Internal Circlip Groove - How to machine?

I wish to machine a few dozen internal circlip grooves of around 3/8"
ID and about 40 thou wide in Acrylic, PTFE and 303 stainless.
For an external groove I could probably narrow down a parting off tool
to do the job but I have doubts I could grind up a carbide or hss tool
accurately enough for an internal one particularly with my eyesight.
Insert tooling seems very expensive for what will probably be a one
off job although having the capability in the future would be useful.
I was toying with the idea of mounting a dremel sized grinding wheel
in the lathe chuck and trying to grind the toolbit accurately in
position but I can't go faster than about 1500 rpm on the stone this
way.
Is there is a better way to do this or is there something available
off the shelf for a tenner rather than a hundred quid?
Reply to
The Other Mike
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I doubt you'll find anything cheaper than these although they are in the USA so it's a bit more hassle.
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Any of the insert systems will cost a fortune so it's either the above or grind one up yourself from HSS.
Reply to
Dave Baker
message
eyesight.
useful.
available
For a one off / few can you not turn up a piece of silver steel to a Tee shape - ie a disk the width of your groove on the end of a bar of reduced shank, then file the disk into a boring bar cutter shape by removing three quadrants plus clearance. Heat, quench and temper and you have your tool.
AWEM
Reply to
Andrew Mawson
He wants to machine stainless. I wouldn't go near that stuff without carbide or HSS. Silver steel is ok for light work on non ferrous and easily machineable ferrous but I'd bet it wouldn't last 5 minutes on stainless.
Reply to
Dave Baker
Just an idea, but what about thinning the end of a woodruff key / t-slot milling cutter?
Graham
Reply to
Graham
To get inside a 3/8" bore ????
Reply to
Dave Baker
carbide
I am experimenting with a damaged circular saw blade. The TCT tips seem to be ideal tool tips and separate with the application of a little heat.
Grind appropriately then braze onto the end of a bar.
I did learn to grind the tip before separating it, they are a bit small on their own.
RSSS
Reply to
rsss
Process is much the same eyesight-wise - get a brazed carbide tip boring bar and thin and shape the end 'till it's as thick as/the shape you need.
Don't use a stone, use a 40mm diamond disc,
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They don't last long, but at £1.25 each .. they'll happily chew up and shape carbide for a bit, long enough to shape a boring bar anyway. They work better in a dremel, but they'll still do it in a lathe, I just tried. Keep them wet and they last a fair bit longer.
-- Peter Fairbrother
Reply to
Peter Fairbrother
A quick look on ebay reveals HSS WOODRUFF KEY CUTTER 3/8" X 3/32" (item: 350336708448) and they also do a 5/16's one, I'll grant you that some modification may be needed to the shank to make it work properly and I'm presuming that the groove is near the end of bore....
Reply to
Graham

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