Glass Heat Bed Adheasion

Hello,

Sorry if this is another my print wont stick thread but I have spent quite a while trying to get my PLA to stick to glass but I just cant get it to work consistently enough that I can control it! I dont want to use tape as this is why I invested in a heat bed and I can see it will work because occasionally it does but most of the time it does not!

I have a pretty typical 2012 setup ( i started building it then )
Prusa i2 running off Ramps 1.4 with a Wade extruder and a Jhead 0.5 nozzle.
Printing onto a mirror clipped on a Heatbed MK2
Powered from ATX PSU
Slic3r set to 1.75mm 0.3 layer height ( I set it to this when I had adhesion once! )

I have been systematically through it and I just need a bit of guidance on how to solve my sticking issues!

Variables I have checked and know 100% are good enough
Extrusion steps - If I extrude 100mm I get very close to 100mm filament take-up.
Electronics - this is my background and I have no overheating or skipping issues and the PSU is working well.
Bed cleaning - I use IPA and rub the surface down thoroughly with toilet paper ( does lint cause issues? )

Variables I think cause bad adhesion
Bed Temperature - I have a laser thermometer that I check against the thermistor and it is pretty close. I started at 60 and stepped upto 70 with a slight improvement. Should I pursue a Higher temp? does too high prevent sticking or is it just warping?

Bed Leveling - I have re-adjusted the bed height non stop with little result using the paper dragging under the head. After repeated tries I got it so close that the PLA was barely a trace then tried increasing the z offset .1mm at a time in slic3r. This worked but it was still not consistent each time I tried.

Variables I am unsure of
PLA quality? I purchased the PLA cheap of ebay, does cheap filament not stick?
Mirror Glass - Could this be an issue, perhaps a different glass could work better?

Observations

The beginning of a line always lifts up, sometimes only a few mm sometimes most of the line especially if its wiggley
the head oozes a little when heating up causing the outline to become a mess, I sometimes have to clear it because it almost messes the whole print up.
I had success when my Extruder steps were wrong over extruding

Any tips on what element is more important for adhesion and what is not would be really helpful as I feel like there is a lot distracting me from what is actually the cause!

Edited 3 time(s). Last edit at 01/09/2014 05:46PM by clack.

This sounds daft, but try something else than toilet paper, they put stuff in toiler paper to keep it soft!

I kid you not, try kitchen roll.

I used to have all sorts of problems till I switched to kitchen roll.

PLA;

Here's some points to try before you revert to hairspray.

I use some very cheap nail polish remover I got from the chemist, I rub that over about every 5 prints and wipe off with kitchen roll.

I changed my first layer fill to rectilinear - 90 degrees.
I'm convinced the 90 degrees is important,
I've not had a print not stick for months.

Bed: 62
Nozzle: 186
Home your Z, then issue a G1 Z8 F200
The nozzle will rise 8mm, pass the shaft of an 8mm drill under it. Adjust you Z endstop till it *just* goes under with a tiny scrape, it's 8mm off the bed.
You have to
1.adjust the endstop,
2.press home,
3. issue the command,
4. check with the drill,
repeat 1 to 4 till it's perfect.

One more thing: Google for Triffid Hunters Calibration page.
It's a way of calibrating your extrusion while your printer runs. This made a MASSIVE difference to my prints sticking, over extrusion = prints not sticking.

Thanks for this tread.. I have the exact same issue. I bought my heat bed over Christmas thinking it would pay for itself in not buying tape.. but i have yet to get the print to stick. I have tried everything everything you did.. but i used kitchen towel ( paper towels for my part of the world). Infact i just finished with my frustration for the night.. will be trying these sugestions over the weekend..never thought of, or read about, checking height after i homed the z and leveled the bed..good tip

A bit of sucess!

I had an idea, I flipped the mirror upside down so I have a less shiny surface and it worked much better!



I dont know if the foil will eventually pull off.

Is it a possibility that different glass products have different stickyness?
Mirror glass is tempered, and I guess it is used because it can withstand the heat and resist extruder crashes?

P.S Dave thankyou for your help, the drill bit is a good idea! I am using 99.9% IPA so its pretty much like (acetone free) nail varnish remover and the toilet paper is super vailue 2 ply stuff so no bum moisturiser in it. Now I have a bit more adheasion those guides are a lot more helpfull!

