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Cincinnati Dividing Head Gearbox Dimensions

Dick Streff

Aluminum
Joined
Sep 12, 2003
Location
Omaha
I posted a WTB over on the for sale section for a gear box for a Cincinnati mill dividing head, specifically for a 205-12 machine. Not surprisingly the response has been tepid at best.

To that end I have several of the internal parts already and a mostly complete set of the change gears. I've been investigating constructing the rest. Per the attached two photos downloaded from previous PM posts I need some dimensions to clarify some of the layout. I've been able to ascertain a few of the dimensions from the parts I have and the notes in the parts manual available online. But I could use some help with a few key centerlines and lengths that would go a long ways to eliminating some tedious mock-ups.

If you have a regular lead gear box for a Cincinnati similar to the ones pictured I'd appreciate if you could get me some rough, ruler type measurements to start from. I need the dimensions shown with the yellow notes. I can calculate the ones already indicated in blue, but verification wouldn't hurt.

Gearbox Centerline Dimensions.jpgSliding Bracket Dimensions.jpg

Note, all these dimensions are for the outboard side bracketry and shafts. Inboard where the box connects to the head there is more flexibility as I can make a variety of things work to match the shaft location on the head I am using.

Thanks in advance if you can help.

Dick
 
Are the dimensions you posted known? I have a good friend with an autocad who may be of some assistance but he's going to have questions. I can link you up of you like

Sent from my SM-G975U using Tapatalk
 
Are the dimensions you posted known? I have a good friend with an autocad who may be of some assistance but he's going to have questions. I can link you up of you like

Sent from my SM-G975U using Tapatalk
Also, do you just need gears and brackets or are you attempting to make an entire door?

Sent from my SM-G975U using Tapatalk
 
Thanks for the offer. I can lay it out in CAD myself, but having these additional dimensions would make it much easier.

I currently have most of the reverse gear parts (the triangle at top) and the two gears that mesh the leadscrew for the table to the first gear in the change gear cluster (which is D, of A,B,C, and D). I have some additional splined bushings and assorted hardware also. I'll need to make the mounting plate and all the spindles, etc.

I have the gears and also checked the center distances doing the math and the numbers shown are right on. But those don't locate x or y distance from the leadscrew centerline. I'd have to play around quite a bit with the largest pitch circles possible in the change gear group to get a better idea where the remaining gear centers could be. Since I am using the original Cincinnati parts there is no sense in reinventing the wheel if not needed.

The K&T head I have is a much simpler arrangement for the normal lead gearing. The banjo mounts right on the output shaft of the dividing head and there are many less moving parts involved. The older Cincinnati heads were similar. But since I have a pretty good number of the original parts and change gears for this version it just makes more sense to me to continue on down that path.

Dick
 
I have never seen a Cincinnati dividing head drive up for sale that was not attached to a mill. How much is one of these things worth? My #3 Universal didn't come with the drive or dividing head and I've always wanted to score one but have no idea what market value might be if/when one comes up.
 
I don't think this is the kind of object where a reasonably consistent market value would apply. They are rare, but not in a way that would typically translate to valuable. I believe the prices would be all over the map if you could even find a data point.

I agree you would rarely see them for sale by themselves. But there are probably as many of them attached to a machine that the owner neither has the correct dividing head in their possession nor the inclination to ever use as there are being actively used for their purpose.

They can be removed from the table without causing any further issues in the sue of the machine, as the right end never had a handwheel without the gearbox, just a domed cover that bolts on to protect the end of the leadscrew.

Dick
 
My understanding is that the universal machines came with the drive and head. It kinda chaps my hide a little that the original parts for my machine may be out there somewhere sitting on some shelf somewhere. Mine does have the factory PTO cover on it though - so who knows?

Making your own drive is a pretty cool project I must admit!
 
Does your dividing head drive come in on the centerline of the dividing head, or slightly below it? It was challenging to find the right dividing head, and I never really did. I ended up with one that was intended for the open style gear train and made a splined shaft for it. I have a 2MI which I believe is the predecessor and it has the bracket. I printed out your photos a week ago and haven't made it in the shop for any useful amount of time yet.
 
The picture of the second drive box with the red inside is mine. It is presently buried on the back of a shelf in a box on the bottom or I would have posted the dimensions for you. Not sure when I can get to it as there are some very heavy things sitting in front of it.

