Lathe Cutting Tools

I have no doubt that Splat's success with the tangential style tool, has been excellent, but my venture down that path, was a gut wrenching disaster. About 6-8 years ago I bought a tangential tool, from a supplier, the tool came from Australia, first it took almost 4 months to get it, and my results went down hill from there. Cut quality was terrible, the tip needed constant sharpening, just extremely frustrating to deal with. They replace the tool twice, with absolutely no change in operation, they sent me, different and per-ground tool bits, still crap poor results. I tried many different speeds and feeds, 3 different brands of HSS tool bits and different cutting heights, no matter what I did, it looked like I used a hacksaw or blunt wood chisel, as a cutting tool.

I tried it on all of my lathes, a Atlas 12 x 54, a South Bend (both long gone) and my current 14 x 40 Jet, also tried it on a few of my friend's lathes, they got similar results to mine. I have a friend with a TOS lathe, who I believe, still has the tool in his shop, he tried it and said it was crap. Then again, 2 friends, I have in Texas and Georgia, have them and love them. I have and neither did the supplier, have any idea of what was wrong.
 
Jack, was that the Diamond version from Eccentric Engineering? I know they have changed the tool around a little but I believe it had to do with the angle of tool presentation. That sucks you had bad luck. I love mine.
 
Buffalo20 said:
I have no doubt that Splat's success with the tangential style tool, has been excellent, but my venture down that path, was a gut wrenching disaster. About 6-8 years ago I bought a tangential tool, from a supplier, the tool came from Australia, first it took almost 4 months to get it, and my results went down hill from there. Cut quality was terrible, the tip needed constant sharpening, just extremely frustrating to deal with. They replace the tool twice, with absolutely no change in operation, they sent me, different and per-ground tool bits, still crap poor results. I tried many different speeds and feeds, 3 different brands of HSS tool bits and different cutting heights, no matter what I did, it looked like I used a hacksaw or blunt wood chisel, as a cutting tool.

I tried it on all of my lathes, a Atlas 12 x 54, a South Bend (both long gone) and my current 14 x 40 Jet, also tried it on a few of my friend's lathes, they got similar results to mine. I have a friend with a TOS lathe, who I believe, still has the tool in his shop, he tried it and said it was crap. Then again, 2 friends, I have in Texas and Georgia, have them and love them. I have and neither did the supplier, have any idea of what was wrong.
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Odd. In all the comments I've seen about the Diamond tool holder sold by Baycom and the one from Eccentric Engineering, I've never seen a negative impression. It would be interesting to figure out why your experience was the exception.
 
It is interesting to read that several people shy away from hss b/c of having to grind/re-grind

if hss is better for your application, can't you have the best of both worlds by using inserts that are made of hss and not carbide? - according to this clip:


they can be resharpened, come in every varity (like carbide inserts), are a lot cheaper, and have the benefits of hss as a material (where hss's pros are a benefit) and yet have the convenience of a quick turn of a screw and having a new perfectly ground edge and the luxury of not having to hand grind?

are there many out there that use inserts but made of hss rather than carbide?

is there some downside to hss inserts that make them undesirable?

thanks
 
i vacillate between carbide insert tooling and hss, dependent on the job requirements or material.
insert tooling is very convenient and quick to use, but sometimes inserts break at the WRONG TIME :mad: and can foul the work
i'd offer the suggestion of getting Inserts (both Carbide and HSS) and HSS blanks, so that you may make the comparison for yourself.
If you are turning some tougher materials, i'd also suggest 8%Cobalt HSS blanks , they are really useful.
HSS is generally very inexpensive can easily sharpen hundreds of times by hand on a bench grinder with common aluminum oxide wheels.
Carbide is generally more expensive will need Green Stone or a Diamond wheel to sharpen, then hone to best effectiveness. (an AlO3 wheel can sharpen carbide but it tears the wheel up due to the application force necessary to grind)
 
thanks Mike - i am new it at this so forgive me if i am being slow

i thought the breaking issue was with carbide (and ceramic?) only and NOT HSS inserts, such that all of the convenience of an insert can be had w/o breakage and without being as expensive and being able to to sharpen the HSS insert? is that not correct?

even with all of that, it may be that you are saying (as many other threads have) that certain spots just require you to grind something special and you need an hss blank or blanks...this i get

but is the reason people are avoiding inserts (for those that are) b/c of the breakage and cost issue primarily? - if so, it seems that hss inserts should solve that...probably i am missing something

thanks!
 
Flyrod said:
It is interesting to read that several people shy away from hss b/c of having to grind/re-grind

if hss is better for your application, can't you have the best of both worlds by using inserts that are made of hss and not carbide?

they can be resharpened, come in every varity (like carbide inserts), are a lot cheaper, and have the benefits of hss as a material (where hss's pros are a benefit) and yet have the convenience of a quick turn of a screw and having a new perfectly ground edge and the luxury of not having to hand grind?

are there many out there that use inserts but made of hss rather than carbide?

is there some downside to hss inserts that make them undesirable?
Click to expand...

