Insert Lathe Tooling - an education?

JHenriksen · Post by **JHenriksen** » Thu Oct 16, 2008 8:22 pm

Check the Ingersoll cutting tool web site. Lots of info. GKItool.com is another good place to look around
www.gkitool.com
http://www.ingersollcuttingtools.com/en/index.htm

BadDog · Post by **BadDog** » Thu Oct 16, 2008 8:26 pm

Much thanks for the great information. I'll be digesting all this for some time. That info from Mark is particularly useful and provides some actual starting numbers/points from which I can experiment with my new found capabilities.

I also picked up a selection of inserts from a friend so that I can experiment. They came out of a pro shop and all have some use but remain unused on at least a couple of edges. I got TNMG 431, 432, and 433 to try out. Likewise a selection of 80* negative inserts, some molded, some ground, different chip breakers, some with effective-positive rake, and even some Top-Notch inserts just for grins (and because I got a holder for scrap metal price). Once I decide what I like, I'll then have the basic information to start looking for good deals on what works best for me. I don't have holders for some of the others listed by Mark, but I can probably borrow some to experiment with.

Thanks again!

Post by **GlennW** » Thu Oct 16, 2008 9:42 pm

Russ,

If you are doing TNMG research, I'd be happy to send you an insert to try that I think you might like.

If you're interrested, send me your address.

Glenn

seal killer · Post by **seal killer** » Fri Oct 17, 2008 12:56 pm

BadDog and All--

This is a great thread. Makes me wish I had a lathe!

Do the concepts transfer to the milling environment?

Now that I can grind any shape in any tool, radius down to the infinitesimal, and have already built all the adapters necessary to hold smaller tooling in larger holders, (it sure surprised me when it worked!), I feel a need to get into insert end mills and boring bars.

If insert-based lathe tooling concepts transfer to milling work, then I have already learned a lot from this thread. If not, then I need to buy a lathe.

--seal killer
ps My mill has a 2HP motor and will turn the spindle at 270 - 2950 RPM.

BadDog · Post by **BadDog** » Fri Oct 17, 2008 1:23 pm

In my (limited) experience, you don't want to get into insert tooling on a small(ish) vertical mill. On my Bpt I've had very limited success with several insert "end mills", and these range from cheap Chinese (my first - GARBAGE) to high end US brands (sorta work, but not well). They all pale compared to regular EMs.

It seems The only workable exception for Bridgeport and smaller machines is the high shear high double positive high $$$ inserts. This mostly applies to "face mills", and I do have some of those that work well enough for certain things. And that may also work for "insert end mills", but I have no experience there.

I've found the following to work for me.

Fly cutters for finishing and squaring stock already close to square. HSS for clean steel or aluminum, carbide if I'm removing mill scale or cutting CI.

Inserted EMs for bulk slabbing type operations. I've got 3, each between 2.5 and 3", each for a different purpose.

Regular EMs for all else...

My insert EMs gather dust, can't remember the last time I used one. I don't think they are practical in less than a high speed VMC type environment.

seal killer · Post by **seal killer** » Fri Oct 17, 2008 1:41 pm

Russ--

Thanks for the words of wisdom. You doubtless saved me some bucks. I owe you. Come my way and I'll buy you a beer.

--Bill
ps I have no problem with owning a "smallish" mill. It is what would fit in my garage and, mainly, I knew it would handle the aluminum I would throw at it. But, what would a "mediumish" mill look like? Maybe 5 or 6HP?

Mark Hockett · Post by **Mark Hockett** » Sat Oct 18, 2008 2:09 pm

Glenn Wegman wrote:Hello Mark,

Good info, thank you!!

Have you tried any Cermets?

Pretty impressive little felllas.

