FwStingray

I am currently flying a Concept 30 SX and just recently replaced my old OS 32 with a Thunder Tiger 39. Anyhow, I am only able to get a maximum positive and negative pitch of 10 degrees out of my main rotors and am forced to keep the throttle well below 75% at full collective in order to keep the rotor speed below 2000 rpm and it just doesn’t seem to have very much spunk . I guess, what I am looking for is a way to take advantage of my new motor (without getting a new aircraft) and give my concept a little more vertical authority.

My first choice would be to get a longer boom and use some 550 blades in place of the stock 500s. My question here is will the extra 50mm make much of a difference. Also, does anyone know where a person could get a longer boom that would fit the old concept line? I don’t think I would have any problem with building a new drive shaft or tail rotor control rod.

My other thought would be some sort of after market rotor grip that has the linkage ball closer to the pivot point allowing for more pitch in the main blades.

Any help would be appreciated

Thanks
T.J.

davidj

good luck on finding either solution. I put a longer boom on my nexus and paid the price. The flapping head design allows the blades to get close to the boom. When you lengthen the blades they get closer. Your best bet is get a caliber 30 put the tt39 in it and you will never be sorry.

Balsabasher

My Feedback: (4)

As you found out, this engine and a SX is not a good match due to the 500mm blades. You must convert to a SR or SR-X spec which means taller mast, longer linkages, stronger head, and longer boom and tail drive. You are talking in the range of $150. It would still limit you to 530mm blades (I sure someone will tell you 550s. User beware!). You are then half way or more towards a price of a new heli with 550 blades. This is your better choice.

Steve Campbell2

These guys are right, T.J. The Concept is a marvelous little ship. I still fly one, and it is a favorite. But you need to keep in mind that it was designed to be an ideal beginner's machine. The wild 3D antics so popular today were not even a distant dream when Taya designed the Concept.

Going past 530mm blades will definitely be flirting with disaster. The DDF head on the Concept/Nexus Deluxe is the most prone to boomstrikes of any model helicopter I know of. It is one of the best hovering machines out there, but trying to stretch it beyond it's design parameters is asking for trouble.

I know this is not what you want to hear, but truth is truth. Your TT 39 is far too much engine for the small Concept, as you discovered. The VR version is a bit beefier and better suited to handle that power, but is still limited to 530mm blades.

To answer your original question, yes, more blade disc area means better performance; providing it is turning fast enough. The larger 30s that use 550mm blades do fly with more authority than the little-disc Concept.

I still have a Concept mainly for nostalgic reasons. Some critical parts are getting difficult to locate. That's not a big issue for me, since I just don't crash much these days. But I am always on the look-out, and in fact just bought a slightly used stripped SR. I've got quite a stash of parts built up. But I mainly fly an X-Cell 60; the Concept is for infrequent interludes.

The point is that a Concept requires some effort and planning to keep one going. Unless you are firmly attached to yours, I think you would be better off with a current-production machine of some sort that can better handle the power of your new engine. The money you spend on "upgrading" your Concept would be better if applied toward a new ship that you don't have to worry about modifying, finding parts, etc.

Steve

FwStingray

Thanks for all the quick responses. Looks like I will hold off on the upgrades and continue saving for a Caliber. I picked up the new engine because my old OS32 was acting very finicky after 10 years of storage and the new tt would be great for the Caliber when I have the resources to purchase one.

I do still enjoy flying the Concept and it is very capable of loops, rolls, inverted flight and pinwheels but after seeing what people are doing with helicopters now days it’s hard to be satisfied with the lack of power.

Thanks again for the help
T.J.

Balsabasher

My Feedback: (4)

A parting thought T.J., a Concept VR is a 3Ding fool and you can still get parts for it. It came as a 32 and a 46 but it is still limited to 530mm blades. If you can get a used one cheap, I think it would like your TT 39 engine. A good used Concept SR-X would be a second choice. Both are 3D capable machines, just do not practice autos with them. I think the Caliber will take their place after it is upgraded in the future.