Making centering rings.....

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Fuddrucker

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Has anyone ever used one of the circle cutter tools (see attached picture) that attaches to a drill press to make centering rings? I need about 20 rings from 4" to 5.5" and was about to order them until I remembered I had one of those tools to cut circles. How does it work on 1/4" birth plywood? I am trying to deceide if I want to cut all the rings myself and save $90.00 or just order them.

Thanks!

...Fudd
 
hey Fuddrucker - we recently cut a dozen 4" rings out of 1/4" birch with a circle cutter, like the one in your picture. my kids like doing it because they can run the drill press themselves.

some notes:

turn the point of the cutter so the "good" side is in the circle, on the ring, and the chip/waste side is out of the circle, in the stock

cut a few test rings out of something cheap like pressboard. take your time to get the outside diameter _exactly_ right.

set the drill press to the slowest RPMs

go slowly while cutting so you don't jam the cutter

be prepared to sharpen the point every two rings or so. just a quick touch-up with a file will do it.

consider using a hole saw for the inside cuts: 1 5/8" fits LOC 38mm MMT pretty good; 2 1/4" fits PML & LOC 54 mm MMT pretty good
 
CLS , solid advice but something caught my attention right away ...if you can file the tool bit ... time for a better tool ... it sould be as hard ,if not harder , than a file... and require hitting with a stone or a grinding wheel to sharpen.
 
Well, I have made 7 "Good" rings. It took me 3 to get the diameter size just right though! Now that I have the size set on the tool, they go pretty quick. It might be because the tool is new, but so far I have not had to sharpen it. Still seems to be cutting fine.

...Fudd
 
There are circle cutters like this with two cutters, one on each side of the bar. If you can get one of these, you can cut your CR in one pass.

p.s. be REALLY careful using these things, keep your workpiece clamped firmly and keep your fingers WELL away from those cutters.
 
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