I am looking at converting my 2-bladed rotor head to a 4-bladed setup.

My candidate for conversion is currently a standard, typical, 2-bladed setup with a typical HH / Rate gyro. I fly it pretty well and I'm not a 3D'er; I just cruise around

The 4-bladed kit includes all the necessary mechanical parts and pieces for the conversion - but includes no additional stability electronics.

I've read the threads and articles about fly-barless (FBL) conversions - both with & without the electronic stability systems. Most of the conversions revolve around removing the fly-bar from a 2-bladed system.

Assuming a well engineered 4-bladed rotor system, and decent (but not stellar) flying skills: How hard is flying a 4-bladed system without an electronic FBL stability system?

ticedoff8 (Yahoo IM)
Shogun V2 - daily flier (retiring soon)
3 - GMP "King Cobra" .61 w/ 620mm blades - 25 yo heli.
AMA 171886

I did a five blade on a TREX 450 SE. Both with and without a stabilizer. I had a borrowed GAUI stabilizer. With it was much worse, you are constantly fighting the stabilizer to do anything and there are times it acts like it has a mind of its own.

You really have to dumb the heli down, pitch curve was -2 to ~+6. Swash mix for Ail was 8-10% and Ele was about 10-12%. It was a challenge and fun to fly when it flew right but that was only 30% of the time. The multi-blade wants to be run at an RPM around 2000 at at that speed with the added weight and torque of the added blade (torque might not be the correct word here) the tail would not hold very well, even with bigger paddles. Also running it rate mode was better than HH mode on the gyro (401). There is a thread on RR with a lot of information but I do not have the link handy. I will post it later

Check this thread:
http://rc.runryder.com/helicopter/t518212p1/

Nobody realizes that some people expend tremendous energy merely to be normal. - Albert Camus

My candidate heli is my 1986 GMP Cobra - it can muster only +8 / -8 degrees today and it runs at 1800 rpm.

I may have an issue with tail rotor - it is marginal now.

I was thinking of using shorter blades - keep the "swept area" of the rotor disk about the same. Instead of 2 600mm blades (600mm x 55mm chord x 2 = 66,000 sq mm), I could run 4 425mm blades (425mm x 25mm chord x 4 = 68,000 sq mm). Not sure if that works "aerodynamically".

ticedoff8 (Yahoo IM)
Shogun V2 - daily flier (retiring soon)
3 - GMP "King Cobra" .61 w/ 620mm blades - 25 yo heli.
AMA 171886

What have you got to lose trying it, except parts. I was running 315 woodies. I tried heavy carbons and while more stable it would load up the head on turns and the tail would go out. Hovering in one place though was a piece of cake. Need bigger tail blades or a way to speed it up if it is marginal now it will only get worse.

When spooling up it will be very unstable. Get the RPMs up quickly (throttle curve) and off the ground ASAP.

Nobody realizes that some people expend tremendous energy merely to be normal. - Albert Camus