I need advice from a professional who has built and flown nito powered scale helicopters. My creditials are that I have built and flown RC helicopter ranging from 30 to 90 size airframes all of the pod and boom design. Now I want to get into scale. The model I desire to emulate is a MD500E. I have choosen to mount a fuselage of this design on the mechanics of an Align 600N LE. I have encounted very little information on this airframe but what I have read is that vibration is a serious issue that seems to manifest once a scale body is is attached to an existing airframe. Before I take the pluge into this realm of RC helicopters what are the things I must be aware of and how to negate the possibility of failure.

Biggest thing is to make the mechanics as perfect as you can BEFORE you fit the fuselage. Make sure everything is as smooth as you can make it.

You dont want to have any mechanical tinkering left to do when you install the body.

Thanks' for the information, although limited in content. I need to no the pitfalls before I committ myself. When I got into building and than flying model helicopters my goal was to become a profficient FAI pilot and this I believe I have obtained after many years of practise and patience. Knowing that I am capable pilot I want to transfere this knowledge into flying a scale subject. What I don't want is failure due to inherent problems associated with scale airframes. This is were I am seeking advise from those who have gone this route.

Does this count?

I guess what I'm saying is that helicopters aren't any more failure prone with a fuselage on them than not, they just cost more to fix when they fail.

You're obvoiusly competent with setup and your FAI setup experience will serve you well as must FAI guys I know are very precise and meticulous. Heavy paddles, soft dampeners, and conservative cyclic throws make for a smooth flying, scale looking flight regime.

Building the Trex on glass and making sure the main shaft drops through the bearings when everything is tight, dial indicating the fan/clutch to minimize vibrations, in short, things you very likely already do.

You're obvously concerned about harmonics. Pay attention to the mounting directions and make sure the fuselage is properly braced, make sure the blades arent too tight in the grips so they can find center promptly when powering up and get ready to power swiftly through the spool up resonance that most any machine has.

Thank you for your reply. I found the information you provided both informative and instructional. The bottom line is to pay attention to detail and the flying will take care of itself. I just might take the plunge. Thanks again.

No problem.

I can promise you this, if you're at an event and after an hour the same old 3D flying is making everyone catotonic, if you drag out a good looking scale helicopter and fly it in a scale manner, everyone will be up paying attention, the cameras will be clicking, and the video will be rollling.

Some things will drive you crazy though. It takes 20 seconds to pull the canopy and replace a worn glow plug on a Trex. It will take 20 minutes to pull the front windscreen and change the plug on a Trex600 covered by a scale fuselage. I just find it worth the extra tinkering.

 Hope you guys don't mind if I chime in here, I certainly agree with Barracuda and by the way, nice nice looking birds there cuda. My first Heli was a Concept 30 with the supertiger engine many years ago until Xcell provided their 50 size nitro. I have flown both nitro and electric and really like both but for my scale stuff I always go electric.

The two reasons I choose electric for scale flying is the ease of setting a constant speed rotor system and the really cool harmonic sound you get out of the body. Gives a turbine sound and makes more decibel room for the rotor system to chime in with the blade sounds at a hover. I also love being able to hear the tail rotor on turns that I miss flying nitro but hey, thats why we have chocolate and vanilla right?  All of my builds are on the Trex and the FHH 600 airframes.

I use a 8S setup so I get 7.5 minutes of flight time. I fly for RC Aerodyne and provide build and flight videos and just happen to have a Hughes 500D I completed a few months ago. Thought you might enjoy a little peek at the 500.

[youtube]http://www.youtube.com/watch?v=Jlm4oY1aMog[/youtube]