Great circle cutting router jig

[jdattolo]

http://practical-technologies.com/index.html

This is way better than the plastic plate ones. It is really well made and the metal slide is a dove tail held in place with a couple of set screws. All you do is pop in a 1/4" bit into your plunge router pull the slide out and using calipers measure from the outside of the pin to the outside of the bit. It should be 1/2" of your circle diameter + .0625" (1/16") Drill an 1/8" hole in your panel pop the pin in and you can route the circle.

It is totally adjustable and the baseplate can hold a template adaptor bushing for template routing and the metal slide can also attach to a T bar for rabbeting (including around curves)

It was $50 which is higher than the other ones but the other features make it worth every penny.

-Jim

[Tim A]

This is way better than the plastic plate ones.

Disagree. I've used all type of circle cutters over the years. Anything with an adjustable slide can slip, and will eventually not want to hold in place at all. The Jasper Jig won't do either, and you don't have to measure anything.

[jdattolo]

This is way better than the plastic plate ones.

Disagree. I've used all type of circle cutters over the years. Anything with an adjustable slide can slip, and will eventually not want to hold in place at all. The Jasper Jig won't do either, and you don't have to measure anything.

To each their own then! I was pleasantly surprised to see the tight tolerancing in the dovetail slide mech. Also the plastic used did not appear to be simple ABS but something slightly glass filled so it will not change dimensions later. Using the set screws allows it to be tightened up with minimal force and if things eventually loosen up then the dovetail will take up the slack. If it were a simple straight walled slide I would totally agree with you.

With a fixed template you must use the bit it was designed for or your circles will be the wrong size. Since my shop floor is concrete I have in the past *ahem* dropped bits and chipped them. With the adjustable jig I can use any router bit I want and the thing still works. Yes you need to measure but I always measure twice and cut once

[Tim A]

With a fixed template you must use the bit it was designed for or your circles will be the wrong size. Since my shop floor is concrete I have in the past *ahem* dropped bits and chipped them. With the adjustable jig I can use any router bit I want and the thing still works. Yes you need to measure but I always measure twice and cut once

Yes, it uses 1/4" bit. I typically have 6 or 8 on hand, never fewer than 4. If you do have to change the size it doesn't take a lot of math. Example: You want to use a 1/2" bit. That's an increase of 1/4", half of which (or 1/8") will affect the cut. So move the pin 1/8".

[dheafey]

This is a "whatever works for you" situation. It also gets hashed about on the PE boards quite a bit. The advantage of the router buddy is it's infinite level of adjustment. Personally, I've never found a need to go any more granular than a 16th, but some claim they need 32nd and even 64th granularity. I've used my Jasper for years and would sooner sell the wife than part with it.

[Tim A]

Personally, I've never found a need to go any more granular than a 16th, but some claim they need 32nd and even 64th granularity. I've used my Jasper for years and would sooner sell the wife than part with it.

Wow! Do they think a 64th would make a difference on a driver cutout?

Even at that, the right router bit will let you do just about whatever size you need. A 5/16" bit will let you get down to 32nds.

[bgavin]

I've used my Jasper for years and would sooner sell the wife than part with it.

Rental makes more business sense...

[WB]

My diy jig does 1/128" granularity, up to infinity.

[Tim A]

My diy jig does 1/128" granularity, up to infinity.

As soon as you figure out how to measure and cut that accurately let us know!