I recently came across this idea:
<https://makezine.com/article/workshop/how-its-made-wooden-reciprocating-rack-and-pinion/>
<https://www.youtube.com/watch?v=JraeIyGqjdg>
and I was wondering why you never see them "in real life" (rather than
as a novelty).
It seems to have one advantage over a crankshaft: the assembly can be narrower (perpendicular to the direction of linear motion) than the
length of travel, whereas a crankshaft has to be slightly wider than
the length of travel.
I recently came across this idea:
<https://makezine.com/article/workshop/how-its-made-wooden-reciprocating-rack-and-pinion/>
<https://www.youtube.com/watch?v=JraeIyGqjdg>
and I was wondering why you never see them "in real life"
Adam Funk wrote:
I recently came across this idea:
<https://makezine.com/article/workshop/how-its-made-wooden-reciprocating-rack-and-pinion/>
<https://www.youtube.com/watch?v=JraeIyGqjdg>
and I was wondering why you never see them "in real life"
No advantage over a Scotch Yoke?
On 2025-01-07, Andy Burns wrote:
Adam Funk wrote:
I recently came across this idea:
<https://makezine.com/article/workshop/how-its-made-wooden-reciprocating-rack-and-pinion/>
<https://www.youtube.com/watch?v=JraeIyGqjdg>
and I was wondering why you never see them "in real life"
(I didn't have internal combustions engines in mind when I asked the question.)
No advantage over a Scotch Yoke?
I see two advantages of the reciprocating R&P: you can put an axle all
the way through it, instead of using crankpins [1] offset from the
axis; and it can be narrower than the length of travel. I can only
guess there are no real-world applications where those are important.
[1] I think you could have several yokes side by side using crankpins
between wheels, a bit like an engine crankshaft, but I don't think
I've seen such an arrangement.
Reading on this it looks as though both this and the scotch yoke won't
last as long
I recently came across this idea:
<https://makezine.com/article/workshop/how-its-made-wooden-reciprocating-rack-and-pinion/>
<https://www.youtube.com/watch?v=JraeIyGqjdg>
and I was wondering why you never see them "in real life" (rather than
as a novelty).
It seems to have one advantage over a crankshaft: the assembly can be narrower (perpendicular to the direction of linear motion) than the
length of travel, whereas a crankshaft has to be slightly wider than
the length of travel.
On 07/01/2025 12:05, Adam Funk wrote:
I recently came across this idea:
<https://makezine.com/article/workshop/how-its-made-wooden-reciprocating-rack-and-pinion/>
<https://www.youtube.com/watch?v=JraeIyGqjdg>
and I was wondering why you never see them "in real life" (rather than
as a novelty).
It seems to have one advantage over a crankshaft: the assembly can be
narrower (perpendicular to the direction of linear motion) than the
length of travel, whereas a crankshaft has to be slightly wider than
the length of travel.
With the rack and pinion - if the rotary part turns at a steady speed
the back-and-forth part has to go from steady speed one way directly to steady speed in the other, so you will have a violent, jerky reverse of momentum twice every revolution. With a crank the piston part slows and accelerates sine-wave fashion: much better.
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