# Gear Hobbing



## MattM (Jul 10, 2021)

I'm interested in gear hobbing.  Anyone built a gear hobbing machine.


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## Norseman C.B. (Jul 10, 2021)

Hi Matt I remember seeing a vid. on you tube the other day but didn't watch it as I was
looking for something else at the time...........


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## MattM (Jul 10, 2021)

I did see probably the same Vid.  It was a hobbing machine built from a kit.  I tried seaching the internet but nothing was available on the links that were given.


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## j-becker (Jul 10, 2021)

Here is the video I saw from AndysMachines -- it  did not look like a kit to me: 




Actually pretty stunning what machines the guy is building.


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## MattM (Jul 10, 2021)

Fascinating.  That is not the video I saw.  The mechanical side would stretch my abilities but I'm pretty sure I could bring it off.  No clue on the electronic stuff but I have a friend who might be willing to do it.

Does that guy sell plans?


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## MattM (Jul 10, 2021)

j-becker said:


> Here is the video I saw from AndysMachines -- it  did not look like a kit to me:
> 
> 
> 
> ...


Does he sell plans?


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## MattM (Jul 11, 2021)

Anyone know where I can get plans?


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## MyLilMule (Jul 12, 2021)

Greg Halligan is recording a series on his YouTube channel where he is machining and building a hobbing kit. I think he references the source of the kit in his video as well. I believe it is an attachment for a lathe.


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## JRaut (Jul 12, 2021)

You might toss this one into your searches. It's a bit of a toy, to be sure. But most of us deal with toy machines on a daily basis.




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						Jacobe Gear Hobber
					





					www.lathes.co.uk
				




It piqued my interest a few years ago and I bookmarked the site. I had intended to order a set of plans for it and _maybe_ _think about_ making one, but the website seems to be down right now. Hopefully it comes back online. Or perhaps plans exist somewhere out in the ether.








						Gear Hobbing Machine Complete - College Engineering Supply
					

Designed on good machine tool principles, the machine incorporates dovetail slides and an Acme screw and nut for the auto feed cross slide The main components are cast iron, with mild steel used for shafts and small details. With the exception of the bed plate, most machining can be done on a 3″...




					www.collegeengineering.co.uk


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## vtcnc (Jul 12, 2021)

I’ve begun the process. Other priorities/projects have cut in line. Check my moderator project forum for details.


Sent from my iPhone using Tapatalk


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## JRaut (Jul 13, 2021)

Way cool @vtcnc.

Did your set come with the drawings?

I don't know what the copywrite laws might be surrounding a set of plans that are no longer available on the free market.

But if there were a way for the drawings to find themselves in my possession, I'd be quite grateful...

I suppose the other way to go about finding plans might be to somehow find/acquire the relevant issues of Model Engineer.


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## ArmyDoc (Jul 13, 2021)

MattM said:


> I'm interested in gear hobbing.  Anyone built a gear hobbing machine.



Here are a cuple of videos from a guy who made his own hobb and cut his own change gears, and did it on the cheap...

How he made his own hobb:






How he used it (good part starts at ~14:15)


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## vtcnc (Jul 13, 2021)

This is not exactly gear hobbing in the purest sense of the term more like a kissing cousin. While it is using something like a gear hob to cut teeth, it is not the gear hobbing process unless the work material and the cutter are both rotating at the same time. Also, the cutter couldn't be used as a gear hob because the cutting teeth are essentially straight tooth cutters. A gear hob cutting profile is on a helix.


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## vtcnc (Jul 13, 2021)

Here is an adaptation that demonstrates gear hobbing. There are something like 8 videos in this series.


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## pdentrem (Jul 13, 2021)

I have been looking at this kit.








						Gear Hobber Casting Set
					

The gear hobber is a machine for producing gears by the hobbing process: a rotating gear blank is fed into a gear hob (in the shape of a worm). The maximum capacity is about 4” in diameter, 20 dp (diametrical pitch), 1.25 module down to 1/10” diameter, 120 dp, 0.2 module. The prototype uses...



					www.martinmodel.com
				



Pierre


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## ArmyDoc (Jul 13, 2021)

vtcnc said:


> This is not exactly gear hobbing in the purest sense of the term more like a kissing cousin. While it is using something like a gear hob to cut teeth, it is not the gear hobbing process unless the work material and the cutter are both rotating at the same time. Also, the cutter couldn't be used as a gear hob because the cutting teeth are essentially straight tooth cutters. A gear hob cutting profile is on a helix.



Understood, and I agree.  I thought it was interesting though, what he was able to accomplish "on the cheap" without a true spiral gear hobb and linked process.

I did see another video where they used a spiaral gear hobb, and let the work piece rotate freely - granted they were more chasing a gear they'd repaired, but it worke - the hobb turned the gear while cutting it.


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## f350ca (Jul 13, 2021)

I've tried the rack type hobb and it seams to work. Built a depthing tool to hold the gears at the correct spacing and they rotate freely with minimal backlash. 



Greg


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## vtcnc (Jul 13, 2021)

ArmyDoc said:


> Understood, and I agree.  I thought it was interesting though, what he was able to accomplish "on the cheap" without a true spiral gear hobb and linked process.
> 
> I did see another video where they used a spiaral gear hobb, and let the work piece rotate freely - granted they were more chasing a gear they'd repaired, but it worke - the hobb turned the gear while cutting it.


I assumed you knew the difference but thought it worth distinguishing the two methods for clarity. I find the method you linked to interesting as well, because most hobby machinists could achieve gear cutting more easily than gear hobbing using said method. The other "chasing" method you refer has also been called "free hobbing". I'm not sure where the terminology comes from for sure but  I wonder if the chasing terminology is used because a hobby machinist could conceivably use a tap to hob a gear. I've heard machinists say, "chasing a thread" and I wonder if that was adopted for "chasing a gear."


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