S800 EVO - landing gear help.

[ddikie]

Ok guys I need a bit of help with the landing gear on the S800 evo..
Using a Futaba T14SG and its stock receiver R7008Sb in mode A
D-Bus selected in wookong with a single servo lead via S-Bus connection to X2 on the wookong.

The Servo lead from the landing gear is plugged into X3 & I even tried U with no luck..not even sure if this is correct but still getting slow flashing red on the landing gear controller..I have only been flying for a while and am new to all this can somebody shed some light on how this is supposed to work...its 1.45 am here and I am desperate to maiden it in the morning..everything else seems ok.

I am on the new 5.24 firm-where as well...

Also does anybody also know the xyz exact measurements for a medium height GPS post & the IMU on the back tray above the battery?

I have them set as follows.

IMU
x -15cm
y 0cm
z 0cm

GPS
x 0cm
y -6cm
Z -15cm

Any help would be very much appreciated ....

 

[ProPilotWannaBe]

Out of curiousity, why are you connecting the landing gear to X3? I recommend you reserve X3 for actual Wookong functions, and wire the landing gear directly to your receiver. I use channel 8.

As for the red flashing LED on the landing gear, have you read the manual? The slow flashing red means it isn't getting a good input signal. Maybe that's because you have it connected to X3? Try it connected to a spare receiver channel and see if that helps.

Everybody has a slightly different setup, so GPS and IMU numbers are largely different from setup to setup. Your IMU numbers look pretty reasonable. The GPS numbers indicate to me that the post is at the base of your M3 arm. (This is presuming that your Center of Gravity is laterally located in the center of the hub, and about and 1 or 2 cm below the bottom plate.)

I know the feeling of really wanting to get the thing flying, but do double and tripple check everything you can. The last thing you want is for the thing to do a flip on you because you have your numbers wrong, and you break arms and props or whatever. Keep in mind you can fly it without your retract landing gear fully operational while you figure that out, but you can't say that for the other stuff.

 

[ddikie]

I have been wondering myself about X3 & U as well ..on the receiver I have 8 ports & s-Bus..i have presumed that if the S- Bus is utilised then ports 1-8 are via this cable and can not be used..will try plugging it into Ch 8 and see what I get.

I dont have a zenmuse connected yet and have a 2 battery setup Thunder Power 7800 - 6S PP25..one under the supplied battery plate & the other strapped to the front plate but its about 5 cm higher laterally than the one at the back which i suspect is not good..I think i need to get a spare battery plate and connect it to the H frame before I fly...are there some more exact ways of determining the centre of gravity accurately?

I attach a pic of the setup..to indicate the battery placement.

Take care.

View attachment 13465

 

[deluge2]

You might use another DJI battery tray or you could use a tray like this:
http://www.cnchelicopter.com/servlet/the-2332/DJI-S800-(x650V)-multi/Detail
that is designed to fit the s800 frame (ChrisViperM pointed out this option in another thread). I received one of these recently and it's high quality.

Steve

I have been wondering myself about X3 & U as well ..on the receiver I have 8 ports & s-Bus..i have presumed that if the S- Bus is utilised then ports 1-8 are via this cable and can not be used..will try plugging it into Ch 8 and see what I get.

I dont have a zenmuse connected yet and have a 2 battery setup Thunder Power 7800 - 6S PP25..one under the supplied battery plate & the other strapped to the front plate but its about 5 cm higher laterally than the one at the back which i suspect is not good..I think i need to get a spare battery plate and connect it to the H frame before I fly...are there some more exact ways of determining the centre of gravity accurately?

I attach a pic of the setup..to indicate the battery placement.

Take care.

View attachment 17026

 

[ProPilotWannaBe]

I have been wondering myself about X3 & U as well ..on the receiver I have 8 ports & s-Bus..i have presumed that if the S- Bus is utilised then ports 1-8 are via this cable and can not be used..will try plugging it into Ch 8 and see what I get.

I dont have a zenmuse connected yet and have a 2 battery setup Thunder Power 7800 - 6S PP25..one under the supplied battery plate & the other strapped to the front plate but its about 5 cm higher laterally than the one at the back which i suspect is not good..I think i need to get a spare battery plate and connect it to the H frame before I fly...are there some more exact ways of determining the centre of gravity accurately?

I attach a pic of the setup..to indicate the battery placement.

Take care

ddikie, all of your 7 Wookong inputs should be mapped to your receiver if possible, which is the case with the transmitter/receiver pair you have. You can do that via s-bus (which is what I would recommend) through one servo wire. Then, output 8 of your receiver connect it up to the retractable landing gear. The U, X2, and X3 inputs on the Wookong should be left for Wookong functions. If you had a gimbal that needed to be connected to the Wookong, then you would use X3 for that, but that's not the case here because the Zenmuse won't use that.

