Tool holders

[Jake M]

I was reading a bit in "How to Run a Lathe" yesterday and I can't quite figure out why the upward rake was so common in the past.

It makes the tool bits far faster and simpler to grind from scratch. The top rake is already baked in, so for 98 percent of the bits you ever grind, you've just got to knock two sides off, and you can orient the holder/post assembly to get good results from there.

I know I'm in the minority here (and that's fine), but I kinda prefer those. Fast, easy, and intuitive. (Not "QCTP fast", but surely not slow. One screw, put it where it needs to be, and you're done. The "T" holders do a great job presenting a tool in a "flat" position, which is great for insert tools where the center height is fixed, so you can set it up one time (most likely with a spacer or shims in lieu of the rocker), but at the expense of the versatility of having the tool depth set center height as is typically very useful for hand ground tools. Both types take the same cutting geometries for whatever you're doing,, but it's going to be ground different, the "point" of the tool is the same shape, but it's applied (to all sides) at a different angle.

You've gotta watch that too. The older books that tell you how to grind HSS into the common cutters- You've got to pay attention to how they are holding those tools, as that was based on their tool post, not yours or mine.

 

[GeneT45]

It's been years since I used that style of toolholder, but when I did I always found it easiest to grind the tool in the toolholder. Then you don't have to translate angles, etc. Just use the bottom of the holder as if you were grinding a "straight" tool and Bob's your uncle.

GsT

 

[Jake M]

I always found it easiest to grind the tool in the toolholder. Then you don't have to translate angles, etc.

Guilty as charged....

If I'm making a "standard" type tool, I've done enough that I usually just go to the grinder with the HSS. Although I really don't do much of that since my collection has come to have enough. For something "not so standard", I'll do that in the holder for sure. The last one I did was a trepanning tool, in the "T" carbide holder, but it sat a little low so there was gonna be "some" but not much angle imparted from that... Yeah, I'd have been all day if I didn't carry the holder over to the grinder as well. Gotta be careful though, if you're doing that, the tool bit is NOT going to tell your fingertips when it's time to dunk it again...

 

[Harry Knutz]

I have a 14"x 40" Harbor Freight lathe, and I know all the sad tales about Asian lathes are junk and whatever, but how many people get to have a new lathe in their life time. I did cut a 40" piece of mild steel stock, from 2 1/2" down to 2," and only had three thou run out over the whole length, without using a steady rest, so the Asian lathe is doing a fine job for me.
My problem is finding tool holders that have "straight" square holes for cutting bits that are absolutely horizontal. I can't use square holes that point, or angle, up. I need my tool holders to point the carbide, or tool steel bits straight out towards the work. As in being parallel with the floor. I admit to being somewhat retarded, but some one out there might be able to take pity, and clue me in on the science here. I have about 20 Ebay, and Craigslist tool holders (of varying tool bit sizes, that point the cutting bit up hill, and this is just hateful when I try to point the cutting edge just below the centerline of the stock. I like the old stuff, and have spent hundreds of dollars buying Armstrong, and etc., but for the most part have received these damn uphill tool holders. I can't regrind the tool bits, as the up angle causes too much metal to be removed from the cutting bits to be usable. What magic words do I need to know in order to buy tool holders that project the carbide bits out in a horizontal plane rather than this infernal uphill mess. I have both lantern and Aloris (sp) type holders for my tool holders.

If this is the lathe you have, These are actually very good ones. I believe they also sold a Taiwan 14x40 lathe that was made by Tida in Taiwan.

I have a 14"x 40" Harbor Freight lathe, and I know all the sad tales about Asian lathes are junk and whatever, but how many people get to have a new lathe in their life time. I did cut a 40" piece of mild steel stock, from 2 1/2" down to 2," and only had three thou run out over the whole length, without using a steady rest, so the Asian lathe is doing a fine job for me.
My problem is finding tool holders that have "straight" square holes for cutting bits that are absolutely horizontal. I can't use square holes that point, or angle, up. I need my tool holders to point the carbide, or tool steel bits straight out towards the work. As in being parallel with the floor. I admit to being somewhat retarded, but some one out there might be able to take pity, and clue me in on the science here. I have about 20 Ebay, and Craigslist tool holders (of varying tool bit sizes, that point the cutting bit up hill, and this is just hateful when I try to point the cutting edge just below the centerline of the stock. I like the old stuff, and have spent hundreds of dollars buying Armstrong, and etc., but for the most part have received these damn uphill tool holders. I can't regrind the tool bits, as the up angle causes too much metal to be removed from the cutting bits to be usable. What magic words do I need to know in order to buy tool holders that project the carbide bits out in a horizontal plane rather than this infernal uphill mess. I have both lantern and Aloris (sp) type holders for my tool holders.

 

[Turnaround]

That is exactly mine. I cut the bottom edge surface of one of the positions of the OEM's four sided tool holder so now I can stick a shim under the Armstrong tool holder and line up the carbide's cutting point with the horizontal centerline of the work. And now, from what the Canadian feller said, I can just order Armstrongs that start with "T" and get my required "straight tool post holders." Life is good.

 

[Turnaround]

For Carbide Tipped Tool Bits - Heavy Duty

www.msdiscounttool.com

These may be what you need. They hold 3/8 tools, you may need 1/4. McMaster Carr still sells them too. I think the Craftsman tool holders use 1/4 cutters. Maybe this is a #1 size?

What an education I just got from reading your attachment. Thank you very much. My single high school machine shop class was back around 1953 or so. The school had a gang of Southbend lathes, and some kind of gear hob for cutting gear teeth. That class was all the formal training that life allowed me to experience. At nearly 87 years old, I now just want to get jobs done. Its great that you guys use the modern stuff. More power to you. For me, it perfectly fine to just chug along making chips, just like I did in 1953. The members do not know how much their advice helped me. So, thanks to you all.