Why spending time on making if you can buy them for little money, plenty of suppliers, see **LINK** Niko.

See **LINK**

Also several threads on this site about variations of the process including what you describe, also known as free hobbing.

You select Branche Offices at the top of the page, find the UK distributor and contact them. Niko.

Great Britain Huco Engineering Ltd. 5-7 Merchant Drive GB-SG13 7BL Hertford Tel.: +44 (0) 1992 50 19 00 Fax: +44 (0) 1992 50 98 90 sales@huco.com **LINK**

For larger tooth counts the tooth form will surely be involute as the tap is in effect a rack form cutter? But indeed the pitches will not mesh with other "standard" gears. A 10 tpi tap as the OP suggested would cut teeth of ~31.15 DP which isn't any kind of standard, and pressure angle 27.5*.

I feel like giving up sometimes, why not just got to the web address for Huco that is in Speelworks posted image, then go to products and then gears which give you this. Do you need more help getting to a specific type of gear?

Personally I find the ones from Belting online very reasonable, MOD are cheaper than DP.

try it yourself, for me it just leads to a dead end back to germany

There is a phone number quite clearly indicated and easily called. Why not call it? Seems a simple enough way to get sorted? A lot of people seem to miss the simple options to sort out a problem.

I ordered from Madler Germany directly or from their Dutch branche Koppe, for little money they even made it to your spefication, all very friendly and helpfull, just phone or mail them. Do not know of course about Huco but expect them to be the same. Niko.

Not really. It depends what machine you have, and what material you're using, but if you use a proper gear cutter I wouldn't say it was painfully slow, and a lot easier than trying to jury-rig something with a tap.

Home-made single tooth cutters are slow and tiresome, but work if you don't want to fork out for a proper gear cutter.

Another approach if you don't have a mill is to use a single-tooth cutter in the lathe toolpost, shaper-wise. That really would be painful, but again, you'd get there in the end (I haven't tried that one myself, but I don't see why it shouldn't work given sufficient patience).

I have made gears using a proper shaper and a home-made cutter. It works fine, but it's very easy to forget to wind the toolholder back up before indexing to the next tooth. Result – a loud bang as the shaper punches out the entire tooth* in one go, but, surprisingly no discernible difference in tooth quality, at least with benign materials like nylon or bronze. Best avoided though I think.

*Really the gap between teeth of course

Unfortunately you seem to have mislaid the first step. If the tap is skewed by the helix angle to get straight teeth on the gear how does it drive the gear blank as there will be no tangential force. The tap drives a worm wheel because it creates teeth that are not straight and hence there is a force causing the blank to rotate.

Andrew

Not sure I see that Andrew. My headstock dividing attachment is a worm gear (which is the same form as a tap without the flutes but also with involute instead of straight flanks) driving the bull wheel on the lathe spindle. It is cranked over at the helix angle of the worm and it certainly drives the spindle. It's a poor mans worm gear as it has only line engagement but it's only called on to do light duty. In the free hobbing of straight spur gears the hob/tap is as you say set over at the helix angle but the gear has to be gashed first in order to be driven. The hob/tap then just modifies the tooth form. Well thats how I see it anyway. I've only ever done it to produce curved knurling wheels.

regards Martin

Ooops, I think you're correct.

However, that raises a question; if the tap/hob can drive the work why do hobbing machines go to the trouble of actively driving the gear blank?

Andrew