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How to operate a hobbing machine?

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Proposed merge from gear hobs

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The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.
I merged it. Wizard191 (talk) 22:51, 18 April 2009 (UTC)[reply]

We currently have three articles pertaining to gear hobbing: this one, gear hobs, and hobbing machine. This seems a little excessive, so I think that the most specific of them, gear hobs, should be merged into this article. Gear hobs is currently not long enough to really warrant its own article. I would also be open to merging it into hobbing machine if that's what others think would be better. Wizard191 (talk) 21:16, 8 February 2009 (UTC)[reply]

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Move?

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Right now hobbing redirects to this article, so I figured it wouldn't be a big deal to move this page to that page, however I see your point. I wouldn't have a problem if hobbing redirects to hob and then this page gets moved to hobbing (manufacturing). Wizard191 (talk) 12:05, 21 April 2009 (UTC)[reply]
Does the verb form "hobbing" have other confusable meanings though? (There's probably something disreputable you can do with a ferret, but I don't want to know about it) Even if "hob" needs ample disambiguation, I'd expect that hobbing is clean and this gear hobbing page can be moved straight to it (shouldn't even need an admin?) Andy Dingley (talk) 15:36, 21 April 2009 (UTC)[reply]
I tried moving this page over hobbing but it errored out, which is why I submitted it to wp:requested moves. Wizard191 (talk) 17:41, 21 April 2009 (UTC)[reply]

I'd support this merge. I can't see much call for them as separate articles.

It's an obscure process and is usually performed on these dedicated machines. Any reference to the machine is likely to involve the process description too, and refs to the process wouldn't be harmed by its converse. Andy Dingley (talk) 02:05, 22 April 2009 (UTC)[reply]

Thanks! FWIW sprockets and splines can be hobbed. Todd notes splines and Degarmo notes both. As for gear cutting, it's a rather ambiguous term, it could refer to broaching, hobbing, or shaping. Wizard191 (talk) 20:47, 22 April 2009 (UTC)[reply]
I used to work on the manufacture of metrology machines, mostly on production lines around car factories, which included gearboxes and driveshafts. Although I wasn't doing much hobbing myself (outside of model engineering) I was measuring the output of the manufacturing process and doing SPC (Statistical Process Control) on it. As these were plants that did a lot of hobbing, they tended to make lots of things by hobbing, even when another plant might have done it by broaching - particularly splines and sliding splines or keyways. I'd agree though that we tended to call the cutting of gears "gear cutting", and only describe it as hobbing when it wasn't for making gears, even on the same machines. Andy Dingley (talk) 21:13, 22 April 2009 (UTC)[reply]

Dubious tag

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I'm dubious of the "NHS Swiss tooth standard". I've search all over the internet for it and can't come up with anything but mirrors of this article. I realize that that's not proof that it doesn't exist, but it does say something. I need someone with more authority to chime in. Wizard191 (talk) 00:25, 30 April 2009 (UTC)[reply]

I found a link with sources, unfortunately in german: [1]. It describes a "NHS-56702" gear standard, a modified cycloid gear used for clocks. I didn't find any source saying this shape cannot be hobbed, actually I found toolmakers offering hobbing tools: [2]. They just say there is one separate hobbing tool needed for each tooth number. Search for "NHS 56702" and you will find more informations. The standard exists, but the claim it cannot be produced on a hobbing machine seems wrong. —Preceding unsigned comment added by 62.203.35.181 (talk) 23:11, 4 November 2009 (UTC)[reply]
Thanks for that! I found an English version of your second link: [3]. I can take care of that dubious tag now. Wizard191 (talk) 23:37, 4 November 2009 (UTC)[reply]

Expansion

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Just an FYI, if anyone wants to expand this article further, Drozda has a TON of info available. Moreover, everyone can access it via Google Books. Wizard191 (talk) 00:11, 5 May 2009 (UTC)[reply]

Incorrect captions?

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In the section discussing "Equipment", the captions below the two pictures appear to be reversed in reference to the description of vertical and horizontal hobbing machines.99.191.73.46 (talk) 23:19, 15 October 2010 (UTC)[reply]

No, they're like milling machines. "Vertical" refers to the orientation of the powered shaft carrying the cutting tool, not the workpiece. Also a "vertical" machine can often swivel, again like a milling machine. Andy Dingley (talk) 23:28, 15 October 2010 (UTC)[reply]
I'd have to disagree. At least for Gleason and Pfauter machines, horizontal and vertical distinguishes between the orientation of the work spindle.[1] Deoc4114 (talk) 12:04, 14 June 2013 (UTC)[reply]
Yup. Liebherr, Lorenz, G&E, Barber-Colman, Fellows, Michigan, Schiess, Maag and Newark as well. And probably a few dozen others :) 210.22.142.82 (talk) 09:28, 28 June 2013 (UTC)[reply]

References

Drawing

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I'm not going to make a new one but the drawing is totally wrong. The face of the teeth on a hob is almost universally radial to the center of the bore. Once in a very great while you come across a hob with "hook" like the drawing : I've never seen one with more than 5*. Those are a pain in the patootie to sharpen. The dressing diamond on a sharpening machine travels along a fixed path which intersects the center of the cutter's bore and moves radially. The rear (grinding) face of the cup-type dished sharpening wheel is thus tangent to a plane that would intersect the center of the axis of the hob being sharpened. Not that easy to describe in words, sorry :)

Anyway, the teeth of any hob VERY VERY rarely have a hook as illustrated, and when they do it is for some special purpose or material. — Preceding unsigned comment added by 210.22.142.82 (talk) 09:20, 28 June 2013 (UTC)[reply]