Dutchman Bow Tie

I am trying to create a jig to use with a piloted router bit to make Bow Tie inlays. I drew the poly line in shape of bow tie but cannot get 4 outside corners with 9/16 inch round corners to match pilot.

Any suggestions. Tried 9/16 circle with boelean but can’t get to work.

Hi Guy, Try to create an inside offset path by your desired corner radius. Then from the new vector create an outside offset by the same dimension. The straight lines will be back to their original positions but the corners will be rounded at your desired radius.


You will need to rotate the circles to get them to allow positioning of snapped nodes.

Something like:

First draw the circles:

Then rotate the circles by the desired angle of the Dutchman:

(repeat for each circle)

Then draw a polyline which connects to a circle on the tangent:

and duplicate it for each circle:

arrange things so that they overlap:

and then Boolean union things:

(rounding off the internal angle is left as an exercise for the reader — basically you position a rectangle of the width of the diameter of the circles use, and a height to align at the lines, union it, then punch a pair of circles out of it)

Alternately, take advantage of the rounding of offsetting things to the outside:

Thank both of you, Will Adams and Lester Shaw, for your advise. I will try this tonight. Will’s is a little longer so I will Try Lester’s suggestion first.

Lester thank you, it worked. I will cut it tomorrow to test but that was simple. I will try Will Adams method tomorrow but it is a more complicated way at first glance. This is what I love about this community is all the help you get to questions.

Let’s try something a bit different, please see:

Well I did a test cut on my Shark Pro HD and it worked as Lester posted above.

My Shapeoko had the Z switch break today. Support is working on getting me a new one. I has posted several months ago about editing gbrl post processor files to work on my Shark. I had not used the Shark in a while so I had to clear a few cobwebs both literally and mentally.

The Shark is a good machine but the Shapeoko is so much easier to use with HDZ, BitSetter, BitRunner and BitZero it is night and day.

Here is the jig for use with Rockler Inlay Bit Kit. I need to make several in different sizes.


The advise worked and I am happy with the result. Why does the offset work. Is it strictly a function of CC or what makes the rounded corners form?

I like things to work but understanding why it works helps me to learn. Thanks

Glad it worked out for you. Please post some pictures of the finished inlays.

Our offset is specifically engineered to round off corners with the radius — this allows one to create the outline a tool will cut with it.

Thanks Will. I have read through the tutorials and there are a lot of functions in CC that are not documented. Things that work automagically are ok but I like to know why they work. On the test piece above I got out my circle template and the rounded ears are 1 1/8" that is twice 9/16". So I will need to put the radius and not the diameter of the offset in. Thanks for all the help in the past, now and in the future.

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