What S3D setting causes this?

[BigBadBry]

Im using ColorFabb XT, and the settings are listed below. Look closely at the first few layers (this is not infill yet) and how it doesnt actually bond to the perimeters of those holes. Its actually a couple of mm away from it! If I left it go, the next layer will try to fill in ythe gaps but sinks in and starts to get squirly. My suspicion is that I need to disable "coast" but is the extruder actually stopping there or is it just changing direction with continuous flow? More odd, is that my coast is set to .2mm, which is almost negligable. Anyway, Im very open to advice



Here is a screenshot of what I had hoped to see
https://www.dropbox.com/s/cdpmodon72mp7 ... 6.png?dl=0
Here is a shot of the actual print:
https://www.dropbox.com/s/x1m6q1ps0w8dj ... 6.jpg?dl=0


Nozzle: 245
Bed: 110
retraction: 1mm
coast: 0.2mm
wipe: 5mm

[jimc]

ok looking at the 2 extrusion beads that are down for your skirt it looks like your first layer is way too far from the bed and its not sticking. the extrusion look very thin and round. if the first layer isnt stuck 100% then the rest are going to get all screwed up. are you printing on bare glass? you should put something down if you are. some hairspray then tighten up that bed gap a bit. 110 is way too hot for the bed with pet plastic. 80c is all you need.

[ednisley]

[quote="BigBadBry"it doesnt actually bond to the perimeters of those holes[/quote]

After you fix up the Z=0 setting, take a look at the speed: it's probably running too fast around those little holes.

Slic3r can slow down on "small perimeters" specifically to (help!) prevent the thread from pulling away from the infill; perhaps S3D has a similar parameter.

I use 25 mm/s for PETG, but that's probably far too slow. On the other paw, they're small holes and don't take all that long, anyway.

[Dale Reed]

S3D can also slow down on perimeters --- I don't remember the parameter name, because I'm at work now and the printing PC is at home. (Not sure if there is a separate override for "short" or "small" perimeters. I know there's a reduced speed for small layers, based on cooling time required.) Also, I believe the setting gets re-applied to successive perimeters. So if you have, say, 4 perimeters and print inside-out (you can also select to print perimeters outside-in), then the inner-most perimeter will print a bit slower than full extrusion speed, the next perimeter out will print even slower, the next slower yet, and the outermost (visible) perimeter the slowest of all. At least I think this is what it does. I'm sure I've seen it behave this way on prints with 3 perimeters. (I have a rather musical memory, and I can "hear" the descending tone sequence of the steppers as I think about it...)

Dale

[jsc]

There is not a separate parameter for small perimeters. There is one for all external perimeters. But, first things first, I think the primary issue is lack of adhesion on the first layer as diagnosed by jimc, it is cutting the corners. You can slow down the first layer speed to help. Print a thin wall calibration to help get your first layer height setting.

[BigBadBry]

Hey guys, thanks for all the feedback,

I lowered the bed temperature to 80, and slowed the print speed from 4800 to 4000. I also beefed up the 'first layer height' and 'first layer width' to 125% (previously 100) in hope sthat would fatten the base a bit. Things appearsed to be working out much better, until I started getting bumps forming in the turns (not necessarily gathering on the head) After trying to snip them off with clippers I eventually gave up and let fate have its way., the head hit one hard enough to shift the nozzle and throw the registration.


Clealy PETG hates supports but I cant eliminate them from this particular design.


By the way, I calibrated several times, its actually a perfect 1.0 with XT!

https://www.dropbox.com/s/raqrc0nnfp8hy ... 3.jpg?dl=0
https://www.dropbox.com/s/bpfnu5m2483gx ... 4.jpg?dl=0 <--great example shot of the bad supports. this problem is probably amplified by the head shift, no doubt, but even early in the print similar bumps were present before the big hit.


Im trying really hard to love PETG

[jsc]

Even that seems fast. PETG likes slower speeds. I would drop to 3600 and work up or down from there.

Put infill and support extrusion width to 200%

[jimc]

post a factory file or fff. you need to zip it then upload it. what hot end do you have? this is black xt?

[BigBadBry]

Roger that!

Here is the link to the factory file

https://www.dropbox.com/s/9vr9nbhziwhhz ... s.zip?dl=0

[jimc]

here, i made some changes in the xt profile. download your file and run it just like i have it set and lets see what happens. some changes i made have nothing to do with your issue. i just made them how i have mine set to help increase quality or issues. assuming your bed gap is good to go this should print relatively decent. may need some fine tuning but i think it should be in the neighborhood. the one thing i noticed is that you had your extrusion width set the same as your nozzle width. this will work on some things like solid surfaces but it can make infill screwy especially with pet. with a .35 nozzle you should keep it .4 or higher.


https://dl.dropboxusercontent.com/u/319 ... ed.factory