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Engines Plugs Mufflers Fuel > OS 55 power pipe is it a rebadged A395 FunTech 50 3D Muffler ?
 
 
heli_headcase
Key Veteran
Location: Hovering around Atlanta

My Posts This: Topic  Forum		Got one...

Quote 
What we need is a dyno machine which u strap the heli on then instead of us all just guessing u would have a graph to see the difference.

I built a chassis dyno 13 years ago for tuning my straight-line speed heli. It's really very simple (no pictures available currently) and is basically a small bicycle wheel who's axle is screwed into a pole and a platform for tying the landing gear is secured to the opposite side of the wheel. The pole was 2" diameter and strapped to the side of a big dumpster. With the lid closed, this gave a working surface as the dyno platform was high off the ground.

The nature of this speed heli and the head speed made holding it high necessary for added safely and the dumpster was the perfect solution.

To measure torque a flexible cable was tied to a crossover point in the spokes (distance to the wheel center carefully measured) and then the cable was routed downward over a ball bearing supported pulley and then to a digital scale. The torque value was read directly off the scale and the cable attach distance figured in to give the real torque generated. Tail blades removed so they couldn't influence the readings.

I don't recall the HP formula but in the case of simple comparing things like pipes, the torque value at a fixed pitch is the primary number needed.

Does any of this make sense?


HHC

So many heli's - too little time...
11-06-2009 02:39 PM
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lightningrc
Elite Veteran
Location: UK

My Posts This: Topic  Forum		yes but seems like alot of hassle a purpose built accurate unit would be nice.
Would like to see some pics though ? thanks
11-06-2009 10:06 PM
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raptorheli2
Elite Veteran
Location: rip off britain and no changing it

My Posts This: Topic  Forum		why not bolt a prop on it and get a rev counter?

cheers


www.waterfoothelis.com
11-06-2009 10:09 PM
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heli_headcase
Key Veteran
Location: Hovering around Atlanta

My Posts This: Topic  Forum
Quote 
why not bolt a prop on it and get a rev counter?

That would be SO easy but -

Many of today's mufflers are shaped incorrectly for convenient mounting of the engine to a standard test stand. 'Something' gets in the way of 'something' else. Try to imagine the configuration.

In the case of my speed heli, the engine (OS 61SXH modified) and pipe/header combination did fit a standard engine running stand but I wanted to measure real horsepower not just relative (to other test runs) power. The dyno was the only choice. Lots of runs with the normal stand were done to tune everything and figure pipe and header lengths first. It still didn't completely prepare me for the problems I eventually had when the engine was mounted in the airframe. But that's a story for an entirely different time


HHC

So many heli's - too little time...
11-06-2009 10:19 PM
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raptorheli2
Elite Veteran
Location: rip off britain and no changing it

My Posts This: Topic  Forum		i'm sure us being modellers could find a way to make a mount and a prop work.

cheers


www.waterfoothelis.com
11-06-2009 11:05 PM
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lightningrc
Elite Veteran
Location: UK

My Posts This: Topic  Forum		Ur not looking for maxium rpm , ur looking for how much load it can hold
11-07-2009 01:16 PM
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raptorheli2
Elite Veteran
Location: rip off britain and no changing it

My Posts This: Topic  Forum		and?

i never said maximum RPM. you prop it to get into the butter zone and see what revs it can pull. you put same prop on your other 50 class engines and compare.

for example an OS50 hyper maybe able to spin a 10x8 at 17,000rpm. you may get the 55 to spin an 11x8 at 17,000rpm (unlikely but you get gist)

i never said the above was ideal, but to joe bloggs it's a simple way to compare.

cheers


www.waterfoothelis.com
11-07-2009 01:41 PM
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lightningrc
Elite Veteran
Location: UK

My Posts This: Topic  Forum		Boys some news for you !!

Fitted the OS badged pipe today , governor sensor was playing up but it was a dissapointment , heli was bogging down easily

Im just renewing the sensor and will test again tomorrow , will even take the Align pipe to the field with me .

Any one else got any views on this combo ?
11-07-2009 05:27 PM
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tim deakin
Veteran
Location: gloucestershire uk

My Posts This: Topic  Forum

They are the same! Arnt Radix blades funtec aswell???
11-07-2009 09:29 PM
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payne1967
Key Veteran
Location: warwickshire uk

My Posts This: Topic  Forum		lightningrc
i've fitted an os pipe to my 50 hyper and it's making more power and a broader spread of power compared to the zimmerman that came off it in my sdx50
you may have a tuning issue hidden by the governor
11-07-2009 10:44 PM
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lightningrc
Elite Veteran
Location: UK

My Posts This: Topic  Forum		Nope sorted the governor then flew 6 tanks through her , the performance is way down with this power pipe compared to with the Align.

Going to start another thread as this is not the right subject.
11-08-2009 01:30 PM
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2 pages [ <<    <     1     ( 2 )    >    >> ]1066 viewsPOST REPLY
ReadyHeli . Power Helis . CANOMOD

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Engines Plugs Mufflers Fuel > OS 55 power pipe is it a rebadged A395 FunTech 50 3D Muffler ?
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