round flutes in round stock

mbond

Well-Known Member
Premium Member
Hi I am working on what I though was going to be a simple project, but I'm stuck on one part

The main body of the work is 1/2" round stock aluminum. I need to add rounded flutes on the outside of the cylinder at 60 degree intervals. I made a test piece with a rotary table and a 3/8th" end mill, but I can only cut the 1" or so length of the end mill and I need 3-4 inches of fluted stock.

Does anyone have any suggestions as to how I can make these cuts?

probably I need to turn the whole thing 90 degrees and mill along the length of the piece, but how do I get the appropriate radius from an end mill?
 

Dabbler

ersatz engineer
You could also try a 4" long annular cutter. The annular cutter might be faster, but there is the worry about chatter and deflection... There's a rotary table option. You can spin it off centre in your lathe and drill/bore it out. Many ways to skin this cat.
 

mbond

Well-Known Member
Premium Member
thanks

For these ball nose end mills, none of them seem to document the radius of the hemispherical portion. Is it always half the shank?

I think it is better to try cutting this way than to use a long cutter.
 

thestelster

Ultra Member
Premium Member
thanks

For these ball nose end mills, none of them seem to document the radius of the hemispherical portion. Is it always half the shank?

I think it is better to try cutting this way than to use a long cutter.
Generally yes, though some of the smaller ball endmills are also available in a larger shank. I.e. 1/4" ball endmill with 3/8" shank.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Generally yes, though some of the smaller ball endmills are also available in a larger shank. I.e. 1/4" ball endmill with 3/8" shank.

Don't those ones have a smaller neck (say 1/4" or less in the case you mention)?
 

Upnorth

Well-Known Member
thanks

For these ball nose end mills, none of them seem to document the radius of the hemispherical portion. Is it always half the shank?

I think it is better to try cutting this way than to use a long cutter.
A ball end mill has a constant radius. If you want a radius with a flat bottom that is a bull nose end mill. Available in tons of configurations.
 
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