Create radius (fillet) between to non-parallel bezier curves

I am attempting to create a mould for creating a replacement switch thumb guard for an OLD Festo Orbital sander (made I think approximately 1956).

I aim to forge this switch from Carbon Fibre. The original was Bakelite so CF might be the easiest of the most difficult options to make this with.

I have created a rough image to see how this might progress to 3D print but I need to ensure that the two wings taper slightly so that the Carbon Fibre Resin will release. I have therefore created 1 Bezier curve, and copied 4 times (left and right of thumb), angled towards each other at 2 degrees from vertical.

I have at least two challenges that I see for now Note: it may be a version issue given my SketchUp instance is old - I use it so infrequently that I don’t yet want to purchase a newer version just for this):

  1. I cannot join these two sides across the “top” - you will see I drew lines to each endpoint to “force” the face to show
    I cannot create a smooth curve, instead of the 90deg face that I have drawn as noted above. The reason I struggle here I think will be that this curve will at the bottom be 3mm diameter reducing to ~2.5mm at the peak before increasing again.
    Even when I “Pull” one face 6mm in the required direction

In the attached SKP I have drawn two semi-circles to give some idea of what I aim to repeat on one of the two sides and I have also included an image of the type of switch I aim to make in this file.

I also show a couple of notes and comments in this file

Finally, this will not be my final image - I’m just seeing what I can do here :slight_smile:

Thanks in advance

Festool carbon switch guard.skp (567.9 KB)

You should look at Fredo’s Curviloft (not free) or Tig’s Extrusion Tools (free). Both available from Sketchcation.

Hi Box
Wow - that was fast!

You have done exactly what I needed (except that I really wanted to go full bezier curve length as you have done with the right hand image you provided but that was my description …).

Spot on - thanks

Going to Fredo’s Curviloft and Tig’s Extrusion Tools now

I didn’t bother finishing the second one.

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Good stuff as usual Box!. I’m thinking about getting into the 3D printing- does Make 2017 support .stl export?

Sorry @Box
In answering your post on my phone and then soon after noting that your solution was “the solution” I inadvertently marked my own response as the solution… OH DEAR

Thank you @Wo3Dan for letting me know

To both of you - thanks again

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If I remember correctly, it doesn’t export .stl natively but there is a sketchup team authored .stl export extension in the E Warehouse.
The extension actually works better than the later added native export.

No worries, but it does help others find the actual answer.