Bedmesh not to bad, but first layer not good
This is my bed mesh. I would say < 0.3 mm is a very good bed. At the moment I am printing ABS and the bed is fired to 100 °C. How long do you wait until starting the print? because I worry about that the printer needs some time to stabilize the bed expansion process. - otherwise the bed will come up and the first layer gets to much pressure. That is exactly what I see. If I print maybe 6 parts on the platform after probing the mesh the first 1-2 parts have a perfect first layer. The do not need to be aligned in the middle of the bed. But after maybe 10 minutes the bed has expanded more an the layer of the following parts is to much pressed. I need to lift the nozzle manualle about 0.05 - 0.08 mm. That the layer is perfect again.
So I think my bed expansion process is not finished before the print starts. So my question is: how long do you wait until you start printsing?
17 Replies
In an enclosure its not the bed expansion its the entire printer warming up and expanding. I put a thermometer in the lid and when it reached 40-45C, I waited another 30 minutes to soak. I would then adjust z-offset, take a bed mesh and, if there was too much bowing of the X or Y rails, I'd unscrew them (all but 1) and refasten them (I follow a procedure for that). If the bed mesh is oke, I do 1 last offset check before I start the print. While it was never perfect allover, it was good enough to continue.
More recently, I installed this and followed the setup in README_EXTENDED, and after some trial and error my first layers were much better
https://github.com/JiMcNulty/FDC
GitHub
GitHub - JiMcNulty/FDC: non-linear frame deformation calibration an...
non-linear frame deformation calibration and compensation 2.0 - GitHub - JiMcNulty/FDC: non-linear frame deformation calibration and compensation 2.0
correct-apricot•2y ago
Do you maybe have some photo previous and afterwards?
@FlorianM 🇪🇺 /🇩🇪 a photo of what? first layer?
you mean this? Each outer corner and center
that was after
before some of them would almost scrape the bed
correct-apricot•2y ago
OK. Same here. Where did you plase the temp probe?
in the underside of the extrusion, in the middle. Cut some stiff foam to press it into the aluminium
correct-apricot•2y ago
on one of the outer rails?
* profiles?
in the gantry
thats the ptfe tube I put the thermistor wire through
correct-apricot•2y ago
ah okay. I will order everything I need and will try. And the probe goes to the mainboard right?
yes, I hooked it up to a free thermistor on my octopus 1.1 and configured it in klipper
make sure the tip of the thermistor has good contact with the aluminium
basically thats all you need, a thermistor
I use a cheap EPCOS
100K
correct-apricot•2y ago
FDC runs and dude, that's a difference!!
@tom.cruise look another happy customer 🥳
complex-teal•2y ago
Amazing!! another printer with great layer lines