Using ABS

[imsmooth]

Is the lack of an enclosure a significant issue when working with ABS?

[JohnnyRobot]

When I first started working with ABS, I struggled a lot.

Now that I've figured it out I'm printing great

I spray on a thick layer of Aqua Net hairspray, heat the bed to 96*C and the extruder to 235

[Capt. John]

ABS was grief for the long thin parts I was making.

Warping and builds detaching for the bed caused me to give up on ABS.

Default in S3D for ABS with the new hot end was 110 bed temp, stepped this up to 120 and run the extruder at 245.
Now ABS prints as good as PLA and from pull tests, at breaking points, ABS is a lot stronger.

Noticed S3d turned off the heat to the bed with 15 minutes remaining.

Is this normal?

[rrohret]

I found that I had to leave the bed heated to 100C during the entire print. My first prints in ABS would pop off shortly after the bed temperature was dropped. The default had it set to something like 5 layers or so and then drop significantly. Instant failure. I now leave the bed at 100 degrees C for the entire print. This apparently keeps the glass and part at their same relative sizes without a sudden difference in size due to their different coefficients of thermal expansions. Also set the clearance at start to .003 inch with a feeler gage.

[jimc]

yup me too. i run 96deg through the whole print

[imsmooth]

How does one set the Simplify default to leave the hot bed on all the time?

[jsc]

Under the Temperature tab, select Heated Bed, then modify the set points to be layer 0/100C, or whatever.

You may want to have a look at http://jinschoi.github.io/simplify3d-docs/ for a run through of what (almost) everything in Simplify3D does. It was written for the previous version of S3D, but almost everything is still accurate other than some screen shots.

[imsmooth]

I just read the document. It was very helpful.

I want to print a project box for electronics. It is hollow in the center. The walls are about 1.5mm (I forgot the exact measurements right now). I was reading in the document that one can control how many layers are solid before the printer starts a partial-fill pattern using the outline/perimeter shell selection. Since this is a hollow box, and not a solid, how do I make sure there is 100% fill? Do I just specify enough layers? Do I turn the partial-fill mode off?

thanks.

[jsc]

There are several ways to make a hollow box.

If you want totally solid box walls and floor, you can actually model it as a solid object, then specify the number of perimeters to give you the wall thickness you want, a suitable number of solid bottom layers, and an infill of 0%. This trick is useful for a number of other hollow thin-wall pieces as well, to get the walls to be perimeters-only.

Generally, enclosures need other bits and bobs to be useful, like standoffs, openings, closure mechanisms, etc. In that case, you will want to design it as a hollow box. It is helpful to have the wall thickness be an integer number of perimeters so you can print them as all perimeters, or else you will get rapid machine-gun infill for the gap, which is slow and noisy. If you want a solid enclosure, you can specify 100% infill, but generally that is not necessary. 50% is, I find, sturdy enough for a large range of heavy-use items, and 15-20% is fine for enclosures. Most of the volume will be in the walls, which will be near to 100% from perimeters, anyway.

[imsmooth]

I had made my design some time before getting the printer. The box does have all of the other "things" you mentioned, so it is a hollow box with standoffs and openings. The floor and walls are 1.75mm thick. Is a shell 0.25mm acceptable? This would be 7 shell perimeters. I should have 2-3 solid plus infill? Does this mean 2 solid shells, 3 infill shells and 2 solid shells?