My snazzy new circle jigs :) (1 Viewer)

[Dustin B]

Well my second sub project has officially started. Sad part is neither of the subs are for me. Two identical subs are being made. One for my parents, one for my roommate.
Going to be Dayton DVC12" in 125L sonotubes tuned to 20hz with 4" flared ports.
Anyways, started today after supper and the only thing accomplished besides getting all the mdf cut into 20" squares and glued into 1.5" thick pieces was the construction of significantly better circle jigs than were used in building my first sub.

Here are links to three more images:
Close up of pivot point from top.
Close up of pivot point from bottom.
Close up of router mounting holes.
These were inspired by Brian Steeves. Yes we drilled a hole in the middle of the 1/4" bolt to get that pin there
The wood piece has a grove that fits in the top slot so that it can't rotate at all. Its' purpose is to be a fixed point from which distance reference marks can be made.
These along with an up cutting spiral bit should made endcap construction much easier this time around.

 

[Cam S]

Very nice work Dustin, how small of a hole will those router?

BTW, when you order your subs and amps, did you have to pay PST on them??

 

[Leon Van Dongen]

Quick question.

With these jigs, do you attach it to the centre of the circle you're going to cut out? (Would make sense, but what happens right at the end of routering, when the cutout drops down?)

 

[Kerry Hackney]

Dustin, those really look nice. I bet you'll like them better than a Jasper.

Leon> My jig, as well as the commercial ones, work on this same principal. I have used two methods for cutting the holes. If I am cutting the holes from a flat blank, I put a sacrifice piece under it and screw through the waste piece that will come out of the hole. And, I clamp the keeper part to the table. With the sacrifice piece under the cutout I can lower the bit until it cuts all the way through, remove the screws and clamps and your done. The other method is to route part way through using the jig and then switch to a top bearing pattern bit to finish up the hole. The bearing rides against the keeper part so that everything stays stable when the circle is cut out of the hole

 

[Dustin B]

Well the groove goes past where the base of the router starts. I have to remove the wood block and use a different washer to get as small as possible. I haven't mounted the router to them yet to measure how close I can get the pin to the base. Rough guess is a circle just under 5" in diameter. So I should be fine for a 4" flared port's flange, but for a straight 4" pipe I'd need something different.
No PST

 

[Dustin B]

Off by a little bit, smallest hole they can cut with my router is 5 1/8" in diameter.

 

[Andrew Pratt]

Nice job Dustin...want to make me one

 

[jeff lam]

I wouldn't mind having one of those either. Nice!

 

[Mike Strassburg]

Dustin,

Hard to tell in the pics, but did you make any markings for the "standard" driver/port cut-out sizes??

 

[Dustin B]

No, I didn't. I suppose I could have made the appropriate marks when the correct size was found (hadn't gotten that far when those pictures were taken) but all the endcaps and port/driver holes are cut now and the plexiglass is still clean. Reguardless, I still feel more comforatable making a test cut no matter what.

 

[Rick Thomas]

Dustin how long are you making your port.I'm making the exact sono as you?thanks

 

[Dustin B]

I used full length FP4 port kits from Adire. Should tune the subs to just under 20hz.