How to calculate movement at a pivot?

[Arnak]

Hi,

Could someone help with this question, please?

If an axle is pivoted at the centre point then movement at each end (up and down) would be the same.

How do I calculate the movement at the one end if the pivot point is not in the centre but to one side?

Assume an axle is 10" long, while the pivot is 2" from one end of the axle.

If the long end is raised 2" how much will the other end move downwards?

I've tried Google but all I come up with is formulae for moments, torque etc.

What formulae would I use to determine the movement at various locations on the axle, please?

Martin

 

[Zeb]

Hello,
If I understand you correctly, and with the assumption of zero axial play, you could use trigonometry to calculate it or a simple diagram in your favorite CAD application.
-Z

 

[petertha]

I changed the example values so the numbers are all different. D=A/B*C

 

[Rotormac]

Assume an axle is 10" long, while the pivot is 2" from one end of the axle.

If the long end is raised 2" how much will the other end move downwards?

[/QUOTE]

In the example above, you have a 4:1 lever so if you lift the long end 2" the short end will drop 2/4" and so on.

 

[Arnak]

Hi,

Thanks for the replies.)

I know I should have paid more attention to trig when I was at school!

Martin

 

[SmithDoor]

Most take trig never use it.
A few programmers use trig for programs and very few engineers .
Now you find a app.

Dave

Hi,

Thanks for the replies.)

I know I should have paid more attention to trig when I was at school!

Martin

 

[ajoeiam]

Most take trig never use it.
A few programmers use trig for programs and very few engineers .
Now you find a app.

Dave

Never got fluent in spherical trigonometry - - - - that's a 'lot of fun' country!!! (wacky beeg grin!)

 

[Gordon]

In my business of designing and fabricating special equipment I found that I used trig a lot until I started drawing in cad. Once I was able to draw things with precision I frequently used a cad sketch to scale and then was able to actually measure the result. I also did some sheet metal layout which is basically just manual trig.

 

[Zeb]

I had one occasion where someone calculated distance from their CAD camera view instead of the part's normal (easy to do, but difficult to catch). Root cause found with pencil and paper.

 

[charley Leight]

Most take trig never use it.
A few programmers use trig for programs and very few engineers .
Now you find a app.

Dave

HI when I worked at a plastic injection molding plant , I was designing and building fixtures. I had the same problem I took trig in school never used it. The tool maker told me to use the 90 degree triangle solutions if possible be applied. Walaa! the light bulb lit , it was like opening a whole new world, why did not they use better examples in school. I guess maybe my mind was not ready to accept trig. I have used trig in many of my work and glad I have used it. charley

 

[SmithDoor]

Never got fluent in spherical trigonometry - - - - that's a 'lot of fun' country!!! (wacky beeg grin!)

I guess you did not do any ocean navigation.
Lots of fun before computers

Dave

 

[ajoeiam]

I guess you did not do any ocean navigation.
Lots of fun before computers

Dave

Not much call for ocean navigation when you're living on the North American Prairies - - - grin!

It would be useful for 5 axis machining planning is why I'd like it (bigger grin!)

 

[SmithDoor]

Not much call for ocean navigation when you're living on the North American Prairies - - - grin!

It would be useful for 5 axis machining planning is why I'd like it (bigger grin!)

It is also used for long distance flying too.
Using big guns like the 14" and 16" rifles.
A string on a globe works to check your calculations .

Dave

 

[ajoeiam]

It is also used for long distance flying too.
Using big guns like the 14" and 16" rifles.
A string on a globe works to check your calculations .

Dave

I really really like your check method!!!!

I just ride when it comes to flying and I dunno if anyone is making any of this poppers any more - - - or ?????

 

[wazrus]

The axle centre is known, or at least its pivot point is, from which a circle can be described, whose circumference - which is, i think, what is being discussed here - is calculated using Pi x D. Find what proportion of the circle is being 'tracked' and it seems to me you might be in business. If i recall, too, the 'track point' was also(!) known as the 'locus'. Never did understand how the calculate locus.

 

[SmithDoor]

I would hate to navigation in the air using a slide rule. Many thanks for the E6B invention.
The first time I did great circle navigation formula it took over hour using a slide rule and paper.

Dave

I really really like your check method!!!!

I just ride when it comes to flying and I dunno if anyone is making any of this poppers any more - - - or ?????