help improve forward/reverse speeds?

[victory7]

Heyall,

any ideas to improve forward speed (and reverse).

have tried the following.
-cat killer prop trim (good improvement)
-slid tail motor to front or rear more (no improvement either way)
-use scotch tape and created larger tail rotor blade area (i think it would push more air but increase drag slows motor, net effect zero)
-move CG forward (ideally without adding weight) - this increases forward performance, and backward becomes more like a STOP. am currently accepting this tradeoff.


*****

would like to try:

if no improved motor, maybe i'll order a few stock replacements and hope to get one which is slightly better (due to manf variances).

can i improve the tail rotor or find a new one to modify?

can i increase the voltage to the tail somehow?


Thanx for any input!
happy flying (and crashing, repairing, modding)

[Endeavour]

Hi

Same problem - BR is great but can't make it go forwards or backwards at all - tho tail rotor is spinning OK.
What is "cat killer tail rotor"?
Your message was useful - I was going to try moving the position of the tail rotor forwards/backwards, etc, but seems it doesn't help much.
I'd be interested in anything else you've found which make an improvement ....

Cheers

[petter]

Hi,
Moving the tail motor does not help.
"Cat killer mod" is when you remove (cut off) the ring around the tail propeller. This allows the small propeller to spin a lot faster and gives better control forwards and backwards. The max speed is intentionally kept low to not loose stability.

Petter

[Tres Wright]

Victory, what kind of forward speed are you getting now? The BR cannot fly faster than walking speed. Any more than that and the rotors start clashing (usually results in a crash).

Endeavour, as Petter said the "cat killer" mod is cutting the small ring off the back prop. The rear motor is only used for forward and backward flight, so altering the prop only affects that. Removing the ring reduces the weight and lets the prop spin faster. My BR would only fly forward at a very slow walk, but once I did the cat killer it improved forward and backward flight significantly. Removing the body and doing the cat killer mod turn the BR from a nice little floater into a very responsive heli!

By the way, the title "cat killer" is tongue-in-cheek. The prop spins far too slowly to hurt anything, even without the protective ring.

[victory7]

ok....

i replaced the tail motor with the smallest micro car motor i could find, which is very heavy by comparison. amazing power now, but the blade clash thing happens.

i spaced my top blade about 2mm higher than the top post, so no clashing, but it goes fast forward then out of control and pendulums.

then i thought maybe if the floppy blades didn't flop quite as much or were slower to respond, so i put light duty open cell foam chunks between the heads at 8 places. (tiny tiny pieces). now the blades are slower to respond and it goes out of control much faster. haw haw.

my asian girlfriend says "you are not IMproving this hericoptor, you are DEproving it".

ok, so back to stock with the rotor heads.

the tail motor is too heavy. i put a cf rod out front an inch past the rotors with a tiny weight to compensate, but having weights way outboard rather than centralized creates this penduluming instability.

so now i'm back to the light tail motor and i'm going to cut my own rear prop. i notice that airplane props are not the same shape as this flower petal thing, so maybe it's not a good design.

but maybe due to the super stable design, this thing just can't fly quickly forward???

can i change the rotor heads to trade off stability for faster forward speed and agility???

good luck to y'all

[Freakazoid]

Whats the point of going 50mph indoor? :D Well, maybe in large halls or something, but I woulnd mess up a bedroom flyer so it can do that. :p

I guess you could aim the prop backwards so it acts more like a thruster prop then a tilt operator, so it ll start flying like some weirdt gyrocopter or something. :D But dont shoot me if it homes in on the nearest wall. :p

[Tres Wright]

Your GF is right, you're just screwing it up :p As I said in post #4, you cannot expect more than average walking speed for forward flight.

[Josh_high_flyer]

ha de ha

[Steve Shepard]

If you guys would do a search on the USPTO.gov. site, for the name Muren, Petter as the inventor, you will find a 17-page document describing the BR's teeter-totter mechanism, how and why it works, etc.

For all of you that are too lazy to wander around in the document zone, and are shy of knowledge of things that smack of the word "physics", here's the bottom line---The very physical, aerodynamic forces that make the BR so stable in the hover mode, are just exactly the opposite of what it takes to make the chopper want to travel in ANY direction, except down. In other words, don't waste your time trying to make the BR go any faster than it does with the above-described mods. It just ain't gonna work ! The bird was intended to hover, not fly like a bat out of Hades !