Question about Dividing Heads

[jdanger2001]

Recently, just for the heck of it I bought a dividing head. My thought is when you find the tools buy them just in case, that rare case, you might need them. Really didn't need one. But hey, I'm a sucker for a really, really good deal. It seems to be a good deal. I hope.

So I told a friend of mine in another state that I had purchased a dividing head and he asks me, "is it a tilting dividing head, a universal dividing head"?

I don't know. Hell, I don't even know how the darn thing even works. But I got it. You never know.

Can someone take a look at the photos and tell me just what I purchased? The tag says Cincinnati Dividing Head. Here is the information on another tag: AAK1N/94 57149.

Thanks guys.

[HuFlungDung]

It is a universal. It is tilted straight up in those pictures, and probably would not normally be used in that position. You can see a graduated scale in the first photo. I'd imagine if you clamp the thing down, loosen those two large nuts on the 'shoulders' of the main casting, squirt a bit of WD40 in there to loosen rust, that you can rotate it back to the horizontal axis position.

To be really useful as a universal, you need the set of change gears and idler brackets that goes along with the unit when new. Said gears permit such feats as differential indexing, and spiral milling when a gear train is set up between the table feed screw and the back input shaft of the head.

[jdanger2001]

I see. So it's a universal, tilting dividing head and some of the more important pieces are missing. Well that sucks. I suppose the missing parts are to be found on ebay.
The more that I think about it the more I realize that it's something that I can live without. Serious doubts that I will ever do indexing in this lifetime.
Thanks for the information.
john

[chich2]

John,
Do not worry for a second that you dont have the change gears. Most people will never ever use them. Especially if you have cnc control of a machine. You can do LOTS of things with the dividing head just as is. Gears, sprockets, timing pulley's, splines, and hole PCD's are all now at your fingertips even if you don't have CNC.

Well done, and nice purchase,

Chich

[jdanger2001]

Chich,
The ability to cut gears is intriguing I must admit. It is nice to know that if I wanted to perform those kind of tasks that the ability is there for me. Even if I never actually cut gears. And splines, yes, I can see that happening.

Of course it's that kind of thinking that has filled my garage to the rafters with tools that may never, ever get touched. Just call me Impulse Purchaser of the Year.

Still, it could be worst.

Thanks,

john

[gdgrinder]

i can see from picture that it is universal dividing head, it can be used in milling machine for indexing tools, perform the milling operation for flute spir gear,spiral gear,spiral flute,Archimedean cam,helical flute and etc.

[handlewanker]

Hi all, I've got a dividing head just like this, except for one problem, when it's in the horizontal position it points to the left....in the past I've always used a dividing head pointing to the right, and if'n you're on a horizontal mill you'd be milling in the direction towards the head with it on the left hand side, otherwise the nut on the spindle would unscrew if'n you had it on the right side of the table and reversed the spindle drive.

Does this mean it's a special purpose head....never came across one of those....and as far as I can see stripping the head down and reversing the body in the frame might not get the engraved surfaces to agree, but it's been repainted previously so it might be universal.

I can't see that just swinging the whole body over in the frame will work as the quick indexing plunger mechanism would foul the table holding down bolt at the bottom.

It looks just like the Cincinnatti model in the photo, but without the drive for the differential gearing.....it also doesn't have a Cincinnatti label on it, but that might be missing when it got painted before I bought it....any suggestions will be helpfull.

BTW, Djanger, before you attempt to do a job in the div head, make sure you rotate the part in the chuck by winding with the handle and test for run out with a dial indicator...same as you would do for a job in the chuck in a lathe.....3 jaw chucks are notorious for not running true.

The hole plate on that model is double sided, which means you have two sets of hole spacings, one on each side.....as you get to know it you'll understand the reason why you need all those various hole spacings.

The ratio of the turns is 40 turns of the handle to one turn of the chuck, so anything that divides into 40 is a variation of the turns ratio.....a 6 hole division is five turns of the handle etc etc, but that is just simple dividing......get a book on the dividing head on Ebay and you'll know all there is to know for any gear or hole pitch you want to do.

