Mortise and tenon joint as a Library Feature
Posted: Sat Sep 09, 2023 6:48 pm
I am developing a Library Feature to split a part into two pieces with a mortise and tenon joint with a small gap between the two:
This is for 3D printing, I tried many different joints and this one is very convenient for some scenarios. I will have a model which I'll need to split into ~50 bodies using many instances of this Library Feature. Normally I'd use surfaces to build a body that represents the cavity, and the subtract it from the main body to split it into two. Unfortunately Library Feature doesn't support surfaces or Combine.
So I worked around like this:
1. Split the part using Cut-Extrude. Unfortunately this requires a sketch that envelops the part, but I didn't find a good alternative here.
2. Create offset sketch on the face of the lower piece, and extrude it upwards:
3. Add chamfer to the edge loop of the lower part (this is required for printability):
4. Reuse the same sketch to make a cut into the upper part:
5. Reuse that sketch again to make a thin-cut into the upper part again (to add clearance gap). Done.
Now while this works (all these features are accepted as part of Library Feature), there are two big issues:
1. The first cut requires an enveloping sketch - it doesn't automatically "capture" the outer silhouette of the part at the plane level;
2. Because the extrusion is created using offset sketch, it creates a Library Feature references to 4 edges:
Of course these edges cannot be selected when using Library Feature part, since they don't exist until the first cut is made. And even if one could select them, the bigger issue is that not all parts I will cut will have 4 edges - typically much more, and they might be lines, arcs, splines, etc.
Can anyone suggest a better approach to build this Library Feature without these limitations? Attaching the library part to this post if you want to take a look (saved with SW 2021).
This is for 3D printing, I tried many different joints and this one is very convenient for some scenarios. I will have a model which I'll need to split into ~50 bodies using many instances of this Library Feature. Normally I'd use surfaces to build a body that represents the cavity, and the subtract it from the main body to split it into two. Unfortunately Library Feature doesn't support surfaces or Combine.
So I worked around like this:
1. Split the part using Cut-Extrude. Unfortunately this requires a sketch that envelops the part, but I didn't find a good alternative here.
2. Create offset sketch on the face of the lower piece, and extrude it upwards:
3. Add chamfer to the edge loop of the lower part (this is required for printability):
4. Reuse the same sketch to make a cut into the upper part:
5. Reuse that sketch again to make a thin-cut into the upper part again (to add clearance gap). Done.
Now while this works (all these features are accepted as part of Library Feature), there are two big issues:
1. The first cut requires an enveloping sketch - it doesn't automatically "capture" the outer silhouette of the part at the plane level;
2. Because the extrusion is created using offset sketch, it creates a Library Feature references to 4 edges:
Of course these edges cannot be selected when using Library Feature part, since they don't exist until the first cut is made. And even if one could select them, the bigger issue is that not all parts I will cut will have 4 edges - typically much more, and they might be lines, arcs, splines, etc.
Can anyone suggest a better approach to build this Library Feature without these limitations? Attaching the library part to this post if you want to take a look (saved with SW 2021).
