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Are ballnose endmills useful on a manual lathe?

leeko

Stainless
Joined
Jun 30, 2012
Location
Chicago, USA
Hi all
Do ballnose endmills have a useful place on a manual lathe? I see them used for 3d contouring on CNC, but not so much on manual.

Thanks

Lee

Sent from my SM-N960U using Tapatalk
 
Decades ago, I made some batches of parts on my Hardinge ESM-59 turret lathe. One part called for a drilled hole with a hemispherical bottom in 12L14 steel. I used a screw machine drill to do the hole and then a standard ball end mill to finish the bottom of the hole. It worked very well.

Larry
 
You need to get some trade experience usually they are mill only tools the reason ( except for above example) on a lathe the work rotates the tool is stationary. however on a mill the tool rotates the work is stationary. ( non cnc )
Design of the tool is different for the different applications.

Only when you know the basics can you think outside the box to get things done a different unconventional way.
 
I've got ball end mills that I use on a mill. Not a lot, but if you need it, there's no good substitute. I just recently used one on a straightedge casting to establish a shallow depression adjacent to a scraped surface so I wouldn't have to be scraping up to a wall with all the attendant problems. Yeah, it could have been a square end mill for functionality but the curved recess looks a lot more sensible.
 
Years ago before I had cnc lathes I used a ball nose end mill mounted in a square 5c collet holder mounted in the tool post to put some radius’ on some pieces that I didn’t have a correct radius button tool for. I have also do it with outside corner radius cutters in a pinch, just make sure the flute you are using is level to the bed and your rpm isn’t too high to eliminate any chatter as the contact point can be quite large depending on the size of your radius/cutter.
 
Hah!
I was reading through the posts and thinking - what are they talking about? Then I re-read my post and realized I wrote "manual lathe" instead of "manual mill". Oops!

Thanks for the replies though!

Lee
 
Actually I just used a ball end mill on my lathe. I made a expanding type locking fixture using ball bearings on a tapered shaft. The 1/4 ball end mill provided a good seating surface for the ball bearings. So there...:)
 
They definitely are, for certain applications. Just not so much for contouring like on a computer machine. On a manual mill, you use them more akin to how a form tool is used on the lathe.
 
With having a lathe mill attachment the can be handy, A mill attachment is also handy for keyways if not having a mill handy or open. Most shops don't have radius end mills except for the ones they need for a job..

In a pinch with having a grinder one can grind flats at the corner of an end mill, say a 30*/45* /30* then are at the size radius and then by hand roll the radius to just clean up the flats..yes this takes practice..and makes a scale size not a precision radius.
 
Actually they do have few uses in a lathe. The way oil pump on my B & S surface grinder wasn't working. Traced it to the seat of the suction side of the ball check valve. Took a lite cut on the fitting seat with a 5/16 ball end mill in the tail stock to match the 5/16 check ball and all was good to go............Bob
 
Thanks everyone for the input!

I picked up some big ballnose insert endmills along with an auction lot I bought for something else last week
I'll make sure to keep a couple of them just in case :)

Thanks again

Lee

Sent from my SM-N960U using Tapatalk
 
Are they useful on a manual mill? Any tool is only as useful as the person using it.

That being said, would I stock a variety of ball end milling cutters. Probably not. I do have a few end mills with a radius on the corners. They are more useful for leaving a fillet between a flat bottom and the side(s) of a cut. Besides, it is a nice way to rescue a cutter that has a chipped or worn corner. That can usually be done by hand if the radius is small.
 
I would stock them. But not large ones. 1/8" up through 1" by 1/8" increments for sure. Not an everyday thing but when you need them, you need them.
 
I've designed parts in my past that the drilled holes had to have a spherical bottom of the hole to reduce stress risers. When pressured up to 10,000 psi. The parts were made of cast iron. Yeah, I know, but these parts went down hole in the oilfield, no chance of anyone getting hurt from them. Ken
 
Guy Lautard wrote a handy little book with tables for generating radius shapes. It is not hard to generate a good approximation of a .687 radius with a 5/8 ball end mill.

SavageBaseRadiusRS.jpg
 








 
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