nGen sticking too well to Lulzbot Mini PEI bed?

Hey folks,

I’ve been printing with nGen (light gray if that matters) and it is mostly good. However, there are two problems I’m encountering:

  1. It’s pretty brittle.
  2. It stick really well to the bed. So good I’m having lots of trouble removing prints.

Any thoughts on (a) if other people are seeing the same issues (b) any remedies to make it stick a little less well to the bed?

Regards,


Waleed.

A couple things that should help… with nGen, I run my bed at 60-65° C and set my Z Offset to +0.15mm. Make sure you bed doesn’t cool below 50° C when done printing until you’ve removed the print. Luzbot recommends keeping the bed at 50° C for easiest print removal. If your bed does cool below that, just warm it back up to 50-60° C and the print should release easier.

nGen is closer to PLA in the filament spectrum so it is more brittle than many other filaments except PLA.

I have noticed the same problem with stuck prints!

Also, with nGen, Cura starts the bed out at 110C!! Then after the hot end warms to 230C after leveling, it then drops the bed to 85C.

How do you permanently change the header data in Cura? If I change it to 65C, then it reverts back with the next print. I looked but couldn’t find a gcode header file.

Thanks,
Kent

I found out where the filament .ini files are.
They are in:
Program Files (x86)/Cura_19.08/quickprint/lulzbot_profiles/Mini_single_extruder_v2/nGen_medium-quality_Mini_single_extruder-v2_0.5noz_cura.ini
Look for S110 and change to S85.
These files are also read only. You need to change that.

I’m going to try that first and then figure out how to lower everything down as CoParaTech said.

Thanks!
Kent

As a followup, once I modified the .ini files for nGen for the Mini, I am having basically no issues.

I left it as stock at 85C. Now, I can remove the prints with relative ease once cooled. They do still stick well, but not ‘almost’ permanently as before.

I really believe that the initial 110C that the .ini file was using was WAY TOO HOT for the initial layer. At least part of the first printed layer was way hotter than 85C and close to 110C.

I am leaving the bed at 85C now. If I have other issues, then I’ll try a cooler bed.

Note that this is with an almost new PEI sheet. I replaced it a week ago or so. Everything sticks better with this new sheet.

Best,
Kent