Need circle routing advise.

[Tom Spallone]

I need to route a 3" diameter circle, 1/4" deep into 1/2" stock.

Also, the stock measurement is 1/2" x 3.5" 3.5".

Think coffee cup holder.

I've been wracking my brain trying to figure some sort of jig so that I can just drop it down and move it around a bit and bango, perfect circle, 1/4" deep right where I want it.

Not sure if I should approach it from the perspective of moving the piece around the router or moving the router around the piece.

Suggestions? :confused:

Btw, I MAY need to do this many, many times.

[Chuck Trisdale]

A lot of old schoolers will tell you to make you own our of whatever wood you want. You just cut out a piece of wood, attach it to your router, measure the proper distance out from your bit, drill a hole in the wood the proper distance and spin the router around a nail you put in that hole you just drilled. A tip is - you are going to be in the router base with your drilled hole, so cut the tip off the nail and use it as a pin. I am sure I explained that well enough to make it clear as mud. If you decide to make one - I will see if I can find some pictures

I personally use a Jasper jig though. One of the best investments I have made.

[Mark Rios]

I don't have a jig idea but whatever you use, could I suggest cutting/routing the hole out BEFORE you cut to the 3.5" x 3.5" size? Trying to rout something that small seems like it would be a little scary without clamping it down REALLY well. Just a suggestion. Hope you figure it out.

[Jim Becker]

Make a template guide for the circle and a jig to hold the workpiece with the template on top. The template can have screws to hold it down to the "holding jig" which in turn holds the workpiece securely. Use a collar on the router base to follow the template. You'll get a hole exactly the same as your template every time. Remember to account for the distance between the outside of the collar and the edge of your straight/spiral router bit.

[Doug Shepard]

What Jim said although I'd personally prefer a bearing guided bit against the template rather than a collar. I'm currently working on some circular stuff. Normally I'd reach for my MicroFence circle jig but the radii I needed are below the jigs minimum. So I used the disc sander and a pivot pin to turn small MDF templates.

[tod evans]

use a 3" forstner bit much easier.......02 tod

[Cliff Rohrabacher]

I'd move the router.
I'd prefer to have the work oversize so I could clamp it screw it whatever.
I'd consider making a large plywood pattern to let the whole router base run around in the circle - as I think you want ot completely remove all the stock from inside the circle to get a flat smooth bottom.

[Don Baer]

Like Cliff said. Make a circle out of MDF or plywood that is equal to you router base plus 3" then use it as a guide to cut your 3" circle in the piece you want to route.

[Lee DeRaud]

Like Cliff said. Make a circle out of MDF or plywood that is equal to you router base plus 3" then use it as a guide to cut your 3" circle in the piece you want to route.Uh, careful, guys:
1. not everybody's router has a circular base (e.g. Hitachi?)
2. not every circular router base is perfectly concentric with the collet. DAMHIKT

[Chris Dodge]

I'd use a circle cutter on my drill press to cut the outside edge of the 3 inch circle and set the stop for 1/4 inch deep. Then I would use my plunge router, set at 1/4 inch deep, to do the cleanup on the inside. I would think that would be fairly simple and quick.

[Tom Spallone]

I'd use a circle cutter on my drill press to cut the outside edge of the 3 inch circle and set the stop for 1/4 inch deep. Then I would use my plunge router, set at 1/4 inch deep, to do the cleanup on the inside. I would think that would be fairly simple and quick.


That's the ticket!!!!!!

Genius!!!

[Tom Spallone]

use a 3" forstner bit much easier.......02 tod


This is good too. Hmmmmmm. Ok, off to Home Depot. Thanks all.

[Tom Spallone]

uhhhh, you guys aware of the cost of a 3" circle cutter or 3" Forstner bit?

Yikes!!!!

Back to the jig/router combo I guess. wow!

[Jim Becker]

What Jim said although I'd personally prefer a bearing guided bit against the template rather than a collar.

Excellent point...and it does away with the concentricity problems that Lee mentions. Good call, Doug!!

[tod evans]

I need to route a 3" diameter circle, 1/4" deep into 1/2" stock
Btw, I MAY need to do this many, many times.

tom, the "many many" quickly justifies the 30-some bucks for a forstner...02 tod

[Lee DeRaud]

Re: 3" Forstner bit

This is good too. Hmmmmmm. Ok, off to Home Depot. Thanks all.I'd be astonished if Home Depot had one anywhere near that big, but they're $28 at Rockler.

Don't know if it matters, but since you're not doing through-holes, note that a Forstner bit will leave a 1/8" or so dimple in the bottom of the hole from the spur.

[Mark Singer]

use a 3" forstner bit much easier.......02 tod

Your cheating again:confused:

[Ted Jay]

uhhhh, you guys aware of the cost of a 3" circle cutter or 3" Forstner bit?

Yikes!!!!

Back to the jig/router combo I guess. wow!

If your looking at the Bormax bits at $140, yeah :eek:
A standard 3" is around $20.

Depends on what your time is worth.

[Tom Spallone]

Right you are Tod. The problem is, I'm making a one-off to possibly get a contract. No contract, that's the last one I'll make. Actually, my partner in this said "Would ya just get the right bit? $20, $30 what does it effing matter?".

I dont' know, I guess I'm more frugal when it comes to that stuff.

Certainly I've been known to buy a tool for a project with the idea that, "I'm sure I'll use it again". It's just that....

I paid $2.40 for gas yesterday and I'M GETTIN' KILLED OVER HERE!!!!!!!!!