Silhouette Cameo 4 not able to cut hollow equilateral triangles with equal sides. What should I try?

Question

I'm new to using my Cameo 4. I'm trying to cut out some reflective equilateral triangles from fabric and heat transfer vinyl.

I'm able to cut all sorts of other shapes from this material, including some shark shapes that came with the software, and some different plant shapes that looked good as well. They all looked exactly how they looked in the software.

However, for some reason, my hollow equilateral triangles (yield signs) are not cutting very well. One side is always narrower than the others and it looks odd. I tried flipping the shape over to see if that made a difference, but it did not. I have every reason to believe that the PNG or SVG files that I'm using have equal sides. I double-checked this in Figma, where I generated the shapes.

So, I just don't know what I might be doing wrong, or where I'm possibly missing something, or misusing the machine somehow.

Do you have any ideas or things to check?

Answer 1

My guess is that the cutting tool itself isn't as precise as you expect and you have to factor this inaccuracy into your design. (Please note that I've never used a Cameo, but the nature of the problem in inherent in all plotters / cutters.)

The blade tools of the Cameo (and other plotters / cutters) looks like this:

The blade itself is centered, but the point of the blade (where the actual cut is made) is not. That means, when the tool changes directions, the blade tip still follows the old direction for a few millimeters until it gets dragged into the center of the path. In addition to that the material you cut (fabric backed vinyl) may stretch and bunch up in front of the blade, increasing the inaccuracy even more.

Looking very closely at your sample, we see that one corner of each triangle is very pointy and the opposite one is rather rounded:

My suspicion is that the cutting tool moved clockwise when cutting one of the triangles and counter-clockwise when cutting the other one. That means that the little distance between the cutting point and the actual center of the path is applied twice in your case (outer triangle too much to the left, inner triangle too much to the right) and becomes too obvious.

The way around this is to plan for the tools inaccuracy in your design. Deliberately move the inner triangle to the left by the measured distance in your finished cuts.

Answer 2

I've used a Cameo a few times at the local makerspace. The flexibility in the settings is quite substantial. I would suggest to shift to a different material, adjust the settings appropriately. A light paper or construction paper will be less expensive and will provide a suitable test bed. If you have a plotter pen option, that would also be useful, drawing the shapes rather than cutting.

Examine the carrier sheet for damage from previous cuts, rotate the sheet, try a new one. If the HTV material has a backing, you can get away without a carrier sheet if the settings are correct.

You mentioned a program different from Silhouette Studio as the source of the design. Consider to create the shape in Studio to see if that changes the result.