cylinder stroke for pivot force transfer

[bjr]

I think that's the description of what I'm trying to accomplish. I need to know if the arc length is the same as the stroke length of the cylinder or is there a ratio of some kind to the chord length. I'm obviously not a school boy so this has to be pretty straight forward calculations or explanation. bjr

 

[bjr]

I just realized that I should have said the sprocket only needs to rotate 90 degrees. bjr

 

[J_J]

Depending on cyl length, the sprocket will turn until the cyl shaft touches the sprocket shaft. The speed of the sprocket turning will depend on the distance of the cyl pin mount to the sprocket shaft.

If the cyl shaft is 1 in, you can use a 1 in wood rod with a bolt to simulate the cyl shaft length and the number of degrees the sprocket will turn.

Based on shaft length, and placement on the sprocket, you can fine tune it to turn exactly 90 degrees.

 

[rus_geek]

For 90 degrees, I believe the chord length is the radius times the square root of 2.

-rus-

 

[bjr]

That PDF drawing was supposed to be rotated clockwise 90 deg. so the cylinder was horizontal. What was giving me problems, was, as the rod end travels the arc it's raising vertically as its traveling horizontally, so, is the distance the rod end travels the same distance as the arc length? I'm guessing it's almost the same distance. See that would give me what stroke length I would need for a given radius to achieve the 90 degree rotation. I was going crazy tryin' to get wayy to precise for a piece of farming machinery. But, a coworker ask me how did I come up with the correct stroke for the cylinder and I couldn't show my work, mathematically. bjr

 

[rus_geek]

The rod end will travel the entire length of the arc. However, the distance between start and finish (needed cylinder extension) is the chord length.

Arc is .5 * pi * r
Chord is sqrt(2) * r (about 90% of the arc length)

-rus-

 

[BHD]

IMO there is a diffrnece as the arc is further than the stright line, the cylinder will rise slightly as it arches over the curve, (going from your drawing), but your sprocket and the attachment point is two different circles your teeth on the sprocket will travel more than the stroke of the cylinder in measurement.

but my guess is unless your really into precison, you will never know the diffrnece in operation,

 

[Pooh_Bear]

The stroke length is the radius multiplied by the square root of 2.
The arc length doesn't affect the stroke length.

Pooh Bear