adhesion issue ; emergency stop

Hi all,

After having printed successfully 2 androids, I am having serious adhesion issues. First layer is not sticking at all to the glass.

I am trying several solutions : acetone, alcool, dish washing liquid, etc... but every unsuccessful trial causes a mess of plastic that takes me a long time to clean before the next trial.

So I am looking for an emergency stop command that would not require homing again etc... That would enable me to be much more efficient by saving time inbetween two trials.

I have tried the M0 or M112 command, but nothing happens.

Is there a better solution than abruptly shutting down the machine ?

you can press the reset button on the melzi to stop it and use an M82 command to use absolute distances, set it back to 0,0,0 and try again.

Try one part PVA glue to water if you're printing PLA, works great.

If you are using the PLA, the glass and settings provided with the kit then it will stick if you clean the glass with something that does not leave a residue. Also the first layer height has to be correct. A common problem seems to be using a solvent with a cloth that has a component that dissolves in it.

I use acetone and lint free wipes and it always sticks. Vinegar is supposed to be very good but I not tried that yet. I have never had to resort to glue, beer, hairspray, etc, but that might be needed with other makes of PLA that have "greasy" pigments in them.

To stop I just press the pause button, turn the heaters off and home.

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[www.hydraraptor.blogspot.com]

Just had the same problems as you.
My suggestion: recalibtate your z_home_position and then use vinegar - this really works !!

I got some Faberdashery filaments and printed the big Wade's gear after a good thorough of the glass with small piece of kitchen paper towel soaked with vinegar. Used the clear PLA. After the print cooled it did not pop or crack as happened before. It was not letting go. It was a major chore to pry that object off with the putty scraper. The adhesion was incredible! So I think you would like vinegar too ...

Joe, I have had very little success with bare glass. Even with cleaning it with acetone and lint free cloths. You will find that what works for some people, does not work for others. Your room environment seems to make a big difference, as does the filament type, brand and quality. Make sure you have no drafts in the room and it's not too cold or too warm. My most reliable solution to bed adhesion so far is the PVA\Water mix. I've yet to try the glue stick method, but I suspect this will be a good option too. I got mixed results with blue tape. ABS and Nylon seems to like it, but PLA does not.

Bottom line it, you need to experiment for the first couple of dozen prints to learn how the machine and materials work. Keep at it.

I get the best results with blue tape printing even cheap PLA. Lemon juice is also quite good.

hi,

Thank you all for your answers. We have made additional trials, and got pretty good results with vinegar... even too good actually, as it became almost impossible to unstick the part from the bed.

Any tip for that ?

Put the glass in a freezer for 10 minutes usually works. Failing that stand the glass on its edge and knock that parts off sideways with a hammer and block of soft wood.

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[www.hydraraptor.blogspot.com]

We'll try that, thank you Chris !

By the way we have damaged the glass while unsticking a part : a piece of glass came with the printed part...

For the moment we plan to flip it, but we may need to replace it if it happens again. Can we buy any kind of glass, or is it specific ?

I use SÖRLI mirror tiles from IKEA. £6 for four, which I have setup with different printing surfaces (PET tape, ABS slurry, PVA, etc) so I can just swap the entire glass whenever I want to use a different material.

They're 1mm thicker than the stock glass and a tiny bit smaller (you have to spend a little effort centering the glass to ensure full 200x200 printable area) but I can live with that for the cost!

Ha, the Sorli tiles seem to get cheaper every day. First £10, then £8 now £6! I wonder if Ikea know what they are being used for.

Ordinary 2mm picture glass works fine. A high street glass shop or a picture framer will cut it to size for you and smooth the edges. Probably a bit more expensive but lighter and more thermally conductive. The mirror tiles do seem more robust though. I have never known one to flake.

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[www.hydraraptor.blogspot.com]

I asked a local glass shop to cut me some pieces of ordinary 2mm glass with clipped corners. When we picked it up they were 3mm but working very well. But 2mm would be lighter for sure ...

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Garry Bartsch
I asked a local glass shop to cut me some pieces of ordinary 2mm glass with clipped corners. When we picked it up they were 3mm but working very well. But 2mm would be lighter for sure ...

2mm glass is a standard size for picture framers as Nophead says and strangely, I have never seen it for sale at any glass merchant. The 3mm stuff is usually used for windows. One type of anti-reflection glass, (as used by picture framers), is etched on one surface to diffuse incident light and although I have never tried it, may be useful for 3D printing as it will present a greater surface area on the etched side to the first layer filament. Take care though if you ask for anti-reflection glass as not all types are etched - the more expensive types have an anti-reflection optical coating.

If you cannot find a friendly framer - you could take the glass out of a cheap frame from a "Pound shop" - not sure what they are called in other parts of the world - "Dollar Store"? However, this would mean cutting it to size yourself - see this as an opportunity to acquire another skill if you don't have it already :-)

Alan (a DIY picture framer)

Hi,

Quote
Alzibiff
2mm glass is a standard size for picture framers as Nophead says and strangely, I have never seen it for sale at any glass merchant.

Odd, I went to my local glass merchant (Gibbs and Dandy here in the UK) and purchased three pieces of 2mm float glass for 6.05 GBP. The original kit glass was 2.1mm thick and the replacement nearer 1.8mm but otherwise it works fine.

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

Quote
Alzibiff

Quote
Garry Bartsch
I asked a local glass shop to cut me some pieces of ordinary 2mm glass with clipped corners. When we picked it up they were 3mm but working very well. But 2mm would be lighter for sure ...

2mm glass is a standard size for picture framers as Nophead says and strangely, I have never seen it for sale at any glass merchant. The 3mm stuff is usually used for windows. One type of anti-reflection glass, (as used by picture framers), is etched on one surface to diffuse incident light and although I have never tried it, may be useful for 3D printing as it will present a greater surface area on the etched side to the first layer filament. Take care though if you ask for anti-reflection glass as not all types are etched - the more expensive types have an anti-reflection optical coating.

Sorry I missed your reply. Funny thing is when I talked to the fellow on the phone I specified 2mm and he said they could get it. Must have been a miscommunication somewhere along the line since he took my order over the phone. I do think I would eventually like to get 2mm because of the weight difference.