Hofmann dividing head manual

I've just bought a lovely Hofmann 4" centre height universal dividing head. It came with one plate and the gear banjo so I'm looking for a manual to identify the hole numbers for any other plates and any information on the gears normally supplied with it. The only source for a manual I've identified is METools online who sell a CD with the manuals for 4 or 5 different dividing heads including a Hofmann but they seem to have stopped trading.

Any information gratefully received or, miracle of miracles, a source of plates or gears. Many thanks.

Sandy

Sandy

Turn the plate over and you should find some more indexing numbers.

Emgee

Might be worth dropping an inquiring e-mail to Zeatz UK (used to be Zeatz Hofmann when I dealt with them at my previous employment) here : [email protected]

Never know - might have something at the back of a filing cabinet !

Nigel B

"I'm looking for a manual to identify the hole numbers for any other plates "

It's not as difficult as needing a manual to identify the holes you are missing. All dividing heads use pretty much the same basic set up to 50 and the only variation is how many plates they use and which numbers are on which plate.
A few examples:
Brown and Sharpe 3 plates

(new page 'cos it doesn't like too many tables at once)
Elliott do it in 2 plates but go through the sequence on alternate plates

Some can replace a small number like 15 with say 30. It is really all about primes and multiples of primes. Above 50 most manufacturers supplied extra plates with more big primes which mostly nobody needed.
eg Elliott had 4 more (don't know why they threw in the 24)

Hi I have the 4inch (100 mm) Hoffman head,with tailstock,banjo and a full set of gears for spiral or differential indexing, the dividing plate is double sided,after removing the index arms and the 3 c/sunk securing screws the plate can be jacked off its spindle by one of a pair of grubscrews,about m5 with slotted heads,you will then find on removing the plate there is a different pattern of holes on the other side.The two sides will cover most of the normal divisions required and further numbers can be achieved by differential indexing,including useful numbers like 127The one thing that it will not do,nor will most heads is combine spiral milling with differential indexing say to achieve a 127 helical gear,using Standard quipment.Indexing info and tables can be found in Machineries Handbook.I have never seen any ads for items such as backplates,or other spindle fittings I just have a 3 jaw chuck,and catch plate for between centre work..

METoolsonline was set up by my late wife, the much lamented Gert. Unfortunately when she died I shut the site down and also her Ebay account of Marypoppinsbag.

Hopefully later this year i hope to open the METoolsonline site again and I'm in the slow process of stocking up before it goes live again.

I do still have CD of the manuals she used to sell at £9.50 post paid to any UK address so if anyone wants one can they please drop me a PM.

In stock are the Dividing head CD, the Tool and cutter grinder CD, Bridgeport CD and the Shaper CD.

I have a Hofmann and a set of gears but not sure if it is complete. I have 100,86,72,64,56,48,44,40,32,28, & 24 x2.

Hello Sandy, I have a Hofmann UTH dividing head, the operating instructions and the tables for indirect, differential and spiral milling. The set of change gears is as listed by Vintagengineer above.

If you would like me to copy this information then send me your email address as a PM.

Regards, John

The list of change gears given is 'standard' for universal dividing heads; I have the same set for my Elliott dividing head.

Andrew

Last year searching for info on the Hofman head on the net I found that the later Hofman dividing heads had a hydraulic locking device for the spindle,and there were various threads on a US site that mentioned the hydraulic fluid was a special very expensive grease. Looking at my head I cannot see any way of even topping up the grease,via a screw plug or other device or even dismantling the lock. My spindle locks grip has deteriorated over the last 25 years and needs some attention,though from years of experience I have always found that though most mechanical items can be dismantled and renovated,when it comes to very precise devices they are best left undisturbed if possible ,back in the 1950s my old boss always believed that when installing machine tools make sure they are in the right place in the factory and bed them down and don't move them,they settle and then remain stable. Has anyone found out how to renovate the spindle lock?

Just wanted to bring this one up to the top again so that I could thank all the people who contributed, sent me a copy of the manual or improved my knowledge of the basics of dividing head maths so that I might be able to work it out for myself next time. I don't know how we would manage without this site.

To answer Nigel McBurney's question above about the hydraulic spindle lock, the manual specifies BP HLP5 oil but I found another thread on this site (Dividing Head Help - Steve Garnett) where it was discussed and apparently any modern hydraulic oil with a viscosity of 32 will be OK - just need to find out where to put it now as it's not exactly clear from the manual.

Thanks also to the organisers of this marvellous site.

Sandy

The thanks belong with our marvellous contributors!

Neil

Hi,

I had some correspondence with Hofmman in Germany. Regarding the lubrication they told me and I quote:

"use Klüberplex GE 11-680. Manufacturer is Klüber. You can also use other grease with similar specifications."

I also asked about the spindle external taper on the UTH125. The internal taper is MT5 but the external looks like a American short taper D camlock type but it isn't. I did not get a clear answer. I've also asked Rotagrip as they sell a range of backing plates for chucks and they don't know either. The closest I've got is that it is according to some DIN specification but I can't seem to find that information at the moment. Does anyone know? I would very much like to order a backing plate, I'd prefer not to have to make one as face and taper needs to be really precise to work well.

Steve

There seems to be a bit of confusion here about the correct oil for the hydraulic spindle lock on the Hofmann dividing head.

The one I have is quite old and is a type UTH. The manual I now have has a diagram which matched exactly the dividing head I have and it clearly states that the hydraulic spindle lock uses BP HLP 50 oil. The recommendation Steve has received for Hofmann is for Kluberplex GE 11-680 grease. I had a look online and this is a high pressure adhesive gear tooth lubricant. So one is an oil and the other is a grease and, from my admittedly very limited experience, I would not have thought they would do the same job, so either something has been lost in translation or we are talking about 2 different types of dividing head. Any thoughts, anyone? Could Hofmann in Germany have meant to use the grease for the external or internal gears rather than the spindle lock?

Sandy

Sandy,

Common sense suggest you must be correct. Mine is a UTH125 and I have no idea how old it is but I provided the S/N to Hofmann in my email. I have no idea if the design has changed over the years either. Perhaps my post was lacking in clarity, I asked Hofmann about all the lubrication specs and specifically the spindle lock and got that answer after 3 attempts. It was like pulling teeth. I never did get an answer about the spindle external taper instead only getting the answer that it was in the manual. I have not spotted the exact spec in the manual. Having said all that it is a very nice dividing head except when I am lifting it!

Steve

Sandy, my Hofmann UTH 100 sadly does not have its driven spindle that protrudes from the reverse side of the chuck and which is required for differential dividing (and also helical gear cutting). Would it be possible to describe this removeable spindle and how it is fixed? Adam