Help with gear size and ratio

[Porknar]

I have a home project that I need some help with. Is there away to figure out the gear size for something like this? gear input: 2.29:1; gearbox ratio: 115:1Pulls 32 FPM and 1800 lbs. single load; I am not sure home figure out the size and number of gears. I would like to try to run this from a chain saw with turn 2700 to 9000 rpm. Any help is greatly appericated.

Thanks,
Darrell

 

[MikeHalloran]

You can _buy_ one here:

http://www.loghomestore.com/tools-chainsaw.shtml?gclid=CIvrueLfwpYCFQZqswodvBh9yQ#lewis-winch

for less than 1000 USD.

You can't homebrew it for that.


Mike Halloran
Pembroke Pines, FL, USA

 

[Porknar]

I know that, but I have access to some machine tools and thought it might be a fun project. Just looking for some advice, help and or direction.

 

[MikeHalloran]

I suggest you make something that involves much smaller forces, e.g. a grandfather clock.

If you persist, consider using stock gearboxes or stock open gears. Manufacturers of such things typically provide engineering sections in their catalogs; you will find the information useful.

One such:

http://www.emerson-ept.com/eptroot/public/prod/dynamic_frame.asp?strMain=http://

http://www.emerson-ept.com/EPTroot/Public/bnames/browning/Browning.htm

Mike Halloran
Pembroke Pines, FL, USA

 

[hydtools]

Here is lots of gear design info:

http://www.engineersedge.com/gear_menu.shtml

Ted

 

[Porknar]

I have looked at these gear boxes, and that is not what I am looking for. I would like to figure out the gear sizes, so I can make them myself. I know there are easier solutions, but I need a winter project. Thanks for the links lots of good information.

 

[MikeHalloran]

Well, you've got a design load and speed, so all you have to do is reflect that back through the cable drum and the geartrain to figure the load conditions for each gear, shaft, bearing and structural element.

They still teach that in engineering school, right?



Mike Halloran
Pembroke Pines, FL, USA

 

[Porknar]

It has been a long time. I am not worried about the load calculations on the shafts and bearings yet. I am worried about the size of the gears. I just can't remember how to how determine the size of the gears. I came here for help and some advice. Can some one help me?

 

[MikeHalloran]

You analyze a single gear tooth as a cantilever beam.

Does that help?



Mike Halloran
Pembroke Pines, FL, USA

 

[Porknar]

Not really, lets say I use a 6 tooth spur gear coming off the motor, the next gear need to be some many teeth but, I need to keep the second gear small enough lets say around 4 to 5 inches in diameter. I understand the cantilever beam and applying to a a gear tooth, but it does not realte to size or does it?

 

[hydtools]

For the rear ratio you need consider a worm gear drive.

Or planet set(s).

http://en.wikipedia.org/wiki/Epicyclic_gearing

Ted

 

[digger2008]

Have a look at gear companies catalogues, compare their sizes & ratios with yours. That will give you a start.

 

[vc66]

Maybe your winter project should be reading up on gears?

In all seriousness, there are a number of factors that determine the size of gears. You can pretty much get any input to create any output using a certain number of gears (depending on how much room you have). I suggest buying, "The Handbook of Practical Gear Design", by Dudley. That is one of the bibles of gear design.

There are many things that are involved in gear selection that are much too lengthy to discuss here.

Good luck.

V

 

[MikeHalloran]

I second vc66; Reading the Dudley book from cover to cover would be an excellent winter project.



Mike Halloran
Pembroke Pines, FL, USA

 

[Porknar]

Thanks guys, The Handbook of Practical Gear Design is on its way.

D