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View Full Version : [Question(s)] Who Wants To Make Their Own Gears?



Steve Garrison
10-15-2008, 04:13 PM
Hello everyone! I am new to this forum. My name is Steve and I like woodworking, sculpture and solar power. The only "robot" I have built was a sun-tracking parabolic dish I experimented with for a while, it had two linear actuators and could concentrate enough sunlight to melt a few pounds of aluminum.

I have developed in my workshop a new technique for making accurate spur and helical gears out of wood or plastic using either a tablesaw, router table, or scrollsaw. I use a gear calculator with standard gear formulas to calculate the required dimensions for any size gear I want to make. I've got a web site with pictures of some of the gears I have made along with my other artwork: www.stevengarrison.com (http://www.stevengarrison.com)

I also have a video on youtube showing my gears: http://www.youtube.com/watch?v=jmFG6unpAw4

Take a look and see what you think.

Thanks!

Steve

darkback2
10-15-2008, 04:49 PM
The action on those is really smooth. Thats cool. You should build some sort of walking robot out of wood using your wooden gear system. You could probably make something pretty cool if you wanted.

Question though? Why are the naked charity's comming up as a related video? just thought that was funny...

No seriously though...you should totally make a walking robot using some sort of cam/gear set up.

DB

Steve Garrison
10-15-2008, 05:31 PM
Thanks! I couldn't venture a guess about the naked charities unless the related videos are somehow tied to my search history - just kidding LOL!

It would be cool to build some sort of walking robot. If I put my mind to it I could probably dream up the mechanical part of it. The gearbox towards the end of the video was an attempt to make a mechanical maglev device that would levitate an NIB supermagnet, but I think my copper cylinders aren't thick enough. I got the rpm's though - maybe seven or eight thousand. The bronze bushings I used for bearings aren't as smooth as ball bearings or else I could have added another stage to the multiplier. I saw another video where a guy used an electric motor to spin the copper pipes to levitate a magnet and wanted to do the same thing with hand power.

Does anyone use wood in their robots, or are they mostly plastic and metal?

Steve

www.stevengarrison.com (http://www.stevengarrison.com)

darkback2
10-15-2008, 05:53 PM
I personally use wood with larger robots. Its just got too low a strength to weight ratio for my current walkers. though i should probably rethink that last statement. I'm sure a lot of people use wood though because it is readily available and easy to work with. I would say the difference is that for you wood is the major element, while for most of us, its more a component.

Oh...sounds like a cool project by the way.

DB

wireframewolf
10-15-2008, 08:20 PM
I don't know if I'd necessarily want to use wooden gears on a robot (because it seems like they're rather heavy and wear out quickly), but just making them like you do is an amazing art in and of itself. Those gears are friggin' awesome. And I suppose that if your robot was as much an art statement as much as anything else (like if you're building a steampunk style 'bot), then you would get a ton of Fonzes (unit measure of coolness) for having homemade wooden gears :P

I think I personally don't have the hand-skills required to make these things, but should I ever have some time on my hands, I would certainly like to learn how :)

Adrenalynn
10-15-2008, 08:31 PM
I don't know, WFW, how about Purple Heart or Ironwood? Ironwood on Ironwood probably has pretty good wear - and would be gorgeous besides. Wish I had the patience to make stuff that cool.

Steve Garrison
10-15-2008, 11:22 PM
I think purpleheart would work good. The process for cutting them is very simple. I would estimate that the time required to make one of the gears pictured is about 10 or 15 minutes from a board to a finished gear. I can also do the same with delrin, nylon, or phenolic. Phenolic gears are meshed with steel gears to reduce noise and can handle very heavy loads. Of course those materials cost more, but think of the "Fonzy" factor.

I've never attempted to build a robot other than my solar concentrator if that is considered to be a robot. What do you do for parts? Do you design around what is available, or do you have manufacturers who sell just about anything you could want?

Steve

www.stevengarrison.com (http://www.stevengarrison.com)

Adrenalynn
10-16-2008, 02:03 AM
A combination there-of. If you look in the catalog here, you'll find all the little bits and peices necessary. From there it's about vision and putting it all together.

Your hand construction and fabrication skills will suit you well there. My stuff is never all that pretty - it's prototype-and-move-on.

Look at 4mem8's Wall-E - all hand construction and amazing.

4mem8
10-16-2008, 04:23 AM
Thanks for those kind words adrenalynn, It was fun to build.


Just looked at your site Steve, Brilliant work, I appreciate your work as I also work in laminated wood and just love it's texture. My wood turning site http://saltandpeppershakers.page.tl/
(http://saltandpeppershakers.page.tl/)

Steve Garrison
10-16-2008, 08:58 AM
Looks like the parts you use are quite a bit smaller and finer pitch than what I can make. I think I am barking up the wrong tree. I need to figure out the finest pitch I can make which is limited by blade thickness.

Mike - I looked at your woodturning site and you have some excellent work! I like the laminations slicing through at various angles. Great job on the robot too.

Steve

www.stevengarrison.com (http://www.stevengarrison.com)

4mem8
10-16-2008, 12:47 PM
Thanks Steve. I'de say, you would have your work cut out for you in making wooden gears small enough for robotics, But all the same would like to see you try and post the results.

Steve Garrison
10-16-2008, 02:35 PM
And maybe I will do that. What pitch or module is commonly used in robotics? I think I have an idea for plastic or possibly metal gears.

Steve

www.stevengarrison.com (http://www.stevengarrison.com)

Adrenalynn
10-16-2008, 02:41 PM
It's all over the board, based on size and application. There's no real standards.

For chain-driven stuff, #25 Roller is common. For gear drive stuff, it's whatever you can force to mesh together and still fit in the required space. ;)

Steve Garrison
10-16-2008, 02:52 PM
I'll see what I can do.

Steve

www.stevengarrison.com (http://www.stevengarrison.com)

metaform3d
10-16-2008, 11:26 PM
This is the site I use for gears: http://woodgears.ca/gear_cutting/template.html

I recently used it to make gears for linking a position pot to a drive axle. The gears are visible about two thirds of the way down this picture, made from laser-cut acrylic.

http://forums.trossenrobotics.com/gallery/files/1/7/0/5/cimg2045.jpg

The template requires a little massaging to make it work for laser cutting. You have to move the tool path to outside the cut line to account for the width of the beam. Also acrylic is a bit brittle for this application. If I was transferring power with the gears rather than just tracking rotation I'd have looked for a different material.

Adrenalynn
10-16-2008, 11:27 PM
You had some similarly cut gears for your bartender too, if I recall from the photos, didn't you?

metaform3d
10-16-2008, 11:44 PM
You had some similarly cut gears for your bartender too, if I recall from the photos, didn't you?Yes and no. They are acrylic, but I designed those myself and they just had triangular teeth with rounded tips. The large gears were also broken into pie wedges that were assembled after cutting. I think the applet makes teeth with better shapes.

Adrenalynn
10-16-2008, 11:54 PM
Very pretty though!

Steve Garrison
10-17-2008, 12:10 AM
Those look nice. Matthias Wandel made that gear pattern generator and I have checked my straight-cut gears against a template printed from his applet after I scaled it to fit the two marks. Turns out that those are stub-tooth gears, the outside diameter is a little bit smaller to make the tips wider and stronger than full depth gears. So when I made stub-tooth gears, they matched his pattern perfectly. I never have liked working with acrylic and prefer polycarbonate for clear plastic. Delrin is probably the best plastic for gears and can be easily cut with woodworking tools.

Steve

www.stevengarrison.com