XAircraft How do you balance rotor output on XA 650v?

A

Andy

Member
I've got the kit assembled and carried out the basic props off/props on test before giving it a little more juice at which point it very rapidly tilted to the right and took out a prop.

Notched out a couple of 2x3's to allow a couple of inches of vertical movement (over cautious novice or what) when sitting over the LG skids. Retested with new prop and I can clearly see that the front LH motor (2) is lifting quite aggressively.

Removed props and hooked up Laptop and calibrated RC in Xaircraft Center. Sure enough, pitch, roll and yaw were way off centre.

Refitted props and retested - same bias towards front Lh Motor (2).

What's my next step to introduce some balance so I can get this thing airborne?

What flight mode is best for take off/landing cruise or hover?
 

DucktileMedia

DucktileMedia

Drone Enthusiast
Make sure you calibrate the AHRS and the radio to the FC very accurately. After that, assuming everything is spinning correctly, you should be fine just flying it. Ground effect can be deceiving when you are just trying to see what happens a few inches off the ground. In a way you are better making a leap of faith on a nice grassy field. Get it off the ground a few feet quickly as it will fly much smoother and have some room to correct itself.
 

C

CMonteiro

Member
Test your XA the way I tested mine. You can identify tendency to tilt without ruining the copter and learn things about its behaviour. Have a look at my post "monitoring attitude".
Good flights
C. Monteiro
 

A

Andy

Member
That's a great setup for 'no risk' testing CMonteiro. Thanks for providing us with the video. Love your counterbalance weight!

I'll try exactly the same setup. I've got a couple of ball heads knocking around. At what height does the ground effect that WindHorny mentions cease to be an issue for a quad this size?

Could someone tell me the preferred launch mode: cruise or hover?
 

C

CMonteiro

Member
The answer to cruise / hover mode is in the test setup I showed you.
Try this: put the copter attatched to the tripod. use cruise mode and switch on. give throtle. What happens? the copter keeps inclined on one side. Motors turn, but copter keeps exactly it's inicial position. This means that in cruise mode, you have to use the roll stick to tilt the copter to the the closest to horisontal possible. This means that the tilting is controled by yourself.
Now repeat the experiment but in hover mode. What happens? As soon as you give throttle, the copter assumes automaticaly the horisontal position. This means that in hover mode, the AHRS board is controlling the horizontal position for you. That's why you have to be carefull when calibrating the AHRS keeping it precisely levelled at the moment of calibration, so that it memorises that position as horizontal.
Conclusion... you must launch the copter in HOVER MODE for a rise as close to the vertical as possible and avoiding sudden tilts.
Hope this helps
C.Monteiro
 


A

Andy

Member
Just couldn't wait to test using the tripod method so went the Windhorny route. Placed it in the middle of the lawn and gave it sufficient throttle to leave the ground. Took off sideways and reached about a metre and a half, rapidly travelling on the axis of the rear right hand motor arm (M4) at which point I had to ditch into a fern. Despite the nice soft landing, it still broke another rotor.

When I assembled the quad, I noticed that one of the motors had a much more well defined "notchiness" when you turned the motor, more like a poor bearing than a magentic feeling, and it turns out that this motor is on the corner that lacks lift.

I swapped it with the opposite clockwise motor and the lack of lift then shifts to the front left.

Seems like the motor either has a dodgy bearing or some other issue that prevents it from delivering the same power as the other 3 motors.

I guess this is a warranty issue.
 

DucktileMedia

DucktileMedia

Drone Enthusiast
If you did that test as you say i cant imagine they will have any issues replacing that for you. I too wondered if there were consequences for this variation in motor "feel" when hand turning them. I was assured that they even out over time. But I dont know as i have never owned high end motors like AXI's. But the simple fact that you had the same reaction where that one motor is says alot. The only other thing I can think of would be that the rotation was off but it sounds like you have that correctly configured.
 


A

Andy

Member
New motor arrived today, and despite feeling even more notchy than the suspect one, we had a vertical(ish) lift off. So it does appear that the suspect motor was performing below par.

As total novices to RC flight my son and I are both struggling to master the controls. Broken props and landing gear are proving obstacles to making any real progress! Props I expect to break, but I didn't expect to see the clips come off 3 of the landing gear legs.

Will adding some weight to a second battery mount improve stability and make it a little easier to fly?

I'm assuming the quad is set to X flight as standard. Is this correct, and how do you determine what it's set to and and how do you change it? I cannot see any reference to it in the manual!
 

C

CMonteiro

Member
Look at the assembling instructions. If you assembled according to the instructions, from the beginning to page 13, you made it plus style.
I f you assembled it according to the instructions, from page 13 to the end, then you are in cross style. Just look at the top titles in each page.

www.cnchelicopter.com/05102010/09302010_x650.pdf

Hope this helps
CMonteiro
 

A

Andy

Member
The manual for the X650 value has no reference (as far as I can see) to plus or cross configuration. All the illustrations are cross config, perhaps because they are pitching this as an AP/FPV quad.

AP is my intended use, but I need to get a massive amount of practice in before I feel confident enough to hang a camera off it! But the 2 axis mount is ready waiting.

I'm now actually enjoying flying it since I replaced the dodgy motor and recalibrated the AHRS. When I set the quad on a perfectly level surface, I checked the underside of the motor mounts and found that they weren't level ie. not parallel to the landing gear skids. I levelled the quad using the underside of the motor mounts as the datum points and as I recall roll and yaw were out by about 0.2 and 0.5 respectively. Recalibrated and in hover mode it lifts vertically and maintains its position, whilst prior to this it would wander backwards and over to the right.

My landing technique needs some work as I've now managed to get through my spare set of props. Unfortunately, no one in the UK appears to have stock!

Are there any alternative props I could use with the 650v? Perhaps some that are more flexible/durable. The stock ones seem rather brittle - but then, as a novice, I have nothing to compare them with!

Will adding weight to the quad make it easier for a noob to master the controls?

How can I make the throttle more progressive?
 


X

Xaircraft USA

Member
Andy said:
The manual for the X650 value has no reference (as far as I can see) to plus or cross configuration. All the illustrations are cross config, perhaps because they are pitching this as an AP/FPV quad.

AP is my intended use, but I need to get a massive amount of practice in before I feel confident enough to hang a camera off it! But the 2 axis mount is ready waiting.

I'm now actually enjoying flying it since I replaced the dodgy motor and recalibrated the AHRS. When I set the quad on a perfectly level surface, I checked the underside of the motor mounts and found that they weren't level ie. not parallel to the landing gear skids. I levelled the quad using the underside of the motor mounts as the datum points and as I recall roll and yaw were out by about 0.2 and 0.5 respectively. Recalibrated and in hover mode it lifts vertically and maintains its position, whilst prior to this it would wander backwards and over to the right.

My landing technique needs some work as I've now managed to get through my spare set of props. Unfortunately, no one in the UK appears to have stock!

Are there any alternative props I could use with the 650v? Perhaps some that are more flexible/durable. The stock ones seem rather brittle - but then, as a novice, I have nothing to compare them with!

Will adding weight to the quad make it easier for a noob to master the controls?

How can I make the throttle more progressive?
Click to expand...

Propeller ISSUE?? : Factory has NOW completed safety, durability and stress testing on NEW Props, this means Spare propellers will be plentiful in the NEXT couple weeks "Worldwide" !
 


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