Cutting out mating part with margin for a locating lug

[jamesqb2001]

I want to create two parts which, after 3D printing, will join together.

I can use lugs or locating pins to achieve this, with part A having lugs sticking out on the side to which I want to join part B. Part B would have matching recesses for part A’s lugs.

To achieve this, I can design the parts together, then use the combine feature with part A set as the tool, to cut out the recesses in part B.

The problem with this is clearance, the fit would be too tight after printing.

Is there a way that I can use the lugs/locating pins as a tool to cut out the matching recesses, but with an added margin or offset to give clearance?

Thank you

[davebYYPCU · Accepted solution]

When you work out the clearance value, (parameter?) let's say 0.25mm or equivalent (diameter).

Draw the pin at size.  Extrude the pin.

Combine > cut with the pin - the sockets for part B.

Then using the same pin sketch, Thin Extrude the sketch as Cut - Wall thickness uses Radius values set to half clearance (0.125mm), set cut side on the outside of the pin.

Same idea for tab / sockets.

Can decide which part to add clearance to, but keep all the same for the project, 

Might help....

[Drewpan]

Hi,

I think you are going to have an issue if you want to 3D print this stuff. The problem is that you can look up what the

tolerance should be on a Fit Chart, but then you have to work out what kind of shrinkage, ie % and directions, to

actually fit the parts together. I think the best you will do is to get it close and then file the plastic to get the fit to

work properly.

Fusion will work fine with subtractive manufacturing like CNC and metal but unless you have a high precision 3D

Printer (read very expensive) and you are working with materials that do not change after being laid down, I just

don't think additive manufacturing will work.

A common 3D printer that uses PLA or such like only has a resolution of 0.2mm and most PLA can shrink up to 5%

and that is not necessarily in all three axis.

As I suggested - best bet is get it close; see what the printer spits out; adjust as necessary.

Cheers

Andrew

[g-andresen]

Hi,

In the slicer, you can do this automatically for both parts by selecting the cutting direction, shape and position of pins/drilled holes.

günther