Jacobs Gear Hobber

[Robert Wallace 1Participant @robertwallace1]

Hi

Has anyone made the Jacobs type gear hobber from the castings sold by CES. Many years ago there was and article published in Model Engineer in 1976 on making one ,any help would be greatly appreciated

[Robert Wallace 1Participant @robertwallace1]

[Chris HembryParticipant @chrishembry84309]

Hi Robert

 

I have a set of castings and am at an early stage in construction. There was also a series published in MEW issues 58-60. The ME articles were for a slightly different version although the principles were the same.

 

Regards, Chris

[Robert Wallace 1Participant @robertwallace1]

Hi Chris

Many thanks, could I obtain the back issues  as mine only go back 6 years

 

Bob 

[John Stevenson 1Participant @johnstevenson1]

Bob, drop me an email at

john [at] stevenson-engineers.co.uk

 

John s.

[Steve WanParticipant @stevewan33894]

Hi Robert and Chris

 

Very interested in your venture in making gear hobber and seen those

cast pieces at CES…but am quite confused between a gear hobber

and pinion cutting machine…ain’t they the same???

 

Also I know that CES stated that their cast includes a tech. drawing

to assist the build up…any difference from ME articles??

 

I hear from both of you, tks!

 

Steve Wan

[Robert Wallace 1Participant @robertwallace1]

Hi Steve

I am hoping to cut both pinions and gears on the hobber when finished but if I am wrong I am sure a kind hearted soul out there will let me know I have yet to lay my hands on the ME and MEW articles 

 

Bob 

[Steve WanParticipant @stevewan33894]

Hi Bob

 

Thanks! Possible we get in-touch by email?

 

This gear or pinion cutting machine is my next project. Perhaps we can exchange more design ideas…see my gallery photos, I was successful in making the tool and cutter -Quorn more simple for light users. Tested, work like a Charm!

 

My email: stewan@gmail.com

 

I do have other pictures of gear cut machines, yet to re-design and make it

smaller and simple to build. The basic foundation is of a horizontal mill before

more stuff are added…indexer, tailstock etc.

 

Steve

 

[GoCreateParticipant @gocreate]

As far as I know, a pinion is just a gear cut integral on a shaft and in use engages with a rack, i.e. rack and pinion, otherwise it’s a gear.

I notice the CES gear hobber uses a vertical slide, are castings for this included in the kit? I am also interested in building one of these well, it’s on my list of projects.

 

Nigel

[Richard ParsonsParticipant @richardparsons61721]

 

Some moons ago I wrote a challenge to the Editor on a similar topic. I what it said was that if you could read the rotational speed and (position) of a shaft (say of my milling machine) and factor this into a stepper motor which could then drive a shaft with a gear blank on it. Behold you have a gear hobbing machine.  The problem for me my ‘electronic’ stopped with the introduction of the pentode valve. Any one out there want to design the black box to do it?

The advantage of hobbing is that you only need one hob for each Module/Diameteral pitch and that is cut as Rack’. With gear cutting you need several cutters for each Module/Diameteral pitch depending on the number of teeth you are cutting.

[KWILParticipant @kwil]

The Jacobs device works very well and was demonstrated at the Midland ME Exhibition (as well as Harrogate I believe)

[John Stevenson 1Participant @johnstevenson1]

Posted by Richard Parsons on 25/07/2010 10:24:26:
 

Some moons ago I wrote a challenge to the Editor on a similar topic. I what it said was that if you could read the rotational speed and (position) of a shaft (say of my milling machine) and factor this into a stepper motor which could then drive a shaft with a gear blank on it. Behold you have a gear hobbing machine.  The problem for me my ‘electronic’ stopped with the introduction of the pentode valve. Any one out there want to design the black box to do it?

 

Already been done.

Read MEW 108, article by Brian Thompson  also includes the circuritry.

 

John S.

[Richard ParsonsParticipant @richardparsons61721]

 

Hello John,

Thanks for that reference. Although I have been subscribing to MEWS since 2004 here in Hungary (and before that in the U.K.) MEWS No 108 is missing.

This would have been about October 2005. In 2004-5 the publishers of ME/MEWS were using a Swiss distribution company for the Euro Post. Summertime distribution in 2004 was bad –well there were holidays, so they would be short handed and the batch for Hungary was very small! It was forgotten –dimmed-. The same thing happened in 2005. 

