Bed adhesion issues

General Hardware
1

Hi Everyone,

Ever since I got the modular bed on my Mini I have been having bed adhesion issues. I’ve been dealing with them for a while, with some materials it’s worse, but I’ve made it work.

Lately, I have been trying to sort them out and I feel like I have been just driving into a brick wall every time.

I have adjusted the Z offset, but I still have lines. If I move it down any more it will be too much. Currently it’s at -1.54.

I took the bed apart and noticed the metal plate was bowed a bit, so to fixed that to make sure there is constant contact with the glass. I’m going to be hitting the PEI surface next with 1500 grit sand paper and see if that helps at all.

Here are some sample prints with IC3D ABS. Roctopus tune with fine settings (0.15). This is the best I could get, there’s a little lift at the red arrows, but the print stuck and was good. Still a lot of lines on the first layer.

IMG_0208
IMG_02082100×1575 842 KB

IMG_0209
IMG_02094032×3024 2.94 MB

Now same settings, but less detail (0.25) and here is the part I am trying to print. First layer looks horrible. Part 1 is a complete print, and part 2 is shortly after with a higher bed temp. The red arrows point to the corners that lift at print. Lots of scaring on the surface.

IMG_0206
IMG_02062100×1575 1.22 MB

IMG_0207
IMG_02074032×3024 3.41 MB

This is super frustrating, I never really had these problems with the original 3 part bed, but I refuse to give up thinking that this bed can’t work. I know ABS is hard to deal with, but I’ve had worse luck with PLA.

Any advice would be greatly appreciated! Hoping to get this little bugger dialed in.

2

Well I finally figured this out. I followed the instructions here: https://www.lulzbot.com/learn/tutorials/pei-print-surface-maintenance

Hit the PEI surface with 1500 grit sand paper and ABS is sticking like magic. I’ve never had this good of adhesion to the bed. I also ran the stock settings for the filament and it ran fantastic. There was like 1mm of lift on one corner, but I think running the bit a warmer and tuning down the part cooling will fix that.

1 Like
3

I find that I have to do the bed sanding every now and again on my Mini. When it starts to look slightly shiny I sand it lightly with 1600 wet&dry paper and use a little water with the paper wrapped around a small block of wood. Takes about 30 seconds and makes a huge difference.

4

I agree, it’s no work at all. I have been running a batch of parts in the same spot. After a lot of parts in the same spot, I’ll do a quick pass over the parts that have constant use.

It also highlights imperfections in the PEI. Here’s a pic after I added a light and camera mount today. You can see tiny “waves” on the surface.

image
image1280×958 286 KB