Edited 2 time(s). Last edit at 01/10/2014 10:22AM by clack.

I made some good progress on this issue also. While trying to set my z height i could not get it to say put. I'd dial it in,and print. With in a print( just doing a single layer print) it would either drop and drag or raise up too high. Found that my motor shafts have 1mm of play in them ,basicly causing backlash. Not sure why i never noticed it before. I kept blaming my z stop not being cooperative . So with the play taken out of the motors I have been able to get some better results. Prints still have a hard time sticking, but i have not tried any sort of glue to help out yet. The good news is i have consistant height, so that battle( I hope) is over.
While playing with all of this i came up with a few questions.
Do optical end stops work better then mechanical endstops? Seems to be a bit of delay(caused by travel) in the mechanical ones, from on to off while raising the z and wondered if that would cause height problems. Or if the software accounts for that travel. And why lever action switches, do they have some advantage over a momentary push button switch?
Would auto bed leveling help resolve the height issues?, seems like it would be, but im guessing it only works as well as your printer will allow. It is on my list of upgrades, but i need to know that I can get repeatable good results before I throw something else into the mix.

Clean mirror with Dawn dish soap and hot water. Rinse/rub with cleaning vinegar (or plain white vinegar). Rinse thoroughly with water. The water should not bead up anywhere. It should look like it is 'sticking' to the glass. Dry off with a plain paper towel (facial tissues, toilet tissue, etc usually have additives in them that leave a greasy or oily residue). Nail polish remover isn't the best. It is acetone with other junk in it. Use straight acetone. Even that isn't the best. A LOT of acetone you buy is reclaimed/recycled, which means there is a good chance there are still oil residues that weren't completely removed during the reclamation process.

Quote
clack
Hello,

Sorry if this is another my print wont stick thread but I have spent quite a while trying to get my PLA to stick to glass but I just cant get it to work consistently enough that I can control it! I dont want to use tape as this is why I invested in a heat bed and I can see it will work because occasionally it does but most of the time it does not!

I have a pretty typical 2012 setup ( i started building it then )
Prusa i2 running off Ramps 1.4 with a Wade extruder and a Jhead 0.5 nozzle.
Printing onto a mirror clipped on a Heatbed MK2
Powered from ATX PSU
Slic3r set to 1.75mm 0.3 layer height ( I set it to this when I had adhesion once! )

I have been systematically through it and I just need a bit of guidance on how to solve my sticking issues!

Variables I have checked and know 100% are good enough
Extrusion steps - If I extrude 100mm I get very close to 100mm filament take-up.
Electronics - this is my background and I have no overheating or skipping issues and the PSU is working well.
Bed cleaning - I use IPA and rub the surface down thoroughly with toilet paper ( does lint cause issues? )

Variables I think cause bad adhesion
Bed Temperature - I have a laser thermometer that I check against the thermistor and it is pretty close. I started at 60 and stepped upto 70 with a slight improvement. Should I pursue a Higher temp? does too high prevent sticking or is it just warping?

Bed Leveling - I have re-adjusted the bed height non stop with little result using the paper dragging under the head. After repeated tries I got it so close that the PLA was barely a trace then tried increasing the z offset .1mm at a time in slic3r. This worked but it was still not consistent each time I tried.

Variables I am unsure of
PLA quality? I purchased the PLA cheap of ebay, does cheap filament not stick?
Mirror Glass - Could this be an issue, perhaps a different glass could work better?

Observations

The beginning of a line always lifts up, sometimes only a few mm sometimes most of the line especially if its wiggley
the head oozes a little when heating up causing the outline to become a mess, I sometimes have to clear it because it almost messes the whole print up.
I had success when my Extruder steps were wrong over extruding

Any tips on what element is more important for adhesion and what is not would be really helpful as I feel like there is a lot distracting me from what is actually the cause!

pla has always been the easiest to stick for me.

level the bed PERFECTLY. set nozzel to lightly drag on glass. spray with extra hold hairspray. i extrude at 200 and keep the bed at 50.
i print for a living (24/7) and have zero problems with pla lifting using the above method.

abs is much more picky for me. i do all the above but make the nozzel drag heavy on the glass and BATH the glass in hairspray. 99.99% this gives me perfect prints.

now, i print large, long (3-4hr) prints most of the time. for small stuff, i dont even have to spray hairspray on the glass. they just stick.

i have a ton of glass beds so i can quickly rotate and keep my bank of printers going.

every 3rd day i soak half my glass in lacqure thinner for 30 minutes. let 'em air dry and go again.

the KEY is pressing the 1st layer to the glass HARD and a PERFECTLY level bed.

