The Trials and Tribulations of my first ABS prints

[BigBadBry]

Hey guys, Ive got to print 25 instances of a plastic enclosure in a material that can tollerate being locked in a car on a hot sunny day. I figure until eSun releases their Black PETG, IL have to drag myself along using ABS; lol. I figure itl take some trial and error and anything Im not sure about (troubleshooting wise) I can post to you guys for some insight.... I'm still a greenhorn

Anyway, I used the stock ABS-Medium profile is S3d (235/110) and increased the first layer width to 125%. BedPrep, Suave MegaHold spray (4 coats)


The first layer "seemed" to stick pretty well to the hairspray coated glass, but it had a boatload of little fuzzies. Is that a red flag for something (like a temperature) being off?
https://www.dropbox.com/s/bixbvedps8jpg ... 5.jpg?dl=0


Then later on its second layer, in an area where the nozzle moves very quickly to fill in an area, the plastic seemed to pull off of the first layer and clump on to the nozzle, leaving a pretty rowdy surface
https://www.dropbox.com/s/d3kdqux6832hw ... 9.jpg?dl=0



Im letting it cool off to clean now, any ideas what I should be modifying here? Head speed maybe?

[jsc]

Looks like over-extrusion to me. Double check your z endstop height setting. Running off an extrusion calibration would also help you. It's very easy! viewtopic.php?f=3&t=1964

[BigBadBry]

I bought shim gauges to help with calibration, but admittedly I'm not sure what exactly the ideal gap should be (between the nozzle and the glass). Also,

Does it matter if I run that calibration in ABS or PLA?

Should I assume that each "material process" might have its own unique settings to get it calibrated or that this is a machine thing (material irrelevant)

Thanks

[benavery]

Z endstop is the same no matter what filament you load. The exact filament diameter, and extrusion multipliers vary for every different spool of plastic - check the thread mentioned above for the best ways to calibrate those.

[ednisley]

Should I assume that each "material process" might have its own unique settings to get it calibrated

That depends on the setting... [grin]

Each material is different and the filament on each spool may have a different diameter, so you should expect the Extrusion Mulitplier to be different for each combination. The values may be close, but that's a happy coincidence and not to be expected.

The width / thickness / speed settings you choose for the first layer depend on what you're trying to achieve, so they will vary with each model. For my simple needs, I have the first layer set the same as all the others and that works perfectly: neither fatter nor thinner, just a much slower speed to ensure platform adhesion.

The Z-axis zero position relative to the platform will be the same, because that's part of the printer hardware setup. It may vary if you clobber the printer or readjust the platform alignment, but in general it should remain constant.

After you go through the calibration process for the filament you're using, you should expect that level of quality on every part. If things look wrong, as they do for the first layer in your photo, then you can re-slice the calibration objects with your current settings to help discover what's gone wrong.

[BigBadBry]

Hey guys,

So I ran the calibration piece and sure enough, my walls were way thicker than they were supposed to be (.475mm to be exact), the wall target in S3D was set to .40mm

I adjusted my extrusion modifier back to 0.85 and pretty much solved that problem (they are now measuring .401)

For height, it was only very slightly off, but I adjusted my layer height to .197 and now the entire part measures .200 on average.


here is the gotcha, The first test, despite being fatter than it should have been, was actually a very clean part (corners held together well, very consistent)

The second part, though measuring very close to proper targets, was now delaminating in the corners (layer-to-layer, NOT layer-to-bed)

Nozzle Temp: 245, bed temp 110

https://www.dropbox.com/s/an67x3jgur62l ... 7.jpg?dl=0


Im starting to Dislike ABS...lol

[jsc]

You don't adjust layer height to get the height you want, you need to adjust the z set screw. If your part were taller or shorter, it would again be off from what you want.

Your photo doesn't show delamination, what is happening is that one layer is cutting the corner because it didn't stay attached, and the succeeding layers follow along. Set your layer height to 0.2, adjust your z screw until you get a 20mm high object, and your first layer will be right on.

[BigBadBry]

In a perfect world, which feeler gauge should I be using for setting the Z-Stop? I've been using the .008" (.203mm) The only formal documentation I can find for it is "a business card" but that's a pretty loose target.

[jsc]

I've used .006 to good effect.

[BigBadBry]

Well I finally got the Multiplier calibrated and the machine actually made it through the job. I would say the final parts are about 90% successful, which is great!
https://www.dropbox.com/s/68pawc838w5zp ... 8.jpg?dl=0
https://www.dropbox.com/s/6lqi2c9id4l6m ... 6.jpg?dl=0


Once the build layer reached about a half-inch off of the bed, the warp became too much and a corner lost it's grip of the glass. I used several layers of hairspray and a 6-loop connected brim
(To Solve I am thinking about adding a 2nd brim layer, re-coating and trying again, or cleaning the spray off, and using glue sticks instead.... Thoughts?)

Also, one or two rounds of walls seems to lose their grip on their nearest neighbor and as a result, I've got a couple of loose bands.
(To solve I am thinking I'll change the draft angle of the surface to something more like 20 degrees (its 30 now)
https://www.dropbox.com/s/dfepb3dd6d9ts ... 0.jpg?dl=0