The inserted HSS tools from AR Warner are very nice, for the reasons you cited. However, they have the geometry of an inserted tool and therefore cut like an inserted tool and this is where I think a well-ground HSS tool has a significant advantage. I own the ARW set and rarely ever use them because my HSS tools easily outperform them, just as they outperform carbide on my lathe for most jobs.

The problem with HSS tooling is that the geometry matters and you sort of need to understand how things work. Lots of guys try grinding HSS tools but they don't really have an appreciation for the geometry. When they try it, they find the tools don't cut much better than an inserted or brazed carbide tool so they come to prefer those carbide tools; I don't blame them, either. The downside to this is that many hobby shop carbide users have smaller, less powerful lathes that also lack the rigidity and speed to use carbide well and this limits what the lathe is really capable of.

So, IMHO, if you just want to use your lathe then sharpened brazed carbide tools are a good starting point. If you wish to use inserted tip tools then I would go with an SCLCR/L tool holder that uses CCMT or CCGT inserts that work better than the old geometry that the ARW tools use. If your lathe is small and not really rigid or powerful then you are far better off learning to grind a good HSS tool, and the smaller and slower the lathe, the more important HSS tooling becomes.
 
One thing I didn't mention in my previous post is that I just plain enjoy grinding my own tool bits! My shop is a hobby shop and grinding my own cutting tools is part of my enjoyment. I get satisfaction from being able to sharpen bits, drill bits, etc.. Even after all these years I'm still trying to improve my skill. Grinding, then finishing off with a fine hone to get that really nice surface finish! Grinding threading tools and other geometries offer an even bigger challenge.

So, use whatever you enjoy using and have fun! :)

Ted
 
Mike thanks

i think i get it now - yes hss may not break like carbide and may be cheaper, but they come in a set, limited variety of cuts and so any insert set (carbide or hss) is more limited than hss blanks that you can grind any way you want

++++++++++++

as to whether i can use inserts if i wanted to, I have a Logan 11" lathe

my guess is that is in between "small and not really rigid or powerful" and a powerful, rigid beast

with that in mind, is there enough power and rigidity there to effectively use inserts?

thanks
 
Flyrod said:
with that in mind, is there enough power and rigidity there to effectively use inserts?
Click to expand...

This is a difficult question to answer accurately because there are many factors involved. You have to understand that a inserted carbide tool also has geometry that is optimized for cutting conditions (speed, feed and depth of cut) most older lathes cannot meet. This is not to say the insert will not cut; it just won't cut as intended. On a short, rigid, high speed CNC lathe, they work extremely well. On a old, less rigid and slow lathe, they will still cut but they won't work as well. It's tempting to just leave it there because it is true ... sort of.

There is a lot you need to know about inserts before choosing and using inserts. There are literally thousands of them to choose from and each is optimized for a particular material and each has its own cutting conditions. All of them assume your machine can handle these cutting conditions, especially the required speed. The vast majority of inserts require speeds beyond what most older lathes can achieve, and the smaller the work and softer the material the faster the required speeds are. In addition, most inserts have chip breakers that require a certain depth of cut to work effectively. Add in the effect of the nose radius, which has a required depth of cut and feed rate to both rough and finish and the picture gets complicated. And we haven't even considered rake angles yet.

Add to this the fact that choosing an inserted carbide tool is not just about which tool you choose. It is also very much about how you use that tool. You need to understand the minimum depths of cut you can take and how the nose radius impacts on the cutting forces you deal with in every cut. Only then do you gain an appreciation for deflection and how this affects accuracy. If you doubt that deflection, nose radius, feed and speed have an impact, try taking 0.0005" off the diameter and see how accurate your cut is. And this applies whether your insert is carbide or HSS.

I am not saying you shouldn't use carbide or a HSS insert. I am saying that there is more to it than you think and you need to learn more before choosing if this is the route you go. Personally, I contacted Seco and asked questions before choosing the SCLCR tool and inserts I use, and I use them when I can meet the cutting conditions those tools require. That is, mostly largish pieces of harder steels. Otherwise, I use HSS tools that will cut well at the speeds and feeds my lathe can easily meet.

And if you think this is all complicated, wait until you try to figure out how to bore an accurate hole using inserted carbide boring bars. ;)

EDIT: I should add that your lathe was intended to use HSS tooling. It is rigid enough, has enough power and can run at the right speeds for HSS. The only problem with this is that you have to learn to grind a HSS tool. Luckily, this is not hard to do and will allow your lathe to work as it should.
 
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