Need help with wood working

[AudioIsFun]

I am planning to build a sub enclosure which uses internal braces with circles cut out. I have a rotozip in which I can use to cut the circles out but I need to know how to round the edges like this picture. I think I need a router with a round-over bit but what else do I need? A router table? How do I keep it so that it routes the circle perfectly? I don't free hand it do I? Is there a tool that can do this for me? Also how to I flush mount my drivers? What tool do I use to do this? Please let me know. Thank you.
-Ed

[Nappylady]

You do not need a router table for this operation.

You need a router, the correct router bits, and a special circle-cutting jig. These can be found at Parts Express, or you can hack one up from acrylic for less $ and more time.

My dad and I make speaker cutouts with this method (an acrylic circle-cutting router jig) and it works very, very well. Used with the roundover bit, the end result is very pro.

Good luck to you!

[Vikash]

Check this thread out, and this one.

A couple of points. Firstly, there is no [real] functional advantage of making your bracing holes pretty, rounded over, or even very neat - unless you plan on being able to see through the cabinet walls.

Secondly, the recess for flush mounting in the second pic is simply two pieces of wood with different diameter cutouts. I use a router set to the required plunge depth and the circle cutting jig to make the recess more accuratly. Alternatively you could use a rabbeting bit.

[Nuuk]

I have only just got my Rotozip so am prepared to be corrected but it seems to me that it has a limited cutting depth (around 6mm).

[Centauri]

A simple trimmer (non-plunging router) tool works fine here. The router bits used have a ball bearing on the end of the bit which guides the tool around the hole. You can get bevelled, stepped, curved bits etc to produce the required profile - and it can all be done by hand quickly and accurately.

Cheers

[Hybrid fourdoor]

Originally posted by Vikash
A couple of points. Firstly, there is no [real] functional advantage of making your bracing holes pretty, rounded over, or even very neat - unless you plan on being able to see through the cabinet walls.

Secondly, the recess for flush mounting in the second pic is simply two pieces of wood with different diameter cutouts.

Nice.

I didn't even notice that was a brace board in the first, and you definently caught that second one.

I have seen the second method several times. Very effective and cheap. Two layers together is stronger that one solid piece of same thickness, plus no special tools required.

[AudioIsFun]

Originally posted by Centauri
A simple trimmer (non-plunging router) tool works fine here. The router bits used have a ball bearing on the end of the bit which guides the tool around the hole. You can get bevelled, stepped, curved bits etc to produce the required profile - and it can all be done by hand quickly and accurately.

Cheers

This sounds like exactly what I am looking for. My question is, can I use a plunging router to do this same thing? Can I turn a plunge router to a edge trimmer? Can the ball bearing bits used on a trimmer be used on a plunge router to do the same thing? Please let me know. Thank you.

[leadbelly]

Yes.

[5th element]

Well my dad and I also use the same method! perspex thingy made for the purpose. HOwever for xmas he got a circle cutter which is increadible easy to use and adjust, ive just used that today to rebate driver cut outs and its a doddle to use.

[tacomaboy]

Originally posted by Nappylady
You do not need a router table for this operation.

You need a router, the correct router bits, and a special circle-cutting jig. These can be found at Parts Express, or you can hack one up from acrylic for less $ and more time.

My dad and I make speaker cutouts with this method (an acrylic circle-cutting router jig) and it works very, very well. Used with the roundover bit, the end result is very pro.

Good luck to you!

Hey Nappy, and templates or instructions for how to make this router jig? can it be done with 1/4" MDF? I am veyr interested in doing this to save 30+ bucks.