Some useful mechanisms

[path_finder]

For the builders I recommend this excellent web site: http://www.mechanisms101.com
In particular you can find here:
- the Looney gears: http://www.mechanisms101.com/looney_gears.html
- the linear Cardan mechanism: http://www.mechanisms101.com/cardan_gear.html
- the Ferguson paradox: http://www.mechanisms101.com/fergusons_paradox.html
(Click on the top right button for viewing the dial, and select a slow speed (pe: 0,5) for a more stable not flickering display)
- the Whitworth Quick Return Mechanism:http://www.mechanisms101.com/whitworth_ ... eturn.html
This mechanism could be very useful for generation of a variable rotation speed and/or exchange of weights (Buzzsaw)
- and for the fun this beautiful walschaerts valve explanation (for the damp locomotive lovers): http://www.mechanisms101.com/walschaert ... _gear.html
You can accelerate, stop or reverse the speed clicking in the upper right box.

And don't forget the way to make the gears: http://www.besslerwheel.com/forum/viewt ... 3985#65428

[Fletcher]

Now there's a really useful post with sites to bookmark - thanx Pathfinder.

[path_finder]

Another interesting (useful?) mechanism: the linkage of Kempe. See here:
http://steiner.math.nthu.edu.tw/disk3/c ... kempe.html
The Java applet can be looked with a 90 grades clockwise rotation: in this case we get the famous path at 3:00 for the COG of the wheel.

[savoniuspiral]

here's another interesting site.
contains a large collection of Kinematic models.

http://kmoddl.library.cornell.edu/

[AB Hammer]

savoniuspiral

Welcome to the forum and thanks for the link. It is a very large collection. Also thanks to Path_Finder for this string and other links.


Alan

[Timothy]

For those who post designs and links, esp. path_finder:

"An ambitious farmer, unhappy about the yield of his crops, heard of a highly recommended new seed corn. He bought some and produced a crop that was so abundant his astonished neighbors asked him to sell them a portion of the new seed. But the farmer, afraid that he would lose a profitable competitive advantage, refused.

The second year the new seed did not produce as good a crop, and when the third-year crop was still worse, it dawned upon the farmer that his prize corn was being pollinated by the inferior grade of corn from his neighbors' fields."
Ralph Woods

"The miracle is this--the more we share, the more we have."

Leonard Nimoy

THANKS

[justsomeone]

These links are exactly what I had in mind for this thread:

http://www.besslerwheel.com/forum/viewtopic.php?t=4664

Often times someone will post such interesting links and I will forget where it was posted and not know where to search. Thanks Path!

[path_finder]

Few links from my personal archives:

Some corn for the mill of the builders: http://www.scribd.com/doc/53063195/Five ... -Movements

Remember Bessler was a pipe organ maker: http://www.concertartist.info/organhistory/begin.htm
Click on the left side on the button 'The organ and How it works' then on the link 'Chests and action', and finally on the link 'mechanical action' (direct access adress not known)

Cardano was very known at this time: http://www.mechanisms101.com/genova301.html
He is the inventor of the Geneva mechanisms, see here: http://ebooks.library.cornell.edu/k/kmo ... 02_010.pdf

A plenty of good ideas here: http://www.mechanisms101.com/menu_new.html

The theory of straight line mechanisms: http://www.wlym.com/~animations/part3/39/index.html
After the chapter 39, don't forget to click on the 'next' link at the bottom of the page.

The cycloidal reductor: http://www.darali.com/page17.html

Also make a search on youtube with the keyword 'Theo Jansen'.
One example: http://www.youtube.com/watch?v=-GgOn66knqA

[broslad]

A useful tip for anyone building i find when everything is complete and all the leavers and weights for your new design is on, tie all the leavers in the same position with cable ties then turn the wheel slow to find any heavy spots and counter balance it moving some small weights on the back until the whole thing is balanced, Then you know your idea has the best chance of working. Another tip i have, when i'm there and it's the moment of truth and my days/weeks of fitting leavers weights and spring etc and i descover iv'e built another balanced wheel i try to see if it would wok back words.

[Art]

.

Hi Broslad ,

Yes you are quite right with that .

You might find also , that if you take it another step further and turn it with a known input force and measure the number of turns you get , that the number of turns clockwise versus the number of turns anticlockwise (or counter clockwise) will give you valuable insight into what is actually happening as the momentum of the weights change during the course of a revolution .

With some finely tuned mechanisms you will notice that the direction of rotation in relation to compass direction (North South East and West) will change the number of turns the wheel will do in the clockwise versus the anticlockwise direction also.

I have measured these differences as higher than 7 % with simple low friction pivoted contraptions .

I now do most of my wheel spinning in an East /West direction to pick these differences up , which adds a level of complication to everything , but these are the breaks - this whole search gets pretty complicated at times . : )