Acrylic spark plug cover idea

[cjkiii]

I cut this thing by hand (terrible craftsmanship)
Anyone ever 3d print or clear mold these things with the center section raised for the spark plug wires?

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[We're on Boost]

I cut this thing by hand (terrible craftsmanship)
Anyone ever 3d print or clear mold these things with the center section raised for the spark plug wires?

I haven't, I'm just noticing it looks like you got a lot of chipping or chunking when you made the holes.
That happens when you use a normal drill bit, or if you try to use a normal countersink cutter, on this type of plastic.
If drilling holes in acrylic or polycarbonate, you should use a drill that has 0 rake angle. Rake angle is what I call it, might not be the correct term, machine shop classes were a long time ago, sorry! And the diagrams I'm finding online for it totally suck.
You can make your own 0 rake bit from a normal bit by grinding a small (narrow) flat all along the 2 cutting edges with a bench grinder.

But, I used TAP Plastics brand bits called PlasDrill bits. They are pointy-er (60 degrees) and have a 0 degree rake angle.
Here's their chart:

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So, they don't have a full range of sizes, but it's probably good enough for flange head bolts or flat washers, or for a flanged drill bushing if you want to have the clamp load taken by a steel drill bushing instead of by the plastic (which is what I did for my timing belt top cover). I could show you a pic of what I did for this (the drill bushing) if you want. I already have a good pic of it, just haven't ever posted it.

Anyway I have 1/2" and a 5/16" PlasDrill bits that I could take pics of if you want me to try to show you what the 0 rake angle is.

Here's a link to the web page for the bits. If you go there, pick the link they have that says "Click here for tips on how to drill plastic" and read that.