CPE / PETG terrible first layer & surface quality

[P3D 46]

On ‎8‎/‎31‎/‎2018 at 10:35 AM, Smithy said:

Print finished and it looks great. No stringing, no crumbs, perfekt skin. So after using both CPE and XT, I like XT much more. Only annoying issue is, that CPE stick well with glue stick on the bed and XT not. But I will try it again with just glue, because the blue tape is also not the best solution. XT sticks too good on the tape and after each part I also have to renew the blue tape.

 

I am now printing another part with XT but with layer height 0.2 and default speed of 60mm/sec and I can see now more crumbs and stringing, so I think best is 0.15 and slower for XT.

 

Great that this is working out for you! Concerning the glue, UHU Stic doesn't seem to be very good, I had a lot of problems with it. Somewhere I saw a post that mentioned it had a very low PVA Content - anyway, according to my experience you'll be much better off with something like the Elmer's washable glue. 3DLac also works like a charm but is quite expensive.

[Smithy 1,144]

Some UM3s were delivered with some other glue stick, I was wondering, that I had UHU stick in my box. I heard very good things about 3DLac also and I will give it a try. But also Elmers glue or PVA slurry should be a good alternative, but haven't tested it yet. 

[P3D 46]

So, to sum it up so far for future reference:

 

1. If you print with UM CPE and get crumbs and ensuing holes in walls with the default profiles, try setting "Max Comb Distance With No Retract" to e.g. 0.1mm, or disable combing altogether. This solved the problem for at least two people with different printers and different CPE colors. 

2. CPE seems to print better at higher temps than the standard profile. Avoid going lower, as this will worsen inter-layer adhesion and makes for less clean overhangs. Propensity for stringing will increase with higher temperatures, however.

3. XT is a related, but different material to CPE. It is not as prone to crumbs and bad surface quality, but should be printed slower than the default CPE profile and with lower than max. layer height. It is more difficult to get to stick to the print bed than CPE.

 

Edited September 6, 2018 by P3D

[Smithy 1,144]

Thanks P3D for the summary, definitely helpful for future reference.

 

To make it complete, I got today Colorfabb HT and Colorfabb ngen, both Copolyester. I will report how they print. Will probable start with ngen, which should be easier, HT is more like CPE+ and more difficult to print what I have read so far.

[Smithy 1,144]

I want to give a short update regarding printing CPE material.

Today I started a CPE print after a long time not printing CPE and got great results!?

I used the default profile, turned off combing at all and adjusted all print speeds to 40mm/sec. 

 

So maybe there were some changes in Cura between my last try with 3.41 and the current beta 3.6 which are related to the print quality. But the result is more than ok now.

[CTotten 18]

On 8/27/2018 at 8:09 AM, P3D said:

I have the same problem (crumbs and holes) with black CPE, especially when printing multiple parts. Anyone printing successfully willing to share their CPE settings?

I have been printing almost exclusively with CPE for over a year now (been through about 10 spools).  I basically use the default Cura settings from Ultimaker, and I have had no issues with the print quality.