Bonded Carbide

[Mayhem]

Ken - at some point I'd really like you to post some of the info that you posted on the forum that cannot be named, as that was such a wealth of information.

Prior to reading that, I had resigned myself to the fact that I could only use HSS tooling (even carbon steel tooling, given the vintage of my lathe). Whilst I do use HSS, I really appreciate the fact that I can get good results with insert tooling and spend the time I use to spend at the grinder actually making something.

For example, the VG112 R 16-30 parting/grooving tool has seen some heavy use recently and despite my top speed being less than 500RPM, it has worked beautifully.
The one thing I find problematic at times is the grade and chipbreaker. I've read the manufacturer's data and got the depth of cut dialed in so that it is at least breaking chips but some of the inserts that are for steels perform worse in 1018 (or similar) than some that are designed for SS or even cast iron. However, the flexibility of a quick insert change has made this less onerous.

However, it does beg the question as to how much do you believe the manufacturer versus testing and seeing what happens?

[PixMan]

Darren,

I'm not recalling what I had posted elsewhere, so help me out with that.

As for the VG112 grooving tool and it's inserts, it's not uncommon for 1018 steel to act more like a 300 series stainless in terms of chip control because it's such a stringy steel. Is it grooving and parting the 1018 that you are referring to, or is it turning where you have issues, or....both? Is it a matter of chip control or tool life?

Manufacturer's recommendations are based upon their tests in given materials. With a lathe such as yours, it's impossible to duplicate or even "imitate" their results due to the low cutting speeds and (I think) you also don't have known feed rates. When a guy like Russ looks up recommended parameters and can program a machine to the given values, it's a whole different ball game. Those recommendations are meant to get you close, then one adjusts speed, feed and depth of cut to get the productivity dialed in to their needs. Some shops will favor maximum material removal rates over tool life, quite the opposite with most home shops. Chip control is important in both environments because it's a safety issue. No one wants long stringy chips wrapping around the work piece, the machine, nor (especially) the operator.

Shoot more questions anytime!

Ken

[Mayhem]

I just saw my post was written a little unclear. I'm having no problems with the VG112 grooving tool and inserts - they are working fine and I love that tool. If I had any complaints, it would be that the surface finish of the parted piece isn't pretty but I can simply face it. I know this is down to the lack of sufficient SFM but I can live with that. I just have to allow for that when using it.

I understand what you are saying about manufacturer's not testing their products on circa 1890 lathes with babbit bearings and (in the case of my busted feed system) no auto feed. However, some have worked extremely well using the specified DOC and broken the chips. I simply experiment with the DOC, try to crank at a different speed or switch inserts and keep notes. Sometimes I have the same issue on my friends late which has a much higher top speed than mine. However, I can generally work around it.

The post I am thinking about was one in which you detailed the toolholder nomenclature and the steps in using that information to make smart decisions about inserts. There was a fair bit of Q&A stuff in there too but you covered the major areas: turning, boring, parting, threading and milling. Information on common pitfalls, such as proprietary tooling, avoiding the cheap toolholder sets etc. Lots of pearls of wisdom for those of us who often feel like we are looking at ancient Egyptian hieroglyphics! I basically went from knowing absolutely nothing to the point where I can work my way through issues that arise as a result of that. Of course, your personal tutelage over the years has also helped a lot. I'm sure that Ed may recall the thread I am talking about.

You have probably covered a lot of the info here but it is dispersed over multiple threads on a site with an iffy search feature. I'll have a look through my files, as I think I cut and paste a lot (if not all) of your info in that post into a word document. All this said, it may well be something that you simply don't have the time to put together.

[stevec]

Good move Ken! I quit in July 1976 and haven't looked back since. I can't say I have 28 yrs. of savings jingling in my pockets though.