Bed Adhesion - tricks and tips?

[Redbrickman]

Hat, It was a pleasure so send you Mr Elmer after all the help you have given me in the past. You can get them on Amazon UK, that is where I got mine and they are not expensive either which surprises me, hovever, it might be too expensive when the shipping is added for the Emerald Isle .

Just now I saw it at a good price...

https://www.amazon.co.uk/Elmers-X-A...1514917946&sr=8-3&keywords=elmers+purple+glue

This one is for 6 sticks, no free postage, but it caught my eye as on the reviews there is one guy using it for printing ABS!

https://www.amazon.co.uk/Elmers-Dis...1514917946&sr=8-4&keywords=elmers+purple+glue

 

[FryingSaucer]

I'm in two minds at the moment on bed adhesion. On the one hand I was perfectly happy using hairspray on glass with PLA. However, I've now been using PETG on naked glass, even better. In general bed adhesion has been fine with PETG on glass and the prints came off easily when done.

However, I did have some problems getting the first PETG layer to adhere, though with coaxing the print was perfectly acceptable. After making many unsuccessful changes to print settings and temperatures to solve the first layer problem, I tried reducing the height of the nozzle to what I'd been using for PLA. Everything I'd read said you should allow a larger gap for PETG because it doesn't need to be squeezed on the bed. When I set the gap back to about 0.1mm there was no first layer adhesion problem. Possibly there was a bit more stringing though. However after that, one of the prints (OK a very small one) was very difficult to remove and I chipped the glass getting it off. I've never done that before. PETG is supposed to stick very hard, and maybe my early attempts came off so easily because I was printing at too high an offset.

So now I need to do more experimenting. Do I get significantly more stringing when I have the nozzle lower. Am I going to have problems getting the model off the glass if I improve first layer adhesion, and if so should I try Elmer and/or hairspray rather than just glass. I need to do more stringing tests and so on. So I've quite a bit to try.

However in general I've been fairly happy with the prints so far with PETG. I've just been using the same temperatures as @ninj, bed=80, hotend=130 and the same print settings in CURA as I'd been using for PLA. The Benchy I printed was not perfect, there was a small amount of stringing, but it was fine for an initial attempt. It looks better than the photo. The filament was Real Filament PETG Translucent Blue.

 

[FryingSaucer]

When I used to use sticks of glue at school it tended leave lumps. Is it easy to get a level layer on the bed when you use Elmers Glue Stick?

The great advantage I've found with hairspray is that you just spray it on thickly so there's a layer of liquid on the bed then to a large extent gravity distributes it evenly over the bed.

 

[Redbrickman]

I just lightly smear the Elmers acoss the build area, wait a few secs then do another light coat on top. As long as you don't lean hard then the glue is very spreadable without any lumps like some other glue stick products.

 

[The Hat]

Is it easy to get a level layer on the bed when you use Elmers Glue Stick?

When I used Pritt stick, I had to scrap the surface clear of any little lumps that came off the glue edges, with Elmer stick it glides on and leaves a lovely clean and shiny surface, you can apply more over the exiting glue surface without any problems either...

Elmer 10.... Pritt nil...
P.S. the funny thing is, everyone swears by the product they use...

 

[Fenrir Enterprises]

Has anyone tried vinyl decal masking/transfer tape instead of blue tape? You can get 6" wide or more! I have 6" and 12" rolls already. I just bought a Monoprice Mini Select and I need to test it out before Jan 31 since I got a used model (missed Black Friday) and need to know if it works before Christmas returns are over! I only have ABS on hand - I'm planning on casting with epoxy and ABS will dissolve in acetone, PLA won't! I was going to go with dissolvable filament but it looked like more trouble than it was worth.

 

[Nifty]

I'm planning on casting with epoxy and ABS will dissolve in acetone

Wow... that definitely is interesting and requires it's own thread once you get started!!

 

[FryingSaucer]

I've had an adhesion problem with this PETG print.

The model is an arm that clips on to a slat of a wooden shelf in the airing cupboard. You hang damp shirts on hangers along the arm while they're drying. The clip end looks like this:

I first printed just the clip end in PLA to check it would hold securely. One of the arms broke at the corner when I pulled the arm off the wooden slat. I could have made the corner wider to provide more strength, but decided to try PETG as it's more flexible than PLA. This worked well, so I started to print the whole model, with the results shown above.

When I experimented with PETG before, I found using a raft best. I was printing a long thin rod vertically on the build plane. The raft held this steady, a brim did not. So I used a raft for this latest print.

I wasn't sure why the corner of the print hadn't adhered to the raft. I'd not been using exactly the same CURA settings as the previous time - I was using a bed temperature of 50°C vs 80°C the previous print, but I'm not sure why a different bed temperature would stop the print adhering to the raft. The filament manufacturer says you don't need to heat the bed anyway.

I wondered if too fast travel speed (120mm/s) might be the problem. It's quite a long print (230mm) which only just fits on the build plate. I think the head was travelling to the corner from the far end of the model. So I've changed the travel speed to 50mm/s (and changed bed temperature to 80°C).

So far it's printing OK. So long as the raft holds on the bed, it should be successful. If it doesn't, I'll try using an Elmers glue stick with a brim, not a raft. I've never used a glue stick before. I've just printed PETG straight on to the glass so far.

Any other ideas why one corner was not adhering to the raft?

 

[Nifty]

I actually haven't done a lot of wide printing, but I have experienced lifting even with PLA and it's frustrating. So, I'm sorry I don't have an answer for you, but I'm also wondering if travel speed and/or cooling (too much? too little?) could be a factor?

 

[FryingSaucer]

I actually haven't done a lot of wide printing, but I have experienced lifting even with PLA and it's frustrating. So, I'm sorry I don't have an answer for you, but I'm also wondering if travel speed and/or cooling (too much? too little?) could be a factor?

The print was successful this time. My bet is that decreasing the travel speed fixed it.

The print comes off the raft very easily and the raft off the untreated glass. Perhaps too easily. The raft may be close to slipping on the build plate while printing. On the other hand I've heard reports that PETG sticks too well to a heated build plate with Elmer's glue, so I'm staying with plain glass unless I have a problem.