Learning to sharpen HSS lathe bits......A lesson in futility.....

[TheOldHokie]

Thanks to everyone for helping me out.

After some "intensive research" I have decided to "try" HSS inserts.

A few things that I have noticed/realized/learned.

My machine is pretty small as compared to many of yours which puts me in a "weird category" that is somewhere between "mini hobby lathe" and "Big 'Ole Industrial lathe"

One thing that struck me as odd, just this weekend, was that all of the tooling that came with the machine, some 10+ years ago, was HSS.....I literally have "hundreds" of HSS blanks, but the Old Man did not have even one "carbide" bit.

Hmmmmmm.........So maybe/probably the Old Man that used it before me "knew something"??????.....He did have a massive work shop.

Long story short.....I found a company that makes HSS inserts, and so I ordered a LH and RH tool, and a few inserts.

At 10+ bucks per insert, they are not cheap, but I am hoping that they are a good choice for my machines size, capability and my experience level.

They get great reviews on the "machinist sites" that I have been perusing, and apparently they are "easily" and quickly sharpened on flat stone, so they last a long time.

I have also decided to "not give up" on my "lathe bit grinding", but just "takees my time" and practice, but am keeping my "options open" for carbide tooling as well.

I will post my results when I get a chance to try them out.

The size of your lathe is not the issue
There are a gadzillion small lathes using solid, brazed, and/or indexable carbide. You simply have a learning curve to climb.

Dan

 

[Lil Foot]

Another thing to keep in mind with carbide tooling; they resist wear far better than HSS, but they don't like interrupted cuts.
Carbide is brittle.
Use light cuts in interrupted situations.

Worst scenario I have found is turning a flame cut disc of steel round.
It is interrupted, uneven, out of round, has slag & hard spots; none of which are conducive to long insert life.
Once you are below the bad stuff, you are golden.

 

[TheOldHokie]

Another thing to keep in mind with carbide tooling; they resist wear far better than HSS, but they don't like interrupted cuts.
Carbide is brittle.
Use light cuts in interrupted situations.

Worst scenario I have found is turning a flame cut disc of steel round.
It is interrupted, uneven, out of round, has slag & hard spots; none of which are conducive to long insert life.
Once you are below the bad stuff, you are golden.

All true. And like most things understanding the process helps to maximize results.

Interrupted Turning

Turning is a game of fundamentals more so than other machining operations such as milling, drilling, or grooving. There is really nothing fancy about turning.

www.canadianmetalworking.com

Dan

 

[Yooper]

Thanks to everyone for helping me out.

After some "intensive research" I have decided to "try" HSS inserts.

A few things that I have noticed/realized/learned.

My machine is pretty small as compared to many of yours which puts me in a "weird category" that is somewhere between "mini hobby lathe" and "Big 'Ole Industrial lathe"

One thing that struck me as odd, just this weekend, was that all of the tooling that came with the machine, some 10+ years ago, was HSS.....I literally have "hundreds" of HSS blanks, but the Old Man did not have even one "carbide" bit.

Hmmmmmm.........So maybe/probably the Old Man that used it before me "knew something"??????.....He did have a massive work shop.

Long story short.....I found a company that makes HSS inserts, and so I ordered a LH and RH tool, and a few inserts.

At 10+ bucks per insert, they are not cheap, but I am hoping that they are a good choice for my machines size, capability and my experience level.

They get great reviews on the "machinist sites" that I have been perusing, and apparently they are "easily" and quickly sharpened on flat stone, so they last a long time.

I have also decided to "not give up" on my "lathe bit grinding", but just "take my time" and practice, but am keeping my "options open" for carbide tooling as well.

I will post my results when I get a chance to try them out.

After reading this a bell started ringing in my head. Some years ago I purchased a set of HSS lathe bits and inserts. So I opened up the the drawer and there they were. Forgot that I even had them!

 

[Yooper]

So everybody understands what we are dealing with, the images are the speeds, hp and feeds that our lathes have. Yup, a whopping 1/4 hp on the original motor! If you want to put on a larger motor you will run the risk of wiping out the aluminum (Zamack) gears that drive everything except the quick change gears.

As an example of what I use on my 15 x 50 lathe with a 7-1/2 hp motor turning a 2" x 1045 round, I'll take between a .050 to .100 depth of cut at 500 rpm with a .010 feed rate to get a beautiful finish. Might drop the feed rate to about .005 on the final cut and up the rpm to 750 to even get a better finish. For 1" steel I'll be up at 1000 rpm. Might be able to take a .005 depth of cut with the Crafstman lathe but I don't think it will even handle this. And carbide does not like that depth of cut.

 

[TheOldHokie]

So everybody understands what we are dealing with, the images are the speeds, hp and feeds that our lathes have. Yup, a whopping 1/4 hp on the original motor! If you want to put on a larger motor you will run the risk of wiping out the aluminum (Zamack) gears that drive everything except the quick change gears.

As an example of what I use on my 15 x 50 lathe with a 7-1/2 hp motor turning a 2" x 1045 round, I'll take between a .050 to .100 depth of cut at 500 rpm with a .010 feed rate to get a beautiful finish. Might drop the feed rate to about .005 on the final cut and up the rpm to 750 to even get a better finish. For 1" steel I'll be up at 1000 rpm. Might be able to take a .005 depth of cut with the Crafstman lathe but I don't think it will even handle this. And carbide does not like that depth of cut.

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Yikes!!!

Dan

 

[Lil Foot]

After reading this a bell started ringing in my head. Some years ago I purchased a set of HSS lathe bits and inserts. So I opened up the the drawer and there they were. Forgot that I even had them!

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Been there, done that!
There have been a couple times when I thought "Boy, XYZ tool would really come in handy".
Then I think, "that sounds familiar", and I dig in a drawer somewhere, and there is my XYZ tool.
It is hell getting old.

 

[Runs With Scissors]

After reading this a bell started ringing in my head. Some years ago I purchased a set of HSS lathe bits and inserts. So I opened up the the drawer and there they were. Forgot that I even had them!

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Hahahah....well look what just showed up in the mailbox yesterday.




Edit: cant post pics for some reason, but My ARW stuff just showed.