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??:rolleyes: 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.....:D

[tuck]

Thats all well and good, but what does it do??:rolleyes: 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.....:D

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

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/ (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

[tuck]

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

Hello Brady, you old timer you!;)

When I set the planetary gears and the sun gear at the prescribed number of teeth (as I did with the ring gear), they (the gears themselves), were too small in diameter to engage, being off maybe 15-20%. I can't increase the sizes in diameter proportionately for engagement because then the gear cogs get bigger (wider) too and won't mesh up with the outer ring (which is actually called an "inner gear"):confused: lol
The outer ring is tricky in any case and I'm saving that idea for another project. If it's going to be employed as an "electric wall sculpture" (what else would I do with these?), it will need some type of retainer around it to keep it from working itself off of the planetary gears and I haven't figured that out quite yet. That's part of the fun of it though. I get to pretend I'm an engineer!

Following is another brief video of the design I'm playing with now. It's just a rough mock-up cut out of some old 1/4" plastic I had laying around, very plain jane. Intricate spokes and whatever else will be added for the final production and fabrication, and I'll cut the gears again out of 1/2" sheet PVC, which cuts like butter and is easily paintable with the Krylon plastic paints available now. http://www.youtube.com/watch?v=ZWoprtB_7zE

Call me crazy (you won't be the first), but I think I can sell these. Folks gawk at the first one I've made. They love to look at it and ask what its' purpose is. I reply with "Its' purpose is for you to look at!", to which they generally say something like; "It's AWESOME!" haha. I thought about adding some kind of clock to the works, but we already have enough clocks, don't we? Anyway, what can be done is only limited by imagination and a little engineering!

[scottbot]

I love that! Cool designs for the gear centres too.

[tuck]

I love that! Cool designs for the gear centres too.

Why thank you sir! :)

[Brady Watson]

Mark,
I mentioned the sun gear because if they are off 15-20% in dia, then it might be possible to enlarge just the sun gear by 15-20% by adding the appropriate number of teeth to get you there. There's no reason, off the top of my head, why you would need to mess with the planetary or ring gears.

Liked the vid...Yeah, sure why not? Sell the heck out of them. I'm sure there are millions to be made in the novelty market, and if executed in the right materials to the right people, it can bring in good money. Liked the background music too - Helps to get stuff done! :D

You could add a threaded shaft/nut instead of just the plain axle to retain the gears, or use a tapered drift pin or roll pin that sits in there by friction.

-B

[feinddj]

Brady, something like this? It is a capstan gear like you would see on a sailboat.

Gearotic is totally worth the price.

David

[tuck]

Brady - Oh yes, I know that I can work out the problems by adding more teeth to the sun gear to get things to add up and mesh correctly. I'm gonna tackle it when I'm done with what I'm working on now.

Brady and David Feind- concerning the ring gear in the example (link) that I posted - am I missing something? The sun gear will be driven by the drive motor and it in turn will spin the planetary gears, which will in turn drive the ring gear. The sun gear will be attached to the drive motor and the planetary gears will be thru-bolted to the mounting box. Being as how the ring gear needs to spin in accordance with the planetary gears, it can't be bolted down. I see it as needing to float free and that's why I think it needs some kind of retainer to keep it in place,.....right?

David Feind - did you make that? It looks very cool. Does the ring gear (outer gear) spin? Can you shoot a short vid? I'd love to see it in motion. And yes, Gearotic looks totally worth the price. I am gonna buy it soon, but right now I'm having fun and getting pretty far with Inkscape thanks to Terry Porter.

As i said, the possibilities are endless. You guys will see when I finish what I'm working on now that a "sun gear" can really be a "SUN GEAR". :)

[myxpykalix]

Mark,
I liked your video but unlike Brady, I HATED the music...lol:)

I guess thats the difference between you "squirts" and us "old timers", personally I would have preferred some Mitch Miller for the soundtrack:rolleyes:

I did like the way you are designing these gears and there is no limit as to how elaborate some of these can be made, so keep it up.

