Thanks for the insight @jamesdhatch.
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Just very quickly looked at that (another great project) but there too you cut twice to get a clean edge it seems.
It is small at the focal point, maybe 0.2mm, but as it leaves the lens it will be a few mm in diameter, hence the cone. So over a 2" focal length it goes from something like 5mm down to 0.2mm. The shape is actually a bit better than a pure cone as it has an elongated point.
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Yes, best to do it twice rather than full power and slowest speed.
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I have done one that was around 20" (500mm or so) which had about 20 something rings. I went upwards half way, then continued back down so the last ring was on plane with the bottom. Looked cool. I’ll try to find a pic.
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Holy cow! that is some fine workmanship. I can’t imagine having to cut them all out on the scroll saw. Very nice.
chip and salsa bowl.
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Wow!
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Totally cool …love thecolors…thx 
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Seriously Wow!
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Stunning. There’s a real Escher thing going on there with my eyes…
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I’ve only ever tried once on a scroll saw, and either my scroll saw sucks or I do. Reasonably certain my scroll saw is ok.
I did this on an old 3axis biesse rover CNC. 1/16" straight bit. 1000mm/m. 4 passes .
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That makes sense now. I couldn’t figure out why the proportions of the width of the bands was so narrow. It was the wider kerf with the mill.
This will be a great test for a pass through on the Pro. You could make a pretty large bowl. Heck, even a sombrero!
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Indeed - cutting twice vs. once is a question of finish, speed, and other factors. We’ll find the best balance for Proofgrade settings, but you can always switch to manual mode and experiment.
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Ok thanks.
I’d have thought adding heat to the cut face twice doubles the risk of melting the acrylic.
I have always had in my mind that GF would be able to cut most wood & acrylic up to 1/4 inch with a single pass (for both the 40w and 45w tubes). Was that a misplaced perception or was it part of the marketing or specs at some point?
An idea I’m toying with for regular owners is a two part file. And basically have all the half rings have a puzzle joint in the centre. If the split is with the grain as opposed to cross, it should be mostly hidden or not noticeable. That way you could get a 20inch bowl no problem.
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I think it can if you are in a hurry. Two passes apparently gives nicer edges on acrylic. Perhaps it stops the heat from spreading as far laterally.
It can cut 1/4" fine. I do it often. Different materials require different settings though. While you can make it through acrylic in one pass, it’s a lot cleaner finish if you do it in 2 passes. I can go through poplar like butter in one pass with no charring. 1/4" ply however takes a lot more power. Crappy ply takes even more than that
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I’m not sure where that came from - maybe 0.25" single sided? We’ve said that.
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