First layer calibration help  

Re: First layer calibration help

I just cant seem to get the filament to stick. I have tried acetone also. I have been able to print first layer calibration a couple times. Sometimes it sticks and sometimes it does not.

Re: First layer calibration help

have you printed fine before?

you should try dish soap and water (like washing a dish, and rinse)

Re: First layer calibration help

Here is what i came up with. When i first started printing it was sticking ok. The more i cleaned the sheet it got worse. The pla would not stick. I tried 91% isopropyl alcohol and acetone. That did not seem to help. I noticed a haze on both sides of the steel sheet. I attached a picture. I then cleaned the sheet with dish soap and water. One side i was able to get all haze off. On the other side i could not get it to come off all the way. I tried washing it a couple times but still could not get it off all the way. Very strange. Does anybody have any clue what might be going on here? The side with no haze i did a print on and i think it turned out pretty good. I attached a picture. The pla stuck very good with no issues. I am affraid to clean it with the alcohol or acetone since it seemed to cause problems. Is there any other recommendations to clean with besides what i have already tried. I really do not want to have to wash with soap and water every time i print.

Re: First layer calibration help

I think I only have to wash my sheet every 10 prints or so. I only use 99.9 alcohol every 5 prints maybe (pla) maybe slight Z or slight temps change can make it look even better. maybe try temp down 5

Re: First layer calibration help

I was thinking about going .025-.050 down on z. I will also try going down on temp. I would still like someone to chime in on the cleaning problem. Would denatured alcohol be better? I can only find 91% alcohol locally . Where can you get 99%?

Re: First layer calibration help

you can find it on amazon. lucky for me I use it at work. so I get a discount. 99.9 is abit overboard. but it's what I got. good enough to clean fancy optic lens with no residue.

was your acetone pure?
i know some people have used a green scrubby lightly on the sheet. but I would try to read up on it more before doing that. at least one side is fine till then.

denatured alcohol might work, but I have a feeling it leaves some residue of some sort.

Re: First layer calibration help

What is pure acetone? The acetone i bought is from home depot. It does not say anything about being pure.

Re: First layer calibration help

When i get to first layer calibration i am having some problems. The pla will stick but when it makes its first turn it does not stick and starts to ball up on the tip. I have cleaned the surface multiple times with 91% alcohol. The piece it did lay down i did measure it at .23 mm so i think i have the height alright. I did notice that the pla does start to ooze out of nozzle around 200 degrees. I pull it off right before it starts calibration but still comes out a bit after the nine point calibration. So there is a little build up on nozzle before it starts printing.

Make sure that the first layer is really correct - the 0.23mm sound quite good, but maybe still too high.

1. make sure the bed is clean. IPA is very convenient between prints, but washing it with dishwasher and drying it with a paper towel works really well
2. make sure the extrusion is good. Bontech gear tension needs to be right, not too tight and not too loose. Nozzle must be clean, when feeding filament it should extrude straight down in a steady stream.
3. dry filament: PLA is less critical but also affected, wet filament oozes more and crackles.

4. after 1-3 is OK the Z level can be adjusted. The Prusa code is not very useful, as it's really hard to judge if it's perfect. A 1 layer square is much better.
After printing, the surface should be quite smooth and the infill should be completely bonded together. So if you try to pull the infill strands apart they won't break apart, but the layer will stretch.

I was printing for months, thinking that I had the first layer set correctly, but after having problems with a filament and doing the whole process with the 1-layer square method I ended up 50 microns lower with my nozzle, and have had very good results since.

Re: First layer calibration help

What is the right tension for bondtech gears?

Re: First layer calibration help

For me.

I Remove the filament so the gears are empty
Then release the screws till there is no grip
Then I advance the screws one at a time. Until then literally just start to bind against the springs
And then Re insert the filament. This causes the Idler to move out a bit. And tensions the springs for me.

Regards Joan

Re: First layer calibration help

I'm new to all this but I was having this same exact issue. I did all the calibration and then during the first layer calibration I moved the axis down and I'm at .767. it seems to be doing ok on the first layer. I was balling up and thinking I was too close when all actuality I was too far away and the PLA wasn't getting squished down enough to stick. Someone please correct me if I'm wrong because this is how I see it and have figured it.