WM2D

[Magnum]

What I am trying to do is make the inner wheel run at a different ratio than the outer wheel. The two wheels need to be connected on the same axle.
Also an idler gear would be needed to make them run in the same direction. I cannot separate the two wheels due to the way they need to interact. Can someone please help.

Ken T.

[rlortie]

Magnum,
try http://auto.howstuffworks.com/gear-ratio4.htm bottom of page.

Also find at;

http://www.du.edu/~jcalvert/tech/planet.htm
http://en.wikipedia.org/wiki/Epicyclic_gearing
http://www.innerauto.com/Automotive_Sys ... anet_Gear/
http://www.dliengineering.com/vibman/planetarygears.htm

Purchase an interchangable ratio for research at:

link

cost, $19.95

[Magnum]

I know how gears work Ralph. What I am trying to do is setup gears in Working Model 2005. This is an example of what I need.

[jim_mich]

Ken T,
Make circle one and circle two as you have shown. Then make a third circle off to one side to act as an idler gear. Click the gear tool icon and then click circle one then circle three so you have connected the first circle to the idler circle. Again click the gear tool icon then click circle three then circle two so you have connected the idler circle to the second circle. The gear ratios will default to the circle sizes but you can change them in the properties window.

One thing that WM will not let you do is have two circles on a same center location geared to each other. The real world won't let you do it either.

[Magnum]

Thanks Jim_Mich U Da Man.

[Magnum]

For the life of me I cannot figure out how to make a pulley. Can anyone help?

Ken T.

[graham]

Click on the pulley icon, then click once where you want the pulley system to start. Move to the next point where you want the idler pulley ,click once again. Move to the next point and click once again ,now you have two idler pulleys.
When you have the rope the way you want it then double click and you're done.

Graham

[jim_mich]

There is no way to make a "pure" pulley system where belts wraps around pulley wheels like the belts on your automobile engine. WM pulleys are actually ropes which are threaded through idler pulleys. If you want a pulley system where belts connect two (or more) pulleys then you must use gears. Sometime you need to be a little creative to make WM simulate real life.

[Magnum]

Jim,

A friend of mine has an idea that uses pulleys. Gears will not work in what he wants to do. It has nothing to do with a pm machine. Could you can wake me through it.

Ken T.

[Tinhead]

Not easy to do for a WM2D beginner, but it is possible to create pulleys in WM2D .. see the attached example.

The catch ... you have to use formulas to drive the rope lengths and the position of their fixing points to the 'roller'. Select the ropes and their endpoints and check the properties ... there you will see. WM2D takes care of the rest.

Cheers,
Rainer

[jim_mich]

Yes, that works.

Beginners should be aware that when righting your own formulas if you write the formulas wrong then your results will be wrong.

[graham]

Hi Jim, I am trying to display force vectors on a pin joint but cannot seem to adjust vector length to keep it on a scale that does not go beyond the borders of my display.
Setting the vector lenght to .001 ,the lowest setting helps a bit but not enough.
Do you have any tips on this subject since the "help" on this topic is not much help.
Thanks.

Graham

[jim_mich]

Set the Fx and Fy (Forces X and Y) to what ever you need to accomplish what you desire. Then click 'Define' and 'Vector lengths' and adjust for visual appearance.

On another note, you can enter numbers using more than the standard three decimal places (such as 0.0015 or 0.0002) and WM will store and use the extra decimal place put it will only display the normal three decimal places. Also you can change the number of decimal places that are displayed.

[graham]

On another note, you can enter numbers using more than the standard three decimal places

Thankyou Jim very much . I thought that I was limited to only 3 decimal places.
I tried it again, this time to 4 decimal places and now have a nice vector readout that displays properly on my screen.

Graham

[graham]

Here's another question .

Why is it that if you pull weighted arms against stops with springs, and then pre tension the springs to pull the arm more tightly against its stop, the wheel will rotate in the direction of the springs pull.
Everything is in balance but if you remove the pre tensioning on the spring it does not move.
Leave the pre tensioning "on" but hold the arm with a rigid joint has the same effect . ie. the wheel does not move.

Graham