DIY Toolholders

[Shotgun]

It seems that every Youtuber machinist has a video on making toolholders. Take a big block of steel. Cut the dovetail down the whole thing. Chop to individual length. Mill a slot and then drill and tap holes. Then you use the drilled-tapped holes to clamp a bit holder in the slot.

Those last couple of operations are quite a bit of work. When using carbide tooling, wouldn't it make more since to mill a landing directly on the nose of the holder for the bit? The point of making the holders in the first place is so that you can have a separate holder for each tool. Why not skip the extra steps and end up with a tool that will be much more rigid at the cutting face since it doesn't have to transition through as many connections?

 

[woodchucker]

WHAT ARE YOU TALKING ABOUT? a little more info, maybe a link, maybe a pic, maybe a clue?

 

[Shotgun]

I'm talking about making QCTP type tool holders. Here is This Old Tony's version:

The question is why make a slot and hold down screws to hold another tool, that in turn holds a bit, instead of machining in a place for the bit directly?

 

[matthewsx]

Are you talking about making something like this?



I think the point of the regular toolholders is you have the flexibility to use HSS or a carbide insert holder with the same part.

John

 

[wrat]

I think i see what you're saying and I believe they actually exist for the big CNC lathes, but the question would be 'why bother'?
It would seem to be quite a lot more machining, but like you say, once it's done, it's done without all the fiddly bits.
On the down side, there's such a thing as a 'crash'. Let's say you crash by some astronomically random accident. Do you wanna replace a cheap, straight holder piece you get off-the-shelf? or an entire machined holder?
Especially if you had to machine it yourself.
Everything's a tradeoff.

 

[Shotgun]

Are you talking about making something like this?

View attachment 411812

I think the point of the regular toolholders is you have the flexibility to use HSS or a carbide insert holder with the same part.

John

Yes. Just like that, except machined as one piece from wedge to the bit bolt down screw.
I agree that the point is the flexibility. But, then everyone gets tired of swapping out tools, and gets a separate holder for each anyway. At least, I do.

I've just recently upgraded lathes, and have gone from an AXA to a CXA toolpost, so all the holders have to be replaced. I'm thinking what is the quickest way to get the most rigid setup. Machining a flat out on the nose seems so much simpler than a slot with 3 or 4 tapped holes, and it seems like the rigidity could be significantly higher.

 

[mmcmdl]

If you like that holder , give me a shout out . I have Alrois CXAs down the basement that are going out . Or , just make them as you said .

 

[woodchucker]

many already put a dovetail in the larger tools already. But larger tools cost more.
And many will have a limited supply of both holders and tools.

Do what you want.. the flexibility remains for folks that want to do different things.

 

[mattthemuppet2]

main reason not to is that you're stuck with that insert and stick out from the toolpost. I often have to change how far a tool is sticking out of the holder to get around other issues.

main reason to do so is more rigid and you do alot of the same sort of op with the same style insert.

which matters more depends on the kind of work you do and I guess how big your machine is

 

[Shotgun]

I like that thinking, @mattthemuppet2 . That would lead me to want just a couple "rigid" holders for rough operations. Maybe cut to use the "waste" corner of CCMT or DCMT bits. Then the rest would be the more flexible type.

Ok. Make some. Buy some.