yes, and like i said im not sure whether it increases or decreases stability on these quads. it really blew my mine when somebody suggested lower cg dont help a heli. i kept thinking "pendulum effect" but thats only true for planes. there were two thread that went on for hundreds of posts arguing the point. one was in (i think) sr70 fellows jar (just aint right) megathread where one aerodynamic expert was piled on by 20 guys who refused to believe. another thread was about the ball type frames used in some japanese copters where it was also eventually explained convincingly but took some effort. finally most of us came to believe lower cg did not make it better. i still have to think twice about it though.

I've just tested my new v929 8 plug replacement board from banggood.

There's no more wobbling anymore even if I use small motor diameters (115mm) !!!!
I've plugged UDI motorarms complete into the v929 frame as you can see.
The board is more stable than the v929 4 plug board, but it has slower yaw.
Speed is between the v929 4-plug and v939 yaw.
You can fly very agressive turns with this stability. Full Yaw stick doesn't let the quad crash like with the old v929 or the v939.

It does have same less lifting punch like the old v929 and I need more throttle to lift which seems to lead to shorter flighttime.

For Midelic: Weight is 28g / m2m diameter : 115mm

Ingredients:

* v929 8 plug replacement board
* v929 frame
* UDI 816 clockwise & anticlockwise motorarms
* MJX X100 props

@mystman
Look for my mod of V929 main frame and cut off 1.6 grams.
with UDI motors every gram counts.

Sorry!Job conditioning.Now you have it....at least on this page.

Originally Posted by midelic

@mystman
Look for my mod of V929 main frame and cut off 1.6 grams.
with UDI motors every gram counts.

I KNOW ! It's just a try, if it works. You always must have the last words

Do you want to tease me ?

(After this try, I put the board back on a already weight reduced frame with 150mm m2m diameter)

recently somebody asked me "what was the ten cent tach mentioned in diy quad thread?". i thought people read EVERY SINGLE post on rc groups. lol! anyway here is a link to that i started some time ago which is somewhat related to the current thread:

http://www.rcgroups.com/forums/showt...9#post23197098

below are a couple photos that might be of interest in case you missed them. first shows scope trace of tach signal from a "weak" aliexpress motor with udi props on 4v. the second photo shows an s107 motor under same conditions. you can see the pulses are farther apart in the first one indicating lower rpm. looks like 1.2ms per blade for 23k rpm vs 1.9ms at 16k rpm:





ps stop teasing your brother or I WILL TURN THIS CAR AROUND RIGHT NOW!

Originally Posted by dave1993

ps stop teasing your brother or I WILL TURN THIS CAR AROUND RIGHT NOW!

We're both fine again, DAD

ok then. next stop... disneyland. ooh la la!

btw those are really fine constructions. i got couple meters of the square cf and considered canibalizing my v929 frame. but it does such an excellent job of lifting, far more than any of the direct drive quads, so i like to keep it in stock condition. maybe time to consider picking up a body from bangood. but i got half dozen goodies on the way now so probably will wait a bit. tgif.

Anyone got their Syma-X1 control board? Recommended?

its now over a month since ive placed my order for one. im getting worried. funny thing is they get to the usa from china in 2-3 days. then sit in some warehouse right here in ny while homeland security checks them for fissionable material.

thanks a bunch george bush....

I got mine few days ago but unfortunately I'm not at home to test it.I'll test it in January.

Gents,
My Syma X1 fcb's arrived a couple of days ago after about the typical BG month of so wait. The only thing I've had time to check so far is to confirm they will bind with a FlySky protocol.
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index

Hi All, I have finally received 2 v939 boards. After connecting all of the wires according to the drawing below, it looks like the CW motors are spinning much slower than the CCW and after raising the throttle to max once would take more than half throttle to start spinning again.
If I take one motor (doesn’t matter which) and connect it to connector 1 in the pic – it spins ok but when I connect the same motor to connector 2 it goes slow.
This happens on both my v939 boards. Has anybody seen this behavior?

My guess here is that you trim is set way off to the right, give it some left rudder trim.

I've still only had one DIY quad in the air so far so that all I can offer I'm afraid.

Originally Posted by gilcd85

Hi All, I have finally received 2 v939 boards. After connecting all of the wires according to the drawing below, it looks like the CW motors are spinning much slower than the CCW and after raising the throttle to max once would take more than half throttle to start spinning again.
If I take one motor (doesn’t matter which) and connect it to connector 1 in the pic – it spins ok but when I connect the same motor to connector 2 it goes slow.
This happens on both my v939 boards. Has anybody seen this behavior?

Does it fly? I notice often motors don't spin until I actually put it in the air.

Thanks all! Next time just tell me to switch RUD and AIL
Works perfectly now - what a great little quad!

My build:
- red/blue aliexpress 7mm motors
- v939
- bamboo frame (m2m 135mm) with PU enamel impregnated motor mounts
- LB props
- 260mah battery.

Overall weight including battery: 30g