Thread: is this thing as simple as 2 x 45 degree bevel gears ?

Clever idea

Lathe for drill press - HomemadeTools.net

Is it as simple as 2 x 45 degree bevel gears ?

I've made spur gears but not bevel gears, will look at the Workshop Practice book and do some googling, must be awkward with the circumference getting bigger towards the fat end.

Bill

I think they used a right angle drive like you can get for portable drills.

Michael

I just read the relevant parts of Ivan Laws Workshop Practice book ...........

Don't be put off by the first description of Bevel Gears in Chapter 5.

It seems that a mug like me with a bog standard milling machine can do a reasonable approximation by following the technique described in chapter 11.

Have always wanted find a project that gave me an excuse to have a go at a bevel gear.

Have got a reasonable collection of Workshop Practice books now - if you keep your eyes open on ebay and bookdepository and abebooks you often find 2nd hand ones for $4-$5 and negligible postage if you have a friend in the right country.

Is a right angle drive made of two x 45 bevel gears or is it something infinitely more complicated that will cause me to run away screaming ? Maybe they are made of that odd square section flexible metal cable that is used in flexible dremel tool shafts ?

Bill

Yeah, it's just bevel gears; I don't think the flexy stuff will handle such a sharp bend.

Hi Guys,

The Aldi and Lidl tools do a 90 degree drilling adaptor that is just a pair of bevel gears in a housing ! Plus you get a free drill chuck...

Thanks for the replies gents.

- bevel gears are on the list of things to have a go at one day - doesn't matter if I can buy them cheaply or not -

would it be fair to say that 60 years ago when my lathe had its first owner that person would be gobsmacked at what we can buy today for a few dollars and that a lot of the stuff he made he wouldnt bother nowadays he'd just buy it.

I guess the ratios of average wage vs. cost of living vs. disposable income vs. cost of a 90 degree gadget would have been very different back then.

Bill

Yes.

I made a set of bevel gears as part of a project earlier this year, the first gears I have ever made. The project was a pedal-powered potters wheel that was a birthday present for my daughter. I got hold of a copy of Ivan Law's book, also used some online resources to clarify a few things as the language in that book is often anything but clear. It was a fun project. The resulting gears are quite noisy, as they are not a perfect involute bevel, which apparently can't be achieved without special equipment (apparently a milling machine and dividing head are not special enough). The calculations were complicated by the fact that I had to have a particular diameter at the large end of the gear to work in with the bicycle components, whereas bevel gear calculations are based on the small end of the gear. I'd encourage you to go ahead and make a set 'because it's there'. Anyone can buy stuff.
finished potters wheel 1.jpggearset and throwing head.jpgdividing head setup.jpg

Originally Posted by Pete O

apparently a milling machine and dividing head are not special enough

Not quite

Originally Posted by elanjacobs

Not quite

I was amazed by that photo so I tried to find a youtube video

I think this is a video of it - if you google "youtube bevel gear machine cutter generator" there are a heap of fancy machines

https://www.youtube.com/watch?v=QTlo6bIIieE

Some of the other videos of the new bright shiny machines are astonishing.

Bill

And that's just for straight cut bevel gears, wait till you get to helicals and hypoids https://www.youtube.com/watch?v=gj2szHk0OCU

Originally Posted by steamingbill

Thanks for the replies gents.

- bevel gears are on the list of things to have a go at one day - doesn't matter if I can buy them cheaply or not -

Bill

Hi Bill,
I wasn't for a moment suggesting you go out and buy anything ! Just pointing out that yes, a 90 degree change of angle is a simple as a pair of bevel gears.
My comment about a free drill chuck was just a throw away. Only said because I did buy one, and the gears inside those are castings ! No lubrication in there other than a smear of oil on the shafts, which are steel.

Originally Posted by BaronJ

Hi Bill,
............, and the gears inside those are castings ! No lubrication in there other than a smear of oil on the shafts, which are steel.

Hey BaronJ,

Does that mean that the gears were not machined, but rather they were made by pouring hot metal into a mould ?

Thats interesting, I previously believed that if things are made by casting you then had to machine them to exact required shape after they cooled down. Off to do some googling on this.

I've bought various things from Lidl and Aldi and had great use out of them, I don't depend on them for a living and they do a good job of keeping me amused in my retirement. Cold and rainy day so playing on the internet a lot, shed too cold, daft weather for springtime.

Would be a good project for a 3D printer these days.

Have you considered using gears from auto differentials?