Smallest possible hole through a 2" ball bearing? How?

We use a EDM made for tiny holes in hardened steel. Smallest is 0.006" but I believe 0.004" is possible. We usually make 0.012" to clear 0.006" wire. Full stroke of about 4" I believe. Most of the time we are using 1/2" to 1 1/2" steel. This is not our machine but similar. http://www.sodick.com/products/smallholeedm/k1c.htm They may not be common in your area but a quality shop should know who does. Surprising fast, it uses a brass hollow tube that the flushing coolant flows through as the tube spins and plunges down and through the steel.
Pierre
 
Pdentrem, that's one i've never heard of! Thanks for sharing!
 
We use a EDM made for tiny holes in hardened steel. Smallest is 0.006" but I believe 0.004" is possible. We usually make 0.012" to clear 0.006" wire. Full stroke of about 4" I believe. Most of the time we are using 1/2" to 1 1/2" steel. This is not our machine but similar. http://www.sodick.com/products/smallholeedm/k1c.htm They may not be common in your area but a quality shop should know who does. Surprising fast, it uses a brass hollow tube that the flushing coolant flows through as the tube spins and plunges down and through the steel.
Pierre
From http://www.ebay.com/bhp/sodick-wire-edm looks like they range in price from like $6K to $60K used on eBay. This is more than a small step up from my hobby mill, but also looks like a blast. -Bill
 
From http://www.ebay.com/bhp/sodick-wire-edm looks like they range in price from like $6K to $60K used on eBay. This is more than a small step up from my hobby mill, but also looks like a blast. -Bill

Bill, a wire EDM uses a moving wire as the electrode. The wire is threaded past the surface to be machined, which in your case would be a through hole, and the wire is a consumable. since you don't have a pilot hole, it wouldn't work for you.

You would need something like their K1C small hole EDM. You can pick one up on eBay for $20K.
 
Last edited:
EDM comes to mind
i suppose carbide will be the next possibility
otherwise i'm scratching my head.
Well, I tried several carbide bits. The ones from Home Depot--carbide tipped, would literally not even scratch the ball. (I have flatted the 1" ball a bit with a small grinder, so I am trying to learn to drill on a flat surface). And I bought a 10$ 1/8" carbide bit from JTS. Well bolted down. Cutting oils. Light pressure, different speeds, nothing. Medium pressure, different speeds, nothing. Slightly more pressure--yeah, what you would expect-snap. Carbide shards clear across the shop. Most glad I had safety glasses and a face shield--bits sure can fly when they shatter. So, I am in agreement now with the wisdom/experience of this thread. Drilling a ball bearing is not something for a simple garage hobbiest. But, as it is the journey, I'll call it a qualified success. Even if my ball bearing still isn't even scratched. -Bill
 
Most of the "Newton's cradle" I have seen just attach the strings to the balls with a small bump of epoxy. Waxed strings so they can be adjusted later (string pulls thru the epoxy)
Mark
 
Most of the "Newton's cradle" I have seen just attach the strings to the balls with a small bump of epoxy. Waxed strings so they can be adjusted later (string pulls thru the epoxy)
Mark
I am aiming more for something like
 
I am aiming more for something like
Whoops, didn't finish that post. It is bouncing steel, thus my reference to the cradle. But actually it is a triple (or quadruple) ball bounce on a 20 foot (or more?) rod (or very taught (turnbuckle taught from a ceiling beam) line/wire) with an anvil-like chunk of mass on the bottom. Normal steel balls (not hardened) will probably work too, but I was hoping to get the best possible coefficient of restitution. I have given up on drilling ball bearings.
 
Back
Top