I paid $700 for my dividing head back in 1997, ex tool room model, and considered it a rare find.
Ian.

[handlewanker]

Hi again, looking at the second photo it seems that my dividing head is exactly the same as this one, except no gear drive etc.

I still can't see how the head can be used pointing to the right, the quick index trip lever assembly will then be at the bottom and inaccessible...any solutions?
Ian.

[juergenwt]

jdanger2001 - Get a Machinist Handbook - any Edition - and look up " Dividing Heads".
most likely you will see a B & S Universal. It will have all the tooling listed. Than find an old timer in your town and have him show you how to use it and what you can do with it.

[HuFlungDung]

Hi again, looking at the second photo it seems that my dividing head is exactly the same as this one, except no gear drive etc.

I still can't see how the head can be used pointing to the right, the quick index trip lever assembly will then be at the bottom and inaccessible...any solutions?
Ian.

I don't see any particular reason to worry about which way the head is set up to work. The handedness of the chuck thread is not a particular concern when doing spiral milling anyways, because you might have to rotate the spindle in either direction, depending on the job at hand. Just make sure the chuck is on tight. If in doubt, secure the chuck by adding a setscrew onto the spindle threads. Use a brass or a aluminum plug under the setscrew to protect the threads of the spindle from getting distorted.

[handlewanker]

Hi, I wouldn't expect anyone buying a Cincinnati dividing head to have to drill holes through the backplate boss to hold the chuck onto the spindle for reverse spindle cutting.

The point is....if'n you were going to cut a gear on a horizontal mill and the head pointed to the left......looking at the spindle....the spindle would have to run in reverse (clockwise) and have the gear cutter rotating clockwise, with the bottom of the cutter cutting on top of the gear towards the chuck (right hand side), and as the spindle nut is right hand thread it would tend to loosen when rotating clockwise.

The head can only be moved from the horizontal position (chuck pointing left) to over the top and down to 45 deg on the other side (chuck pointing right).....not being able to go down to a parallel position on the right hand side due to the quick index mechanism fouling the base hold down bolts.

All the dividing heads I have ever worked with had the chuck pointing to the right when in the horizontal positon, parallel to the table......the question is....why is this Cincinnati head different?

Anyway, I've just bought a BS1 dividing head and 160mm 4 jaw chuck package from our local tool supplier, Hare & Forbes, who have a 5 day super sale on, and the Cincinnati head will go up for sale on Ebay etc, can't mess with oddball tooling anymore.
Ian.

[handlewanker]

Hi all, the Cincinnati head in post #1 comes with 3 double sided hole plates (as far as I'm aware), and depending on which one you got with the head would be the range you could divide to do any gear cutting.....that's the position I'm at right now.....only one double sided hole plate on the head when I bought it....Grrrr GRRRRRrrrrrr!

For any accurate work you'll find the 3 jaw chuck is useless....they ALL are.....when you mount a job in the chuck, and it is 99.99% of the time a round item, you'll find that the job runs out a couple of thou......tell me otherwise and you'll make a good politician.

The solution is like in a lathe mounted 3 jaw chuck to get the job to run dead true, to as good as .01mm (.0005"), you remachine the spigot on the back plate to give you .08mm (approx .003") clearance as opposed to making the spigot a close location fit....this will enable you to slacken off the backplate screws to tap the chuck body with a soft hammer to bring the job to truth.......works 100% every time....can't be beat and works with ALL worn 3 jaw chucks (and a lot of cheap new chucks too) when the jaws have been reground.

Your problem (and mine) with the missing hole plates won't go away, and unless you can buy the missing Cincinnati plates as spare parts or on ebay, the only other recourse is to buy a set of the Taiwanese hole plates (and fit them) that are sold to make rotary tables calibrated in degrees also capable of dividing.

You might be lucky and find that the plate that the head cam with was used to divide the lower values, so can be used to do all those 2,3,4,6,8, etc common divisions for general work, but the quick index plate behind the chuck will also be able to do this too.....on mine it has 3 sets of holes, so covers quite a range without having to wind the handle or punch holes.
Ian.