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View Full Version : Small Face Grooving Help??



madman
02-12-2015, 10:31 AM
Face Grooving Stainless Steel 304 , .050 depth and the large dia. is .411 and small is .245 My problem is i have tried grinding cobalt tools with a round side for clearance and it just wont cut. My day has come to a crappy end so far. This was the last operation on a part i worked on for a whole day. I cant get the cobalt cutter to cut properly and by the time I grind enough side relief into the tool it breaks wiping the surface badly and wrecking the piece. Any hints or suppliers who make tools like I need would be great to know thank you Mike

Rustybolt
02-12-2015, 12:08 PM
What's the radius of the groove.

Toolguy
02-12-2015, 12:29 PM
Could you use a 1/16 or 2mm end mill on the milling machine with rotary table or a toolpost mounted spindle in the lathe?

Carm
02-12-2015, 12:44 PM
You need rake on all cutting edges of the tool, including the outside radius. Best to fashion a groove in the top face to let the chip out. If a small homeboy lathe, more positive (angle) to the cutter. If a stout lathe, the cutter top doesn't need the groove for the depth you said, but you need to plunge assertively and be done lest you rub and work harden. Just the way stainless is.

Keep your toolgrind short, and support the bit as close as possible.

RussZHC
02-12-2015, 03:11 PM
if you are talking insert tooling, http://www.iscar.com/Products.aspx/CountryID/1/ProductId/369
lowest, right hand side
did not investigate size available based on your measurements; I am sure there are other makers, just recalled this as "abom79" had done some face grooving with an Iscar tool recently

were your original tool bits square/rectangular and then you were trying to grind partial round for clearance?
I don't think I could ever get that correct without running into the breakage issue (have tried and got it to work but nowhere near as small as you are talking about, so there was a lot more meat left AND that was just plain carbon steel), I am envisioning using a round tool bit as a starting point and taking a pie shaped wedge out to give you the start of a cutting surface...(that wedge out viewed from the end)

mine is not the reply of experience, so take it for what its worth
my first instinct was to see if an annular cutter would be anywhere close to those diameters you gave, and if so, just touch it down...
I could also see finding a small high quality tap (spiral groove) and letting the spiral act as some relief...