Milescraft 1210 small circle compass "router jig"

I’m making cornhole boards and needed to cut some 6” holes for cornhole boards. I practiced with  jigsaw but the holes turned out terrible. I was then going to make a jig for my trim router but realized that it wasn’t plunge so I abandoned that. On to plan 3. I got my big old porter cable 690 full size router and made a jug for that. Trouble was that the base and the 6” hole was the same diameter. I could fit  brad nail against the base but it was so scrawny that it lasted for bout a half of  hole before the nail worked loose and the router made a nice vole looking track in the board.

I went to my local tool dealer with the idea to get a new trip router and plunge base and got directed to the Milescraft 1210 small circle router jig. It makes holes from 1 ½” to 12” using a big router. For 30 some dollars it sounded like a bargain to me.

Unpacking I found full xeroxed set of instructions. Pretty cool when most things have a QR code that points you to a website.

1st task was setting the plastic base on the router. The jig comes with a variety of predrilled hole for various routers. Some slots have enlargements for quick removal I assume. That’s unfortunate because the screw won’t tighten against the base in that hole, washers would solve that problem. 

2. They provide  ¼” bit so the centering jig is set up for that. The jig come with a centering “rod” that fits in the collet and a bushing that twists in the bottom plate of jig. The centering rod is plastic so it can wobble a bit hen you’re trying to center the plate. The rod is ¼” on one side and ¾” on the other.  However, the centering bushing is only ¾”. It’d be better is the centering plate also had a ¼” bushing. You put the ¼” side of the rod in the collet and tighten it up. The router base is then lowered so the 3/4” end of the rod fits thru the bushing. There’s not much play so the bottom plate is pretty much self centering. You can flip it and use it for a ¾” bit but then you have to eyeball the rod and manipulate the bottom plate until it appears centered. (Which is what I did first until I decided just to use the provide ¼” bit. 

Once the bottom plate is centered you can tighten the screws to hold the plate against the router. Then the top plate of the jig fits into to bottom plate and locks in by twisting it until it locks using offsetting tabs.

3.  So now you can start thinking about the hole you’re going to route out. You drill a center hole for the pivot screw. They provide  bit with a center so that makes it nice. I drew the circle on the wood and used the center point of the circle and made the pilot hole.  I had a small twist auger so I used that instead of the provided bit. You can then screw the plastic “ruler portion” of the jig into the center hole. 

Set the bit depth on your router now before you put it in the jig. It’s probably good to screw a backer piece on the back of the wood so the router has a bit more support when you[‘re cutting thru the wood. I didn’t try it without a backer so I don’t know how that works.

Once that’s done the top plate of the router fits in the ruler portion in a t-slot and tightens down. This was frustrating part since the t-bolt kept twisting and I had a hard time lining it up to fit in. Once that ‘s done you tighten both pieces together with a knob in the t-slot bolt.

4, Time to set the jig to the circle diameter you want. The jig has 2  marks. One if you’re cutting an inner circle e.g. making a cut out and another if you’re saving the cut-out circle. I double checked the ruler with the circle I was cutting out and it seemed to be spot on. Since I’m retentive I went around the whole circle just to be sure.  Everything seemed to be fine.

5. Yea!! Time to cut the circle. I made 2 passes in the 1/2” plywood and it came out beautifully. 

Overall, for 30ish dollars it can’t be beat. You can cut small circles with your large router without any issues. I’d give this a 4+++ on a scale of 5. If the centering device accommodated ¾” bits and the centering rod was a bit more unbendable (maybe make it out of metal). I’d give it a perfect score. This is a very good jig and I’d recommend it to everyone. 

0.0381m is very impressive!

If your first cut is too short... Take the second cut from the longer end... LBD

Does seem like a decent deal. Cutting circles smaller than the router base is where the trickery comes into play.
Sorry for the over metrification... 38.1mm dia. is awesome.

If your first cut is too short... Take the second cut from the longer end... LBD