# Tang'ed Arbor on Milling tools??



## itsme_Bernie (Nov 8, 2013)

Someone offered me a very high quality Universal Precision boring head, with a B&S 9 TANGED arbor.  This surprised me.  This company made good tools, and the arbors are NOT replaceable- so it is original.

Would this concern you?  Swinging a 3-3/8 head and then a bar extending off of that?

I know B&S #9 is pretty big, close to MT4.  But no drawbar?  And the mill I am getting has a 1/2-13 drawbar.m I even considered putting it in the lathe and tapping it out for 1/2-13 VeRy carefully..  (8

I don't want to buy something I'll regret- any thoughts from experience?  

Thank you! 

Bernie


----------



## toag (Nov 8, 2013)

you could cut off drill and tap the end, though how you hold it would be tough (being tapered)... maybe by the boring head itself,  with a steady on the taper.
i'd use a existing collet as a reference, doesn't sound too crazy


----------



## LJP (Nov 8, 2013)

I got an old Bridgeport (brand) boring head with a damaged arbor. Someone had done a terrible job trying to turn the taper down, but only for 1" at the end. I chucked in the 4 jaw, holding it by the head, and dialed it in. I turned the taper to a straight shaft that fits in a 13/16" R8 collet and use it in the Bridgeport. No problem.
Larry


----------



## itsme_Bernie (Nov 8, 2013)

toag said:


> you could cut off drill and tap the end, though how you hold it would be tough (being tapered)... maybe by the boring head itself,  with a steady on the taper.
> i'd use a existing collet as a reference, doesn't sound too crazy



Exactly what it was thinking Jerry-  I though some folks with more experience with these could say "nah, it's just fine like it is!"  ...  Hah hah- but I guess worst case scenario is that I put it in a chuck and the taper in a steady rest, and drill and tap it out for the drawbar.


Bernie


----------



## Bill C. (Nov 8, 2013)

itsme_Bernie said:


> Someone offered me a very high quality Universal Precision boring head, with a B&S 9 TANGED arbor.  This surprised me.  This company made good tools, and the arbors are NOT replaceable- so it is original.
> 
> Would this concern you?  Swinging a 3-3/8 head and then a bar extending off of that?
> 
> ...



Bernie you have a good point, does your mill have a slot for a tang? If it doesn't then drill out the center of the tang and tap for the 1/2"-13 thread.  The rod only keeps the head from falling out.  Tne taper is the driving force.

There is another trick my boss used.  He had me grind a taper for an adapter, he used Prussian Blue (paint) to see if the tapers matched.  Basically you put a thin coat of paint on the boring head then press it in the spindle.  Remove it and see if all surfaces of the spindle are covered with paint.  If all areas are covered then the tapers are good.  May need a mirror and flash light to check.


----------



## toag (Nov 8, 2013)

agreed. chuck er up and give it what for. let us know how it turned out


----------



## pineyfolks (Nov 8, 2013)

I came into a lot of #9 tooling and that's what I did. Drill & tap them. I didn't do the boring head or drill chuck arbors as there isn't as much side pressure as a milling arbor.


----------



## Senna (Nov 8, 2013)

Bernie, I had the same reservations as you with regard to a tanged arbor staying in the spindle.
On my B&S 10 the facemill arbor I got was tanged and I was assured that it'd be just fine in my mill.
They were right.
I run a three inch facemill on it and there has been no problem with it slipping or falling out.
While I prefer a drawbar, if the tooling I get has a tanged arbor I no longer sweat it.
I'm not sure how easy a drill and tap it would be either.


----------



## itsme_Bernie (Nov 8, 2013)

pineyfolks said:


> I came into a lot of #9 tooling and that's what I did. Drill & tap them. I didn't do the boring head or drill chuck arbors as there isn't as much side pressure as a milling arbor.






Senna said:


> Bernie, I had the same reservations as you with regard to a tanged arbor staying in the spindle.
> On my B&S 10 the facemill arbor I got was tanged and I was assured that it'd be just fine in my mill.
> They were right.
> I run a three inch facemill on it and there has been no problem with it slipping or falling out.
> ...




