How To Quickly Grind Lathe Bits

;) The can means nothing, it just holds the water. All you are doing is quenching the heat from the tool so you can hold it. You will be hard pressed to take the hardness out of HSS. Burned blue they will still work.

If you cool the tool in a soup can does that mean you lunch will be warm ?? ROTFLMBO

"Billy G"
 
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Reeltor said:
Take a look at Oxtool and ABomb79's YouTube video series entitled Chip Control. Tom and Adam go at it trying to take the biggest cut using HSS hand ground bits, showing how they like to grind their tool bits. IIRC one of them uses a hand grinder with the bit clamped in a vise to rough in the bit then move to the pedestal grinder.
Click to expand...

I like using an angle grinder to hog away material, i used a 1mm cutting disc to remove two triangles of material last time i ground a threading tool, made it much quicker :)

Stuart
 
I like to rough my tool bits, for my tangential tool holder, on the belt sander. I have belts now for my 2x72" and a 36 grit gets them shaped efficiently. I still like a bit of hollow grind so I finish on a 120 Norton Blue wheel. I seem to have the best luck with a 1/32" radius on the tip. I touch on the wheel makes a bit of a flat and a flat diamond hone finishes them off.

With these tools you just have to put the bit in the jig a touch the top to the wheel and they are ready to go. I got crazy and roughed in six one day and should have tools that only need touch ups for a while.

I like carbide inserts but man you can't beat the economy or the cut on mild steel with these bits


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This idea came to me from reading this thread and from wondering how to recycle an old 10'' saw blade.
The teeth were turned off the blade on a lathe leaving a 9'' disc. A 9'' peel and stick 80 grit AO disc was added. A smaller 71/4'' blade was used to support the back of the 9'' blade.
This set up ground HSS very quickly and with very little heat. Surface speed varies from 5000 to 11000 fpm depending on where the tool is presented to the disc.

Angles and corners are crisp.It is very nice to dial in the angles accurately using blade tilt and/or the mitre guide.

It does not grind chip breakers very well but for roughing a new blank or modifying angles on an existing tool it is tops.

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Yes good stuff above...I just "snag grind" to sharpen lathe tooling, drills, even endmils... from tinys up to big 2+ inch drills...yes (as said above), a suitable water "bowl" and practice, practice, practice for on center and angles for what material, yada yada....same for resharpening them on a a tool and cutter grinder or drill sharpener (practice practice practice the set up and grinding)
(When drilling from 64 to 220 .o50 holes through a 2" x 2" square pc of 4130 1" thick in a CNC mill; At 1st just count the # of holes when the drill breaks then change to new drills 1 hole before for the rest of the job (while saving all those used drills for practice practice practice resharpening them on a tool and cutter grinder or drill sharpener for the next job (ifn' then they drill just as many holes as a new drill, you know you're doing something right. (Smiley Face here!)
 
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I use the white wheels in the cabinet shop to grind High Carbon Steel, they're great in the fact that they generate less heat which is important there. But they wear quickly. For the machine shop where its all HSS a good quality grey wheel cuts almost as fast but holds a flat surface longer. As said heat doesn't bother HSS. The wheels that come on the import grinders aren't even worth saving in the drawer.

Greg
 
After you have rough ground your Tool Bit have a look at the utube vid below on how to finish the grinding process, worth a watch, I've decided to make one myself.

 
I an another that uses a belt sander to get the final shape then hone on a diamond.

Also there is a difference between a sharp edge & a sharp angle. A edge becomes daul from the edge being bent over or chipped. If a edge is rounded then it is hard to do ether to it. A sharp angle makes the edge weak. I like a sharp edge but not so sharp of a angle so the edge is also strong. I hone mine often to keep the edge crisp. This removed the small damaged edge so I rarely have to resharpen unless I do something stupid.
 
Yes, some good info. above, also to add: Think microscopic...IE Whatever the cutter material is, whether it's HSS, Carbide, Ceramic, Bonded Diamond....the regrind (final sharpening/machining resulting in edge) also needs to be considered....like the grit of a wheel
Any wear surface will outperform and last longer the better the finish is...
Thinking "microscopic" I mean a "sawtooth" effect along any cutting edge will wear off many times sooner leaving "shiny" (dull)

...also to add; Even "light brown" (using color as a heat indicator) to any hardened steel starts annealing its hardness, blue is worse, then the reds
It's the action of quenching high heat (blue...or yikes! the reds) immediately that brings the steel back up (but more brittle and not as tough)
...ifn' you, say sharpen a HSS toolbit or drill and get it a dull red then let it cool slowly in room temp. mid air, it can't help but drop in hardness...putting it on a pc of cold steel that acts as a heat sink is better...and again quenching is better yet (but again; consider brittleness and toughness)...

...when talking tool steels, we're mostly talking about the carbon, man!
 
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