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Gear making.

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cedge:
When I began this hobby I was in search of any available clues I could find to gain a foothold on the learning curve. I bought two of Jose's DVD's, one for the mini lathe and another for the mini-mill. John nailed it pretty cleanly with his boredom comments. Jose definitely provided the needed foot hold but his monotone delivery was excruciating and even with my elevated interest he managed to literally put me to sleep more than once.

He's the first to admit when he's doing something off the "standard" path, so its no surprise that he'd show an alternative to accepted practice when it comes to gears. Duclos did the same with his instructions for single tooth gear cutting. Like many things with our hobby, NASA specs are not required.... if it works we use it. The single tooth  cutter that I made from his instructions was not a perfect 32 involute shape, but it did produce a very usable and cleanly meshed set of gears. I'd be hard pressed to spot the differences in what I managed to cobble up and a set of commercial gears with the 32 involute profile.

I can live with not having to plunk down large dollars for special cutters if guys like Jose and Duclos are willing give me workable hacks that perform as needed. In Jose's case, he's also great for saving money on sleep medication. I recently tried to find his DVD's on LMS and sadly it appears they've dropped them from their inventory.

Steve

bogstandard:
John,

I had already seen the first link, but not the second. Thanks for that.

I am not on about the straight toothed cutters, but the cutters that Arc Euro retail with spiral teeth.

He shows a freewheeling method that uses the spiral cutters to cut gear teeth, not worm gears.

I will be watching that part again, as he shows it being done with a freewheeling dividing head, but by looking at it, a normal simple rotating spindle will do the job admirably. All it would need is an angle adjustment on the base so it can be set to same angle as the helix of the hob, or I suppose I could set the head angle over to do the same sort of thing.

John

John Stevenson:
OK understood but one thing to take into account on the freewheeling  method is the gaps between teeth have to be narrower than the gear width or they can drop out of mesh when revolving but more to the point they can pick the next tooth up deeper on one side.
Home made cutters can have smaller gashes to offset this but bought ones are fixed, just a point worth noting.

There is a lot of good, free gear information out on the web, unfortunately not all in one place and there are many other ways to produce the same results.

It's even possible to produce perfect gears of any DP and tooth form, ie stub tooth, 20 degree PA 14.5 PA [ pressure angle ] and even splines on a Bridgeport type machine or clone using a 50p cutter that can be hand ground on a bench grinder if need be.

You could have a set of gear cutters for all pitches required in a home shop for under £5.00 in fact many have already got them but they don't realise it.

I know you have all the cutters John.  :poke:

John S.

John Hill:
Somewhere! :doh:  On the web somewhere is a detailed article about cutting gears on a shaper using a taut wire to rotate the blank the result being perfectly formed gears using a basic tool shape.

If I recall correctly you start off as if cutting a rack tooth (which is the same as a gear with an infinite number of teeth) but as the blank is being rotated the result is a perfect gear tooth regardless of the number of teeth being created.  I presume that if every gear is a perfect fit to a rack they would also be a perfect fit to each other. :scratch:

No1_sonuk:

--- Quote from: bogstandard on July 17, 2009, 03:18:02 PM ---I have just watched the most boring DVD. Almost four hours of continuous monotone talking, which to me sounds like a mild Mexican accent, coupled with very close up video.

If you can just get thru that monotone voice, you would find it one of the most informative guides to making gears the easy way.
--- End quote ---
The DVD player on my laptop can run at 2x speed with the sound active.
2 advantages:
1) The voice pitch is raised to a less soporific level.
2) The video lasts half the time. :)

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