Edited 1 time(s). Last edit at 01/11/2014 08:40PM by otter5555.

The main thing that seems to matter is how well the hot filament sticks to the build stage - nothing unexpected here, but this is influnced hugely by what is on the surface. As DaveS says, the tissue that you wipe the glass with can contain oils that act as a non stick agent: I used "Thirst Pockets Ultra" on Kapton tape - BAD IDEA. Nothing would stick to that. Presently I use Flents lens tissues after the isopropanol had dried off I use them to wipe the Kapton with laboratory grade acetone.

For PLA I use only 3M Blue Builders tape - cheap stuff from the £ shop is variable to poor. Even here though you can be caught by surprise. After many months of truly excelent PLA prints I did one which had a long angular spike which lifted from the blue tape at the tip. I glued it down with a drop of "Evo-Stick Extru-Fix", a truly marvelous adhesive for PLA and it worked out O.K., but for the next day or two nothing was sticking to the tape. New tape made no difference, playing with the starting Z height made no difference. The clue was that one print that I let run for a while all of the PLA was a huge blob on the hot end tip. My guess is that the Extru-Fix got onto the hot end and the PLA would rather stick to that than to the bed - this would require that the Extru-Fix also increased the melting point of the PLA so that it was setting on the outside of the tip.

After careful cleaning of the tip and recalibrating the height to undo my earlier tinkering all is now well again.

Mike

There are apparently many different methods to get good results. Here's the one I use:

1. Spray mirror with a thin mist of window cleaner (I've used "Wizz" and no-name stuff, both worked well).
2. Wipe dry until literally squeaking with lint free cloth (I use a no-name "miracle" cloth, not quite lint free but good enough).
3. Leave no streaks whatsoever. Buff them out with the cloth.

Having the bed on moderate heat helps getting it dry quickly, but the fluid in the cloth will also heat up, so don't burn yourself.

You may get build up of skin oils and/or oily residue from the plastic in the cloth after a while.
If the cloth starts to leave streaks, wash it with some soap or dish washing fluid.

I prefer this over acetone because I found the acetone I used eventually would leave a film residue.
Also, the acetone smells way worse.

For ABS and very tricky prints I also use a thin film of PVA-glue diluted with water.
I apply this with a spatula (or similar) to get a smooth even surface.
The mix should be thin enough to fill any gaps or streaks by itself, almost like water (keep the printer level!).

I then turn on the heater at PLA temp and leave it for a few minutes for the water to steam off.
When the surface has turned translucent (from the initial white) and dry, it's ready to print.
The film should be thin enough to be nearly invisible on the first print.

I find this PVA film lasts a good few times (5-10 or more depending on footprint), but I tend to replace it for big/critical prints.
It washes off fairly easy if you soak it with window cleaner and apply some heat (plain water + soap probably does the trick as well).
You may have to scrape it gently to get it all off.

I like these approaches because there's no need for special tape or very harsh chemicals.
The supplies are easy to get, you won't need special brands, they're fairly cheap and will last for ages.
They also work well on my not-so-easily detachable bed. No worry about a misfired spray, it will just clean your rods
The window cleaner is on the harsh side maybe, but you use quite small amounts and the vapours are not too bad. ABS vapours feel far worse.

/Andreas

Hey Otter, welcome to da forum!

I can't let the nozzles drag on the glass with my machines. It seals the orifice perfectly and the extruder strips the filament. That is the only cause of stripping I have. I used to have a home made nozzle that was wonky, that one prevented stripping because it leaked when pressed against glass.

For PLA I sometimes use green or blue tape and that doesn't cause stripping because the surface is rough.

---

Yvan

Singularity Machine

After lots of experiments I have found that the thing that improved the adheasion the most was first layer height.

Lowering it from .35 to .2 makes it work so much better, pretty much sticks every time.

only issue of course is there is a slight brim