Fun With Gears

[tuck]

Here's a short video:

http://www.youtube.com/watch?v=Yj9Xtw1Goio

I've been fascinated with planetary gears for some time now (I'm easily amused), and finally got around to putting something together with the help of my old ShopBot. I have seen examples of more intricate gear work in here but this worked out well for what I had in mind and more elaborate designs are already on the drawing board.

For scale, the box they are mounted on is 24" x 48". I cut the gears out of 1/2" sheet PVC, painted them with rattle-can metallic paints, and the drive motor is a simple and inexpensive 3 rpm microwave turntable motor, not much bigger than a half dollar and 3/4" thick.

Most of the fun was designing the gears in my CAD program. You have to work with pi and geometry. I'm no mathematician, but I finally came up with a workable solution.

"Yes, but is it art?" I dunno. Let's just call it a "conversation piece".

[myxpykalix]

Thats all well and good, but what does it do?? lol

Art is in the eye of the beholder, and that looks like a piece of art to me

I am surprised you worked out all the gearing manually. There is a gear program called "Gearotic" I think that might help your next project. I downloaded it but didn't fully understand how to use it.

You did a great job i'm impressed.....

[tuck]

Thats all well and good, but what does it do?? lol

Art is in the eye of the beholder, and that looks like a piece of art to me

I am surprised you worked out all the gearing manually. There is a gear program called "Gearotic" I think that might help your next project. I downloaded it but didn't fully understand how to use it.

You did a great job i'm impressed.....

Thanks Jack. It doesn't do anything except spin around!

I am looking at some gear generating programs now. There are quite a few, but not many that can generate anything for CAD and are free. I'll give "Gearotic" a spin,....no pun intended.

[myxpykalix]

http://www.gearotic.com/
Gearotic Motion is primarily a Gear Template Generator. Its true purpose is to create dxf's for further processing by various CAD/CAM programs.

It's $75.00 but the videos look pretty neat and they have a forum and a free demo. Check it out and report what you think....

[COBOB]

I purchased Gear Generator http://woodgears.ca/gear/index.html
to use with my laser. I am now looking forward to using it with my ShopBot.
I just like to make stuff with gears. You can try it out on the web site and download a dxf for free. $26 if you want it to run on your computer.

[tporter1001]

If all you need is to generate the gear as a dxf, the program Inkscape
will do it. Just input the gear pitch and tooth count and save it as a
dxf. Its under the Render pull down.

[bleeth]

Ryan has a free gear generator on Cabinetpartspro. It outputs dxf.

[tuck]

Thanks for the input, fellas. This is all very interesting to me.

Jack - Gearotic looks like the Mac Daddy for gear design. Unfortunately, the free version doesn't let you output files to test for CNC and I'm not quite ready to plunk down $75.00 just yet, but the program looks to be simple enough and straightforward with lots of tutorial videos to watch on YouTube. I may purchase it,...don't know.

Robert - I have looked at woodgears. You say it will output dxf if you buy the program? Are you sure about that? I was under the impression that it's for printing out designs for scroll saw work only.

Terry - Inkscape is cool! It does indeed generate gears that are easily saved as an .eps for my cad program (I use SignLab5). I'm not sure it's the ultimate answer, but it's free and I'm having fun with it. Thanks!

I'd like my next "electric wall sculpture" to be similar to this cool looking design: http://www.hobbing.com/creations/index.html

Maybe 24" to 30" total diameter. It tells you on the page that the sun gear has 20 teeth, the planet gears 37 and the ring gear 92, but when I replicate it, it doesn't mesh up. Hmmmmm....

Also, as I mentioned, I used a microwave turntable motor as a drive motor. I works fine but I'm wondering if anyone has a better idea?

[COBOB]

My apologies. It will print. I print to PDF, open the PDF in Illustrator and export as DXF.

If you want to try some, I would be glad to send you a file. Tell me what you want to try.

[Brady Watson]

...
Maybe 24" to 30" total diameter. It tells you on the page that the sun gear has 20 teeth, the planet gears 37 and the ring gear 92, but when I replicate it, it doesn't mesh up. Hmmmmm....

What happens when you put the planetary gears in mesh with the ring gear, and attempt to add the sun gear? How much is it off? Try marking each planetary gear in exactly the same spot (center tooth or something) and clock them in a certain position for reference. It is helpful as a visual aid.

-B