MakerGear Forum

Jin (jsc) came up with this cool method for cutting an object in half using Simplify 3D, and it comes up rather a lot, (and since it's easier to type it up once instead of over and over.....)

Some shapes don't print well as designed. You've just got too many things like gravity and warping working against you, making it hard to get a nice smooth finish on the print.

Any object that has a steeply curved surface on the underside of the object is just about impossible to print without support, and even then, the surface has a lot of pitting, sagging and curling with some filaments. For these it's better to cut the object and print it in parts, with the curved surfaces flipped to the top, and a flat base at the bottom of each part.

Perfect example - this little salt pig I designed a while back. (It looks like a very simple shape, and it is, but it's just about impossible to get a smooth surface on the area shown without cutting the design.)
Very easy to do that in S3D:

1. Duplicate the model. (Edit > Duplicate Models > 1)

2. Select the copy and rotate it 180° around the X or Y axis. (Double click on the copy to pull up the menu.)
3. Raise the copy above the bed by X amount. However much you need to clear the curve. 15.0 mm in this case. (Double click the copy to select it and pull up the menu.)
4. Last step - select the original and sink it under the table by -X amount. (Double click on the original to select and pull up the menu.)
When you slice it, anything below the bed surface will not be printed, effectively cutting the object in half at the same place. (Even better, the curved surfaces are on top where they belong.) After printing, the two parts can be glued together.
That's it!

First: pfft, your salt pig has a max overhang angle of, what, 60 degrees or so? Easy peasy.

Secondly: not exactly right. You can't just drop both models down by the same amount. Imagine dropping them both down by just a millimeter. You'd end up with two nearly complete prints. That only works if you drop them both by exactly half their vertical height. If you want a parting line anywhere other than the exact center, you have to drop one by x and the other by z-height - x.

Uggh! Yeah, you're totally right - I'll re-write it tomorrow. (Got to go smash a bird first.)

Or...use Slic3r 1.2.9's cut feature which will allow you to keep both pieces, and to flip the lower portion if desired. Then save model as STL and move to S3D for output.

Rich wrote:Or...use Slic3r 1.2.9's cut feature which will allow you to keep both pieces, and to flip the lower portion if desired. Then save model as STL and move to S3D for output.

Write up a tutorial for it. Some folks do use Slic3r here.

Jules wrote:

Rich wrote:Or...use Slic3r 1.2.9's cut feature which will allow you to keep both pieces, and to flip the lower portion if desired. Then save model as STL and move to S3D for output.

Write up a tutorial for it. Some folks do use Slic3r here.

Where's ednisley when I really need him?

Rich wrote:

Jules wrote:
Write up a tutorial for it. Some folks do use Slic3r here.

Where's ednisley when I really need him?

That poor man needs at least one other slic3r evangelist.

insta wrote:

Rich wrote:

Jules wrote:
Write up a tutorial for it. Some folks do use Slic3r here.

Where's ednisley when I really need him?

That poor man needs at least one other slic3r evangelist.

Hey, I swing both ways...uhh, I mean I use Slic3r and S3D!

Maybe this weekend I can do a short write-up. The technique is both simple and intuitive.
The trick is trying to keep Slic3r 1.2.9 from crashing.

Rich

Rich wrote:.....Maybe this weekend I can do a short write-up. The technique is both simple and intuitive.
The trick is trying to keep Slic3r 1.2.9 from crashing.

Rich

Do it dude! Simple and intuitive are the best kind!

Jules.. What version of S3D are you running?

I thought I had the latest version but mine doesn't show and actual build table like that in the preview.

Maybe because you have a duel setup?