Gear Wheels

I was reading about making gear wheels for my Myford Lathe and came across this on youtube under Mechanical skills.

Handmade Making Process of Large Milling Machine Gear

Wondering if my neighbours might complain.

Edited By Cyril Bonnett on 23/08/2023 20:58:09

It’s OK, Cyril, you won’t find one that large on your myford lathe!🙂

Likely a plastic gear would do (yes, I suppose 3-D printers can seem to be noisy - particularly if running overnight)?

A small lump of 15mm thick Aluminium sheet could be a good starting point - not too noisy to do indoors with hand tools, I would think?

I’ll stick with my mill and gear cutters, mind. Far easier and faster. My hand tool skills are a bit lacking for jobs like that.

If you want to cut a gear, for a Myford, use a 20 DP cutter, 14.5 degree Pressure Angle.

Select the cutter for the tooth count that you need Theyb vare available from various sources, new or used.

They are usually marked with the tooth range and the depth of cut.

It seems brutal but you cut to full depth at one pass with a fine feed.

Not a particularly noisy process.

Well worth supporting the arbor with a tailstock

If you don't have a copy, Ivan Law's "Gears and Gear Cutting", No 17 in the Workshop Practice Series, will be great help.

Howard

I presume this is the very impressive video that you found, Cyril:

i wondered where all the machinery i worked went to. We had Webster bennett horizontal lathes and large planners and shapers mainly used on mining machinery for Dossco and large pipe plastic moulds for gas pipe fittings.

David

Before I acquired a horizontal milling machine and BS0 dividing head I cut gears on a Myford lathe using the correct Myford dividing head, swivelling vertical slide and raising block with the cutter mounted on the correct Myford milling arbor. Apart from being a very expensive combination of Myford accessories it worked perfectly well but was time-consuming to set up and not particularly rigid due to all the over-hangs etc. It is a far better proposition, and much more convenient, to cut gears on a miller although I did manage to mess up the last 90T gear I cut which will now have to have the teeth turned off and the blank used for a smaller gear when the need arises. I think I must have inadvertently nudged the sector arms on the diving head forward by one hole but you don't know this until you cut the last tooth. Doh!

I did manage to mess up the last 90T gear I cut which will now have to have the teeth turned off and the blank used for a smaller gear when the need arises.

You could machine off all the teeth and a bit more, then replace that outer ring and teeth with a a machined ring either with teeth or machining the teeth after fitting the ring (likely the better option🙂 ).

I’ve not done that, but have replaced the central drive hub on an already-cut gear.

You could machine off all the teeth and a bit more, then replace that outer ring and teeth with a a machined ring either with teeth or machining the teeth after fitting the ring (likely the better option🙂 ).

I actually did think about doing that but I don't think I have got a noggin left that would be big enough, can't recall exactly without checking, but I think it's somewhere around 4.6" dia. plus I have been very lazy lately and not been in the workshop as often as I should. Just another unfinished symphony to join a half dozen others.

With gear cutting I “waste” a bit of time on the set up by scribing a line on the blank at the centre of every gash using a scribing block on the mill table and doing a full rotation. Allows a very easy verification on each index. Probably only valid for my type of big chunky gears but when cutting a large gear over multiple sessions it provides reassurance everything is still in the right place! Takes a little longer but still quicker than doing it again when it goes wrong!

Paul.

A 90 tooth gear is one complete turn on the more common rotary tables? I have mis-counted or something before now; I am now much more careful to try to avoid that mistake, whatever it was.

I have mostly made aluminium gears which is more easily cut in a single pass.

A 90 tooth gear is one complete turn on the more common rotary tables? I have mis-counted or something before now; I am now much more careful to try to avoid that mistake, whatever it was.

Yes, you're right, without checking from the drawing and I am not going into the workshop at this time of night, it was a big gear with a lot of teeth and I messed it up. It was to be the large mandrel nose gear of the Parkes home-made hob backing-off device which I am making in conjunction with the Radford thread milling attachment to eventually use with the Jacobs hobbing machine.

"Handmade Making Process of Large Milling Machine Gear "

Around 24 mins in he changes his safety flip flops for a pair of safety hush puppies so he can stand on the smoking casting

Amazing skills to watch though

For large tooth-count gears I set up a pointer to align a previously-cut tooth, and it has saved me from indexing errors several times. It's quite sickening cutting the final tooth gap and discoveing that the last tooth is either too thin or too fat.