Later in 2005 the distribution company was involved with a nasty swindle involving an Italian outfit. The Swiss authorities just cancelled the distributor’s licence and dumped on them from a great height. They should be ‘out’ in a few years time (with good behaviour). The Swiss are very strict.

I cannot get a copy of MEWS No 108 as there are none left. The Swiss just shredded the blooming lot and the publishers had to use up their surplus to satisfy demand.  

That is why I did not know about this article. 

If any one could scan in and message me a copy of the article I would be delighted.

[John Stevenson 1Participant @johnstevenson1]

Richard, drop me an email to john@stevenson-engineers.co.uk and I’ll forward a copy of Brian’s article on with added extras.

 

I can do this as I was involved in the project to the point of getting a dedicated circuit board made up and have Brian’s full permission to share anything so copyright doesn’t come into this.

 

Brian transposed the circuit to veroboard so it would be easier to build and there was a mistake in MEW108 which didn’t get corrected until MEW110 if I remember for anyone using the original articles.

 

I have this setup on a Victoria U2 and it runs as a dedicated hobber, it’s probably done over a 1,000 gears to date as most of them done are in sticks of 10.

 

John S.

[Ejaz AhmedParticipant @ejazahmed98052]

HOME MADE GEAR HOBBER (BIG HEAVY DUTY)

I am looking for complete plan(casting drawing, machining etc.) to make home made GEAR HOBBER (swing 175", Module 45, Face 48", Can hold weight up to 40 Ton). I really appreciated if Some one help me. Ejaz.

(Please send Ejaz a PM. Ed.)

Edited By Diane Carney on 11/03/2013 10:27:26

[joeyParticipant @joey]

Can someone please help with some instructions on how to the determine gears needed to cut spesific counts of teeth in the CES Jacobs type gear hobber?

Joey

[Douglas JohnstonParticipant @douglasjohnston98463]

John S. – I have just fished out MEW 108 and the gear hobbing system looks very interesting, I must have flicked past it at the time without thinking too much about it.

I am interested in trying it out and was wondering if the layout for the PCB you mentioned is available, since I don't like veroboard. I could do my own layout but it would save me a lot of time if one was already available.

Doug

[John Stevenson 1Participant @johnstevenson1]

Doug,

I do have some pictures and PM sent.

[Sub MandrelParticipant @submandrel]

I visited CES several weeks ago. I expressed intedt in the hobber, apparently it is quite a popular projecty. They are quite happy to supply part-sets of castings as the machine has parts which potentially have several other applications, not least a vertical slide.

Neil

[BazyleParticipant @bazyle]

Note that the design appears to have been updated by an American. 'simplified and improved' to make it more ridgid. However his kit is rather expensinve and only available in USA.

Getting interested in the electronic version and of course the relevent MEW has decided to hide itself somewhere, probably in a pile of MEs.

[joeyParticipant @joey]

Doug, I have done the pc board for the electronic synchroniser for the gear hobber on my Mach 3 controlled Optimum mill. if you are interested and can use it, I can mail you the G-code and Autocad 14 drawing or dxf files. I am trying to fit the unit to a Jacobs type hobber and it should then run without the use of lots of gears.

Joey

[BazyleParticipant @bazyle]

Further to Joey's earlier question re calculations this site might help. It is not clear if Duncan ever finished his hobber but he has a nifty program for calculating gear ratios for it. (thanks Duncan if you ever read this).

This program is also useful if you have a universal dividing head but not the gears listed in Machinery Handbook for differential indexing. Just calculate the ratio given by the listed gears and then use the program to find the combination using the gears you do have.

I wonder if it wouldn't be easier to adapt a very small horizontal milling machine. The simple production ones even smaller than a centec come up on ebay but get little interest. Probably end up as scrap but they would provide the necessary X & Z axes plus spindle leaving only a blank rotator and gear drive to make.

Found my copy of MEW 108. Somewhat hard to understand the explanation but found a much better description by JS on another forum.

[david lockwoodParticipant @davidlockwood10028]

Does anyone know what rpm I should be running the Jacobs hobber at ?

I am just about to machine up the belt drive and I have to work the ratios out

many thanks to anyone who can help

David

[Pete RimmerParticipant @peterimmer30576]

The manual for my hobber (which uses 32mm diameter hobs) says the hob speed is 300rpm for steel and 980rpm for brass.

[david lockwoodParticipant @davidlockwood10028]

Thank you Pete

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