What is the best way to frame these tessellations?

I drew a tessellated design and omitted a boundary frame because I was not sure what size to make the image in Affinity Designer. My hardwood workpiece will be 200mm square and 18mm in depth.

The first image shows what the milling intention is; using a 1 inch long 4 flute 1/16" cutter. I may yet separate the toolpaths and cut 4 separate toolpath depth cuts. So that I can rest the machine (and me) and try to look after the cutter.

The next image shows the toolpaths which are selected for cutting. The 200mm square is denoted by the lighter area. I was hoping to put a 10mm border frame around the design so that the cutter would not cut up to the edge of the material. I tried various frames and I felt sure that the answer lay in a boolean subtraction. It did not seem to matter which item was selected first, the boolean operation removed the design. I cannot figure out what I have done wrong and would appreciate a pointer to how this issue should be solved. Thank you.

c2d file also attached.

tessellations.c2d (1.6 MB)

EDIT: I note the design mistakes, which were not there at the start so I have introduced them while specifying the toolpaths

There are two ways to do this:

  • Boolean intersection: draw a box describing the area, select a piece of geometry:

  • Boolean subtraction: draw a box which aligns at the edge, select it, then shift-click to select a piece of overlapping geometry as the key geometry (dashed highlight):

Note that in current versions the geometry used for the subtraction will not be removed, so it may be re-used, making things a bit faster:


Or, export to an SVG and do this in a program which supports composite geometry.

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Here is a .c2d which is framed at the stock area:

But it seems to have some errors, so belike the best thing is starting over.

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Here is a file which is fixed and only has the geometry which you wish to pocket which should work if you want the entire stock area:

tessellations_stock.c2d (708.5 KB)

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Unfortunately when inset, some geometry is right at the edge, so it appears as if there are gaps:

tessellations_inset10mm.c2d (614.6 KB)

Yes, thanks for your advice, Will. I will start again. It was worth the effort to get the 3D cube appearance and it is just plain dumb to spoil it now; with a design that has somehow accrued an error. It really was fine at the point I looked it over and called it complete, so I must have mishandled the image file at some point.

When all else fails… CHEAT! I may end up cutting the 10mm as a shallow pocket. :wink:

We will all know … :smirk:

Looks good. Don’t stop.

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@jepho @WillAdams
I was just wondering … Could you have taken the original file and saved a copy as a .jpg file then open the image and crop or scale to suit your needs, save, then import into Carbide Create and use the Trace feature?

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I find working w/ the vectors better.

Inset 8mm it looks fine:

tessellations_inset8mm.c2d (643.8 KB)

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Thanks Tex. Yeah, I guess I should’ve kept quiet. :wink:

Hi Mike, yep… I absolutely could have done that. Having spent the time designing and drawing the vector, something in me tells me that I should avoid reducing the quality once I have established it. (I feel that it would be akin to measuring everything with a digital caliper and then eyeballing the measurement at some point along the line)

I am trying to understand accuracy a little better so that I can establish where my baseline is for hardwoods. This test trivet (key word to trigger @Julien) will also help me to understand feeds and speeds a little better.

There is no space to add geometry around the detail cuts. I will have to mill very carefully. I have a decent 1/16" x 4 flute bit and I will be milling hardwood. DOC is half the bit diameter and step down is less than half the diameter. Conservative feed rate of 1500mm per minute and then suck it and see. My 1/16" cutter has a 1" length of cut and is from Niagara. (N55795)

I am hoping to mill metals very soon and accuracy is something I know I have to understand. I want to try and see where the tolerance limits of my SO3 are. To that end, I have gone completely crazy. I have a Saunders Machine Works fixture tooling plate and a couple of M6 Hobby Mod Vices on order.

Working with .jpg files, it is unavoidable that the lossy save algorithm steals a little bit of the detail with every save. My understanding is that .png files are lossless on saving. I see vector files as being really difficult to mess up and generally prefer them for accurate working.

This little trivet diversion has shown me that my planning could be a whole order of magnitude better. I knew what I had wanted to achieve but had not considered every aspect of the job. I got sidelined by a simple issue (boolean subtraction) that could not fix the underlying poor design.

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Looks a little too much like the wrong logo. I’d suggest hexagons next time (I know the isometric cubes kinda name a hexagon, but…)

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Hi Neil. Hope all is well with you. I was aiming for a nice 3D effect, which the isometric hexagons tended to lend the image. I just did nor consider the edges.

Straight hexagons would probably have worked better, even if I had been just as sloppy in my planning. :thinking:

Probably just as well that I had not created a height map and milled this a 50mm high.

Hi Jeff,
I was just joking around. The design you created is very similar to that of the “other” home CNC company. Carbide 3D has the simple hexagon logo.
I think your design will look great as is.

Whoops! :blush: Oh heck, Neil. I may have to rework it now. :grin: Hmmm… that may even have given Inventables a laugh. It musta been something subliminal there, honest!

Jeff backs away from the computer and leaves the room/

EDIT: I will have to put in the time to make amends now. :smile: