Hello from Florida!

[andyharwood3Participant @andyharwood3]

I’ve just joined, basically hoping for information and help with a Jacobs Type Gear Hobber that I purchased. First off, I am not a modeler, machinist, or anything such. I do have a fondness for reducing good metals to scrap on my mill and lathe. Well, occasionally I do actually ‘make’ something useful.

Anyhows, I bought this machine at a flea market. It is complete, and runs. I knew it was a type of gear hobber when I saw it, but that was it. The man selling it had no idea what it was. I knew it was something I had no use for, had no idea how to use, but, once seeing it, for the price asked, knew I had to have it.

Questioning the seller, the machine came from a estate sale, he said basically he bought what did not sell. He also had a 4 cylinder engine kit, partially finished, not complete. There were a couple gears included with it, so I’m guessing the hobber was used to machine them.

So, in finding my way here, I also found upon arriving a link to Duncan’s Metal Pages, which appears to have information on how to use the gear hobber. I’m going there now to look. I included a photo of the machine, and a photo of the engine kit, thinking someone may know about it. Only markings on it are “POCO Power” cast into the crankcase.

I’m sure I’ll be posting up soon, with some photos of the machine and engine kit.

Happy to be here, Andy

[noel shelleyParticipant @noelshelley55608]

The Jacobs gear hobbing machine is a very neat bit of kit but as shown is missing the change wheels that set up the train. They did I believe use Myford wheels, the idea was you could rob them from your lathe to get the machine to work and then make new ones to put on the machine.

Anyway Welcome Andy, there will I’m sure be someone on here who will be able to tell you more about how to use the thing. There may well be write ups in ME about it.  Good luck, and best wishes. Noel.

[Andrew CrowParticipant @andrewcrow91475]

Welcome Andy,  I’m sure there will be someone on here will be able  to help. I believe that the original article was serialised in Model Engineer around 1975 with one or two follow up articles by other authors covering some additions and improvements done over the next few years.

Andy

[MichaelRParticipant @michaelr]

Hi Andy welcome to the forum, this link may help you with the engine castings, the engine is listed on the web site as the Panther Pup

ttps://www.billreichart.com  

MichaelR

[BazyleParticipant @bazyle]

If you like mechanisms then the jacobs is an interesting machine with a fair bit of information available on the internet. There is a modification with a differential to enable it to cut prime numbers. The biggest problem nowadays is finding the hobs.

[Howard LewisParticipant @howardlewis46836]

Hi Andy!

Welcome to the Forum.

The Jacobs gear cutter is one that I would like to own, but never had the courage to make.

Instead have to make do with a variety of gear cutters and a Rotary Table, which is effective, but much slower, and probably, in my case, less accurate!

As Noel said, it uses Myford gears (20DP, 14.5 P A, 5/8″ bore)

With suitable gears and hobs, you should be able to cut almost any gear that you need.

Good Luck!

Howard

[BazyleParticipant @bazyle]

You will notice some differences relative to the pictures on https://www.lathes.co.uk/jacobs/ . The design was modified and castings marketed in the USA by someone else.
https://www.martinmodel.com/products/gear-hobber-casting-set

 

[andyharwood3Participant @andyharwood3]

Change gears were included with the machine, luckily. I, at present was daunted by the gear train, and the multitude of gears – have no idea how to determine which go where  for whatever gear attempting to be made. I came across a site link here that I think has a calculator, but not delved into it yet. At present we’re traveling, and it will be Christmas time before we’re back home, and I can devote some time to the machine. Thanks for the warm welcome, and I’ll follow up on the links above!

 

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