I've been eye balling indexable ball mills. The ads finally got to me.

I want to know if anyone out there has any advice as to brand, Dapra, Iscar, Vallenite, and pro, con issues that only a user would be savy to.

Any advice appreciated.

Hey Dave, backed up any files lately? :D

I have had some interest in these also, so I will be interested in seeing what some of the guys say as well.

I purchased an Iscar 3/4" heliball mill lately, after spoiling a solid carbide ballmill on a job milling some C4340 HTSR. I was pleased with the results. The insert seemed to stand up very well. The insert costs as much as resharpening the solid tool anyways. However, the insert has much higher technology design in the cutting edge than is possible with a solid carbide tool. There are both roughing and finishing inserts available, with different geometries.

I myself have used all kinds of indexable ball mills. I machine basic free machining steel. The indexable ball mills I had didn't work all that well. They didn't run as fast or as smooth as solid carbide. Plus the insert prices are quite expensive. Sure they may be comparable to resharpening solid carbide, but I get alot more life out of the solid carbide. I use Hanita Varimill endmills and ball mills. These carbide tools have a TiAlN coating. They run twice as fast and can take a much heavier cut. With a 3/4" ball mill I can cut a 3/8" depth no problem. I used the indexable cutters for many years, and nothing comes close to the Varimill.

Joshman

I have a single insert Carboloy bull nose (D-0.98 R-0.78) style I use for roughing bulk material out for molds. The mill chatters a little as it is single flute but it is tolerable. A good hold of the part is a must. It is very good at removing the bulk material but I would not use it for finishing. I cut 7075, 6061, and 2024 with it.
For final finishing we use .25 or smaller ball mills. The details on the molds are small down to 1/16 ball mill. There are no indexable ball mills that small.
If you cut a lot of contours you might be able to get away using a indexable ball mill. You need to look at the types of indexables. Do you need a copy mill type (with round 'button' inserts), 2 fluted slot insert ball mill (flat disk with opposing edges), or a special radius ball mill with mulitiple contoured inserts.
If you can program for the chip thinning effect of ball mills you can get a good finish with the right insert. If you are not going to take the time to program for the indexable ball mill, then do not buy it. If you plan on cutting the same materials all the time this helps because you know how it is cutting and you do not need as many insert grades.
One last thing. Coolant/fluids definitely help. Make sure you have the spindle speed to support indexable inserts.

Due to the cost of the insert type cutters, I have not purchased any.

For those of you who use them; Do the numbers give a clue of rcommended IPT, I would think the speeds and feeds can vary, due to all the different shapes and radius differances of the inserts themselves. Where does one obtain that information?

Thanks,
Kenny