First lathe, tool bits

I have and use a tangential tool on my Atlas 12" lathe. It works pretty well and is DEAD SIMPLE to sharpen. I have it set so that when the tip of the tool bit is level with the top of the toolholder, it is at center height in my lathe. That way, I can remove the toolbit, sharpen it, hone it, switch to a different bit (like a round one for finishing), and easily set it to center with a blank held on top of the toolholder. I have also found that I can vary the geometry by varying the grinder rest angle and how the sharpening jig/toolbit is presented to the grinding wheel. That way, I have different bits for different applications and different workpiece materials. I figured that part out after reading some of Mikey's postings about toolbit grinding. :D I'm still planning to figure out how to grind a REAL toolbit, but this works well for work that is general-purpose. If I need to reach into a tight area, the tangential tool is a no-go. Other than that, it is pretty good for me and has opened my eyes to grinding variations.
 
Randall Marx said:
I have and use a tangential tool on my Atlas 12" lathe. It works pretty well and is DEAD SIMPLE to sharpen. I have it set so that when the tip of the tool bit is level with the top of the toolholder, it is at center height in my lathe. That way, I can remove the toolbit, sharpen it, hone it, switch to a different bit (like a round one for finishing), and easily set it to center with a blank held on top of the toolholder. I have also found that I can vary the geometry by varying the grinder rest angle and how the sharpening jig/toolbit is presented to the grinding wheel. That way, I have different bits for different applications and different workpiece materials. I figured that part out after reading some of Mikey's postings about toolbit grinding. :D I'm still planning to figure out how to grind a REAL toolbit, but this works well for work that is general-purpose. If I need to reach into a tight area, the tangential tool is a no-go. Other than that, it is pretty good for me and has opened my eyes to grinding variations.
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Thanks, Randall. I'm glad that someone has sought to alter the standard grind on a tangential tool because it seems to me that it would be necessary at some point. If I had this tool, I would definitely try to figure out how to incorporate more side rake into the geometry because that would reduce cutting forces and temperatures a lot. You don't think it matters until you work harden a piece of 1144 and try to do a fine finish cut; then you wonder how the heck you cannot come in on size.
 
Randall Marx said:
If I need to reach into a tight area, the tangential tool is a no-go.
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Yup. That's probably (for me) the most common reason for me to use a normal tool. For most common facing and turning, though, the extra size isn't a problem.

Easy enough to make different grinding fixtures to adjust the rake angles, but the default works well for most of the materials I work with (mostly mild steel and aluminum). As I mentioned: not the last tool you'll ever need, and it's still incredibly useful to learn how to grind a normal tool, but it's great as a standard tool to have on the lathe most of the time (and to give a beginner an example of all the angles to shoot for when grinding your own tools).

Good tip about keeping the tip at the top of the tool holder so you don't need to readjust tool height. I did something similar (scribed a line on my grinding fixture).
 
As far as grinding tool bits, I don't think about it I just close my eyes and grind. Usually works pretty good. My shop teacher is probably rolling in his grave to see my pathetic efforts LOL Oh well nobody has to use them but me :D
Mark S.
 
Ill give you one extra tip I didn't read where anybody said to hone your tool edges . As far as grinding 3/8 or 1/2" or 5/8" . Most all of the shapes will cut , some will cut cleaner and quicker , easier. Others will work good on steel but not brass or aluminum. I have even made and used contour bits . Made to fit a profile those are a different game as to speeds and feeds. Even using other bits to hog out spots. Many times you will need to grind chip breakers in the tool. Clearance angles needed then stoned with an India stone. You will need a couple half round , square 3/8 Or 1/2" , usually there about 4" long. I even have a green set for carbide. Honest it helps to hone the edges the tool cuts better and last longer , at times you can touch them up in the holder . I've found rounded tools work well in cold rolled and brass. When making corners on tooling I leave the inner edge rounded , to many times I've seen sharp corners just snap.
 
your picture shows good hss bits with a little regrinding they can all still be used over and over again you don't need to completely remove the old grinding just make the tool you need at the time bill
 
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