Full blind finger joints in Carbide Create

This was previously discussed:

Doing that specific sort of joint in Carbide Create requires using unsupported tooling:

But if the joint is simplified, and one accepts voids:

then one can cut parts:

which fit together quite well:

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Here are the files:

cjoinery_box.c2d (316 KB)

bottom_center_top.c2d (64 KB)

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Nice! I’d imagine the other benefit is that it’s probably way quicker to cut since it’s just 2d contours? I want to give this a shot in Fusion… I started on your other blind finger joints but didn’t end up getting it done yet because I got distracted trying to set up a parameters table

Cutting efficiency has been one of the reasons for the way I’ve been approaching this.

I’ve got the horizontal version modeled in BlockSCAD:

https://www.blockscad3d.com/community/projects/1478465

I’m probably going to try documenting laying things out manually here in a slightly simpler fashion, w/ a slight change to how the V is cut and a bit more space for the central channel (it is a really tight fit — it took quite a bit of force to separate the initial/dry fit when I disassembled it to install the bottom) — basically it’s the same as before, just no dogbones, shorter fingers, and the ends are V shaped instead.

Could you post a STEP file of the design you posted at the top? I’m trying to create it in Fusion and struggling with some of the finer details…

Here’s an STL:

gcodepreview blind fingers.stl (130.6 KB)

made from this .scad file:

gcodepreview blind fingers.zip (2.0 KB)

It’s not exactly the same as the .c2d file — need to cut the version from OpenSCAD yet.

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To make it step-by-step, as always, begin by drawing the joint and the V endmill up in profile:

and then draw in the fingers:

Then it should be simple to draw in the geometry for the fingers and replicate it as needed

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Draw in the fingerjoint/void geometry:

and then select a matching version offset vertically by the height so that they will be adjacent and then use Linear Array to duplicate it as needed:

Delete the extra and group what is left:

and vertically align it against the part outline:

Then draw in a central channel:

and then either Boolean union the joinery geometry or use Trim Vectors and Join Vector to create the necessary outline:

It will also be necessary to have a clearing pocket — check the profile view and draw in geometry to determine the needed width and depth:

Duplicate the joinery geometry and union it w/ a duplicate of the pocket clearing geometry:

Assign toolpaths:

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There will be two separate sets of V grooves:

  • two sets which run the full height of the joint
  • two addition sets at the edges of the joint which clear the miter at the ends

One, at the bottom of the joint is obvious:

Or would be if the stock was the same size as the parts:

The other paths of this twain are:

Next, determine what the minimum number of passes necessary would be:

One option would be to have a different number of passes on each side.

Draw in a suitable line for one cut and use Linear Array to duplicate it as many times as needed, w/ extras for origin and end points:

If need be, adjust the width of things to line up w/ stock thickness.

Then, measure the distance:

and assign toolpaths working down to the necessary depths:

Duplicating geometry w/ toolpaths allows us to arrive at:

cjoinery_step_by_step.c2d (108 KB)

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This style of joinery is used in:

Dang this didn’t work
The V-bit seems to have carved more than is shown in your pictures

You have to use shorter geometry for carving only the V at the ends — if the 3D preview doesn’t show the fingers being left, adjust things until they show.