shop built tool holder

[Bob Neumann]

I just picked up a small lathe with a rocker style tool post. I think it's designed for a 3/8 by 7/8 tool holders, of which I have zero.

I can see that I can buy them on Ebay or whatever, but I do have some 3/8 flat steel, and the ability to cut it more or less square and flat. And the whole point of owning machinery is to use it to do and make. So buying is out of the question.

Cutting the 3/8 steel into a shank that the tool post can hold is no problem. But drilling/broaching a square hole to receive the tool bit is probably beyond where I'm at.

However, I do have a metal-cutting skilsaw that I think I can use like a fly cutter to mill a slot. So I'm thinking that cut some 3/8 plate to the general shape of a tool holder and then bend a "head" on it "x" degrees to the left or right. Then I'll cut/mill a 1/4 slot in the outer cheek of the head. Then I'll drill and tap a hole in the cheek so that I can clamp a plate against the toolbit and I'm in business.

So for "standard" left/right/straight tool holders, what angles (both left-right and up-down) should the bit be in relation to the shank of the holder itself? Are there any standards or drawings out there?

Any other advice before I charge down this path?

Thanks in advance,

Bob

 

[John Hasler]

I just picked up a small lathe with a rocker style tool post. I think it's designed for a 3/8 by 7/8 tool holders, of which I have zero.

I can see that I can buy them on Ebay or whatever, but I do have some 3/8 flat steel, and the ability to cut it more or less square and flat. And the whole point of owning machinery is to use it to do and make. So buying is out of the question.

Cutting the 3/8 steel into a shank that the tool post can hold is no problem. But drilling/broaching a square hole to receive the tool bit is probably beyond where I'm at.

However, I do have a metal-cutting skilsaw that I think I can use like a fly cutter to mill a slot. So I'm thinking that cut some 3/8 plate to the general shape of a tool holder and then bend a "head" on it "x" degrees to the left or right. Then I'll cut/mill a 1/4 slot in the outer cheek of the head. Then I'll drill and tap a hole in the cheek so that I can clamp a plate against the toolbit and I'm in business.

So for "standard" left/right/straight tool holders, what angles (both left-right and up-down) should the bit be in relation to the shank of the holder itself? Are there any standards or drawings out there?

Any other advice before I charge down this path?

Thanks in advance,

Bob

Before doing that I'd consider fabricating an entirely different kind of toolpost. Those lantern posts are kind of wiggly at best.

 

[Bob Neumann]

Funny you should say that. I have permission from my accountant to spend more-or-less $100 on something. I could buy a cheap qctp setup on ebay. Or a cheap 4-jaw chuck on Ebay.
(I currently have a 3 jaw chuck)

If you had to choose one or the other, which would it be?

Bob

 

[davidh]

4 jaw is probably best option. remember a lathe can reproduce itself. . . . altho a 4 jaw chuck may be a difficult project compared to a new tool holder. which one could you build easiest ?
this will be a test

 

[cathead]

I just picked up a small lathe with a rocker style tool post. I think it's designed for a 3/8 by 7/8 tool holders, of which I have zero.

I can see that I can buy them on Ebay or whatever, but I do have some 3/8 flat steel, and the ability to cut it more or less square and flat. And the whole point of owning machinery is to use it to do and make. So buying is out of the question.

Cutting the 3/8 steel into a shank that the tool post can hold is no problem. But drilling/broaching a square hole to receive the tool bit is probably beyond where I'm at.

However, I do have a metal-cutting skilsaw that I think I can use like a fly cutter to mill a slot. So I'm thinking that cut some 3/8 plate to the general shape of a tool holder and then bend a "head" on it "x" degrees to the left or right. Then I'll cut/mill a 1/4 slot in the outer cheek of the head. Then I'll drill and tap a hole in the cheek so that I can clamp a plate against the toolbit and I'm in business.

So for "standard" left/right/straight tool holders, what angles (both left-right and up-down) should the bit be in relation to the shank of the holder itself? Are there any standards or drawings out there?

Any other advice before I charge down this path?

Thanks in advance,

Bob

Hi Bob,

Personally I would get the 4 jaw chuck and build the tool post. A chuck is more challenging to make than
a tool post and you can use the 4 jaw chuck to square up some material for the tool post. I have both 3 and 4 jaw
chucks and seldom use the 3 jaw because all it can do is hold cylindrical stuff on center. If you use a 4 jaw
chuck very much, you can center parts quite quickly with no runout. You could build a tool post with a 4 jaw
chuck but you couldn't build a 4 jaw chuck with a new tool post and a 3 jaw chuck.

 

[18w]

Bob, though I admire your enthusiasm I think this is a project that begs some thought. Lantern tool post tool holders can be had for next to nothing on craigslist or garage sales. Possibly even from a member here. A lot of work has been done on small lathes with rocker tool posts so for starting out nothing wrong with using what you have. My caution is the standard tool holders typically were forged, quite possibly stronger than your average flat bar or perhaps I should say stiffer. One of the pitfalls of rocker post systems is there lack of rigidity compared to a QCTP. And as others have said, get yourself a 4 jaw, most valuable tool for your lathe. The other posters are suggesting making the tool post itself which could be a nice project. I am talking about the tool bit holders as you are describing. Your description of using a metal cuting skill saw to cut the slot on such a small part is fraught with danger IMHO.

Regards
Darrell

 

[John Hasler]

Funny you should say that. I have permission from my accountant to spend more-or-less $100 on something. I could buy a cheap qctp setup on ebay. Or a cheap 4-jaw chuck on Ebay.
(I currently have a 3 jaw chuck)

If you had to choose one or the other, which would it be?

Bob

Buy the chuck. Build the post. It needn't be a fancy QCTP.

 

[Bob Neumann]

Bob, though I admire your enthusiasm I think this is a project that begs some thought. Lantern tool post tool holders can be had for next to nothing on craigslist or garage sales. Possibly even from a member here. A lot of work has been done on small lathes with rocker tool posts so for starting out nothing wrong with using what you have. My caution is the standard tool holders typically were forged, quite possibly stronger than your average flat bar or perhaps I should say stiffer. One of the pitfalls of rocker post systems is there lack of rigidity compared to a QCTP. And as others have said, get yourself a 4 jaw, most valuable tool for your lathe. The other posters are suggesting making the tool post itself which could be a nice project. I am talking about the tool bit holders as you are describing. Your description of using a metal cuting skill saw to cut the slot on such a small part is fraught with danger IMHO.

Regards
Darrell

1. You're probably right.
a. definitely about the rigidity. Hadn't really even considered that.
b. probably about the skilsaw.
2. But I don't want to hear it.

Looks like I need to think some more...

Thanks for your input.

Bob

 

[18w]

Bob
1 what kind of lathe do you have?
2 let us know the size like the diam of swing
3 I didn't want to hear about you hurting yourself with that skilsaw set up either.

Regards
Darrell

 

[randyc]

I use a lantern tool post, although infrequently. Mostly I don't use a toolholder in it, just put a 3/8 HSS cutter in the lantern with whatever shim underneath is appropriate. The Armstrong and Williams type of toolholders, in my opinion, are very versatile but maybe not the best choice for heavy DOC.

But I have the same opinion regarding QCTP systems - way too much overhang for heavy DOC in small and medium size lathes. Just a personal opinion based on experience

As mentioned previously those old lantern tool posts and Armstrong tool holders have produced millions and millions of precision parts and BIG parts, too. There is still a place for them in lathe tooling collections.