# Large-ish bore dividing head



## wildo (Apr 26, 2017)

Can anyone recommend a dividing head that I can use a collet to pass through up to 1.250" rod through? I have no experience with dividing heads, and I don't quite understand how things mount to them. Saying that- I'd be ok with holding the work in a 3 jaw as well, but I still want to be able to pass through stock up to a 1.25"

One part of machining that I'm still finding shocking is just how much material is wasted in work holding. I'd like to try to reduce this by NOT needing to cut off my material twice (or three times- or more) longer than what I'll need for the part. If I ever get good enough to spring for the super fancy materials like timascus, mokume, or dimascus where a 12" bar can cost more than $1000, then this will be absolutely imperative. With that material, the part off along is literally $50 down the drain.

But even for now- my 12" long bar of 1" diameter tellurium copper set me back $50.  I'd like to get ten $5 parts out of it rather than three $17 parts!
______

For what it's worth- I'm aware of tailstocks for dividing heads. Perhaps I'm thinking about things wrong and using a chuck/tailstock is the correct answer to my question. The problem though is that for what I want to do, I think I will need to mount the dividing head at a 45 degree angle to either x or y axis because I want to mill some 45* slits equally spaced around the rod. For that reason, I figured that working near the dividing head chuck would be the only option rather than at the tailstock end.

[EDIT]- Oh, and it has to fit on my Millrite table which is 8" wide.


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## mikey (Apr 26, 2017)

I'm afraid you're in for some disappointment, Wil. Most dividing heads I've seen have a smallish Morse taper. If I recall correctly, a 12" Yuasa dividing head has a MT3 taper - no way are you going to pass through something large. Moreover, the rear of the head is typically rounded and closed off because it has to swivel so I don't think a dividing head (or rotary table) will work with long pieces. 

Not sure what you're making but maybe a collet block, angled in the vise, would work if its simple enough?

You're right; there is a lot of waste in the shop. It is a fact of life. Be wary of trying to work with really small falloff pieces that should probably go in the trash - you'll get away with it most of the time, until you don't.


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## Superburban (Apr 26, 2017)

Google collet indexers.


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## wildo (Apr 26, 2017)

Superburban said:


> Google collet indexers.


That might just be the ticket! Phase-II has a 5C version with up to 1.125" capacity. That seems like a pretty good option!

https://m.mscdirect.com/mobileweb/product_detail?id=09672023&hasRestrictedParts=false


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## wildo (Apr 26, 2017)

Question- do 5C spin indexes have built in draw bars? I was checking some out on eBay and none seem to mention shipping with a drawbar.

[EDIT]- nevermind. I found a youtube video on using the spindex and yes, the drawbar is built in.


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## Superburban (Apr 26, 2017)

Yes.


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## rgray (Apr 26, 2017)

wildo said:


> Phase-II has a 5C version with up to 1.125" capacity.



That's not through capacity. Most 5c 1" collets will not pass 1" stock through. I have one that will and one that won't. Anything above 1" will not pass through it's collet in 5c.


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## wildo (Apr 26, 2017)

rgray said:


> That's not through capacity. Most 5c 1" collets will not pass 1" stock through. I have one that will and one that won't. Anything above 1" will not pass through it's collet in 5c.



Ugh. So much for me to learn... especially when stuff doesn't work as advertised! Collets are for through stock. And yet a 1" 5C can't pass through 1" stock!??  How do you know if a specific 1" collet can indeed handle 1" stock- is there some other spec that provides this info?

Is this because of the 1-24 internal thread? Looks like this collet from MSC has a 1.041-24 thread which I assume is not the same as a 1.0-24 thread?


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## JimDawson (Apr 26, 2017)

Max pass through on a 5C collet is normally 1.0 inch.  There are 5C collets that will accept 1.25 in the nose, but the pocket is only about 3/4 deep.  The OD of a 5C collet body is 1.250.

Your best option might be a Super Spacer with a 3 or 4 jaw chuck.  For your 45° slots, a CNC would make quick work of that.


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## wildo (Apr 26, 2017)

Ok- so:

1.041-24 is the standard size for a 1" - 24 thread. Good to know.
I contacted Hardinge and got some info about passing stock through 5C collets at the 1" and above size:


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## wildo (Apr 26, 2017)

Ok- a Super Spacer is now on my wish list. For now though, I went with a Phase-II Spindex and a non-threaded Hardinge 5C collet. Seeing that the 6" Super Spacer has a 1.73" bore- I already regret my decision and should have saved up more $$$ for the Super Spacer. Never the less, the Spindex will be handy for the shop...


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## rgray (Apr 26, 2017)

wildo said:


> Never the less, the Spindex will be handy for the shop...



Yes you will always find use for one of those. Having more than one is not even a bad thing.


