Inconsistent first layer from a cold start to subsequent prints
I'm having some issues with the 1st layer settings. I've followed the instructions and also the "life adjust Z - my way" guide printing the 75x75x0.2mm square. My issue is that I get the setting right after multiple runs where I leave the bed to cool down between prints so I can remove the square but the gap is in minutes not hours (so I've classed this as warm). However after leaving the printer to cool down for an extended period i.e. over night, the first print is way off. An example is below where I got the setting for the textured sheet to 1.580 which gave what I would think is an ok first layer, went to bed, got up and printed the square again and the print is way off (second photo). I've now adjust the printer to 1.600 and it seems ok again, will leave it for an hour or so and try again.
Apologies if this has already been answered I did have a look but couldn't see this specific issue. Any advise appreciated.
TomD
RE: Inconsistent first layer from a cold start to subsequent prints
Thats strange., never seen that before, was this a kit just built?
It is as if something is moving about slightly. My Z offset has held like a rock since build.
Do you have 7x7 bed levelling enabled, Is the pinda probe nipped up suffiently so isn't moving slightly, are the bearing holders on the Y axis nipped up to stop the bearings moving (just nipped and no more, also evenly tightened) and all other fixings nipped up on and around the bed.
Z motor brackets and motors both nipped up correctly, no movement.
No play in the X carriage (try and move it very gently up and down to feel for play.
Sorry cant be of more assistance, sure someone else will have some other ideas.
Tank you very much!
RE: Inconsistent first layer from a cold start to subsequent prints
Thats strange., never seen that before, was this a kit just built?
It is as if something is moving about slightly. My Z offset has held like a rock since build.
Do you have 7x7 bed levelling enabled, Is the pinda probe nipped up suffiently so isn't moving slightly, are the bearing holders on the Y axis nipped up to stop the bearings moving (just nipped and no more, also evenly tightened) and all other fixings nipped up on and around the bed.
Z motor brackets and motors both nipped up correctly, no movement.
No play in the X carriage (try and move it very gently up and down to feel for play.
Sorry cant be of more assistance, sure someone else will have some other ideas.
It's a kit and I've checked all the axis screws etc... and the Pinda is rock solid. I am wondering if it is too high and that might be causing it but it only seems to be when I print from cold vs. a second print after everything has warmed up. I've just re-printed the 1.600 from above from cold and again it is out, too high so the threads fall apart. Trying 1.610-1.620 now.
RE: Inconsistent first layer from a cold start to subsequent prints
How did you seat your heat bed? Did you just screw it down? Loosen all of the screws - don't take them out - and then heat it up to PETG temp. Then tighten a bit the pattern here
Center
Diagonal corners, left front, back left, back right, front right
Cross (centers) - front, back, left right.
Don't fully tighten, but gradually repeat this pattern tightening a little at a time. This will help seat your bed and make it less susceptible to flexing when it heats up.
RE: Inconsistent first layer from a cold start to subsequent prints
I am a big believer in heating up the printer before starting a print. While I originally did this due to issues with the original PINDA v1, I found warming the bed consistently before a print helps with a variety of issues, particularly as we swing from summer to winter temperatures. I've developed my own take on the "2-step nozzle warmup" procedure, documented here, which has the side benefit of using the bed to warm the PINDA, thus ensuring the bed is evenly warmed. While my original gcode was based on using the M860 gcode command to monitor PINDA temperatures, I've been contacted by a number of people who find that a consistent bed warmup is also important for the newer SuperPINDA. By moving the bed warmup gcode, this can be easily achieved. One user found that heating the bed to full temperature before doing mesh bed leveling and final nozzle warmup yielded good results.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Inconsistent first layer from a cold start to subsequent prints
One user found that heating the bed to full temperature before doing mesh bed leveling and final nozzle warmup yielded good results.
I'm not the user you are referencing, but that is my method too. I heat the bed to printing temperature before doing the mesh leveling.
Using the Octoprint bed mesh visualizer plugin, I noticed a difference between cold mesh levels and hot mesh levels. Since I only print on a heated bed, I modified the startup code to fully heat the bed before leveling. It made a small improvement of overall quality of my first layer. By small, I mean really small, I needed a magnifying glass to see the differences. But hey, better is better, right?
RE: Inconsistent first layer from a cold start to subsequent prints
Tried a few things, re-seated bed when hot, moved probe etc... but still having issues. The only thing that seems to work is either pre-warming by doing a test print for example or waiting a while between prints for everything to cool down which isn't practical. I'll have a look at the warmup docs and see if that helps.
RE: Inconsistent first layer from a cold start to subsequent prints
@TomDD: PINDA or SuperPINDA?
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Inconsistent first layer from a cold start to subsequent prints
@TomDD: PINDA or SuperPINDA?
It's a brand new MK3S+ so assume SuperPINDA
RE: Inconsistent first layer from a cold start to subsequent prints
It's a brand new MK3S+ so assume SuperPINDA
I don't have a SuperPINDA to test with, but I was contacted by somebody who had problems with MBL with a SuperPINDA. They found that fully warming the bed up to a consistent 65C temperature before MBL was necessary for good leveling results. We modified the 2-step warmup to heat the bed fully sooner in the process with M190 S65 and he reported good results. He did position the SuperPINDA next to the bed during warmup, but unfortunately, M860 no longer lets you monitor the PINDA temperature, so it's hard to say what effect the heating had on the sensor.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Inconsistent first layer from a cold start to subsequent prints
I seem to remember that if you have never successfully or even unsuccessfully completed the on board live z
the adjustment any subsequent changes are not saved
RE: Inconsistent first layer from a cold start to subsequent prints
I seem to remember that if you have never successfully or even unsuccessfully completed the on board live z
the adjustment any subsequent changes are not saved
That was definitely true at one point. I can't say I've tested to confirm it's still the same today, but it's worth trying.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Inconsistent first layer from a cold start to subsequent prints
It's a brand new MK3S+ so assume SuperPINDA
I don't have a SuperPINDA to test with, but I was contacted by somebody who had problems with MBL with a SuperPINDA. They found that fully warming the bed up to a consistent 65C temperature before MBL was necessary for good leveling results. We modified the 2-step warmup to heat the bed fully sooner in the process with M190 S65 and he reported good results. He did position the SuperPINDA next to the bed during warmup, but unfortunately, M860 no longer lets you monitor the PINDA temperature, so it's hard to say what effect the heating had on the sensor.
Thanks for the feedback. I'm going to try this out and will report back.
Also I did run the initial first layer calibration so it should store the settings ok.
Tom