[tuck]

Mark,
I liked your video but unlike Brady, I HATED the music...lol:)


Lol, Jack, "Bodies hit the floor" wasn't my first choice but I'm new to uploading vids on YouTube, and YouTube picked the tune for me. Nothing that I picked seemed to be ok with them, I guess. I did succeed with an arrangement (after the fact), with the first vid I posted in this thread,...you might like that sound better.....

Thanks man and I'm having a lot of fun with this. I reckon anyone with a Bot can make gears but I'm an artsy-fartsy kind of guy and I want to take it to the next level if I can, with unique design and some fancy engineering. If it's art, I'm calling the first one I did for myself "Synchronicity". The one I'm working on now (for my lady) will be called "The Universe Loves You", or maybe just "Have a Nice Day" lol,.....stay tuned.;)

Gears,...they truly help make the world go around. That blender on your kitchen counter,...your cordless drill,....your microwave turntable,...your car's transmission and power windows, your CD player, etc., etc. We rarely see them but the modern world would grind to a halt without them (and a little oil), and I reckon that's why I'm fascinated by them.

Edit to say...I managed to change the tune , Jack. Not sure I don't like "Bodies" better, lol!

[myxpykalix]

One thing i like about the demo vids i've seen for Gearotic is you can make odd shaped gears which make for an added viewing deminsion. I'd like to get that program next if and when i can afford it.

I've always been fascinated by "Rube Goldberg-ish" contraptions. We used to ditch school and ride our bikes to the Science Museum in Chicago and see some of the coolest stuff.

[tuck]

One thing i like about the demo vids i've seen for Gearotic is you can make odd shaped gears which make for an added viewing deminsion. I'd like to get that program next if and when i can afford it.

I've always been fascinated by "Rube Goldberg-ish" contraptions. We used to ditch school and ride our bikes to the Science Museum in Chicago and see some of the coolest stuff.

Yeah money is tight these days for me too (and a lot of other folks), but I know I'm gonna buy Gearotic soon enough. It's just too cool to pass up and the odd shaped gears you can do with it are very cool. You take a program like that, add some imagination and inventiveness, and the world can be your onion. ;)

[feinddj]

Mark,

Yes, I made it. from a reprint of an old book called 500 Mechanical Movements. Fun resource book. Cambium press is where I got mine. As far as the movement of the rings and gears, it depends on what is fixed and what is free. if you move the outer ring it will drive the three small gears and the centre one, if you fix the outer ring, it will drive the three gears around the centre gear. I will send you a vid tomorrow of the movement.

D

[SomeSailor]

You can see an online copy of the book at:

http://www.scribd.com/doc/441240/Five-hundred-and-seven-mechanical-movements

[Paulo]

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.

You're doing it the hard way, the paid version let's you "Export to DXF, HPGL, CSV and SketchUp" (quote from their website).

[COBOB]

You are right, I used the online version for a couple of years, then purchased it and forgot it saves to dxf.

[ironsides]

....

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.....



I downloaded "Gear template generator" from Woodgears.ca yesterday. This is great program and it does export to .dxf which come into Aspire very well.

For the price ($26.00) it was well worth it.

George

[Acmeaviator]

I purchased the plans for this mechanical planetary calendar - now I just need to get the shop time to complete it!

http://lisaboyer.com/Claytonsite/celestialmechanical.jpg

[nepenthes]

Where did you get the plans? That looks like fun.

[fozzyber]

http://lisaboyer.com/Claytonsite/celestialmechanicalpage.htm

[bleeth]

His designs are fabulous. For us CNC freaks it's a drag he won't send DXF's

[Acmeaviator]

I own almost all of Clayton's plans - I built a few of his creations with scroll and bandsaws prior to purchasing my buddy. It is true that he does not sell digital versions of his plans - but he will provide "some" of the files as .dfx once you purchase a set of plans.