Cutting a circlip groove

[cybeeria]

I need to cut a groove for a circlip and I need some help. I am using a circlip (internal snapring) to retain a bearing in a 6061 wheel that acts like an idler pulley. The bearing is 40 mm in OD. The groove needs to be about 1/16" wide and about 3/32" deep and about 1/8" down in the hole. Here's the question:

I am using my mill to machine the pocket for the bearing which it does beautifully and acurately, as well as quickly. Is there a tool that I can use to cut the groove (kind of like a keyway cutter perhaps) in my mill? I can do it in my lathe but that requires a second operation and I would have to make a special jig to hold the part. I would really like to be able to use the mill and just change the cutter and go on. I need to make many of these and if I can make it in one operation and not have to change machines it would save a whole bunch of set-up.

Thanks in advance for the help!

Bill

[Bill Clark]

You are right a keyway cutter is all you need.

[wizard]

Would it not be possible to use a boring/facing head to cut the grove with a suitable tool? These are a lot like boring heads but offer the option of automatically facing a surface. I'm not sure if you would be able to find one with the right control over depth.

Another idea that is very similar is to use a regular boring head and just manually adjust the depth of cut. Slow and tedious but likely to be far easier than fixturing in a lathe. Ideally here you would have a variable speed drive on you mill with good low end control. I imagine though you could also do the entire operation by hand.

The other possibility is to talk to professional tooling distributors as I have to think that this issue has come up before. Many a part has been bored on a mill for the fixturing issues you describe so there is l;ikely to be an overpriced solution to this problem somewhere.

Now I've never had to do any of the above but these are the first things that come to my mind.

Dave

[Kevin Taylor]

If you have a cnc mill use a keyset cutter and a G79 move work's nice be carefull on the feed rate with a small tool like this If you are leaving a step in the bottom of the bore you mite touch of on the bottom with the same cutter and then come up to the hight for the grove that way you can verifie the length of the bore Good luck Kevin

[Bill Clark]

There are automatic "feed out heads" that will do the job and they have adjustable stops for depth, but they are very very expensive. Long ago we would use a regular boring head and feed it out ( about .001 is all you con get at one time) start the spindle then stop the spindle and repeat. You can see what a pain in the neck this is. So if you have alot of them to do and no CNC the lathe is your best bet.

[Geof]

You need a size 204 Woodruff cutter; cutter diameter 1/2", cutter width 1/16, 8 teeth, shank diameter 1/2. Drop in the hole to the correct depth, do a semicircular move that takes the cutter from center to the correct position to put the periphery of the cutter at the groove depth, do a full circle and then another semicircle back to center.

[Kiwi]

Can you mount your part on a rotary table on your mill and machine the hole with rotary table locked, then cut the groove with a woodruff key cutter by rotating the table.

[rboeser]

This is a perfect example of circuler interplation. Mount a "woodruff" keyway cutter of a known diameter and program the CNC to arc into the part, make a complete circle, then arc out of the part.

If you are unsure of the cutters ability, make several passes adding more depth of cut to each pass.

This is the kind of thing that makes a CNC machine worth its weight in gold...

[Kiwi]

Is cybeeria's mill CNC controlled or not?