CAM for CNC code for cutting trispokedovetiles (3-spoke dovetailing tiles)

[Peter Dow]

Peter - when I first looked at your drawing, I couldn't work out what you meant by circle and hexagon. I think that it was a bit like those optical illusions where you can see two different things depending on how you focus your eyes. Having now drawn it myself, I see it differently and I think I know what those value refer to, although I'm not sure whether HEXAGON refers to length of side of a hexagon or a hexagon's width between opposite faces, or half that value (radius of inscribed circle) - I think the latter.

Or maybe it is more like you didn't read my number 5 post carefully enough?

My method for specifying a particular shape of trispokedovetile is to specify the "CIRCLE" length as a percentage of the "HEXAGON" length, as illustrated in this diagram.

This image shows trispokedovetiles with CIRCLE = 130% - in other words the length of the diameter of the (partially drawn) circles is 1.3 times the maximal diameter of the (partially drawn) hexagons.

As a result, I think that I have chosen two different measures, although these are equivalent to yours in terms of changing these design proportions. The other point is that I have expressed both parameters as absolute dimensions rather than one dimension and a percentage of that one. However, you can still tweak either or both parameters to give a full range. It's also interesting to change the corner radius parameter as this changes the general appearance quite significantly.

EDIT - now had a look at the website. I had just been working from the embedded image in your post which was less clear at first sight. I see that HEXAGON refers to the hexagon's circumscribed circle. Make hex_spacing equal to outer_circle_dia in my drawing and you will get the same effect as circle=100% in yours; change hex_spacing for the range of shapes. Adding holes (making them hexagonal?) is clearly trivial in F360 so I shall leave this as an exercise for the reader, as my old maths textbook used to say. Assuming that I have any readers, which seems unlikely for anything as esoteric as this!

At the end of the day, though, this looked like an interesting vehicle to try out a couple of aspects of Fusion 360 that I had not had an excuse to play with before. I think it shows the power of a modern, parametric, CAD package to do things that were once the province of custom code - and it goes direct to gcode with full control of all cutting parameters as well. I'm a bit of an F360 fan but I don't want to take anything away from the originality of your initial design.

I'd like to know how to use Fusion 360 in that way, if you care to explain Neale, please?

I couldn't see the parameters you mentioned - "hex_spacing" or "outer_circle_dia" - I didn't even know where to look for them.

I found the data object tree obviously enough and had fun clicking through it, finding something new each time.


OK found the parameters on the pull-down "MODIFY" menu.

Still finding my way around this software package.

This was the result of changing one parameter - "Outer_circle_rad" from 65mm to 70mm.



Hmm. Not quite what I hoped for.