Nuts and Bolts

[Marm]

Hitting a design issue here. Trying to make project boxes of various sorts, and I'm having issues adding hardware to the designs, post print. I can't stop the print, so dropping in nuts into a print isn't an option. Just screwing a bolt/screw into a hole usually delaminates the structure around it. (Note, I haven't tried acetone hardening on this yet, I will though). Through and through bolts aren't always feasible, like mounting a LCD or switch inside a box, I don't want a nut/bolt on the users side.

How do you guys design your boxes / enclosures? Give me some ideas to spur my mind!

Thanks!

[3dkarma]

A hole in the side, into which you insert a nut, usually works. Can be a little difficult to print if your bridging isn't up to it.

[Davo]

Depending on how much force the bolt needs to bear, you can just undersize the hole a little bit, then do cleanup with a drill bit and tap it. Make sure you have 2mm of solid perimeter to allow for the threads.

[beerdart]

I have had good luck with Heli-Coils.

[Marm]

Depending on how much force the bolt needs to bear, you can just undersize the hole a little bit, then do cleanup with a drill bit and tap it. Make sure you have 2mm of solid perimeter to allow for the threads.

This may be my best bet, I'll have to get a small metric tap set, but that's a good thing. With the normal hole shrinkage I've experienced with ABS, I should be able to size my holes to exactly the final size, and let the shrinkage make it just small enough for the tap to put in plenty enough thread.

[Mjolinor]

This may be my best bet, I'll have to get a small metric tap set, but that's a good thing. With the normal hole shrinkage I've experienced with ABS, I should be able to size my holes to exactly the final size, and let the shrinkage make it just small enough for the tap to put in plenty enough thread.

That's what I do. An M3 hole in Cura comes out at tapping size without any work.

[whythelolface]

nuts slotted into nut-holes post-print (not sure what the term is) always works great for me. to avoid the bridging issue, you can just cut that bridge polygon in half and pull the middle edge up, creating this shape ^, even a small angle helps. Since the force of the nut is going in the other direction, the roof in the slot makes no difference to the strength of the join.
Will post a pic later

Threaded holes don't last long in ABS. In nylon they're great though!

[Marm]

Anything I would be threading wouldn't be for regular on/off use, and any spot I need to place a bolt like this, I wouldn't have access to the end to place an inlaid nut. I can't stop my printer mid print.

Anyways, got some cheap ass metric taps from ebay, printed out a test block of holes (http://www.thingiverse.com/thing:654538) and did a pull test. They all seemed to hold well. Suitable for my needs of mounting PCB's and project box panels.

[LambdaFF]

Can't you insert a pause in the Gcode at the appropriate moment ? Like : retract, go to topmost Z, do useless movements for a while maintaining temp, then going back down and extrude.
Just an idea...

[beerdart]

http://wiki.ultimaker.com/CuraPlugin:_Pauseatz