Please help, My quadrocopter takes off at the minimum rpm

[CsabyTech]

Hello people! I'm building my first quad, and everything seems to be in order, but when I turn on my quad, I arm it and it starts taking off, even thou I only have the transmitter at the minimal thrust level possible. My escs have been calibrated multiple times now, I dont think that's causing the issue. I would like to know if I can change the minimum rpm off my motors from the multiwii code in aurdino. Please help me!

[subaru4wd]

in config.h

find the line: MINTHROTTLE

reduce the number and it should take care of your problem.

[CsabyTech]

That is the first thing I tried but that didn't change anything in the quads rpm. I also reseted the eeprom, changed the mincommand, changed it back, calibrated my escs. None of these helped. Is there a way to tell the motors from the program to start at a lower RPM?

[waltr]

What are the throttle stick end points value as see MW config.exe????

Did you calibrate the ESCs from the RX throttle channel or from the MW #define ESC_CALIB_CANNOT_FLY??
What values doid you have MINTHROTTLE set to?

[CsabyTech]

I've tried both ways of calibrating, the center is 1500 the max is 2000 the min is 1100. I've also changed those multiple times to other values, with no difference in the rpm. I've had the minthrottle at 1100, 1000,900,600. That last one didnt even work, but all the others showed no difference in the rpm either.

[waltr]

Back to basics:
Plug the motor ESC directly into the receiver throttle channel. No FC used.
Does the motor increase RPM smoothly from almost zero thrust up to max thrust when only controlled by the TX/RX throttle channel?
If not then there may be an ESC issue. If so then an FC/MW issue.

[indur]

Your quad is too lightweight, try to add some weight.

[CsabyTech]

If I plug in the esc to the recievers thrust channel (ch3) and then use my transmitter then everything works fine, it starts out slow and smooth and slowly increases the speed as it should be. When I arm it with the FC in the circle then it just starts spinning in insane speed. I don't think addig weight is a solution, as that is not very efficient, and it is only a matter of programming. Think about it, just because you have a 600 HP car, doesn't mean you cant go slowly.

[CsabyTech]

also, no offense to anyone, but do any of you actually know how to program this cind of micro controller? That would be very helpful, because I think this whole thing could be fixed with one line of program, unfortunetly I do not know hot to do that.

[scrat]

also, no offense to anyone, but do any of you actually know how to program this cind of micro controller? That would be very helpful, because I think this whole thing could be fixed with one line of program, unfortunetly I do not know hot to do that.

What FC you're using and what version of MultiWii did you flash on FC? Then what kind of Tx you have, motors, props? How much is quad weigh?

[CsabyTech]

FC: MultiWii PRO Flight Controller w/MTK GPS Module -- http://www.hobbyking.com/hobbyking/s...588&aff=588847

Frame: Turnigy Talon Carbon Fiber Quadcopter Frame-- http://www.hobbyking.com/hobbyking/s...ter_Frame.html

Motor: Turnigy D2836/8 1100KV Brushless Outrunner Motor--- http://www.hobbyking.com/hobbyking/s...dProduct=18969

ESC:HobbyKing 30A BlueSeries Brushless Speed Controller--- http://www.hobbyking.com/hobbyking/s...ontroller.html

battery: Turnigy nano-tech 4000mah 4S 35~70C Lipo Pack --- http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

props: 10x4.5 SF Props Black CW (2pc) CCW (2pc)--- (no link nassesery I belive)

transmitter and reciever: Turnigy 9X 9Ch Transmitter w/ Module & 8ch Receiver (Mode 1) (v2 Firmware)-- http://www.hobbyking.com/hobbyking/stor ... ware_.html
I know the props are too big, but I really think there should be a way to just make the motors spin slower on startup. It is only controlled by a program that we can change as we like. The weight currently is about: 800 g on the quad without the battery, with the battery: ~1200 g

[waltr]

Over powered is not the problem, the motors should run at an idle speed which does not provide enough thrust to lift the quad.

A though I have is do a new download of MW 2.3. Save to a new folder, un-zip and change ONLY the copter type (QUADX) and the FC board type.
Flash this and give it a try.

Another thought is that the FC board you have has a bad XTAL that is running too slow. This would cause the width of the pulses to the ESCs to be too wide which is higher throttle. Do you know anyone with an O'scope that can measure to XTAL frequency and the output pulse width to the ESCs?
Or get another MW FC board to try.

[CsabyTech]

I tried it with a new 2.3, but it didn't even arm. Also I can't afford a new fc, so I have to deal with this one. I don't think it's a faulty fc thou, I think it just needs the correct code, because it is just a micro controller, it only does what you tell it to do.

[CsabyTech]

Somhow this problem has been solved, I don't know what I did, but now it doesn't take off. But there is a new problem, the quad just flips over if I give it some throttle. It is still the least I can give next to none, so I would still like to dicrease my minthrottle, but I'm intrested if one of the motors I have shows less resistance to spinning by hand than the other three has anything to do with this. or if this is a problem. Thank you!