, I don't have a clue how to calculate this.

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SUMMARY

The discussion centers on calculating the effective force exerted by a piston on a crankshaft in a mechanical system, specifically addressing the impact of angles and lever arms on torque. The crankshaft radius is 5.25 inches, positioned at 22.5 degrees, while the rod length is 8.6875 inches at 13.3 degrees. Participants clarify that the force from the piston can be decomposed into components, with only the force in the direction of motion contributing to energy expenditure. They emphasize that losses are primarily due to friction and not from the geometry of the crankshaft and piston interaction.

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  • Familiarity with torque and angular motion concepts
  • Knowledge of crankshaft and piston dynamics
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  • #31
No worries.
The torque is about the center of the crank. This is inclusive of the 5.25" moment arm.
Basically you can think of it as 164 lbf acting perpendicular to the crank arm at that 5.25" distance.
 
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  • #32
FeX32 said:
No worries.
The torque is about the center of the crank. This is inclusive of the 5.25" moment arm.
Basically you can think of it as 164 lbf acting perpendicular to the crank arm at that 5.25" distance.

FeX32,

That is what I thought it was, I did get that number as well as at the cam I believe it's 328 lbf. This is better than I had hoped for in this application.

It is the final answer I needed and I've worked on this machine for the better part of 6 years. I have tried to figure it many ways, never was sure of the outcome tho! Now I fully believe it will work. I had little doubt ;)!

Thank You Again! I won't forget your help!

ed
 
  • #33
You're welcome ed. Good luck with your machine.
All the best to ya,
 

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