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## scwhite (Apr 26, 2017)

wildo said:


> Can anyone recommend a dividing head that I can use a collet to pass through up to 1.250" rod through? I have no experience with dividing heads, and I don't quite understand how things mount to them. Saying that- I'd be ok with holding the work in a 3 jaw as well, but I still want to be able to pass through stock up to a 1.25"
> 
> One part of machining that I'm still finding shocking is just how much material is wasted in work holding. I'd like to try to reduce this by NOT needing to cut off my material twice (or three times- or more) longer than what I'll need for the part. If I ever get good enough to spring for the super fancy materials like timascus, mokume, or dimascus where a 12" bar can cost more than $1000, then this will be absolutely imperative. With that material, the part off along is literally $50 down the drain.
> 
> ...


Have you tried cutting this slot ?
    I don't think you are going to be able to do that 
Unless you put the dividing head and tail stock 
On the table of a milling machine with a table that will rotate . And gear drive the dividing head 
It will need to be on a  universal  horizontal mill


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## wildo (Apr 26, 2017)

No, I don't have the equipment yet, but unless I'm missing something, I don't see the issue. The spin indexer should be able to be toe clamped down to the mill table at any angle I want, no? This is no different than using a dividing/indexing/rotary head with the work parallel to the mill table, just that the work is at a 45* angle to the mill table. Why shouldn't that work?


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## scwhite (Apr 26, 2017)

wildo said:


> No, I don't have the equipment yet, but unless I'm missing something, I don't see the issue. The spin indexer should be able to be toe clamped down to the mill table at any angle I want, no? This is no different than using a dividing/indexing/rotary head with the work parallel to the mill table, just that the work is at a 45* angle to the mill table. Why shouldn't that work?


You said you wanted to cut a slot around the stock on a 45 degree . Are you planing on feeding the table while you rotate the dividing head by hand .
     I might be the one that don't see what you are trying to make. Are you trying to sit  a helix or spiral 
Around that part on a 45 degree


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## wildo (Apr 27, 2017)

The indexing head will sit in the horizontal position on the mill table such that the work is parallel to the mill table. Typically the work would be trammed in so it is actually inline with the x axis. However I'm going to rotate it so that it's:

Still parallel to the mill table
Rotated 45 degrees along the z axis
I will then come in with a ball end mill moving the table only along the Y axis. This will cut a slot at a 45 degree angle to the work. I'll then index the work some undetermined increment and repeat. Think about a rope knurl, perhaps- or maybe something like a star knob/handle thing. Or perhaps even better is something like a helical gear, though I do NOT intend on rotating the index axis while milling. I am cutting straight slots.


Super duper crude- top is the rod I want to cut diagonal slots in, bottom is how I'd setup the indexing head on the mill table. The slots will be whatever my smallest ball end mill is- I think .125" or maybe if I'm lucky .0625" and will be no more than .100" deep. They will likely be something like .25" long at the most- probably much less than that.






I'm making something similar to the copper ring on this top (which sadly- I literally just googled for a similar image to my idea and found almost exactly my idea. I swear this is the first time I've seen this image. Sigh...)


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## scwhite (Apr 27, 2017)

wildo said:


> The indexing head will sit in the horizontal position on the mill table such that the work is parallel to the mill table. Typically the work would be trammed in so it is actually inline with the x axis. However I'm going to rotate it so that it's:
> 
> Still parallel to the mill table
> Rotated 45 degrees along the z axis
> ...


I think I see what you are trying to do .
    I think your slots will feather out on both sides of the arc of the cylinder


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## wildo (Apr 27, 2017)

Yes, that is intentional with my design. Until I figure out some other cool thing to do with slotting... It might look kinda cool for them to feather out like that. There might be better ways to accomplish what I'm trying to do, but the fact is- I don't have a clue what I'm doing and just going with a setup that made sense to me. I'm sure there's better ways...


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## scwhite (Apr 27, 2017)

wildo said:


> Yes, that is intentional with my design. Until I figure out some other cool thing to do with slotting... It might look kinda cool for them to feather out like that. There might be better ways to accomplish what I'm trying to do, but the fact is- I don't have a clue what I'm doing and just going with a setup that made sense to me. I'm sure there's better ways...


No you are doing a good  ornate design 
I think it will look good it is going to be a lot of 
Cuts but you are right it will look good


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## wildo (Apr 27, 2017)

scwhite said:


> No you are doing a good  ornate design



That's one way to say it. I call it "stupidly ambitious for my current skill level."


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## scwhite (Apr 27, 2017)

wildo said:


> That's one way to say it. I call it "stupidly ambitious for my current skill level."


30 degrees will give you a little longer slot 
Before it  feathers out


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## scwhite (Apr 27, 2017)

wildo said:


> That's one way to say it. I call it "stupidly ambitious for my current skill level."


Nothing is stupid in this trade you can do anything you set your mine to .
     I like your design . Early on in this thread I thought you was trying to cut a  helix around that shaft . But now I see what you are doing .
      Cutting them both  directions on a 30 degree will look good or 45 degree might also . 
       I just think the   Diamond shape looks best . 
Play with it


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## wildo (Apr 28, 2017)

Just came back to say thanks for the advice guys. The Super Spacer is still on my list, but for 1" and under, this setup is definitely going to get me by. Going to try out some cool stuff tonight!!


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