Benchy falling off halfway through print  

RE: Benchy falling off halfway through print

The obvious issues would be such things as a slight contamination of the build plate causing incomplete adhesion.  It needs to be Really Most Sincerely Clean.  A stray fingerprint can kill your job.

Z calibration can be the issue here, mostly as in too high for adhesion issues.

Other mechanical issues are possible but not that common, causing the nozzle to crash into already-printed layers.

What I would suggest as a next step is to use one of those 3x3 prints of squares to be sure that your Z calibration is exactly where it should be.  These are in the Prints section, on Thingiverse, and elsewhere.  All squares should be uniform, smooth, and solid.

The Benchy (aka Boaty McBoatface) has enough of a footprint that it should not need additional help to stick to a clean Prusa smooth sheet.

RE: Benchy falling off halfway through print

Posted by: @jsw

The obvious issues would be such things as a slight contamination of the build plate causing incomplete adhesion.  It needs to be Really Most Sincerely Clean.  A stray fingerprint can kill your job.

Z calibration can be the issue here, mostly as in too high for adhesion issues.

Other mechanical issues are possible but not that common, causing the nozzle to crash into already-printed layers.

What I would suggest as a next step is to use one of those 3x3 prints of squares to be sure that your Z calibration is exactly where it should be.  These are in the Prints section, on Thingiverse, and elsewhere.  All squares should be uniform, smooth, and solid.

The Benchy (aka Boaty McBoatface) has enough of a footprint that it should not need additional help to stick to a clean Prusa smooth sheet.

ive got the texture sheet and if anything the calibration is too close lol i just backed it off a tiny bit. i clean it right b4 the print starts and nothing touches it. very frustrated atm. my 800$ printer cannot finish a benchy......

RE: Benchy falling off halfway through print

The textured sheet can be tricky to print on, particularly with PLA.

There's anecdotal evidence here and on some other boards that there are 'good' ones and 'bad' ones, meaning some of the textured sheets just do not stick to the filament as well as others.

There's also anecdotal evidence that some of those plates get better with use, as in 'seasoning' a skillet.

I apparently got one of the 'good' textured sheets (code WA-15, top right corner, which may or may not be significant) but I've still had issues with some PLA prints, particularly those using supports, sticking reliably.

I would, in your case, recommend a small amount of glue stick, light coat right where the hull of the boat sits.  It will act as both an adhesion helper and a release agent.

I'll also make yet another repetitive call-out for a product known as Layerneer Bed Weld.  This works particularly well with PLA on the textured sheet where footprints are small and/or small support footings are used.

I like the texture that the sheet produces, but I've had things such as model building roof pieces curl up at the corners.  I'm in the habit of dabbing a bit of Layerneer where the corners will be, when I do a larger PLA flat piece, and I'll almost always use it for a PLA print with small support footings on either the textured or smooth sheet.

RE: Benchy falling off halfway through print

Thank you very much for the thorough reply. Really is a shame an 800$ printer needs glue but you gotta what what you gotta do. 

RE: Benchy falling off halfway through print

Posted by: @jhopke

Thank you very much for the thorough reply. Really is a shame an 800$ printer needs glue but you gotta what what you gotta do. 

IIAC, they (still) include a glue stick for just this purpose.

Every 3d printer I've used has occasional bed adhesion issues.  There's also a very steep learning curve to climb, both for 3d printing in general, and for any particular machine that you use.

You have one of the better units on the market.  It's capable of stunning prints when operated properly.  It may take some time and some stumbles while climbing that learning curve.

RE: Benchy falling off halfway through print

Posted by: @jhopke

Thank you very much for the thorough reply. Really is a shame an 800$ printer needs glue but you gotta what what you gotta do. 

My textured sheet was so bad it wouldn't even work with PETG. Fortunately, there are options these days:

• Buy a smooth PEI sheet. You can always order from Prusa directly, but I've ordered from PrintedSolid & BuildTak in the US. Lots of really cheap offshore brands, though they vary in quality. 
• Buy a 3rd party textured PEI sheet. Here again, PrintedSolid and others offer alternatives in the US, and cheap offshore options abound. I have had excellent luck with a TheKKIINNGG sheet which works exactly as I'd expected my Prusa original textured sheet to.

RE: Benchy falling off halfway through print

Try lowering your Z by 20-50 points 0.020-0.050 and see if that lets it stick more.  I saw your post above, but another option is hair spray or as JSW said, Layerneer Bed Weld.  Both work when things do not stick and they clean us easily.   I posted links to products available to me in the US.  There are others products around the globe.  I have 8-10 textured PEI sheets and each works differently with different filaments.  Some just need a little extra help.  

RE: Benchy falling off halfway through print

The textured PEI sheets are great on one side but are more tricky to handle regarding 1st layer adhesion.

But my personal experience (I have two of them) is, that they get better in time and cleaning properly is really the key. Frankly, I used Aceton once on my sheet, even when it is strongly not suggested. But at that point I thought that it can't get worse 😉. But do so on your own rish since it might make the PEI brittle. From that point of time it was ok. Since then cleaning with 99.9% IPA works fine. What definetely does not work is 70% IPA or around. 

But cleaning and first layer settings are a basic key for sticking.

What also helps is increasing the brim of the print ... that also helps a lot for prints with relative small footprints. Just give it a try with a 5mm brim or similar. You can find those settings in the Prusa slicer.

RE: Benchy falling off halfway through print

Most important for printing is:

1. A clean bed, use dish soap this clean a lot better then alcohol.

2. First layer should be 100%.

Both settings are needed to stick good.

I just started on using a powder coated sheet, and pla sticks good, after cooling down it releases very good, I like it better then the pei sheet with I used for a few years.

If it still not sticks,  but normally not needed:

First layer temperature extruder 10 higher,

bed temperature 10 higher,

first layer slower to 10 mm.

If you need to do this, the settings are not good, or filament is not 100%

Also I had problems with first layer, and my nozzle had a partial clogged, with was difficult to see, changing cost only 10 minutes, then you know that your nozzle is was your problem.