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Old 12-17-2011 | 01:00 PM
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speedracerntrixie's Avatar
speedracerntrixie
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From: Happy Valley, Oregon
Default RE: OS 33GT Gasoline Engine for Pattern


ORIGINAL: NJRCFLYER2


ORIGINAL: speedracerntrixie

Matt, I appriciate you comments about the soft mount but as these will be used for IMAC competition I will contunue to hard mount. I have been hard mounting for 14 years now without any ill results.
Doesn't IMAC still have anoise score? Should be a slam-dunk 10 if you outfit your engine the way Matt describes. Plus, your servos will all last longer and you will use a lot less battery capacity each flight. Everything lasts longer, and amazingly, you get a little more usable power delivered to the prop. If you think about it, any energy that is not wasted on rattling the airframe and producing acoustic waves from the airframe is going somewhere else - into the prop!

IMAC does have a sound score. At the end of the flight the judge gives you a score of 1 to 10. In reality what happens at least here in the SW region is that if you rip the prop you get 0, if you are running mufflers and managed the throttle you get a 5, if you have canisters and use good throttle management you get a 10. 90% of the time the judge just gives out 5's. A 50cc airplane with an ES pipe and correct prop is already way ahead of most. My major concern with a soft mount is that there is no way to run a nose ring on these and the unlimited sequence has no less then 13 snaps. Thats a minimum of 26 snaps per flight. I'm concerned about the longevity with that type of abuse not to mention the engine moving around during the snap. The last Laser Ihad like the ones I am building had a hard mounted DA 50 with a muffler. The sound was very reasonable and I had about 500 flights on it with no noticable vibration damage. The pipe will smoothen out the engine some so I will already be better off. You of course are correct about less current consumed from the RX battery.