# How do you test the efficiency of a wobbler steam engine

• ME-student
In summary, the student is looking for ways to test the efficiency of a wobbler steam engine. They have found a way to make a prony brake and are looking for advice on how to use it.
ME-student
I have a project for my sophomore design class to test the efficiency of a wobbler steam engine. I have heard people talk of using a dc motor and connecting it with a belt to the flywheel to see what voltage it produces but I don't know how to do that. In addtion, some have suggested to just hang a rope with a known mass off the flywheel. If anyone could help me think of a simple way to test the efficiency of my wobbler that would be great.

You need to have it do a measured amount of work.
The suggestion of making it pull a string and lift a weight seems easiest.
The energy to lift a weight = mass * g *height

okay. I think that a lot of people are going to do it that way so i looked into doing it with a DC motor. So far i figured out that i have to make the motor turn with my flywheel and then multiply (current*voltge) produced which equals work. Do you have any advice on if that sounds acceptable and how would I test the efficiency of the DC motor I have included in the project?

mgb_phys said:
You need to have it do a measured amount of work.
The suggestion of making it pull a string and lift a weight seems easiest.
The energy to lift a weight = mass * g *height

That's a great idea in theory. That isn't how it's done in the real world though. You (ME-student) want to construct what is called a prony brake. This is what you described. I'm currently making one. They are very easy to make. If you want to be crude, a Fish scale and RPM gun will suffice. If you want real measurements, you need strain gauges and hall effect sensors.

## What is a wobbler steam engine?

A wobbler steam engine is a type of steam engine that uses a rotating eccentric to convert reciprocating motion into rotary motion. It was commonly used in the 19th century for powering small engines and toys.

## How do you test the efficiency of a wobbler steam engine?

To test the efficiency of a wobbler steam engine, you can measure the amount of work it is able to do in a given amount of time. This can be done by attaching a load to the engine and measuring the time it takes to complete a certain number of rotations. The efficiency can then be calculated by comparing the input energy (steam) to the output energy (work done).

## What factors can affect the efficiency of a wobbler steam engine?

The efficiency of a wobbler steam engine can be affected by several factors, including the quality of the steam, the design and condition of the engine, and the load placed on the engine. Other factors such as friction and heat loss can also impact the efficiency.

## Can the efficiency of a wobbler steam engine be improved?

Yes, the efficiency of a wobbler steam engine can be improved through various methods such as optimizing the design and reducing friction. Using higher quality steam and properly maintaining the engine can also help improve efficiency.

## What are the advantages of using a wobbler steam engine?

Wobbler steam engines have a simple design and are easy to operate, making them a popular choice for small engines and toys. They also have a unique and mesmerizing motion which can be entertaining to watch. Additionally, they can be powered by a variety of heat sources, making them versatile for different applications.

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