@dc42 Thanks for the suggestions.
Probing is being done after both then bed and hot end are upto temp. I have also tried probing with a 5min wait after both hot end and bed are heated.
Once I get G30 S-1 at various points and find the difference in trigger heights, is there a way to use that information?
I think the X gantry has a sag, and that is why I put the Z Probe on a X=0 offset, but that did not seem to help.
@o_lampe Thanks. I will see if the Z belt path can be changed as you suggested.
I did a M122 after first layer was done, and before print ends, and the drag did not show any skipped steps.
@phaedrux Checked the grub screws again, and they were tight.
@tmicke Yes, the bed is clean.
The bed has PEI steel sheet on it.
With all the tweaking to solve this I do sometimes get finger prints/oil on the bed.
I normally just wash with soap and water.
@fcwilt First layer speed is 20mm/sec
First Layer height is 0.2mm
In a post above I have attached screenshots of most of the slicer settings.
@phaedrux Yes the cooling fan is OFF for the first layer
The first layer extrusion width is 0.42mm (nozzle is 0.4mm), should I try a different extrusion width?
I will try upping the temps.
Thanks
@engikeneer Fair question.
Except for the cooling duct and PINDA holder this printer does not use any plastic parts, it is all metal.
https://seckit3dp.design/kit/sk-go2-essential
@o_lampe I have not heard any skipping, not sure if there is any way to measure the skipping.
Also in the middle of the bed the Z motors don't actually have to move since the bed is pretty flat. I also marked the Z motor pulley with a Sharpie and it does not move from the initial position printing infill in the center of the bed.
This is a CoreXY with bed moving up/down, so if Z is stable then I would think the X gantry is somehow moving up (not sure how that can happen). I also did the bedlevel_nozzel print suggested by Phaedrux and that stuck well all through.
The reason I am trying large flat full infill print as test is because I ran into this issue when printing large footprint models/STLs and got into debugging.
I am going to recheck for any mechanical issues.
Printed without an issue.
The lines are pretty well stuck to the bed, and I could see the Z motors move when printing near the bump in the front part of the bed.
@hekav What gcode is run at the end of the print? Anything from slicer or stop.g file?
@phaedrux Calibrated the Esteps and extrusion multiplier. ESteps did not change, the extrusion multiplier changed by 0.01, so went from 1 -> 1.01.
Still the issue persists.
Running a few more tests it looks like an issue with Z distance between bed and nozzle increasing as the first layer progresses.
On a 150x150mm square print with reclinear infill the layer stops sticking halfway through the layer, I then reduced the distance using baby step, and kept doing that as the print stops sticking again. At the end of the layer I had to move the nozzle closer by 0.2mm (-0.2)!!!. That is a lot.
I tried heating bed for 15 min before starting print/probing to see if thermal expansion is somehow involved. But that did not help and the print still did not stick halfway through.
Next heated the bed for a while and then ran mesh bed leveling. Then moved the head to various points on the bed with a piece of paper under it to see if the nozzle is close to the bed. And the paper is being gripped by the nozzle correctly. If I raise the bed by 0.2mm the paper does not grip. So the moving the bed using the bed using the Dashboard is maintaining the nozzle distance correctly.
Attaching the gcode of the file I used, and slicer settings.
150x150_center_0.2mm_PLA__50m.gcode
Also adding the height map, it is pretty level in the middle of the bed.
@fcwilt Yes, in bed.g, at the end, there is a G30 at the center on the bed. The mesh leveling happens after bed.g is run.
@fcwilt Yup. I ran about 25 test with all the tweaks I mentioned, and most of the time I kept the bed hot when just changing config.g, etc.
For any hardware change I let the bed heat for a while, not 15 min, but around 5.
@fcwilt Adhesion is not a problem, and the first layer speed is slow 20mm/s.
Monotonic is just rectilinear if there are no other patterns in the first layer.
I used Hilbert Curve for the first time because I wanted to make the infill start from left side and go to right to make sure this is not an issue with bed leveling.
For a while I have been having issues with first layer when printing models that have a large surface area on the first layer.
The bed is pretty flat and the print starts out well and as the first layer progresses the bottom infill does not stick well.
I went through the normal debugging with Z Probe, bed leveling etc. Things I have tried that did not make a difference.
When nothing seemed to solve it I tried a few different infill patterns that go in different directions, this was to make sure the issue is not with bed leveling. The model is just a rectangle with 0.2mm height and printed with PLA
I tried
With these infill patterns the issue seemed to be with extrusion "slowing down" as the first layer progresses, since the gaps in infill increase by the end of first layer.
So I replaced the extruder stepper motor and made sure the Bondtech Extruder is setup correctly.
Still the issue persists. So I am kind of lost on what the next steps are to debug this issue.
I have attached a photo with two printouts of the first layer (Monotonic and Hilbert infill style)
With the Hilbert curve style the layer sticks well all through, and there are no bumps to touch, but at the end of the layer the gap between the fractals ends has increased a lot.
Is there something else I can monitor during the print to check on extrusion.
@petriheino You can send M114 to get the current motor positions. This includes the step counts for each stepper motor and the bed correction applied.
@fart_plume Can you provide more details on which filament monitor is being used, and how it is mounted?
Also did you follow the instructions here to make sure you have the right parameters set for M591?
https://duet3d.dozuki.com/Wiki/Connecting_and_configuring_filament-out_sensors
@cncmodeller You can also try the iOS app.
The app does not allow any actions so should help with the view only aspect.
@rkaronde Update after using this for over a month.
Had 0 false triggers
Twice caught actual issues, one was filament grinding leading to no movement. The other was actual jam. Was able to resume the print with grinding issue. For jam had to cancel the print, but saved a lot of time
Have printed PLA, PETG, TPU, Wood fill. Different color (but really that does not matter). It is good to see different material being tracked well.
Reprinted the Axel in Prusament ASA Galaxy Black. This improved the range reported to be more consistent 215-230% over really long prints as well.
Oops, fixed the typos. Thanks for catching them.
The shaft is really easy and quick to print. It has a few different sections of varying diameters and a hexagon shape on it. These are really important parts of the overall design.
Getting those craved on a steel/carbon rod would be hard