I was thinking that it was designed that way for a reason.  This boring head has existed for at least 60 years, and does not show signs of being thrown across the room!  And like I said, it is. It a replaceable arbor, so it was designed by a somewhat renowned, reputable company.

You know, you guys are getting me to thinking- the reason it is probably most important to have a drawbar with a mill, or drill chuck, is that the forces could tend to pull the mill down and OUT.  

I am still nervous about a facing mill with 3/4 inch bars, potentially extending out an inch or two outside the 3-3/8 head itself.  I my drill and tap it after I try it out and see.

I am not terribly concerned about doing it, as a steady rest around the tang end, with soft jaws, would allow a pretty simple setup I think.


Bernie


----------



## Bill C. (Nov 8, 2013)

itsme_Bernie said:


> I was thinking that it was designed that way for a reason.  This boring head has existed for at least 60 years, and does not show signs of being thrown across the room!  And like I said, it is. It a replaceable arbor, so it was designed by a somewhat renowned, reputable company.
> 
> You know, you guys are getting me to thinking- the reason it is probably most important to have a drawbar with a mill, or drill chuck, is that the forces could tend to pull the mill down and OUT.
> 
> ...



I have use radial arm drill presses with power feeds.  That would be the only example I can think of that would use a tang to drive a boring head.  

Good luck.


----------



## itsme_Bernie (Nov 8, 2013)

Senna said:


> Bernie, I had the same reservations as you with regard to a tanged arbor staying in the spindle.
> On my B&S 10 the facemill arbor I got was tanged and I was assured that it'd be just fine in my mill.
> They were right.
> I run a three inch facemill on it and there has been no problem with it slipping or falling out.
> ...



Thanks Ken!  

The Tang'd arbor discussion started on my tool request thread, so I lost track!  Hah

I GREATLY appreciate your experience here.  The only reason I was concerned was that the tool I am buying is a large boring and facing tool, which could potentially reach 5 or 6 inches off center, if I wanted.  Pretty cool one at that, so even outside of safety, I don't want this thing dropping out!  

How hard do you pull your tools in anyway?  I guess I won't have to draw them in too hard with the shallow taper we are talking about ..

Bernie


----------



## Senna (Nov 9, 2013)

itsme_Bernie said:


> Thanks Ken!
> 
> The Tang'd arbor discussion started on my tool request thread, so I lost track!  Hah
> 
> ...



You guess correctly. With the big surface area in contact with the spindle bore you just don't need to torque them up too much.
These ain't R8 tooling with their relatively tiny surface area.
Some problems can arise if you put a cold tool into a hot spindle too. You get what is essentially a shrink fit as the spindle cools down. Being home shop guys most of us just don't get the spindle hot enough to matter.


----------



## itsme_Bernie (Nov 9, 2013)

Senna said:


> You guess correctly. With the big surface area in contact with the spindle bore you just don't need to torque them up too much.
> These ain't R8 tooling with their relatively tiny surface area.
> Some problems can arise if you put a cold tool into a hot spindle too. You get what is essentially a shrink fit as the spindle cools down. Being home shop guys most of us just don't get the spindle hot enough to matter.



Great tips man!  Thank you!  
I don't have much experience with long tapered collets like this- I have used double taper "Y"s and 5C.  Both pretty easy release.  I'm going to have to watch myself!

I used MT2 collets in the headstock of my 6 inch Atlas lathe, but that was light duty work.  


Bernie


----------



## benmychree (Nov 9, 2013)

For about 30 years, I had a #2 B&S universal mill with #10 taper set up for either tang or drawbar; most of the arbors and adaptors had tang drive, and I never had a problem with them loosening; I just set them in with a right smart blow with a lead hammer, and used a knockout bar as originally supplied by the maker with an approx. 3" diameter iron ball on the end for weight to unseat them.


----------

