Poor Nylon Adhesion

[swansboy74 0]

So I have been printing with nylon for a couple of months now I think. Never had an issue with it, I made sure to dry it out before I started using it and have been storing it in an airtight container with desiccant.

I use a glue stick to adhere the print to the bed, although that no longer seems to be working.

Things I have tried so far:

- increasing the temp of the print bed (increasing the temp of the initial layers)

- Increasing the temp of the initial print layers

- Tried printing with a brim and a raft (even the raft is no longer sticking!)

- Increasing the width and decreasing the height of the initial printing layers

As far as I can till it is because the prints are cooling too quickly and warping on the plate. When I try smaller prints they seem to work ok but I have no idea what is going on here.

Please tell me some of you have experienced this before and have found some resolutions!

[gr5 2,069]

Smaller prints are definitely easier as the warping/pulling forces are smaller.

Nylon is definitely harder. I printed some 30mm parts last weekend and one of them came loose. Things that help me:

1) Lots of brim. I know you said you do brim but I do 15 passes.

2) 80C bed temp. Not sure if this matters. Being above the glass temp will make the nylon more flexible so it has more give and puts less stress on the corners that lift (make those corners round also if possible). But the nylon I use has a glass temp of over 100C so 80C won't help with that. But it does help heat the air more so the nylon doesn't cool as much so it doesn't shrink as much. 115C would probably be better.

3) Cover the printer. I put a box on top - just a normal box that used to hold printer paper. No modifications needed. No tape needed. And a plastic bag on the front of the printer held on with blue tape. Air temp gets up to 35C.

3) I re-wet the bed before EVERY Print. Try to remove 90% of that glue stick with a wet paper serviette. Rewet the glue before very print with a paint brush and rinse the paint brush after.

4) Squish. This is the most important of all. I level manually only (no auto level) and I level such that the nozzle touches the glass. No paper. This makes it so the nylon is squished better into the glass.

Having said all that I don't think I've ever printed Nylon parts wider than 40mm.

The raft really should work. But the original author of cura I think never printed ABS and didn't understand the importance of a good raft. It should be at least 2mm thick and it should have lots of gaps. It needs to allow stretching to alleviate the strain on the parts stuck to the glass. It should touch the glass in parallel lines and that should go up 1/2 way and then it should have parallel lines in the perpendicular direction. I think older slicers (> 4 years old) do a better job with raft.

google around for other materials. I don't remember what's supposed to work with Nylon (build tak? PEI?) but some of these newer materials (not glass) I'm told work quite well. Blue tape works okay with nylon also but you need very wide strips so the tape sticks well to the glass.

[gr5 2,069]

One more thing that might help is use a type of nylon that is more flexible. Look at the tensile modulus (or just the modulus). The lower the value, the more flexible the material. All the filament sellers out there publish this. Taulman has several different (quite different) Nylons. I think Bridge is probably the easiest to print of the Taulman filaments.