Printer can no longer print 1 st layer  

RE: Printer can no longer print 1 st layer

This reads like an insufficiently cleaned print bed:

Clean the bed again. Use dishwashing soap and HOT water; rinse well and dry with fresh paper towels.

Avoid touching the surface afterwards.

The curling at the nozzle might just be stickiness due the residues from previous failures, unless extreme this shuldn't be a problem; BUT, have you been printing abrasive filaments (metal fill, luminous &c.) in which case you might have some wear?

Hth, Cheerio,

RE: Printer can no longer print 1 st layer

Clean bed with dish soap and water.  Dry thoroughly.  

If it fails, consider looking at whether you live Z is low enough.  

RE: Printer can no longer print 1 st layer

@diem

I am printing with PLA only. Solid colors, no abrasives. Note I stated that I am using filaments that worked before from the same spool that will not work now. 

I have washed the crap out of the base plate with Dawn and hot water and dried with both paper towels and clean cloth towel. I only touch the edges. This is the same procedure I have used for 3 months in the same sink with the same water and same towels. 

I have replaced the nozzle 3 times with brand new. 

Please read my original post as I have covered all of this in it. 

RE: Printer can no longer print 1 st layer

I have tried every calibration of the Z axis possible. Again as stated in my original post the Z axis calibration runs perfectly all the way from to far to to close to just right. None of them will make a suable print but the all work perfectly running the first layer calibration. 

Again please read my original post more closely as this was covered in that document. 

RE: Printer can no longer print 1 st layer

Post an image of your Z Calibration on the forum.  I am more than glad to assist,  

RE: Printer can no longer print 1 st layer

Wen my first layer does not work I do this:

The problem with myself is, that the first layer is not good, but I think it is good. To low is bad for higher up in the print.

I usually do the first layer calibration to high, a few steps higher, then print a few squares , every square I do a little lower, then I take the one that looks the best, one layer that is very low but still looks good could be bad, model could come loose higher up in the print, if you go even lower the first layer could get waves in the filament.

RE: Printer can no longer print 1 st layer

@peter-m-3

Then use a rim or brim to increase adhesion.  

RE: Printer can no longer print 1 st layer

@jlefevre1

If you are doing all you say then you are getting perfect prints every time...

first layer some parts of it a not stuck very well and other parts are stuck so well I have to scrape them off

This still reads like an imperfectly cleaned steel sheet.

model could come loose higher up in the print,

So does this.

As it's only three months old you shouldn't have had any need for acetone yet.

The next, relatively easy step is to pull and reseat all electrical/electronic connections in case something has worked loose or corroded.  Also a quick clean of the bondtech gears - just a whisk with a clean paintbrush and a visual check that they remain in alignment.

Hth, Cheerio,

RE: Printer can no longer print 1 st layer

I think I may have found the culprit. After cleaning the print sheet for the umteenth time in a number of days that I lost track of, alwasy using hot water and Dawn dishwashing liquid and a very soft bristle brush to scrub of the KORES stick, I headed back to the shop. As I was holding the sheet by the edges as usual the light caught it just right and I notices blotchy areas of white haze on the surface. The light bulb went on and I remembered what a mess our city water is. I have to replace the water pressure regulator and clean the faucet and shower heads at least every 2 months and flush the water heater with vinegar every 6 months to keep everything working due to the extreem levels of disolbed limestone and calcium deosits in our water. I remembered some where that it was recommend to clean the print sheet with alchol or acetone. I grabbed a can of acetone and wetted a paper towel and that quickly removed the white haze from the sheet. Then without putting any of the KORES on it for adhesion I started a part and the first layer was perfect. It finished and I did a quick wipe with the acetone and started another and the first layer was perfect. They stuck to print sheet well and I had only to flex it a couple fo times to get them off. I do thing I have a bad roll of black PLA from another vendor but I am afraid to try it again since it alwasy made things worse and seemed to plug up the head. I have ordered the correct color from PRUSA and will try that when it get here. 

Keeping my fingers crossed. Thanks all for pointing me in the bed condition as being the culprit. I just did not see that as a posibility sind the first layer calibration alwasy ran perfectly. Maybe since it runs much slower and is a simpler pattern that problem was not showing up with it and the little square it prints at the end is in a part of the print sheet that I never use. 

RE: Printer can no longer print 1 st layer

@jlefevre1

From your last paragraph it sounds as if you're using the built-in live Z method ("little square at the end"), which I found to be pretty useless. Instead I suggest you try this: https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

I changed it a bit by using a different sized square but it gives you a much better visual indication of what's going on with the live Z, plus -- to your specific issue -- covers a much wider range of the print bed.

RE: Printer can no longer print 1 st layer

A little spray of Aquanet sticks better than Kore Glue Stick.