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Cutting tools for a AXA tool post?

1BadDart

Plastic
Joined
Nov 5, 2019
For the last month or so I've been gathering some missing and needed parts for my SB 9A. Soon I'll buy a AXA tool post, holders and a set of indexable carbide turning tools.

What size should I buy, 1/4", 3/8" or 1/2"?

Thanks, Justin
 
1/2" shanks are what the AXA size holders are designed for.

You may run out of vertical adjustment for smaller shanks.
 
I have a SB heavy 10 w/ an AXA toolhoder. I use mostly 3/8 HSS tool bits. I do have some 1/4 & 5/16 blanks I use occasionally w/ my AXA. You can always under-shim a tool bit to raise its height. And the toolholder itself can be raised and lowered to suit, obviously.
 
You don't have either the speed or rigidity to make full use of carbide. I run a 13, I use carbide for roughing cast iron, and for threading I use a lay down insert. That's it. Everything else is HSS ground to suit. And the 13 is a bit more rigid and powerful than the 9. The 9 was designed to use HSS, as was the 13.
If you look up SB's book "How to run a lathe" it has instructions on how to grind HSS. I use a white alum oxide wheel, the grey wheels that come on bench grinders are not really suitable. Rockler woodworking sells them if you only have a 6" grinder.
You can grind for any cut you like, you'll never break your last insert on Friday afternoon, and in learning how to grind and what works, you'll then understand *why* it works. Wanna add a chipbreaker to your cutter? No prob.
If you don't understand why something works or doesn't work, you are going to be flying somewhat blind buying 10.00+ inserts.
Another good way to get started is to buy a stash of old HSS cutters off the bay that some knowledgeable person ground before they shuffled off this mortal coil. Dead cheap cutters, and an education thrown in. I bought a large box at an estate sale some years ago for a few dollars, there will be quite a bit left when I'm gone. Old man that ground them was a wizard.
 
Plus one on the HSS. Most carbide inserts at negitive rake and designed for high HP, high speed machines. The South Bend 9 is neither.
 
Plus 2 for HSS but I would consider using brazed carbide tooling, which I have done a lot on small southbend lathes, but I have a diamond wheel on my bench grinder to sharpen/shape them.
 
Thanks for the explanation. I have several pieces of 1/4" HSS and some brazed carbide tooling along with a few pieces of each in 3/8".

Justin
 
I’ll be the contrarian here. I usually use indexible carbide tooling on my 9” Logan, which is directly comparable to a 9A. In fact, every AXA holder on my bench has carbide insert tools except the boring bar and the parting blade. It works just fine for me with sharp inserts. I do occasionally use HSS when I need a mirror finish or a form tool.
 
I won't repeat the carbide vs HSS argument. If you decide to go HSS, I find the 3/8" square stock to be a good compromise. 1/4" and 5/16" pieces can be difficult to hold and and tend to wear quickly. A nice 1/2" square tool is very nice and fits the holder well but I'll tell you that it can take a while to grind a proper shape on the end of a 1/2" square blank of 8% cobalt tool steel--it's hard and tough.

If you decide to go indexable carbide then I'd get the 1/2" square bit holder because the carbides are a little easier to deal with for that size holder. I don't think I've ever seen a 1/4" square indexible holder but I can imagine that they do exist and that the carbides and hold down screw would be difficult to manage.
 
I’d recommend sharp/positive inserts sold for aluminum and the associated tool holder(s). You can use them on steels at lower speeds and lighter DOC very effectively. And while I use some HSS and know how to grind, at the end of the day carbide inserts can be had significantly cheaper than a bunch of HSS blanks. Find a size insert that you can use in various turning holders and boring bars and save the HSS for special stuff.
 
What type of insert are you using? Positive rake?

Honestly, I can't tell you except I use what's cheap that looks good LOL. I'm a retiree doing this for a hobby. I am not a trained machinist like most of people here. I mostly make tools and parts for other machinery projects. I don't take deep cuts. I rarely make more than one of whatever I am making.

