How to change infill settings for specific sections of a model?

[Anonymous]

Hello, all! I'm hoping one of you fine folk can help me on my 3D printing journey! I have a relatively simple piece that I'm trying to get ready to print on a Prusa MK2. I'm using Fusion 360 and Slic3r. There are two sections on the piece, on either end of it, that I would like to have 100% infill for, while leaving the rest standard. I found these three pages as I was trying to figure it out -

https://forums.autodesk.com/t5/fusion-360-computer-aided/quot-exclude-quot-certain-areas-of-part/td-...

http://www.instructables.com/id/Change-Infill-Density-in-a-Specific-Section-on-a-3/

http://slic3r.org/blog/modifier-meshes

Both seem to address my exact issue, but for the *life* of me I can't figure out how they're doing it. When I try to sketch a box around the first section and intersect it, it gets rid of the rest of the original body outside the merged section. I tried saving/reloading in case it was a bug I'd read about (where the model vanishes but is still technically there), but it's not.

I tried saving the sketched/extruded box as a separate Object, saving it as a stand alone .stl, and importing it to Slic3r, and loading it through settings as a modifier, but nothing shows up in slic3r. It shows I've loaded it in the file list, but I don't/can't see it on the print bed display.

Those two sites are helpful but there's some key component I'm missing here and I've spent hours trying to crack it. I'm sure it'll end up being something relatively straight forward but I'm hoping for a nudge in the right direction.

Thanks much in advance!!

[laughingcreek]

I'm not sure if your asking a fusion question, or a slic3r question.  In any case, Slic3r is going to need 2 separate files imported into it to do what you are asking.  Are you having trouble producing those files from fusion?  We can help you with that.  Post a file and maybe some screen shots of what your trying to do.

[Anonymous]

Sorry, I'm so new to this stuff that I'm not great with the terminology and the like yet. I've attached the file that I'm working on so you can get an idea of what I'm working with.

So, the two ends, with the holes, I'd like to have 100% infill, with the connecting bit in-between left normal. My understanding from what I read in those links was that all I had to do was create a rectangle around the end, extrude it up, then choose intersect in the extrude options (then I can save it as an .stl and import it into slic3r). But every time I do it seems to delete the rest of the model, leaving just the stuff in the rectangle I made. Or, I can choose new body instead of intersect, then save that piece as an .stl, but when I try to import it to slic3r it doesn't seem to show up at all. It "loads" it, but it doesn't appear on the bed display.

[laughingcreek]

Ok, a couple of comments.

-I don't think the first link you posted in the original question applies to what your trying to do.

-The next 2 links show 2 different methods of getting slic3r to have different infill settings.  So that may be causing some confusion.

I'm not real familiar with slic3r, so I don't no which approach you will find easier to use.

Did you produce the part originally in fusion?  If so can you upload that file (go to "file-export" and export as a fd3 file, make sure "save to harddrive is checked", and upload that to the forum.)  I can screen cast the 2 different methods of setting up the files for slic3r so you can see what's going on. 

[Anonymous]

I uploaded the file as per your directions. Technically this was originally drawn up in VCarve, and I was tasked with turning it into a 3D model in Fusion. All that went smoothly, but when he asked me to set up the infills on the ends separately I hit a roadblock, heh.

Thanks so much for your help! I'm fascinated by this whole world now that I've dipped a toe in, but every now and then I find myself all jumbled up in a mass of (sometimes conflicting) information and I can't work my way out, so I really appreciate it!

[Anonymous]

Woops! I exported the one i was working on that has a block in it still. Here's the normal one, sorry about that!

[laughingcreek]

So taking another look at the methods silc3r uses to modify infill, I really think the one used in the 3rd link you posted is the way to go.  Here's your file back.  I added 2 bodies that can be used as modifiers.  Don't know where you want them, just push/pull the sides to get it the way you want (changes to the body called "modifier 1" will change both of them symmetrically.) 

Export the 3 bodies as stl files separately. (right click on the individual body in the browser, select "save as stl")

In slic3r

-load the body called "part"

-then go to "settings" and "load modifier".  That's where you will load up the other 2 bodies called "modifier1" and "modifier 2." 

Does this help?

[Anonymous]

This is perfect! Thanks a lot! That's exactly what I was trying to do, but I was wondering if you could explain two things to me - the first is, what were your steps in creating the boxes in Fusion itself? I can get the ones you made loaded in to Slic3r now, but I'd like to be able to make em on my own in the future and I'm still not sure what I was doing wrong in trying to create them. I could never get them saved as separate modifiers that didn't delete most of the original model.

The second is, once I load it as a modifier in Slic3r, I can't figure out how to move it separately from the main part. So it loads it in on the edge of the board and if I try to move it, it all moves. Side note - am I being foolish using Slic3r for this? What would you recommend as an alternative?

[dieselguy65]

Simplify3d has built in to vary the amount of infill in different areas.

otherwise you have do lie has been suggested and make seperate models

[etfrench]

Here's a screencast showing how to do the modifiers in Fusion 360 and Slic3r.

A couple of observations:

1. The left side is higher than the right.
2. The bottom of the left and right sides are not parallel.
3. It would probably be better to print the entire piece with 100% infill as the arc is pretty thin.  It won't be very strong.
4. Add modifiers before moving the main object in Slic3r.
5. If the modifiers have a different origin than the main object, you'll need to use a program like MeshMixer or NetFabb to align the modifiers and main object.
6. You need to switch to millimeters whenever you're creating STLs for Slic3r.  I didn't do this in the screencast and you can see the effect at the end

[laughingcreek]

As you can see, there are many ways of getting things done.  Attached is a screen cast of the approach I used to make the modifier shapes.  I did miss changing the units to MM, that may have been throwing things off for you.  In my screen cast I stopped recoding for the part where I exported the separate bodies, but you've got that part figured out, yes?

observations-

-sounded like your were asking if it was "foolish" to try and use slic3r for this? Not at all.  It's a good place to start, and seems to work for most things.  It does have some limitations, but everything has trade offs.   The way it uses modifier bodies is actually a rather elegant approach to that particular problem.  If you keep 3d printing you'll probably want to upgrade your software to something like simplify 3d (which does everything else expect for use modifier shapes  a little better)

-I think one reason you were having trouble with the approach outlined in your second link is because it was converting some of the bodies into components during the "combine" command.  You mentioned you were new to fusion, so you probably haven't really looked at what's going on with those.  That's fine as long as your only producing single bodies in your designs,  but once you've put a little more time in to learning fusion, You should review rule #1

-don't be discouraged that your design was imperfect.  So what?  Keep coming back to this forum, you'll learn a lot. 

[laughingcreek]

oops, didn't attach the screen cast.  for your viewing pleasure...

[dieselguy65]

slicers will accept models in mm or inches. there is a scaling function in them to convert automatically