where R is the distance from the center of the tube to the center of the helix, r is the radius of the tube, P is the speed of the movement along the z axis.
Ok, the helix will be 400 wide, so R = 200 units.
The radius of the tube will be 30, so r = 30 units.
Now this is where im stuck, they ask for P for the speed it moves upwards / downwards. How should i get this? For example if i want my spring to have 2 complete revolutions and have a total height of 500 units, how should i know what P is?
I also need to know n, which is not explained very well what n is on the page.
Many thanks if you can help me understand.
Aug 12th 2007, 11:07 AM
Your helix has radius 200 and the tubing as radius 30. Correct?. This conflicts with R which says they're both 200.
In this event R+r=230. That's what I'll use.
Assume you're wrapping a tube of radius 30 around a helix of radius 200,
This forms a helix. A helix can be represented by
a in this case is R+r=230. The radius of the helix + radius of tubing.
Since you want two revolutions when z=500 units, you have
You have the helix:
It's length in making two revs in a distance of 500 units is given by
Now, this is a cylinder of radius 30 with height 1466.6
Check my calculations out.
Aug 13th 2007, 10:31 AM
Wow thanks for taking the time to explain that to me more clearly.
Hopefully your message will help others aswell if they find this through a search engine.