A lot of the cutters I use came from auctions. I have a ton of nicely ground HSS cutters that I use as needed. I also have a lot of brazed carbide as well as indexible tooling.

But looking at what I use daily, it's usually those cheap triangular sets from Asia. They are positive rake, and have a chipbreaker. I usually set the tool at a steep angle to the work for faster metal removal, then switch to a shallow angle to the work to get a nice finish. I will say that the cheap inserts that comes with them fail quickly and are replaced with name-brand inserts. This looks like them:

10pcs tcmt110204 vp15tf / tcmt21.51 vp15tf carbide inserts lathe turning tool holder inserts Sale - Banggood.com|Shopping USA

Lately I have been using these diamond-shaped cutters.

machifit 10pcs dcmt070204 carbide inserts with 4pcs 12mm lathe boring bar turning tool holder Sale - Banggood.com|Shopping USA

They work just fine on my 9" lathe. I turned a 1" stainless rod last night with the above tooling. It turned beautifully, and the last cut at a slower feed was almost a mirror finish. It seems to work equally well on common steel, most stainless, brass and aluminum.

When I run into something tough that stresses the 9", I have an 11" Logan at the shop that is tooled with more name brand tooling. It's pretty rare that I have to make a trip just to finish a project started on the 9".

Like i said, it's a Logan, not a SB. I've had South Bend 9As, 9Cs, and one 10K. I have a 9A now waiting for some attention. All the above tooling works on them too.

Without knowing the ideal profile, you can pretty well tell if an insert will be suitable for a light lathe. If it has negative rake or a broad radius, it will take more pressure on the work and probably needs more mass and power to drive it properly. Generally inserts with six cutting edges (both sides usable) have no rake and don't work well, so I stick with single-sided inserts with nice sharp edges.

YMMV etc.
 
I’ll be the contrarian here. I usually use indexible carbide tooling on my 9” Logan, which is directly comparable to a 9A. In fact, every AXA holder on my bench has carbide insert tools except the boring bar and the parting blade. It works just fine for me with sharp inserts. I do occasionally use HSS when I need a mirror finish or a form tool.

Logan user here too. I’m the opposite, all my lathe cutting tools are HSS except the one boring bar that is positive rake. 3/8” HSS fit the AXA holders nicely. I also use 5/16, 1/4, and 1/2.

A great way to start is to buy at auction or eBay used already ground HSS. You can learn a lot from a professionals HSS stash.
 
I use mostly 3/8" HSS on my Logan, similar in size to the SB. I also keep 3/8" brazed tools around, and my larger boring bar takes inserts. If you look at the grinds in How to Run a Lathe, you'll probably find much more aggressive angles for steel than modern inserts. Those smaller lathes can really peel off metal if the tool is ground properly. OTOH, they don't have the power or rigidity to run zero rake tools with heavy cuts.
 
I’ll be the contrarian here. I usually use indexible carbide tooling on my 9” Logan, which is directly comparable to a 9A. In fact, every AXA holder on my bench has carbide insert tools except the boring bar and the parting blade. It works just fine for me with sharp inserts. I do occasionally use HSS when I need a mirror finish or a form tool.

I'm with Rex TX. I'm a retired machinist/shop owner with a Heavy 10L and Bostar AXA toolpost. I was taught how to grind HSS in school but have rarely needed to do so since. I do believe it is important to know how. I am running all carbide, mostly CCMT and laydown threaders, but I even run some CNMG 432 inserts for rough/interrupted turning and boring. I purchased a nice little assortment of CCMT tools with 1/2 shanks and inserts from China (Aliexpress, Banggood or eBay, can't remember). They have been quite acceptable.

Here's my Heavy 10 boring out a 6 in. pipe coupling with a CNMG 432.

 
MrWhoopee,

Your Heavy 10 is quite a bit stouter than a 9A, but the point is still valid.

I like that little cover over your cross-slide slot. I'll have to copy that.
 








 
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