Circle Jig

[Bigander]

Browsing some woodworking forums and came across this circle jig and my first thought was TRF. So i'd figure i'd post this here for you guys that like to cut their own centering rings.https://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=365-250

 

[carl20320]

Here is a better (cheaper) source.

Tyler Tool

I just picked up a 200, a 400, and a 350 pivot plate which allows you to make bulkheads without putting a hole in the center.

Carl

 

[FredA]

Yep -- been using these for years.

Also if you make half-depth cuts you can make stepped bulkheads.
Perfect for EBay & NC End-caps.
Also good for stepped CR's for the ends of the MMT.
No more glueing two different diameter disks together.

I much prefer a solid ply concentric stepped bulkhead over anything else I've seen.

Not sure about the comment about no center hole.
These need a 1/8" diameter pivot pin in the center.

I strongly suggest a scrap piece of wood to use as a work surface, you'll not get the depth perfect and will end up cutting into it.

 

[rocketsmith]

I'm using this circle cutter with my drill press which works pretty well. No center hole unless you want one. It only took a couple of practice pieces to get perfect centering risgs for my upscale Tartar.

 

[11bravo]

snip...Not sure about the comment about no center hole.
These need a 1/8" diameter pivot pin in the center...snip

https://www.tylertool.com/ja350pipl.html

 

[carl20320]

Not sure about the comment about no center hole.
These need a 1/8" diameter pivot pin in the center.

Check out the jasper 350. It is a flat plate that has the 1/8" pin mounted to it. You apply it to the surface with double sided tape, make your cut, then remove it. You can make a solid bulkhead this way. It can eliminate the extra center hole when using a U-bolt.

Carl

 

[pyrovette20]

All those are nice but you can only adjust down to 1/16''.I like rocketsmiths flycutter can you cut 2 circles at once with it. Also were did you get that at. I'm assuming it is infinitly adjustable.The one I have will only cut up to about 4 1/2''.

 

[11bravo]

All those are nice but you can only adjust down to 1/16''.I like rocketsmiths flycutter can you cut 2 circles at once with it. Also were did you get that at. I'm assuming it is infinitly adjustable.The one I have will only cut up to about 4 1/2''.

Use a 9/32" bit and your adjustments are down to 1/32".
More accurate than most anything else we do building rockets.

 

[11bravo]

All those are nice but you can only adjust down to 1/16''.I like rocketsmiths flycutter can you cut 2 circles at once with it. Also were did you get that at. I'm assuming it is infinitly adjustable.The one I have will only cut up to about 4 1/2''.

Use a 9/32" bit and your adjustments are down to 1/32".
More accurate than most anything else we do building rockets.

 

[Stymye]

I'm not sure I understand
within 1/32 ? thats a huge margin when dealing with rings.
you could get closer than that with a jigsaw.

 

[m85476585]

I'm not sure I understand
within 1/32 ? thats a huge margin when dealing with rings.
you could get closer than that with a jigsaw.

You can get a 15/64 plywood bit, but you will probably also need a 17/64 bit (don't know if they are common) and a 9/32 bit to get the the complete range in 64ths.

 

[rocketsmith]

All those are nice but you can only adjust down to 1/16''.I like rocketsmiths flycutter can you cut 2 circles at once with it. Also were did you get that at. I'm assuming it is infinitly adjustable.The one I have will only cut up to about 4 1/2''.

I bought it at Harbor Freight. It says you can cut an 8" diameter circle. It has two independant cutting heads so you can cut the inner and outer circle in one pass. I smallest center I can cut is about 24mm, which is fine. Anything smaller and I just drill using a spade bit. You can also remove one of the cutting heads or make them equidistant from the center to cut bulkheads. I had problems cutting plywood thicker than 1/4" but theat might be my drill press.

 

[pyrovette20]

The problem I have is my drill press will only go down to 500 rpm. Most of the larger fly cutters recommend about 200-300 rpm. I guess I can try cutting really slow. Your cutter looks like it might work ok at 500 rpm because it has the other arm that would offset the weight swinging around so far away from the center.

 

[11bravo]

I'm not sure I understand
within 1/32 ? thats a huge margin when dealing with rings.
you could get closer than that with a jigsaw.

You can?
You must be Super Cutter.

 

[rhickok]

I've used a friend's plunge router & the circle jig being discussed here & it beats the hell out of using the fly-cutter & drill press. It's fast, a clean cut, you can set your diameter without all the fly-cutter's trial & error. When I used my fly-cutter before, it was slow, loud.......the wood would make a cloud of smoke sometimes & with all that fast-spinning, can-fly-off-at-any-minute metal, there's always some inherent danger. When I want to cut CRs or bulkheads in the future, I'm going to his house. Leave the ligt on, Don.

Richard Hickok
NAR 74359
Member MDRA & NOVAAR

 

[Stymye]

You can?
You must be Super Cutter.

No, but a buddy of mine >is< super cutter you should see what he can do with a scroll saw, amazing detail. in fact he made a nosecone with it just to show me it can be done.!

with the jigsaw, I draw the circle and cut just outside the line than touch it up on a sander, I use the jigsaw alot at work so I've had plenty of practice, that helps.

at home I use a mini metal lathe and stack 5-10 rings together ,I can get them within .002 no problem, but I can only go up to 4" diameter with it.

the jasper jig looks like a good investment for bigger rings, in my case

 

[..Pat Butler]

I use a circle cutter attachment for my RotoZip tool. I find that I have more control with the RotoZip for smaller rings as compared to my router which definitely has a lot of torque and is more suited for larger work.

 

[11bravo]

Well, yeah, with a lathe.
My brother won't let me near his lathes with wood though.
I'd like him to turn a nosecone plug on the CNC lathe but he's a little unsure about it.
He teaches Tool and Die at the local community college and isn't too sure the school would appreciate the outside work with wood.
He also won't let me work on parts for guns.

The Jasper guides make nice smooth, finished rings and bulkheads with plenty of accuracy for use in rockets.
And I'm sure it's faster than sawing then sanding.
Not to snot on your method, methods is methods and they're all good enough for whosever.
I just am really happy with mine.
Except for when I forget to add the difference in rings and holes and get rings that are too small.

Greg

No, but a buddy of mine >is< super cutter you should see what he can do with a scroll saw, amazing detail. in fact he made a nosecone with it just to show me it can be done.!
with the jigsaw, I draw the circle and cut just outside the line than touch it up on a sander, I use the jigsaw alot at work so I've had plenty of practice, that helps.
at home I use a mini metal lathe and stack 5-10 rings together ,I can get them within .002 no problem, but I can only go up to 4" diameter with it.
the jasper jig looks like a good investment for bigger rings, in my case

 

[tater1337]

Browsing some woodworking forums and came across this circle jig and my first thought was TRF. So i'd figure i'd post this here for you guys that like to cut their own centering rings.https://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=365-250

myself being as ever frugal a can be, looked at this and though........

I happen to have some stainless screen, that was made by punching a bunch of holes out of sheet. I was saving it for winemaking, but I think I am going to have to salvage some to make a similar jig for use with either my dremel or just an x-acto knife, using the same idea.