Motors speed

[mark36ph]

Hi. I am trying to set up my first quadcopter, but when I arm the motors, they start straight away with no throttle.
Is this normal? Or should they all be stopped until I give them some throttle?

[mark36ph]

I have tried running the motors up, and they are a jumping all over the place.
When plugged into my comp on the GUI, it shows the motors not all equal.
I am using this ESC .. http://www.banggood.com/SKY-30A-4-In-1-Brushless-ESC-2-6S-For-Quadcopter-Multicopter-p-90259.html
Can anyone tell me if I would need to change something on the multiwii board.
I'm new to all this quadcopter stuff!

[victorhugommf]

I have tried running the motors up, and they are a jumping all over the place.
When plugged into my comp on the GUI, it shows the motors not all equal.
I am using this ESC .. http://www.banggood.com/SKY-30A-4-In-1-Brushless-ESC-2-6S-For-Quadcopter-Multicopter-p-90259.html
Can anyone tell me if I would need to change something on the multiwii board.
I'm new to all this quadcopter stuff!

There's a lot of people asking the same question, including myself. You should read the other topics:

viewtopic.php?f=18&t=5356

viewtopic.php?f=18&t=5337

[mark36ph]

I have read loads of posts regarding this, tried alsorts, so resorted to posting my problem.

[brewski]

I have read loads of posts regarding this, tried alsorts, so resorted to posting my problem.

Multiwii Beginners Guide To Basic First Flight

First & most importantly calibrate ESCs min/max points using direct connection to RX. There are other methods but this is easiest. Ensure motors are turning in correct direction with correct props for rotation & not mounted upside down
Next connect to PC running WinGUI or MW Config. Calibrate ACC with FC level & not moving & Mag by moving FC thru all axis in 30seconds. Check graphs & readouts to confirm accurate calibration.
Set your transmitter end points. Using the WinGUI or MW Config open the RC CONTROLS tab look at the live tx data, then use your tx sub trim to set the throttle low at 1000 and all the mid sticks at 1500. Then using the tx end points adjustment make the throttle high point 2000, yaw left 1000, yaw right 2000, pitch dwn 1000, pitch up 2000, roll left 1000, roll right 2000. You may have to readjust for 1500 centre. Ensure that all readings move in direction of TX sticks & switches. Reverse on TX if not.

All flight modes disabled apart from Acro and mag. With all sensors calibrated correctly and mag declination set, using the default PIDs and in a nice open space ARM with throttle low and yaw right. Increase throttle slightly then decrease throttle fully and the motors need to be still rotating, if they stop then your min throttle setting needs increasing slightly.
Try again and if the motor idle speed is stable increase throttle quickly to approx. 50% and hover. If it drifts use TX trims to prevent it.
Next enable Horizon mode. If quad drifts backwards just land disarm with throttle low yaw left. Then trim ACC with throttle high and hold your pitch roll stick in the opposite direction to the drift so in this case forward hold there until the light on your board flashes 5 times then centre stick, throttle low and rearm and try again. Repeat as required. DO NOT touch TX TRIMS to counter drift as you have already set this in Acro. Remember If you calibrate ACC again using GUI (or ACC stick Cal) you will lose these ACC adjustments & have to do it again.

If motors don't have enough power to climb then vibration is probably your issue unless bad or low capacity Lipo. Buy good composite or CF props with quality adapters, balance everything & then retry. You may still need to set Gyro filter to 42Hz in Config.h if it won't climb or flies erratically.

You should now have a nice stable quad (or at least as you can get without PID adjustment) & can then move on to GPS modes for which you will find plenty of info on in this Forum. I hope this will help you and maybe others to get flying. It's a big learning curve but definitely worth it!

PS. Don't expect motor speed graphs to rise in sync & hold speed in GUI when quad not flying. This is normal & part of PID control

[mike105105]

Nice write up, I would say it should be a sticky at the top of this section...but we know no one would bother to read it lol.

Just one thing, the part where you were describing the min throttle settings. If motor_stop is enabled in config.h they will always stop at min throttle.


Mike

[brewski]

Hi Mike,

All the MW experts agree that motor_stop should not be used. The reasons are-
1. Safety- instant recognition that quad is armed. Without this just bumping throttle could result in uncontrolled takeoff
2. Motors are spooled up & synced so when throttle increased quad will lift off evenly

APM & Megapirates also have motors spinning when armed for same reasons.

Thanks for the praise. I just decided to write down the things I learned the hard way getting into this hobby & building/flying my first quad.

[mark36ph]

Hi Mike,

All the MW experts agree that motor_stop should not be used. The reasons are-
1. Safety- instant recognition that quad is armed. Without this just bumping throttle could result in uncontrolled takeoff
2. Motors are spooled up & synced so when throttle increased quad will lift off evenly

APM & Megapirates also have motors spinning when armed for same reasons.

Thanks for the praise. I just decided to write down the things I learned the hard way getting into this hobby & building/flying my first quad.

I didn't know the motors are meant to be spinning when armed. I thought there was something wrong with my config

[sismeiro]

All the MW experts agree that motor_stop should not be used. The reasons are-
1. Safety- instant recognition that quad is armed. Without this just bumping throttle could result in uncontrolled takeoff
2. Motors are spooled up & synced so when throttle increased quad will lift off evenly

Hi,

I'm not an expert but I think it's more safe when you start flying that you have the possibility to rapidly cut the motors, sometimes we won't disarm fast enough. I always use MOTOR_STOP and I don't have problems lifting evenly, the problem is in the frame, the motors aren't really straight.

Regards,
Luis Sismeiro

[mark36ph]

Is it safe to arm / disarm the motors using a switch on aux1?

[mike105105]

Not recommended, too easy to accidentally enable or disable the craft.

brewski, I wasn't advising it be enabled or disabled, just saying that if someone has it enabled and they keep trying to adjust minthrottle they aren't going to get anywhere. There are some boards that come with it enabled in the sketch and if they don't know to check for it they will be very confused with motor behavior.


Mike

[brewski]

Hi Mike,

As you say Motor_stop is disabled by default in all the MW firmware I have downloaded & has to be enabled deliberately. It can certainly make setting Min Throttle setting impossible & so should not be used by new users. Good point that some boards come loaded with (usually) older versions of MW, 2.2 in my case & could have Motor-stop uncommented. I didn't even look just loaded 2.3 on my first 328 based board & then NaviB7 on replacement Crius AIOP V2.

Mark36ph,
If you set TX limits & midpoint as outlined you will not have to use Aux switch to arm, as stick arming/disarming works every time provided you have enabled it in Config.h

[mike105105]

The readytofly.com boards come with 2.3 and motor_stop enabled. It takes little effort to put a warning in that guide to check that it is disabled, that is all I'm suggesting.


Mike

[brewski]

Yeah new builders need to be aware of this. I will add it plus advise new builders to ensure that they download latest firmware & corresponding WinGUI. I still don't know why official Multiwii page doesn't have the latest releases that are only available from EOSBandi website.
If it could be made a 'Sticky' & as you say Noobies would actually read it, then it would take some pressure off the experts so they can concentrate on bringing out MW V2.4..can't wait as I bet it will put Multiwii at forefront of OpenSource flight control.