Motors or Engines?

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bavspaceprogram

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I've always wondered this, since I've heard it said both ways... Is it a rocket motor or a rocket engine? I've always leaned towards motor. What do you think?
 
An interesting one I've heard was from a guy that worked at thiokol who preferred motor for a rocket motivator that did not have moving parts, ie solid or hybrid, and that a rocket engine had pumps etc to provide the propellent and/or oxidizer.....Although people use them synonomously, ie estes calls them engines, nasa refers to the shuttle boosters as motors, ie "Evaluation of Space
Shuttle Solid Rocket Motor" In some definitions motor converts energy to motion, engine does this via combustion....electric motor, automobile engine....where an engine is a subset of motors....although when it comes to rockets normally there is combustion:) But even that is counter-argued that in physics motors convert energy to motion and so are a subset of engine which convert energy to mechanical work, not necessesarily motion... Take your pick.

Frank
 
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If moving parts an engine make...what's up with the Ford Motor Company?

I agree with Roger.
 
I like engine, the mouth finishes better when you say it, motor leaves the mouth unfinished.
 
I use both, though I was once told "if you have to plug it in, it's a motor".
 
Whichever it is, it goes in a motor mount, because alliteration always wins.
 
From https://www.worldwidewords.org/articles/engine.htm

"The propulsion device of a rocket can be called either a rocket motor or a rocket engine, and usage here seems not to have settled on one or the other. The IEEE Spectrum magazine for June 1998 (which Ron Jeffries has thoughtfully sent me) reports that the debate has been so intense, and yet so inconclusive, that some rocket scientist has coined the phrase whoosh generator as “the humorous, genderless, politically correct way to refer to the propulsion device in a hobby rocket, thus avoiding the great motor/engine debate”."

Bob
 
While there is considerable debate between what a motor is, at the end of the day most any definition leaves rocket engines as a type of motor. Which is to also say that all of them also leave rocket motors in the engine category as well. The upshot of all this is to say that either is correct and both are commonly used in reference to what powers our rockets.

Besides, life is too short for long winded arguments about such anyway.
 
I always used to call them "rocket engines". Then in 1988 when I went to work for Enertek, Bill Stine forced me to call them "motors"... I've called them "motors" ever since. While Bill went back to calling them "engines" long ago. :rolleyes:
 
I use the word motors mostly, occasionally I'll use the word engine.

I
 
They're both correct. From Merriam Webster.com:

engine - a machine that changes energy (such as heat from burning fuel) into mechanical motion

motor - a machine that produces motion or power for doing work
 
Internal Combustion Engine uses a Starter Motor.

An electric motor is never called an "engine". This includes regular rotating electric motors as well as transverse linear motors.

Engines have moving parts to generate their output force (turbines or pistons, etc.), while motors have no moving mechanical parts to create the output force. Electric motors and solid rocket motors create a force and the reaction imparts motion.

Looking up an engineering term in an English dictionary is not the best way to understand the engineering technical definition and rationale for that definition since they do not have the space to explain technical concepts fully (nor do they understand them quite often).

Toy or model companies can call things what they wish, but on Estes Model Rocket Engines you will see a California State Fire Marshal classification as a "Model Rocket Motor".

Ditto for other professional groups and agencies.

Also, note how Estes changed their "Solar Igniter" to a "Solar Starter" to indicate that there is no longer any pyrotechnic element/compounds. it now just has a clear coating covering the nichrome wire heating element at the tip.
 
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In the old days the definition was based on thermodynamics. Around the turn of the century if the conversion of heat into mechanical energy was taking place the device was called an engine.

If there was any other conversion (electric, water head, air pressure, wind etc) into mechanical energy the device was called a motor.

For example if you produced work with your internal combustion device by burning fuel it was an engine.
If you operated the exact same device with compressed air it was a motor.

Also the orgins of this terminology were confined to devices the predominately converted energy to product rotational mechanical energy.

James Watt if he were still alive would know precisely what the answer is to this question.
 
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I'd often wondered the same thing. Then I did some research, and found evidence for both usages as being proper. Since then, I don't hesitate to use whatever feels better to use.
 
In the old days the definition was based on thermodynamics. Around the turn of the century if the conversion of heat into mechanical energy was taking place the device was called an engine.

If there was any other conversion (electric, water head, air pressure, wind etc) into mechanical energy the device was called a motor.

For example if you produced work with your internal combustion device by burning fuel it was an engine.
If you operated the exact same device with compressed air it was a motor.

Also the orgins of this terminology were confined to devices the predominately converted energy to product rotational mechanical energy.

James Watt if he were still alive would know precisely what the answer is to this question.
I prefer this, the entropic logic. Otherwise, we might call a search engine a search motor.
 
Once again Fred is right. If you look up the terms in an engineering dictionary, you'll discover that an "engine" converts energy from one form to another and that a "motor" imparts motion. Our rocket engines convert chemical energy into kinetic energy. And our rocket motors make our rockets move. So, as Fred notes, both terms are correct.

-- Roger
 
The important thing to remember is that an A8-3 motor is going to produce the same result in an Alpha III as an A8-3 engine.

-- Roger
 
Or just say an A8-3. I don't say motor, I don't say engine, I say CTI H410.
 
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