Glenn

Glenn,
I have not tried Cermets yet. I want to experiment with them but my shop is so busy right not I have not had any spare time for that. I have tried a PCD insert with terrible results. My industrial supplier recommended it for a job I had cutting plastic. It lasted through 12 parts before the PCD fell off. At $90 per insert and each insert has only one cutting edge I was not happy. The supplier sent it back to the manufacturer with all of the specs on my lathe and they said my lathe does not spin fast enough, 2000 max rpm, for PCD inserts. The manufacturer did replace the insert with a full box of carbide inserts that they recommended for the job I was doing. The new lathe I am looking at is 20 HP and 6000 rpm so maybe I can try the PCD again someday.

BadDog · Post by **BadDog** » Sat Oct 18, 2008 3:32 pm

Heh, I just noticed a misprint in my previous post. Should have read:

Inserted Face Mills for bulk slabbing type operations. I've got 3, each between 2.5 and 3", each for a different purpose

Wow Mark, and here I thought I was getting into some pretty serious equipment with a 7.5hp lathe capable of 2000 rpm, and there you go shattering my illusions.

Mark Hockett · Post by **Mark Hockett** » Sat Oct 18, 2008 5:36 pm

Russ,
A 17X60 lathe with 7.5 HP and 2000 rpm is a very serious piece of equipment.

The lathe I want is much smaller, 6" chuck maximum and only 15" between centers. I need the high rpm for turning small parts and it will also allow me quicker part cycle times. Feeding at .010" per revolution at 6000 rpm is much faster than 2000 rpm. In todays market CNC lathe work is very competitive and jobs are won and lost by penny's per part. The higher rpm and a faster tool turret will substantially lower cycle times. The reason the lathe has 20 hp is most CNC turning centers either have a high-low gear range or no gears on the spindle drive. They require the high hp so there is enough power turning at the slower rpm's.

Your 7.5 hp lathe would probably kill my 7.5 hp lathe turning large parts because mine has no gears on the spindle drive, it is direct drive from the motor to the spindle.

BadDog · Post by **BadDog** » Sat Oct 18, 2008 6:02 pm

Ok, not what I envisioned, but still sounds like an sweet piece of equipment.

And I was kidding about the "lathe envy" bit, I know my lathe is pretty serious and well beyond the typical "hobby" range (and fankly it scrares me a little, which is healthy to a point).

Post by **GlennW** » Sat Oct 18, 2008 9:16 pm

Russ,

I'm not familiar with your lathe, but mine has an electromagnetic spindle brake and for that reason the spindle speed is limited by chuck size. It's a 6hp 2000rpm spindle, but with an 8" chuck it is limited to 1000 rpm. I run it harder with a 6" chuck and max rpm with collets. For short periods of time I will run it at max rpm with either chuck, but if running for any length of time with a lot of starts and stops the brake gets hot and looses it's effectiveness. I can turn the brake off, but the spindle coasts forever without it! You may want to check into yours as it may have a similar braking system.

Edit: Actually the chucks themselves will also have a speed rating. My 8" Bison forged steel chuck is rated for either 3200 or 3400 rpm.

Your insert was mailed yesterday!

Glenn

BadDog · Post by **BadDog** » Sat Oct 18, 2008 10:03 pm

Thank you very much, I look forward to trying it. Gotta make a part for a friend later tonight, so I'll be trying out the other inserts a bit more. But it's mostly a boring (multiple meanings) job with smallish hole, so I won't get to try my latest acquisitions...

I just got through putting my apron back together a second time. I HATE leaks, and it seems that it was leaking round the bottom plate, and around bolts that were in through hole. Pulled it apart and sealed it up again paying more attention. Maybe that's the last of the work on my lathe for a while.

And my lathe has a band brake. I really wanted hydraulic disk, but hey, you take what you get. In any case, it stops my 10" chuck well enough, though it could use some adjusting. As for top speed on the chuck, I was wondering about that myself. There is no information I've seen on it, and I've only spun my Rubberflex collet up to 2k so far. Not sure, but I think most any modern 10" chuck should be safe to 2k. Need to do some research on that though...