We have lift off :( Print failure due to loss of adhesion to the sheet.

[WobblyHand]

@rsterne  Bob, I'd try something like 600 grit sandpaper on the FR-4 to take off the gloss. 

Another thing I found was I had insufficient squish on the first layer.  Adjusting the z height (lower) gave better adhesion as well.  As for the blobs, I wonder if that is quality control on the filament.  I had long runs on these bad reels of filament that were ok, but then had sections that made blobs.  Another thing I found was changing from a fixed layer thickness to a variable one seemed to aggravate the issue.  Variable layers were where most of my blobs were.  My successful, albeit really long print, was when I turned off variable layers and had lots more first layer filament squish.

On your failed part, what does the bottom layer look like?  My initial parts had 20% contact area!  The last part I made has  85- 90% contact.  I found my print bed is rather uneven, (even after adjustment) so I printed my parts on the part of the bed that had the best squish.  Advice from a rank amateur, but been learning the hard way lately.

[rsterne]

It does look like my first layer is not squashed enough (maybe 50-60% contact).... so I added flow to it (120% on the initial layer), but that didn't change the appearance much, but the flat (X) coupon prints (only 3mm thick) are now curling up at the corners!.... That curling is worse at lower nozzle temps.... The blobs are worse the lower the temperature, for sure....

This 3DXTech Carbon Nylon is SURE fussy stuff, and it's not cheap!.... I'll have gone through most of a 500 g. roll, just in testing.... 

Bob

[WobblyHand]

@rsterne  Bob,
Instead of flow, for first layer squish, can you try adjusting the Z height?  Make the head slightly lower, 50 or 100 microns if you have the room to do so without over-squish.  Just want the head a little bit closer, so the first layer is squished more.  This setting may not apply to your whole bed, so print a single layer pattern in the area you want to optimize.

[rsterne]

Bruce, I did some reading on the Garolite, and some suppliers even give you a sheet of 220 sandpaper.... I sanded mine with a block with 220, on the diagonal in a cross-hatch pattern (to get some cross-scratches in both axes), washed it, wiped with alcohol, and then used Elmer's glue stick.... The parts stuck perfectly at 65C.... Mind you, the lower printing temperature didn't produce blobs that were problematic, but I think I at least solved the adhesion issue.... I will check the print thickness on a brim and adjust accordingly....

Bob

[dan_house]

12 hours? yea thats not bad for a decent quality print

#1 reason 3d isnt ready for prime time: Its slow.......

[WobblyHand]

12 hours? yea thats not bad for a decent quality print

#1 reason 3d isnt ready for prime time: Its slow.......

Agreed with slow   Although Bambu Labs has shaken up the market with significantly faster machines.