As a side note when using the pictures for reference please ignore the extra stuff at the bottom right of my picture. It is an unobtanium rare extended lead gearbox which uses two full sets of gears to get the entire range. I didn't even know it existed when I bought it. I spent a long time trying to figure out why it had a bunch of extra parts.

I had intended to fit it to my machine and have two complete boxes of gears, one set never used the other maybe once. But with my move into CNC that is where my money is coming from I only do about a job a year on the Cincinnati and no reason to get the drive adapted to my Plain mill.

As you noted the prices tend to be all over the place and usually in the not worth the time to box them up acceptably to ship. They are heavy. At some point soon I am going sell the mill and most accessories. I even got one of those universal heads with the B&S10 taper so that I didn't need to have a universal table to cut helix and such. Even bought some tooling for it.

It's one of those things I should sell all the parts for but the return just never seems remotely worth the hassle. It will hit Craigslist at some point along with the vertical heads and K&T driven rotab and other stuff.
 
Go one if you need it.

I posted a WTB over on the for sale section for a gear box for a Cincinnati mill dividing head, specifically for a 205-12 machine. Not surprisingly the response has been tepid at best.

To that end I have several of the internal parts already and a mostly complete set of the change gears. I've been investigating constructing the rest. Per the attached two photos downloaded from previous PM posts I need some dimensions to clarify some of the layout. I've been able to ascertain a few of the dimensions from the parts I have and the notes in the parts manual available online. But I could use some help with a few key centerlines and lengths that would go a long ways to eliminating some tedious mock-ups.

If you have a regular lead gear box for a Cincinnati similar to the ones pictured I'd appreciate if you could get me some rough, ruler type measurements to start from. I need the dimensions shown with the yellow notes. I can calculate the ones already indicated in blue, but verification wouldn't hurt.

View attachment 277297View attachment 277298

Note, all these dimensions are for the outboard side bracketry and shafts. Inboard where the box connects to the head there is more flexibility as I can make a variety of things work to match the shaft location on the head I am using.

Thanks in advance if you can help.

Dick
Dick, My brother has one of these units he will off reasonable If you send me an email I will forward it to him and you can deal with him directly.
Regards,
Steve
 
I have never seen a Cincinnati dividing head drive up for sale that was not attached to a mill. How much is one of these things worth? My #3 Universal didn't come with the drive or dividing head and I've always wanted to score one but have no idea what market value might be if/when one comes up.

Got one, if you need it we can make a deal. send me a PM Steve
 
I've been fortunate enough that a member here sold me the bulk of standard lead assembly so I no longer need to fabricate the entire unit. I'll need to make some modifications on the output side to mesh correctly with the head I have on hand, and filling in the gaps of the gear set I already have. But other than that it is ready to go. So I don't need any dimensions anymore. Thanks to all who had volunteered information.

I'd like to share the links to some Cincinnati dividing head literature I recently purchased and uploaded to vintagemachinery.org. It fills in some knowledge gaps that I hadn't seen previously in any of the other Cincinnati literature available freely online.

First, a parts list and service information from 1945 that covers all the heads available at that time, the wide range attachment, the standard and long lead gear boxes, and the older open quadrant system. I hadn't seen this information online previously, as the other literature available on vintagemachinery.org is for the later, streamlined heads from the 1960's on up:

Cincinnati Milling Machine Co. - Publication Reprints - Cincinnati Universal Dividing Heads and Accessories, Indexing Attachments - | VintageMachinery.org

Here is a brochure for those later heads:

Cincinnati Milling Machine Co. - Publication Reprints - Cincinnati 10"-12"-14" Dividing Heads | VintageMachinery.org

And another brochure for an 8" version of the later head that I've never seen before:

Cincinnati Milling Machine Co. - Publication Reprints - Cincinnati 8" Universal Dividing Head | VintageMachinery.org

Dick
 
Thanks for posting those PDFs. The service manual is great to have. I have an operators manual that I will scan later.

I'm surprised to see an 8" dividing head. I had searched high and low and couldn't find any mention of one, because I was trying to identify my tailstock:
Is This Tailstock a Cincinnati?
It was identified as a Toolmaster, but looks the same as the one in your PDF.
 








 
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