate the new Probe_Offset a save_config command in the console will then save this automatically calculated Value into your printer.cfg in the auto save area at the bottom, no need for calculation from your side or anything.
Then print one big or several 1 Layer Squares and adjust again with the Z-Offset Buttons until you get a nice first layer, again press save and type save_config in the console afterwards and your calibration is done
genetic-orange•2y ago
in your case with -1.9mm you are way off and using the buttons would take ages you just can enter into the console to spare time
optimistic-gold•2y ago
Absolutely amazing! Thank you so much for taking the time to explain all that to me!
I now have the nozzle on the bed at Z=0! Amazing!
Time to order a new RatRig PEI plate!
Thank you !