Totally New Method of Cutting Gears 5

[SteveGarrison]

Gentlemen,

I have developed a totally new way to cut either spur or helical gears. I am an inventor with some engineering background and know what I am doing. Using the same basic gear formulas that you use, I input values for the following parameters to calculate data to make any gear I want to make: diametral pitch, pressure angle, number of teeth, and helix angle. Then I make a very simple reusable part needed for my technique to work and also a gear blank. The teeth are then cut using a (are you sitting down?) - tablesaw - my gears are made in plywood. The gears tooth profile is a very nice involute curve specifically designed for the exact parameters I used. The blade has no special profile, it is a simple straight-sided blade.

I have attached a picture of a pair of my helical gears, these are 5 pitch, 25° pressure angle, 16 tooth, 30° helix angle. I have more sample pictures on my site

http://www.stevengarrison.com

Have a look and let me know what you think. And thank you for your time.

Steve

 

[CoryPad]

I think they look like nicely cut gears. Well done.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dinjin]

I am impressed. Great job and design development.
I hope you find a market for these. Did you apply
an mineral oil to the surfaces?

 

[SteveGarrison]

Thank you very much. The plywood has no finish on it or any sanding either, the gears have had nothing more done to them after forming the teeth except for inserting a bronze bushing. I forgot to mention that each gear in the picture is actually two thinner gears stacked together. You can see the edges where they meet if you look closely.

Do any manufacturers of large gears still use cast gear blanks? This might be useful to a patternmaker. Other than that I can only think of things like you might find at a craft fair. But they are cheap and fast to make.

Steve

 

[Matt51]

They look very nice!
John Harrison made clock gears (1722) which to this day are still operating, even with no lubriction. The tower clock in Brocklesby Park has operated continuously for over 270 years. There are manufacturers of wooden clocks who might be interested, you can find them with a google search.

 

[unclesyd]

Checkout Steve's website some other very fine work both in the helix and the shells. The gears aren't bad either.

notice the similarity of names John Harrison and Steven Garrison.

 

[SteveGarrison]

Ironically enough I used to work as a land surveyor using gps equipment. I could measure my longitude down to about a quarter of an inch. Nowadays our gps satellites each have atomic clocks accurate down to a nano-second. Still I am more impressed with John Harrisons chronometer calculating his longitude to within 10 miles with his mechanical device back in the 1700's.

Steve

 

[Matt51]

I am too busy at the moment, but in a week or two I will get back and purchase your system. I have always thought in home size wind turbines (3-10kW) a simple gear stage is needed but usually missing, and using wooden gears made of lignum vitae might eliminate the need for lubrication, seals, and so on, so it might work well for the do it your selfer, as opposed to factory systems. If these guys could cut their own gears they might be more willing to add a gear mesh.

 

[unclesyd]

You might want to take a look at using Micarta to make a bearing that could be used. The gearing grades are a little tougher maching but it makes a fine gear. We run Micarta gears against cast iron gears under pretty heavy loads for noise reduction,
I believe that the Norplex might be real interested in seeing a set of gears by non-conventional process. I definately would give them a call and get a picture of yours gears to them.

By the way they make a flexible grade that can be heated and formed.

http://norplex-micarta.com/products/category-detail.php?page=30

A footnote.
My mother was an artist and ceramacist fell in love with a Nautilus Shell I gave here when she was 85 years old. She made two or three models and extremely frustrated she could no longer work with thin clay sections. I hadn't realized that one shell could generate so much enthusiasm from someone.

Keep up the beautiful work with the shells.

 

[SteveGarrison]

I agree, the generator on a wind turbine probably would be more efficient if it was spun faster. That's a really good idea.

Lignum vitae has been used in the past as prop shaft seals on ships and submarines. In little Rock they have made a tourist attraction out of the U.S.S. Razorback - A WWII submarine - and I believe it has lignum vitae prop shaft seals too. The deck of the sub is made of teak - also an oily and stable kind of wood. It might be easier to find than the lignum. I would say that makes them both weatherproof being used on the exterior of a submarine.

Delrin might work good too and can be cut in a home workshop.

Thanks for the idea.

Steve

 

[SteveGarrison]

Unclesyd,
Thanks for the suggestion and link. I have a tablesaw throat insert made of phenolic - very durable stuff! The insert had to be cut to fit the blade by lowering the blade fully and then slowly sawing through by raising the blade. I'll send them some information and a phone call.

There is something about nautilus shells and fossil ammonites that makes them very appealing. I will continue making my own versions of them.

Thanks for the input!

Steve

 

[sreid]

Have you made a patent application? You should.

 

[Matt51]

Patents -

For a US patent, the key is the date of invention. You can publicly disclose your patent as long as you have documented the date of invention.
Once you have publicly disclosed the invention, you get up to a year to file a provisional patent, which is only $100.
Then by the end of the second year, you have to file the regular patent. The patent usually will cost a few thousand dollars, as well as maintenance fees.
I am not an attorney, could be wrong, so the usual disclaimer, see a patent attorney if you are interested in patent protection.

 

[SteveGarrison]

I found a good use for the wooden helical gears - window blinds. Here's a link to my Youtube video demonstrating them:

http://www.youtube.com/watch?v=rqaMBUSs0Uc