Lots of great ways to make centering rings. The real question is what size are you thinking about. I have a plunge router and Jasper Circle jig that is great for larger rings - i.e larger than 4". These things really work great. If I recall the jig is about $35 and the routers are not cheap. I am on my second Harbor Freight router, so perhaps it's better to get on with a better name or warranty.

For midsize, I have a router table I use. I basically use a setup that is like the circle jig except it is placed on the table top. When I started, I just drilled a small pivot pin hole in the table itself. I then rotate the wood against the stationary router bit instead of moving the router.

For the smaller stuff, I use an adjustable circle cutting drill bit from Harbor Freight. In the drill press, with a sharp bit, sometimes I have been able to cut the inner diameter and outer at the same time.

I have a router, table and a cumpas set up. Have not used it for
centering rings. I still just cut them out with my Dremel Jig Saw
and sand to fit.

My Dad gave Me the Router and attachments So I would have
better parts and less time in the product. But I am slow to
change.

I would consider all options, including some of the vendors. I needed
some bulkheads for My Mad Dog. (G10) I got them from 3 Dogs Rocketry. I knew they would be 100%

I use a these - circle cutters in a drill press:

http://www.amazon.com/General-Tools-55-Circle-Cutter/dp/B00004T7P1

I've cut up to the limit of my circle cutter (8") with no problems. I have one permanently set for ID cuts and one for OD cuts. I also have a grinder (originally for my lathe) that I sharpen the HSS tool steel bits with. I also sharped these with the grinder.

The thickest I go through is 3/4" ply - and I go 3/8" from each side.

With proper clamping these work excellent. I've tried doing them by router but it takes too much setup for me. I've made a set of blanks for every size so I keep those so I can index when I need to make more I just use my index blanks.

I'd say it is the best $50 I spend in rocketry - I've had them for over 5 years and they have cut 100's of rings accurately.

Edward

I use circle cutters in a drill press too. 🙂

Thanks for the input guys. I went with the drill press circle cutter from amazon. Not a bad deal for $20. I'll let you know how it works out!

Got the circle cutter all hooked up and it cuts some really nice centering rings, easy to use as well which I like. Thanks for the suggestion! -Sean

I use a router table in conjunction with the circle cutter to put shoulders on rings so that they fit into tubes. Works very nice.

Edward

My favored method of making centering rings is to pick up the phone and call Kent Burnett of Giant Leap or (ack!) Curtis Turner of Performance Rocketry. Much easier on my tools and my lungs. I should say that I've used G10, carbon or machined aluminum rings in my last 4 birds that had them.

Warren

I have tried cutting rings with a Rotozip, and it is not worth a damn. The centering pin has too much play, and the rotary bits do not cut plywood cleanly. I strongly recommend the router, or the circle cutter/holesaw in a drill press.

I have been cutting a bunch of plywood centering rings and I use a circle cutter in my drill press. One thing I do that I have not seen anyone mention is that I have a piece of particle board with laminate glued to it, like the stuff you might get at Home Depot or Lowes for a cabinet face/ side or for a counter top. I have a piece that is about 18" X 18". I take some heavy duty double sided carpet tape and stick my plywood stock to the laminate surface and then I can cut my rings out. No clamps are needed and the heavy duty carpet tape normally holds the ring in place. I do sometimes clamp down base material to my drill press table, but as long as I keep my spindle speed below 600 rpm and I cut slowly, I tend to be OK. I also set the depth of my cut to within about 1/64" of going all the way through. It is easy to finish the cut with an X-Acto or if it is thin enough, just push it on through. I would also add, keep your cutting tool sharp, and do not go too fast. This has worked for me on up to 8" circles so far. I have also done this with fibreglass and aluminum, besides wood and different types of plastic or laminates.