DIY gear hobbers, anyone know of any?

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GearGeek
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DIY gear hobbers, anyone know of any?

Post by GearGeek »

I have been looking around the internet for home built gear hobbers. Not anything that will do any sort of serious production, but just something that would be a fun project and actually function under the basic principles of a hobber. (and preferable manual with change gears not CNC) I have searched all over google and find a few mentions of people who have built a few but no real good plans or even pictures. I know people have done it but can't find any good sites.

I did find this one http://www.collegeengineering.co.uk/Castings/582.htm
I am curious if any of you have heard of this one or if you know of anyone who could tell me more about it or point me in the direction of someone who has built a hobber.

I am not looking for a mill adaptation or dividing head setup but if anyone has any info I would love to hear it :)

thanks!

~GearGeek
J Tiers
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Post by J Tiers »

There was an article or two in The Home Shop Machinist (or maybe machinist's workshop) which I want to say was by Terry Sexton.

IIRC he had a homebrewed setup that handled hobbing and also cutting helical gears.

Articles were back in the 90's, I think
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GearGeek
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Post by GearGeek »

Your memory seems to be pretty good to me :) Looks like Home Shop Machinist in the mid to late '90 's.. haven't found the article yet but I will look around for it. Just found out that there *was* such an article.
*tries to see how many different search criteria she can run through google*

thanks for the tip. :)

~GearGeek
joegib
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Post by joegib »

It might be worth your while joining the Yahoo "Metal Working, Gear Cutting and Indexing" newsgroup here:

http://groups.yahoo.com/group/mwmills2/

Their files and photos sections have some material on the Jacobs & other hobbing setups. I think at one point their archives included copies of the original 1976 "Model Engineer" articles on the Jacobs machine but they were purged following threats by the publisher's lawyers.

In issues 58, 59 and 60 of the UK magazine "Model Engineers Workshop" back in 1999 Harold Hall described the machining of the College Engineering castings. There's also a partial description here:

http://metal.duncanamps.com/hobber.php

— but the project's incomplete.

Sadly, as you've found, there's not a lot of concrete information on the Web — most of the interesting stuff is locked up in paper publications.

There have been a few interesting electronic solutions described in Model Engineers Workshop in recent years. As you know, the key element of a hobber is to synchronise the motions of the cutting and workholding spindles in the right ratio to generate the gear teeth. These electronic setups involve:

1. Hooking an optical encoder to a milling spindle to capture the rev speed, the output being fed to:

2. A computer or standalone electronic dividing device linked to:

3. A stepper driver driving:

4. A stepper motor hooked to the worm of a dividing head or other workholding spindle to control the rev speed.

If you can handle the electronic side, this seems like a simpler project than a full blown mechanical hobber.
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Old Biker UK
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Post by Old Biker UK »

GearGeek -
Some years ago I bought a part built one of those, called a Jacobs Gear Hobbing mc if memory serves. I never did get around to finishing it and passed it on to a club member. He finished it, made a few hobs and is a happy bunny, giving demonstrations and turning out some decent gears.
It was originally described in the Model Engineer magazine in two articles with pictures :- Vol.140(1974).pp668 & Vol.142(1976).pp697
Mark
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GearGeek
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Post by GearGeek »

Cool! someone who has actually worked on one :) How are the plans for that machine? Are they legible? ;)

I have been trying to locate that article (along with the one J Tiers mentioned but I am not having much luck.) The yahoo group has some good pics but I am having trouble locating plans. I not being in the UK, I can't really afford to have those castings sent over to Washington state :( so I am either going to have to make it from solid or locate someone in the US who has made castings available. You guys have all the neat castings/kits for projects ;)

Also seems like the publisher for that magazine is causing somewhat of a legal to do with anyone who posts that article from what I have seen on the yahoo group. :(

I read about someone who had one at the last GEARS show here (which I missed *doh*) and I am hoping he comes back this year as GEARS is held in Portland, OR only about 15 minutes from me.

It is a shame more information isn't out there on these type of hobbers. As much as I like computers and CNC this would be a really fun manual project and I would like to build this one.

~GearGeek
Mcgyver
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Post by Mcgyver »

there was also a build article on it in Model Engineers Workshop, also in the 90's i think. the series went to describe set ups for gashing and relieving homemade hobs iirc
lugnut
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Post by lugnut »

Try this guys pages on gear cutting. Pretty simple and strait forward. There are several pages in the article.
http://homepage.ntlworld.com/peter_harr ... /index.htm
Mel
Matt
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Post by Matt »

I happened onto a pile of "Machinist's Workshop" magazines in the local used bookshop. Thumbed though the pile and right on the cover a picture of a what looks like a home-made hob in a mill with a half finished steel gear in the background (meshed to it)

April 1999 Vol.12, Number 2 Pages 8-15

Looking in the article, there is the story of how he came to make the hob, and how he used it to make half a dozen gears. The writer (John A. Cooper) admits that they aren't perfect, but with a little backlash work well. It's not exactly what you are looking for, but it's a start if you can't find castings or plans.

If you can't find a copy of the magazine PM me with an address and I will send it your way after I finish reading it. (I would like it back of course :) )

Matt
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GearGeek
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Post by GearGeek »

Just wanted to say a big thank you to the people who have helped me out. :) I am pretty well set with info now and if I ever get the chance to build one of these things you will be the first to see. Don't hold your breath though because I don't have a lot of spare time and machine time is even more sparse than that. Incase no one noticed I am really into gears. ;) (don't know a *whole* lot about them but I want to) I would love to build a machine like the jacob's or CES (they are very similar) so I hope to be able to do it. Just need to find this mythical thing called time... lol

Anyways enough of my babbling... thanks all! this is a great group. :) If anyone else has anything gear related though please let me know. I am always looking for more stuff :D

~GearGeek
the mad machinist
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Re: DIY gear hobbers, anyone know of any?

Post by the mad machinist »

Here is the address to get the plans for a gear hobber. http://www.martinmodel.com/MMPtools.html
For list of other interesting sites email tiggrthedispatcher@gmail.com
Put "Site List" as the subject. You will receive an email with an attachment containing the list. Your name and email address will go into my "Contact Book", A physical book and a flash drive, not the email contacts. This is for your security, if it's not in contacts they can't target your computer from mine! I ask that you do not put me in your contacts for the same reason. As the list grows I will send you an occasional update. If you email me and let me know you want the update list at the time, I will email you the list as it is at that time. You will still receive the occasional update.

Keep those machines well lubed and running as often as possible!

The Mad Machinist.
pete
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Re: DIY gear hobbers, anyone know of any?

Post by pete »

An old thread to dredge up but,
College Engineering Supply (CES) that you already seem to know about offer that original but updated "Jacobs" named gear hobber as a casting kit and drawings. There in the U.K. for anyone who doesn't know about them. To be honest though I think some selective use of the correct materials such as continious cast cast iron for the slides, and welded steel fabrications or even cutting from solid where cast iron's quality's aren't really needed could allow that gear hobber to be built without the castings. It is a pretty extensive project that does require a fairly well equipped shop and the same in experience to match the tooling. The machine is designed to first use a fairly comprehensive set of Myford super 7 lathe gears and it can then cut it's own gearing that's used to gear the hob to the gear blank to give you the correct ratio.

While I bought my CES casting kit and drawings as a way to speed up the production of all the gears required to build an Ornamental Turning Geometric Chuck, I sometimes wonder if I'll ever live long enough to move that Hobber up to the top of my 500 plus year required project list. And Old Biker, if your still a member here ?, your website and your build of that geometric chuck has inspired me for a long time now. I owe you a personal thanks at the bare minimum.

Pete
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