Break-away parts in prints

[lucidpsykosis]

I'm adapting a model from Thingiverse, to have square holes in the sides for a USB cable to come out. I'm not a great modeler, so I'm not sure how to input structural pieces for overhangs. So, my other choice is to build in a break-away piece that can be popped out with minimal effort. Problem is, I tried to have a .25 mil space all around the section, thinking it wouldn't put much material in there, but it did, and I broke my print trying to get it out. I know this sounds long winded and such, but if there's a better way, please let me know. I tried a dremel, but it didn't look as clean.
Attachment 1986

[Roxy]

Posting the original .STL and your modified version would be helpful.

[3dkarma]

I've tried the same thing for support structures and found 0.25mm to be too small a gap. Try upping to 0.5 vertical gap and a 1.0mm horizontal gap. You can get away with a larger horizontal gap as your printer should be able to bridge this easily. Also, if your support sits on another part of your print, you'll need to make it (the support) hollow with walls of a specific width, or it won't come away from the bottom surface at all easily.

[lucidpsykosis]

I've tried the same thing for support structures and found 0.25mm to be too small a gap. Try upping to 0.5 vertical gap and a 1.0mm horizontal gap. You can get away with a larger horizontal gap as your printer should be able to bridge this easily. Also, if your support sits on another part of your print, you'll need to make it (the support) hollow with walls of a specific width, or it won't come away from the bottom surface at all easily.

Thank you for the info...so this is probably where Slic3r or something comes into play I assume?

[3dkarma]

Slic3r can generate supports, but custom supports need to be created in your modelling application.

[lucidpsykosis]

Posting the original .STL and your modified version would be helpful.

I don't see an option to post the file. Do I need to provide the link from my dropbox?

[Compro01]

I don't see an option to post the file. Do I need to provide the link from my dropbox?

When you're doing a post, go into "advanced", then scroll down and find the "manage attachments" button, then use that form to upload the file and attach it to your post.

[lucidpsykosis]

K, here are the two models. The first one I tried had a thin border around the original piece of wall, but it wouldn't punch out, so I went with my version of a support (which obviously doesn't work either). Any help would be greatly appreciated.

[3dkarma]

Here's a couple of options that will (hopefully) work for you. The first has supports generated by meshmixer, the second custom supports I typically use that tend to break away easily.

prx_meshmixer_fixed.stl
prx_custom_fixed.stl

[lucidpsykosis]

Thank you! I'll give them a try.