Screw End Milling Question

[Gene-Yo]

I have a Hardinge Lathe DV-59 and wanting to machine some screw ends where they are current 1/2" O.D. screws down to 1/4" O.D. for fitting into a bearing housing. I only need to finish about 0.40 to 0.50 inches of the end so it's not much machining. Of course, these are stainless steel so it takes a few minutes.

I do not have DRO's on this machine so must go off the dial wheels and of course there's some play or slop in the cross slide. Also, it has a rotary tailstock with holds 6 tools with 5/8" shanks.

What would be the easiest way to turn these screws down to 0.25" O.D. What I'm doing right now is using the cross slide but continually must stop and use calipers to find out how much more I need to take off. Which makes this a lot slower process than it should be.

Is there any tools sort of like an inverted end mill that I could insert into the tailstock which would cut these down to 0.25" O.D. since that diameter will not need to change. Any suggestions?

[djr76]

Use an insert that is made for heavy cuts in a s.s. grade that you can do it in one pass.

[RICHARD ZASTROW]

Hollow-mill??

Dick Z

[Gene-Yo]

Yeah, exactly like a hollow mill or a plug cutter except for stainless steel. Anyway I'm guessing that I'm out luck and will just need to use my slide stage.

Probably the best way for me to set this up is to put in something that is 0.25" diameter and set the end mill to this piece then put in the 1/2" screw then start the end machining process.

Of course, if someone knows a better technique considering my piece of equipment please let me know.

[RICHARD ZASTROW]

Gene, "google" "hollow mill" There's everything from HSS single size to adjustable & carbide insert hollow mills available.

Dick Z

[mc-motorsports]

Make a clamp that goes over your bed ways to set a Z dead-stop, put a bolt in it for fine adjustment, that will solve your depth problem. For the diameter, just have to get farmiliar with the machine and after you make a couple of parts with the same diameter, you'll be able to just turn your cross slide handle "so many turns", then look down and dial in your 0, feed the z till it hits the dead stop, back the tool out and your done.

Or get a DRO like you mentioned.

I don't have a dead stop on my lathe, shop I used to work for had one, tighten the bolts to clamp it in place where ever you need it and a bolt for fine adjustment. In my shop, I do things just as you mentioned, stop and measure but I don't do production turning.