J
JorgensenSteam
Guest
I have seen a number of posts on balancing single-cylinder steam engines, and have pondered how to do that correctly for many years.
Some have stated that engine balance is beyond the capabilities of the home modeler, but I think an engine can be balanced if you understand what you are trying to accomplish.
The first thing to understand is that there is static balance (objects not in motion), and this is commonly seen when the engine crank, rod, piston, etc. is placed on knife edges and balanced such that the weight of the piston, connecting rod, crank throw, etc. equals the weight of the counterbalance weights.
Then there is dynamic balance, and this is the balance you try to achieve while the engine is running, and the parts are either rotating (like the crankshaft) or reciprocating back and forth (like the piston, piston rod, crosshead, etc.).
An engine that is statically balanced only without any attention to dynamic balance can generate great deal of vibration when it runs.
It is also important to remember that the formula for dynamically balancing a vertical engine differs from the formula used to dynamically balance a horizontal engine, since gravity plays a larger role in the vertical engine.
If you are balancing your engine using knife edges, you are not balancing your engine when it runs.
Pat J
Some have stated that engine balance is beyond the capabilities of the home modeler, but I think an engine can be balanced if you understand what you are trying to accomplish.
The first thing to understand is that there is static balance (objects not in motion), and this is commonly seen when the engine crank, rod, piston, etc. is placed on knife edges and balanced such that the weight of the piston, connecting rod, crank throw, etc. equals the weight of the counterbalance weights.
Then there is dynamic balance, and this is the balance you try to achieve while the engine is running, and the parts are either rotating (like the crankshaft) or reciprocating back and forth (like the piston, piston rod, crosshead, etc.).
An engine that is statically balanced only without any attention to dynamic balance can generate great deal of vibration when it runs.
It is also important to remember that the formula for dynamically balancing a vertical engine differs from the formula used to dynamically balance a horizontal engine, since gravity plays a larger role in the vertical engine.
If you are balancing your engine using knife edges, you are not balancing your engine when it runs.
Pat J