HSS Tool Grinding

[Rick_B]

I may have asked this a few years ago but thought I'd try again.  I'm wondering if anyone has developed jigs and/or processes for sharpening HSS cutting tools for a metal lathe.  It seems it would simply be a jig for low angle settings (15 degrees or under) of the tool rest to the wheel and a "miter gauge" type holder to pick up the rake angles (I think).

Any thoughts?

Rick

[RickKrung]

This was a conversation on the Knife Sharpening forum (https://forum.tormek.com/index.php?topic=3365.msg21030#msg21030), but seems more appropriate here:

Rick,

In the 2nd photo which shows the Tormek, I see a metal lathe in the background.  Have you tried to sharpen your lathe tools on the Tormek ?  If so, any luck / thoughts / guidance you can share ?

Kind regards,
Rich

Rich,

No, I have not, part because I understand I need a different stone.  But, I wonder about that because my drills are all HSS and they can be sharpened on the standard stone. Another reason is that I don't use many ground HSS cutting tools, mostly insert tooling, both HSS and carbide.  But...  I want to learn. And third, I just haven't had much time for playing with the lathe lately, and that is in part due to me spending more of my free time fiddling with the T8.  Is that circular logic, or what? 

Further, I never learned how to free-hand grind HSS cutters very well, so have not attempted much.  But... and there is always a "but".  I make bamboo fly fishing rods.  I also make and sell a tool for making the wood reel seat mounting insert for fishing rods (more precisely, I have the parts made and I assemble them into the tool [mandrel]).  For turning of a recess in the wood reel seat cylinder, I had ground HSS cutters with a 3/8" radiused nose.  I had 10 ground, cost me $300 and I sold 9 of them for $30 ea.  Now, if I could rough them on a traditional high speed grinder and finish them on the Tormek, and still sell them for $30, I'd have look at it.  Another but.  There are carbide circular inserts available, so i don't think it pencils out. 

For that one remaining 3/8" radius cutter, I will sharpen it with the Tormek, but I do not yet have the proper jig.  But I do have the toolrest jig, which it seems could be used. 

Rick

I thought I saw another post describing some of the jigs that could be use for turning HSS lathe tools, but have not been able to find it.  I did try sharpening the 3/8" radiused cutter using the SVD 110 Tool Rest.  It worked very well and I'll use it more.  Several photos follow, first couple show the angles and front face, then setting up the
Tool Rest and matching the angle with a marker.  Last shows the finished sharpened cutter.  The finish is much finer than the original, but the photos don't seem to show it as well as I can see it.  The sharpened cutter is much smoother and more uniformly radiused and has a fairly mirror-like finish.  I have to believe it is sharper.

I wasn't planning on buying either the SVD 186 Gouge Jig or the SVS 38 Short Tool Jig as I don't use (or have) those tools, but I may now that I see how they may be used for something I do need. 

Rick

[Elden]

Rick B,
   It seems like I remember reading your previous question.I do not remember anyone making a jig for such. Ken S. has talked  about grinding a lathe bit as a grinding speed test. I am not sure that he was actually sharpening. I will try to do a little more searching. Might it be possible to modify the scissors jig base? I am not sure.
   Are you talking about the old standard bit shown below or a variety?

[RickKrung]

...snip...
I did try sharpening the 3/8" radiused cutter using the SVD 110 Tool Rest. 
...snip...
Rick

Correction.  The rest I used WAS the scissors jig rest, not the Tool Rest.  I don't see why the Tool Rest couldn't be used, but the scissors jig rest has a nice slick sliding surface, so I think I like it better. 

Rick

[Ken S]

Rick,

I remember (with much interest) your earlier post. I inherited a Unimat. I have always wanted to learn to use it, however, unfortunately it has been one of my projects not done.

My tests which Elden mentioned, involve placing a blank square bit in the square edge jig. I set the bevel for 30º and grind for five minutes. I use this test to measure the cutting efficiency of different grinding wheels. The SG performs surprisingly well. CBN wheels also do well. The Norton 3X wheels are amazing, especially the 46 grit wheel. It cuts very fast and, with the Tormek's wet grinding cooling, does not overheat the metal. (It is dustless as well.)

I need to retest the SB blackstone. Used with a heavy touch, like the SG, it quickly glazed and stopped cutting. I have heard that it needs a lighter touch to work well. Tormek users I respect have had good success with the blackstone, so I have tentatively concluded that the problem is my lack of skill. Very sparse mention in the handbook and Tormek videos has not helped any. I do plan to give the blackstone another test.

I hope someone will develop simple jigs and techniques for sharpening metal lathe tool bits with the Tormek. Machinists sharpen them with dry grinders. Why not on a Tormek?

Ken

[Rick_B]

Thanks everyone for your thoughts.  I, too, thought that it shouldn't be such a leap for the Tormek.  Pretty simple angles - seems more of a positioning problem which is where I thought the Tormek excelled.

I hadn't thought much about the wheel - I have the standard wheel that came with the machine and generally starting from scratch there is a lot of metal removal for alathe tool bit.  Maybe I need to thonk along the lines of rough grind on a slow speed grinder and then finessing with the Tormek.    I do have the Tormek tool rest for the slow speed grinder and a few jigs for maintaining the grind position.  I was hoping there was something more adjustable for the sometimes minute chnages to the angles.

Rick