[tumblermonkey]

I work for a wheel manufacturer, and for the past 50 years or so this company has relied on drill presses for all our drilling needs. In the last year we purchased a VMC and have used it to do the bulk of our drilling and milling work, but still rely on the drill presses to do our countersink and ballseat work.

The question I have relates to the ballseating tools. On our drill press we have custom drills made with a specific radius ballseat to handle our ballseating needs. On the VMC we had some custom drill inserts made by Kennemetal, which work fine, but it's a six month process for us to get new ones, and they want us to order 10 or more. I've looked into Ball mills but haven't found the sizes I need, and haven't found a Rep that could quote me a decent price for custom Ball Mill inserts.

Does anyone know of a tooling company that supplies ball mills at the following radiuses:

.875"
.709"
1.188"

Thanks For any help you can give.


**Here's a little explanation on ballseats in case it's unclear what they are and why they're used.

Stud piloted, or "Ball Seat Nut" disc wheels are designed to be centered by the nuts on the studs. The seating action of the ball seat nuts in the ball seat bolt holes centers the wheels.

http://farm8.staticflickr.com/7123/7...610b6f0c_b.jpg

[Lyfordln1]

If I understand correctly, you need an endmill with the stated radii on them. Are the end mills the diameter of 2Xradius? If so, why not have a cutter sharpener company make you the endmills from regular endmills? They have been doing it for ages.

[tumblermonkey]

Thanks for the Reply Lyfordln1.

You are correct that the diameter of the tool needs (or would be) 2 x Radius. I'm assuming when you are talking about an end mill that you are referring to a solid carbide end mill, correct me if I'm wrong.

The issue I'm facing with having a sharpening company machine the solid carbide end mills is the cost versus durability. The cost of those carbides get pretty pricey when you start hitting the 1.5" - 2" range, and then tack on the cost of having them sharpened. The other unknown would be whether or not I could plunge those straight into a hole and machine the ball seat properly without destroying the bit. I would assume that if the speeds and feeds were correct, that it would act like a drill and plunge to the depth I need and create a proper ballseat.

It's a good suggestion and something I'll need to look into further to figure out the costs compared to what I'm currently researching. Thanks for the help.

[Geof]

If you are now able to interpolate these seats on a VMC you no longer need full size ball mills or countersinks. You could get much smaller end mills ground with the appropriate corner radius that matched the desired seat radius and then interpolate around the seat with this. In addition to the initial cost being less the tool life would probably be greater and it would be possible to regrind them.

[underthetire]

I know the seats you speak of. My Porsche uses them. Interpolating the hole may work, but would be slower for sure. Having a tool company grind what you need would be the best. Unless for some strange reason your doing steel wheels, I'd try a cobalt and see what the life is. Much cheaper and easier for the grinding company deal with.

[tumblermonkey]

Interpolating the hole may work, and depending on how much time it takes, it may be a viable option. We generally use ball seat bits because it allows us to open a hole to a certain diameter, while at the same time hitting our tool depth at the proper radius...all while plunging/drilling.

Everything we machine is done with steel. The majority of the wheels we build are for construction equipment, earth movers, and military vehicles. (That photo I found was just an example of a ballseat, and not exactly of something we make. Sorry for any confusion.)

Since we do work with steel, most of the end mills I purchase are carbide, and generally have a coating on them. Majority of the inserts I purchase for my mills and indexable drills are an alloy of carbide and cobalt. Cobalt end mills may still be an option, I'd just have to do a little experimentation.

Thanks for the help.