Carbide Lathe Tooling Advice

Hello Chief Delphi,

Our team is looking to purchase some carbide lathe tooling and I was hoping some team machinists could share recommendations for FIRST-specific work.

I’ve done extensive research and turned up a few recommendations in a sea of “I like this type of insert” followed by responses detailing why that insert is NOT the right tool despite OP’s success with it. Needless to say, going to MSC or other tool suppliers websites just reiterates the fact that the options available are only exceeded in number by the opinions on them :smiley: .

Our applications are typical to all things FIRST but our machine shop is only manual. Skill level: moderate. We’ve made some nice parts on our school’s well worn machines (ok, they were beat up when I was a student far too many years ago). Not having accurate or square machines at the start of build season will force improvement in skills in a hurry…

Anyway, what are some recommendations for basic, robot-grade carbide lathe tooling? I am most curious about opinions on types and geometry over insert quality (the guys on PM made a great case for avoiding the fifty cent specials).

Thanks for any thoughts!

We highly reccomend these. These inserts were recommended by both Cory(254), RC(1323), and the man who owns LatheInserts.com. Keep in mind that we use these on our full size lathe even though they are marked as “hobby”.

Asking for recommendations for carbide tooling is still a little too broad of an area to answer.
Let’s start by answering a couple of questions first.
What type of turning equipment do you have? Are they beefy industrial like an old Monarch or hobby grade like a small Atlas or Craftsman? You mentioned that your machines are worn. Do they seem to have a lot of slop in the carriage and cross slide?
What type of tool holders do you have? Can you hold inserts or only square shank tool?

Another supporter of latheinserts.com /ccmt/ccgt inserts here.

For general OD/ID turning/boring my personal favorites are 32.52 CCMT’s with the LF chipbreaker (http://www.maritool.com/Indexable-Tooling-Boring-Bars-Boring-Bar-Inserts/c50_142_143/p2062/CCMT09T308LF-K68/product_info.html). I prefer the 32.52’s over the 32.51’s for the larger radius, (.032 v .016), this makes the radius a little stronger and gives better finish, as long as you can stand the .032 radius on your parts, or the time it takes to remove it (not much).

The CC_T geometry is relatively common, and has positive rake, which is desirable for aluminum and lower horsepower machines. You can find these inserts all over the place, you can even find great deals on name brand 10pks on ebay. Used properly, CC_T inserts will last a very long time in aluminum, I think I got at least 500-700 gears out of each edge on mine.

With whatever insert types you choose, I strongly recommend you standardize inserts across all your tooling. Having one insert type for your turning/boring tools really helps keep you productive, since you can swap inserts across tools if you run out or break inserts. The SCLC series, for holding CC_T series inserts are my favorite.

For cutoff tools, the self-locking GTN series inserts and holders are my favorite. These make a shocking difference over standard HSS parting blades.

Here’s links to

SCLC Boring Bars:
http://www.shars.com/product_categories/view/80103/SCLCR_Boring_Bars_For_CCMT_Inserts

SCLC Turning Holders:
http://www.shars.com/product_categories/view/80703/SCLC_RL_Toolholder_For_CCMT_Inserts

and a handy insert lookup chart to decode insert designations.
http://www.carbidedepot.com/formulas-insert-d.htm

Thanks for the replies! I’ll take a look at some of those sets.

Our bigger lathes have some power. They are a variation of the imported 1340G model available in several colors and logos. With HSS tooling last year we were pulling some heavy chip coils off aluminum before they started bogging down. Couldn’t quite get a good chip breaker ground into the tool bits with the shop grinder.

The lathes are fairly tight, if made to be. The setup for any precision job involves some form of minor rebuild that will last a week or two before it is back to slop :rolleyes: Judging from the work left around the shop by the usual users, you’d think they were using a tire iron as cutter… The abuse just shakes the screws and gibs loose.

We have no holders yet, which is why I wanted to pick a type that was good for most robotics work and standardize on that, as AlecS mentioned.

I bought a pack of these back in 2006 and it’s all I use for turning and facing on two different lathes. I haven’t even been through half of them yet.

I’ll pile on to the rest - just pick up SCLCR/L (RH & LH) holders in whatever size you like, and a pack of aluminum/nonferrous inserts. McMaster sells Dorin holders at ~$48 each, and the aluminum specific inserts are $6.90/ea for a box of 10 (3244A316 or 3244A318). I forget the brand of the inserts, might be Mitsubishi.

Shars also sells the “CCMT” style aluminum specific inserts, they’re listed as CCGX on their site. Never tried them, but in case you wanted to pick up the boring bar/holder cheaper from them.
http://www.shars.com/products/view/8063/CCGX_3251_LH_YD101

As a side note,

We’ve been going through our tooling and consolidating it all. One thing that we liked doing was making sure most if not all of our lathe indexable tooling used the same insert. We currently have two lathes and are picking up a third soon. So its nice that the inserts work across both machines.

Our boring bars, turning holders (1/2" thick and 3/4") thick both use CCMT. We went with the 32.5X size. Inserts from latheinserts.com or Maritool are awesome.

For all our grooving stuff we use thinbit, the inserts work both in the 1/2" and 3/4" holders we own.

Jim, if you PM me I can send you the list of stuff we just bought/will be buying.

-RC

Jim,

Before you spend a lot on tooling, contact a local dealer and see if they have a holder and inserts to try. You may find that your machines can not handle the heavey cuts that carbide likes.

A few years ago we had a retired machinist mentor our team and he put me on to TCGT inserts:
http://www.kbctools.com/can/Navigation/NavPDF.cfm?PDFPage=251

They work very well for aluminum and plastic.

For steel we use a more robust insert like TNMG:
http://www.kbctools.com/can/Navigation/NavPDF.cfm?PDFPage=260

The triangular inserts work well for general purpose turning and facing. We already had the toolholders, so we stuck with that geometry.

For retaining ring grooves we use the Nikcole mini system:
http://www.kbctools.com/can/Navigation/NavPDF.cfm?PDFPage=330

Another thing to consider is a quick change tool post:
http://www.kbctools.com/can/Navigation/NavPDF.cfm?PDFPage=486

We installed one of these a couple years ago, and it has dramatically improved the efficiency of our lathe.

Any 13x40 lathe will handle a CCGT/CCMT or similar high positive insert with no trouble.

Our mobile trailer has a POS JET 9x19 lathe and the only thing we run on it is inserted carbide tooling (WNMG) and it runs fine.