Need some advice on Circle cutting

[Gilbert Frank]

I'm sorry, I know this is a wood turning forum but maybe someone can help with this question I am grappling with:

I am building 8 outdoor speaker boxes from ¾ marine plywood. Each box holds 2 – 12” speakers so for this project, I need to cut 16 holes into 16 – 20 x 22 inch panels (one hole per panel). How would you cut 16 holes like this in the center of the panels, would you use a jig saw with a circle jig or a router with a circle jig, and based on your choice, which blade or router bit would you use?

 

[hughie]

I would use a jigsaw as a router will give you a much more accurate hole but a far more complicated set up. Take your time with the jigsaw and it will be quite accurate

 

[Brian Gustin]

I'd use my router - Easy to make a circle jig from a piece of 1/8" or 1/4" hardboard - especially if your radius is around 6 inches or so. Just have to be accurate at drilling the mounting holes to mount it to your router in place of the base plate. For that many holes, router (with a 1/4" spiral bit upcut or downcut) would be much faster even if you add in the time to build the circle jig. Even faster if you forego the drilling and screwing jig to router and just use double stick carpet tape to stick it to your circle jig.

 

[Doug Freeman]

Router. I have a circle jig for it, but a piece of string works also.

 

[Mark T Racowsky]

Router hands down. Draw diagonals to find center, drill center hole, use a trammel or a piece of string, or cord as Doug suggests. Also the upcut, or downcut spiral bit will make quick work of it.

 

[Earl McLain]

Router. And if you want to purchase a jig instead of building--tough to beat the Jasper Circle Cutting jig, stable & accurate, easy setup.

 

[Monty Ivy]

Build a faceplate jig to hold the panel and use a parting tool.

 

[Tom Gall]

Build a faceplate jig to hold the panel and use a parting tool.

Not many lathes will be able to handle rectangular panels of that size. That was my thought originally but then I noticed the size.

 

[robo hippy]

Well, if I was to attempt this, I would use a circle template and a bearing guide bit, or what ever they are called. Rough cut with a jig saw, and finish up with the router bit.

robo hippy

 

[Monty Ivy]

Not many lathes will be able to handle rectangular panels of that size. That was my thought originally but then I noticed the size.

Could do it on the Coronet Envoy, outboard spec is 39"