Is it possible to make round balls (1/2" diameter) using...

[brianklein]

... A CNC Lathe??? Or even elliptical shapes???

[Delw]

yes as long as the have a hole or something on the cut off side so you dont have a imperfect spot.
if you need a perfectly round balls then you will ahve to do it in 2 operations. the second op you will have to cut your jaws so when they grab the ball the pull it towards the locating face. 1/2 ball you would need to have a jaws depth of a min .275 and thats on the light side.

location of the cut off spot is not really critical cause the part is a ball and round. get it close to the front and your fine

[wildwestpat]

Hi BrianKlein

May be the method used in lapidary could be adapted to suit your need for a round metal ball. The methods used by the ball bearing makers are rather exotic as they are making many balls all of identical size and highly spherical.

There was a jig made by the Crown Lapidary Company - Los Angeles for making beads out of semi precious stone in the 50's. I converted this as a teenager but had to make do with the following method for a clock I was making at the time.

Having rough turned a ball this can be refined by cupping it between two cups made from soft copper and working down the grinding grit grades by rotating one cup in the lathe / drill press chuck and pressing the ball into the rotating cup with the other cup held at varying angles by hand. The infant ball being supplied with lubricant and more grinding grit. It is at least thirty years since I did this to make a set of brass balls for a congreave clock. Memory may have played tricks so please do a trial run and watch the safety aspects closely. It might be prudent to hold the hand held cup in some form of quadrant holder that can apply the necessary pressure. Needless to say the cups have diameter that suits the ball but leave enough of the ball exposed to facilitate a 30 degree manipulation of the moving cup.

Hope this helps and if anyone has a better method or corrections to my described method they will contribute.

Regards

Pat

[Shotout]

Check out this thread as well.
http://www.cnczone.com/forums/showth...ng+sphere+geof

[brianklein]

Thanks for your responses. I am trying to make balls and elliptical shapes out of stainless steel. Would tis material affect the processes that you are talking about???

[brianklein]

anyone???

[Mcgyver]

Originally Posted by brianklein Thanks for your responses. I am trying to make balls and elliptical shapes out of stainless steel. Would tis material affect the processes that you are talking about???

of course, speed feed etc changes with material. the basic approach and set up does not. what stainless will also play. easiest to use a free cutting like 303 or 416