Bed Adhesion - tricks and tips?

[FryingSaucer]

@Redbrickman Sorry you're having problems with adhesion. I had similar difficulties the first few prints, then forgot about it because it's always worked after this. I think 3D printers are designed to give any starting a hard time initially, just in case they think it's too easy.

I'm using PLA. I used 3mm glass which I got from a local glass shop, cut to shape. I know @TheHat cuts his own glass, but I found it easier to let someone else supply and cut it (for about £3). I clean the glass with isopropanyl alcohol, then liberally coat with hair spray, let it dry, then apply another coat.

My heat bed is at 50ºC. The hair spray I use is L'Oreal something or other, and unfortunately it's the most expensive one there is. I'm not at home at the moment, so can't check exactly, but I chose it because it contained neodecanoate copolymer. As far as I recall this component undergoes a phase change around the bed temperature and the PLA sticks really well, but when the hair spray cools the print comes off really easily. This is all from memory. I'm on a really slow connection and can't check.

I can't say I never have any problems, but usually I don't need to use a brim and can just forget about adhesion. The one coat often lasts a few weeks (but I'm not printing as frequently as some other people on this forum).

As others have said everyone has their favourite method. This is what works for me.

 

[Redbrickman]

@FryingSaucer Thanks for the reply, I'm going to give your method a go with the original glass sheet. I also saw this method yesterday on you tube so will definitely give it a go

 

[FryingSaucer]

and in the process I realised that the centre of my heated bed had a slight dip in the centre

How did you measure this?

I also use several pieces of foil in the middle of the bed (3) smallest in the centre, but this can cause another problem, the centre of the bed does not get as hot as the edges, so I add 5 degrees more to the bed temperature.

How do you take the temperature of the centre of the bed? I could stick my finger on the edges then the centre but I'd have to remove it long before I could detect any difference in temperature

Also, does inserting a few pieces of foil really push the glass up? And can you notice the difference in the prints?

Just curious, because you guys do seem to do a lot more fine tuning than I do

 

[The Hat]

How do you take the temperature of the centre of the bed? I could stick my finger on the edges then the centre but I'd have to remove it long before I could detect any difference in temperature
Also, does inserting a few pieces of foil really push the glass up? And can you notice the difference in the prints?

Yes, the foil does make a difference, I start with a very small piece in the middle, then another piece slightly larger and finally a large covering piece. 50 x 50 mm, 80 x 80 mm, and 180 x180 mm

If you place your whole hand flat on the heated bed and move your hand around you can feel where some areas are hotter than others, use a temp. of 50c other wise it will burn your hand...

As said before, we all have some weird crazy ideas...

 

[RogerR]

I started printing with ABS. It's a nightmare. But since I've started using PLA and PETG, life is good. For both PLA and PETG, I use ~60C for bed temp.

Here's how I do the bed. I have a glass piece on top of the heated plate. I use aqua-net hair spray. Every few prints, I spray some on the bed. Perhaps 5-10 seconds worth. I try to do this prior to turning on the bed heat so I don't create an explosion hazard. Then I turn the bed on and print. The hairspray drys quickly (well before the bed reaches temp).

I only add hairspray about every 3-4 prints. Before the other prints, I use some emery cloth (~120 grit or so) and lightly sand the glass. This gets rid of any old print residue and puts a bit of tooth in the surface. Takes about 15-30 seconds. I use a paper towel to wipe of the dust. And then print (the sanding can be done with the bed heating up).

I like having the skirt printed around the outside of the print area. As the skirt is laid down, I can verify that the amount of squish is correct and that the bed is level. I can even adjust the bed height a bit if it's not level. If I don't get it level before the actual object starts to print.....I'll cancel the print and restart (might need to scrape or sand a tiny bit to get the failed stuff off).

Important note. PLA and ABS should squish some on the first layer....but PETG works great w/o any squishing. I start it higher than the other two....you should see it laying on the bed rather than squished out on the bed.

Don't put your hand on the print surface. The oils on you hand will not help things stick!

My very first print with PETG was 230mm by 100mm in x and y. I had the first layer squished too much (improperly). And it still printed great! I've printed ABS for 3 years and I couldn't come close to that size.

 

[flowrider]

I use glass (borosilicate not that it matters much) and hairspray. Hairspray should be dry when the first layer goes down and I've printed large flat prints with no lifting. It comes off super easy too when the cools. I've only cleaned the glass only once in about 3 weeks as it keeps sticking!

 

[Redbrickman]

I tried the glass coating hairspray trick with Silvikrin which I had bought before reading Frying's post regarding neodecanoate copolymer. Silvikrin does not have it listed in the ingredients so it may explain the total failure to adhere, I was using 65C bed temp to see if that would activate the hairspray. I add a bit of glue stick and it was fine but I'll be prowling the hairspray aisle at the local supermarket this weekend

 

[flowrider]

I bought the cheapest extra strength hairspray I could find.

 

[stratman]

You guys use so much hairspray one would think we were back in the glam rock days of the 1970's!

PS No one knows this is @The Hat's favorite music.

 

[The Hat]

I bought the cheapest extra strength hairspray I could find.

Me too, but I don’t buy the hairspray unless my misses is with me, I reckon I’d get funny looks because I don’t have much hair left to stick down, and If I had to listen to that racket (Ballroom Blitz) all day I’d have no Feckin hair left at all..