Interlocking parts - the best 'wiggle room'

[Matthew_175]

I’m 3d printing an electronics enclosure whereby the frame and base are 3d printed. The wall frame has grooves in it so that a 2mm sheet of plastic/cardboard/whatever can slide in. What’s the best width of the groove so that the slide in sheet is seated firmly yet isn’t difficult to get in? I assume going with 2mm will make it a very tight fit and it will be hard to slide in.

[MichMich]

It really depends on the printer, the print settings, the filament and the orientation. So it’s a matter of trial and error. I usually go for a tolerance of 0.1mm and increase or reduce this tolerance after testing.

[3DMuse]

Every printer is different, you know what I’d do? Here’s an idea. Construct small U-shaped clips around the 2mm interval: 2.01-2.05mm and slowly work towards your perfect fit. The only way to find out is through trial and error. Once you have this info it will help you in the future. You need to know your own printer very well.

[Polariz3d]

It depends mostly on the slicer/print settings and orientation. For horizontal cross section groove I’d start around 0.2 mm clearance each side for a first guess with 0 1 mm iterations. For vertical cross section groove my first guess would be no clearance and with that you are limited to the layer height for the iteration steps.

[Regulus3D]

Hi, I would go with say 2.25 to 2.5 depending on the accuracy of the printer your going to use

[CustomSolutions]

I have a combination of things including all of the above comments… generally for a snug fit i go for a .3 clearance. .5 for a little looser fit… that being said it does depend on both your printers accuracy and the shrinkage of the part… sometimes i will design a piece to represent the groove or channel etc that i can print quickly and calibrate my main part from there… for example lets say you had a part that was a 2hour print but you had a hole for a bearing to set in it… i would print a ring with a .3 clearance… it might take 10min to print, test it and reprint as needed until you had it exaxctly right, then modifiy original part accordingly.

[DavidBoyle]

I would ad 0.4mm to the sheet thickness then print and test fit. Adjust as necessary. This is based on the nozzle width of my FF Dreamer. The actual result will also depend on the material used and various other print settings.

Regards

Dave

[ProtoPrint]

Try 2.5mm maybe if they material is pretty rigid.

If they material has any squish to it (corrugated cardboard), just go with 2mm and it will squish in a little for a solid fit.

The hardest part of this will be designing the part such that a 2mm clearance on your CAD model actually equates to a 2mm gap in the printed part. I find that when working with tight tolerances, the printers are always off a little, generally .01 INCHES in the wrong direction.

So, if you are using a high end printer, I would model it with a 2.5mm+.02inch clearance.

It will no doubt be a matter of trial and error though.

If it’s an expensive print, instead print some test jigs with various clearances so you can see which one works best and how much shrinkage you expansion your are dealing with.

Please post your results here!