# So, Just how big of an engine do I need to spin this? :)



## Twmaster (Jun 14, 2010)

One of the ways I support myself these days is buying used treadmills and parting them out. The motors and controllers in some are great for powering smallish home shop machines. Anyhow, I bought a treadmill over the weekend that was not the usual type/brands I buy. 

It actually came with a seriously studly motor. On the end of the motor was this big honking flywheel:







That's a 6" rule. It's 9" in diameter, 1-7/8" thick at the rim and 13-1/2 pounds.

So, just how much engine and steam?


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## Maryak (Jun 15, 2010)

Twm,

Around 1hp.

This is where I'm coming from. http://www.homemodelenginemachinist.com/index.php?topic=9060.msg97990#msg97990

Hope this helps

Best Regards
Bob


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## Twmaster (Jun 15, 2010)

Bob, my question was more in jest than serious.

However, I do appreciate the answer and link. Doubt I'll ever build a beast that can swing that.

When I took the top cover off the treadmill and saw that all I could think was BIG steam engine time!!


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## Maryak (Jun 15, 2010)

Mike,

OK

Around 0.75 killerwatts, ( a funny horsepower). :

Best Regards
Bob


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## Twmaster (Jun 15, 2010)

.746 KW actually....

But whose counting?!! 

Funny you mention 1HP.... The DC motor out of the thing is rated 1 HP continuous duty! 90V @ ~18A


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## Blogwitch (Jun 15, 2010)

Mike,

You might have said it in jest, but you must really do something with it.

I have just bought a casting set with two of that size, and they cost in the UK 55 squid each, which I think converts to around 80+ bucks. So not something to be discarded or forgotten about.

This is the engine mine fits onto. This is shown with one 12" flywheel.

http://www.homemodelenginemachinist.com/index.php?topic=9233.0

Bogs


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## Twmaster (Jun 15, 2010)

John, be rest assured I would never toss something like this in the scrap heap. I have far too much Pack Rat in my blood for such frivolities!

And as Mr. Flemming once wrote.... "Never say Never..'


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## wizardofwood (Jun 15, 2010)

200 Killerwasps should do it!
[ame]http://www.youtube.com/watch?v=npnZvTLMR1w[/ame]


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## Twmaster (Jun 15, 2010)

Bwahhahaaaaa! 

Ok, that was funny!


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## Kaleb (Jun 16, 2010)

She's a big'un, If you built a steam engine with it, it would need one heck of a compressor to run it, or a huge boiler! I would go with an IC engine in that size, hit and miss diesel with a car engine injector anyone?


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## Chazz (Jun 16, 2010)

It's a matter of perspective, if you want to 'spin it' as a valve handle may I suggest.................






 ;D

cheers,Chazz


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## Lakc (Jun 16, 2010)

Is that an encoder in that hub?


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## Twmaster (Jun 16, 2010)

*Is that an encoder in that hub?*

In a way. It's just a disk with shiny and black divisions. The treadmill controller board uses that for speed regulation with an optical sensor.


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## Jared (Jun 17, 2010)

wizardofwood  said:
			
		

> 200 Killerwasps should do it!
> http://www.youtube.com/watch?v=npnZvTLMR1w



Funny. But somehow "200 kilowatts" just doesn't have the same ring as "268 horsepower".


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## Lew_Merrick_PE (Jun 17, 2010)

Twmaster  said:
			
		

> So, just how much engine and steam?



If this wasn't just a rhetorical question, http://www.scribd.com/Lew Merrick has my paper _Rotational Dynamic Design Formulae_ that will give you the equations based on your desired spin-up time. ???


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