CX WKM Build

[BorisS]

looks good seb !

Im actually getting not to good results having the GPS module mounted directly onto the CX hood so i am going to make a part an put it to the back of the bird.

View attachment 1681

 

[BorisS]

I dont know what going on !

I got a new PMU hooked it up again have the GPS running over the canbus from the PMU. I am constantly getting green flashes which indicated the the connunication is lost from the IMU but only at a certain height and that 2 instead of 1 meter of the ground. Very strange. Loosing it a little with this small bird !

Boris

 

[BorisS]

I had a similar problem on my initial flight. I disabled the battery monitor. Problem solved.

Tahoe can ou elaborate on your problem that you had !

 

[Sebas600]

But is it not the IMU that's broke then?
Do you have multiple Wkm's? If so maybe swop to try?

Good luck!

 

[BorisS]

japp i am going to try that. Its the damm canbus its cool and everything but if one components has an issue it also effects the other. So it could be anything. I had that once with the LED. I extended the LED cable and didn't do it clean and the whole communication between the devices was disturbed.

 

[Sebas600]

As long as it's only one giving the problem it should be easy. maybe dji should have a application in the software to find these problems...

 

[Tahoe Ed]

Tahoe can ou elaborate on your problem that you had !

Sure, about 2 minutes into the flight, I started to loose power and the Quad dropped to the ground. Fortunately it was in a flower bed and no damage. I normally fly with a transmitter timer so I was not concerned since I had two 4S 4000mAh packs on board. Set it back down on the ground and took off again. It was then that I noticed the low battery alarm from the LED. I set it down and took it back in the house to check the batteries. I think that I put back about 1/3 of the capacity. That is when I turned the Lipo Alarm off.

 

[BorisS]

Thanks Tahoe Ed, i seem to have more serious issues thought with my Cx build, i constantly loose the IMU signal even after having changed the PMU, which was borken but i also dont know what happened. I found the time and put the same WKM unit back into my HEXA were i am not having problems with the IMU communication. So i has to be some components in the CX build that give the IMU a hard time.

 

[*****]

the CX is a bit small , where did you route the motor cables?

twist them? on my CX i have put the Herkules all the way aft , i routed the cables twisted on the underside of the frame towards the herkules.
as with MK the gyro,s are sensitive to any power leads running under them.
the herkules in the aft also has good cooling and easy access to programming and batt leads.

 

[BorisS]

japp i have the ESCs and the Abusemark dist board right under the FC mounting plate, thus the IMU right over them. I will have to change that i guess its to close this time or work with some shielding.

Thanks !

Boris

And its noticeable that the IMU green flashes only happen when i give more throttle so its obvious that its linked to the power leads etc.

 

[BorisS]

Just got myself the Tilt mount for the CX, Anybody any experiences yet. Unbelievable how much nothing can cost

Maybe should have asked before i bought it

View attachment 2137View attachment 2138

 

[krleas]

Indeed Boris
I dont see new motors?

 

[BorisS]

Coming on in the next couple hours. Those i am really looking forward to !!!!

Boris

 

[BorisS]

I like this. The KW (kopterworx motors) have the counter bullets connectors already with them. One less car ride to the closest RC store safed. Nice one.

View attachment 2139

 

[BorisS]

Sorry about the bad quality, but i must say i am impressed by the WKM performance and the test i tried here. Hope soon i can take it to a real outside test with the same setup.

Fan Test

Boris

 

[BorisS]

The KW motors MK shop 12 x 3.8 props combo seems to make sense for the CX !

Boris

 

[krleas]

Indeed Boris even better with 12x4,5. U will love this combo on CX.

 

[BorisS]

But there seem to be some truth to the fact that the WKM works bettter on quads when it comes to wind. The Fan is on full blast and the bird is in ground effect some of the time and still no visible movement on the frame. Lets see next we a cam on how it looks.

 

[BorisS]

For all of you who have oscillations already with very low gain settings on the WKM. Check again how solid you connection is between the IMU and your frame. I have noticed now that is essential that the IMU is hard hard mounted to your frame, not allowing the smallest movement of the IMU that is not directly inflicted from the the frame. If you can move your IMU the slightest bit, wobble etc. you should already think about strapping it down somehow to fix it harder to the frame/plate. Especially in wind when the bird has the regulate very hard the imu will be influenced and start a oscillation loop. I have noticed that with a loose IMU i was able to get the oscillation away after going down with both gains to 40% 40% which nearly resulted in a crash once the wind hit the bird with full force. So i conclude the tighter you IMU is fixed to your frame the higher you can go with your gains before oscillations start.

For thos having their IMU mounted with velcro thick double sided sticky tape or vibr. dampners rethink your approach. I am starting to stick the IMU on with the thinest stringest sticky tape i can find and additionally strap it down with a cable strap.

Only thing that changed from the fan test before is that i didnt have the cable straps on the IMU anymore and the sticky tape was less sticky already etc.

 

[Gunter]

For all of you who have oscillations already with very low gain settings on the WKM. Check again how solid you connection is between the IMU and your frame. I have noticed now that is essential that the IMU is hard hard mounted to your frame, not allowing the smallest movement of the IMU that is not directly inflicted from the the frame. If you can move your IMU the slightest bit, wobble etc. you should already think about strapping it down somehow to fix it harder to the frame/plate. Especially in wind when the bird has the regulate very hard the imu will be influenced and start a oscillation loop. I have noticed that with a loose IMU i was able to get the oscillation away after going down with both gains to 40% 40% which nearly resulted in a crash once the wind hit the bird with full force. So i conclude the tighter you IMU is fixed to your frame the higher you can go with your gains before oscillations start.

For thos having their IMU mounted with velcro thick double sided sticky tape or vibr. dampners rethink your approach. I am starting to stick the IMU on with the thinest stringest sticky tape i can find and additionally strap it down with a cable strap.

Only thing that changed from the fan test before is that i didnt have the cable straps on the IMU anymore and the sticky tape was less sticky already etc.

Aye, that's what I've always said Mine is stuck down with very thin double sided tape, AND with a cable tie to stop movement.