Cut Plexiglass, Acrylic, Plastics with Draw Knife Scoring - Cheap, Fast

Plexiglass or acrylic are easily cut with a draw knife, called a hook or scribe knife, or plexiglass cutter. This draw knife strips a layer of the acrylic to with each draw pass so the plexiglass may be snapped.
Using a power saw to cut plexiglass will probably melt the plastic due to heat from the hot blade and friction.
Cutting straight lines the hook knife is easy and quick with a straight edge to guide the scribe knife to snap cleanly.
To use the plexiglass cutter, the first pass should be shallow and easy. The following couple of passes should be deeper and straight, pushing harder with each pass.
A utility knife won't cut as the black will wander along the plexiglass surface.
To cut a curved line, dremel grinders or oscillating tool work OK. A jigsaw blade melting is still a problem.
A draw knife that scribes or removes a groove in the material weakening it thus allowing it to ‘break’ along that line as opposed to using a utility knife that only cuts into the material. The utility knife does not remove material like a draw knife and so it takes many more cuts into the material to achieve a weak enough trough to achieve a clean break.
Usually 3 passes with the knife is sufficient to ‘break’ the plastic along the scribe.
Most plastics cut similar to wood and so I have used all my woodworking tools to cut Plexiglas at one time or another.

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[ReubenMRU]

Thank you, the reverse cutter thingy worked wonders! You're a lifesaver!

[ezwa]

😯both gr8 but don’t see any diferNc(which is fine both gr8)✋

[carold.]

If i drilled a couple of holes close enough to fit the teeth of a jigsaw blade do you think i would be able to cut a circle in plexiglass with the jigsaw?

[Vic-Meow]

Thank you! Does this same principle apply when cutting Lexan, or polycarbonate? I'm trying to cut a large piece of Lexan with a straight edged razor knife and it doesn't seem to be cutting -- I've made about 8 - 10 passes and don't seem to be making progress. I think I'll go out and find this other type of knife.

[xCuckooKittyx]

Up to what thickness can you use a draw knife? Would this work on 3mm acrylic? Also I’ll be doing a longer cut. Would the snap method work for longer cuts? 2 - 3 feet? Ty!

[detroitryder]

how about 1/4 plexi sheet can i scribe it and break it off
?

[gracefullwetrat]

can i make a circle with this or is that a different tool?

[AutodidactEngineer]

Can such a tool be used to score a line on aluminium sheet to then bend and break it off!?

[PoppaSnipe]

The second piece cracked where you didn’t score it when you snapped it.