Circle Cutting Question

[AzeX]

Well my protein skimmer was poop (leaks everywhere =( ) So I'm gonna redo it. My main questions is this...

How do would I go about cutting a large diameter circle in acrylic? I have this circl T Cutter attachment for a drill. Problem is the largest diameter is can cut is 5" with both blades. I need at least a 8" circle. The best it can do is scratch a 8" diameter circle in acrylic when modified to use one blade. The problem that is so dangerous cutting with one blade lol. I, and I think most people will have a tendency to lean to one side and the blade will hit the acrylic hard because of it(not sure if you know what I mean) Basically, with 2 blades, I have balance while with 1, dangerously without.

So what would be the best way to cut a circle?

And my main question is, which is the best way with the avaliable tools I have? I current have, table saw, drill, 2 jigsaws(lol), and a Rotozip Spiral Saw, and a mitering saw(these are the tools I have that can cut)

I do have a dremel with routing bits, which I previously used b4 to cut the circles but they were extremely bad, mainly because of me =( Its broken anyway, I overworked it, the acrylic was thick, 3/8"

any suggestions will help, thank you in advanced =))

 

[bad coffee]

HOnestly, if you're just going to cut one, go buy it.

Or, you could make a circle jig for a router table. But you have to drill a center hole and then plug/patch it.

You take and drill a hole (1/16" or smaller) and then nail/screw the piece to the router table. Then spin the piece of acrylic against the blade and cut the circle. Then you plug the hole with a piece of acrylic rod, or just use a small piece of stock and make a patch over the hole.

 

[FRY]

you can make a 8 inch template from plywood then clamp it to the Plexiglas now use router with Pattern/Flush Trim Bits,do half then clamp the halve you just did remove the clamps from other halve and rout the other halve

 

[AzeX]

wow bad coffee, that sounds like an awesome idea lol.

on reefcentral, someone suggested the same thing, but with the rotozip instead. I'll try that thanks a lot =))

 

[reefer138]

Bad coffee I had the idea of making a circular piece of acrylic also. If I use your idea I guess I have to put that screw through the acrylic at half the distance of the total size of the cap size I need ex. for a 8" cap I put the screw at 4" from the router bit and just spin the acrylic around.

 

[AzeX]

it works pretty good. I used my rotozip instead. However, rotozip has some serious rough cutting. Random jagged edge. I would try my zigsaw next time.

thanks