FYI, just because you are using s-bus does not mean that you can't connect things to the individual output ports. What you don't want to happen is have two things listening to the same channel. But in the case of the Wookong, it's only listening to channels 1 thru 7, so that's why I'm saying you can connect the landing gear to channel 8.

As for your batteries, can't you mount both batteries to the same tray? I use a dual 6S 6000mah battery setup, and I have both of them mounted on the one battery tray that came with the S800.

One last recommendation... from the picture it seems like you might want to do some wiring tidying up. You don't want loose wires that flop around and could get into the prop area or snagged on anything while your carrying it.

 

[ddikie]

Hi there,

All up and running now on ch8 thanks for the advise guys..just out of interest if i wanted to get ch 9-14 working i would need a hub to plug into my receiver right..The wiring has all been tided up it was just for the testing- but thanks for the tip..I could mount the 2nd battery on the tray but as its so far back the COG will be way off unless I move the plate loads ..might give it a try if i cant get a 2nd plate from the hobby shop in the morning then its fly time and keep fingers crossed....

I have had it sine Wednesday and still have not got it in the air yet..I am desperate to try it out..

Will try and post some footage..

Take care

DDikie

 

[ProPilotWannaBe]

All up and running now on ch8 thanks for the advise guys..just out of interest if i wanted to get ch 9-14 working i would need a hub to plug into my receiver right..The wiring has all been tided up it was just for the testing- but thanks for the tip..I could mount the 2nd battery on the tray but as its so far back the COG will be way off unless I move the plate loads ..might give it a try if i cant get a 2nd plate from the hobby shop in the morning then its fly time and keep fingers crossed....

Glad you got that working.
As for channels 9-14, I'm not sure how to help with the 7008, but my understanding is that you can use the S-bus for channels 1-8, then use the individual outputs for channels 9-14. I use an s-bus decoder from HobbyKing to use channels 9-14 on my 6208 receiver.
As for the batteries and COG, what you are doing works good for now. However, once you put the Zenmuse on the front, I have found that I needed both batteries on the one tray to keep the COG in the center.
Have fun! And happy flying! Wish you great flying times!

 

[ddikie]

Ended up making my own battery plate but COG is spot on now..Just reading through the usage notes on the EVO it says that the basic gain settings should be lowered and the aircraft is less manoeuvrable if the IMU is fixed on the IMU mount rather than the hub..I curently have the gain setting as per Wookong manual set at 130/130/150/150/180/180...so question is should they be less than this or what? Can anybody share there EVO gain setting pls?

 

[ProPilotWannaBe]

Ended up making my own battery plate but COG is spot on now..Just reading through the usage notes on the EVO it says that the basic gain settings should be lowered and the aircraft is less manoeuvrable if the IMU is fixed on the IMU mount rather than the hub..I curently have the gain setting as per Wookong manual set at 130/130/150/150/180/180...so question is should they be less than this or what? Can anybody share there EVO gain setting pls?

The first two numbers on mine are over 200, but my configuration is totally different. For the purposes of getting it off the ground, I think you're fine. Setup one of you channels (or two) to adjust those gains. keep it low and close to you until you feel the gains are reasonable. Also, keep in mind that once you put the gimbal on, you'll need to rethink battery placement, and you'll need to retune all your gains, and you'll have to adjust you x/y/z numbers because the COG will probably have moved, at least in the z axis, due to the Zenmuse.

 

[flipfoto]

hey ddikie,

I have exactly the same setup and the same problem! Using a Futaba T14SG and its stock receiver R7008Sb but in mode D !

connected the cable with the 8th channel, but it keeps on blinking slowly. Have you found a solution yet?

 

[ddikie]

Servo cables are the wrong way round metal bits face inwards... That was my problem!


Sent from my iPhone using Tapatalk - now Free

 

[flipfoto]

okay... i'm afraid my problem is different then, cables are connected correctly as there is a notch on the connectors.

tomorrow i will try without sbus. normal cables

 

[Louis O'Dwyer]

hey ddikie,

I have exactly the same setup and the same problem! Using a Futaba T14SG and its stock receiver R7008Sb but in mode D !

connected the cable with the 8th channel, but it keeps on blinking slowly. Have you found a solution yet?

Hi flipfoto,

Why is your receiver in mode D, is it a second receiver? Otherwise I would have thought it should be in mode B for S-Bus/.
In mode D, the physical connection 1 should be mapped to channel 9 on the transmitter, 2 to 10, 3 to 11, etc. Channel 8 looks like it's reserved for S-Bus.

For my config, I use a Futaba T14SG with two receivers, the primary one in mode B and the secondary one in mode C.
I then use the primary one (with S-Bus) for the Wookong stuff and the secondary one gives me 6 channels (mapped to 9-14 on the TX), one of which I use for the retract.
The secondary receiver gets it's power from the primary receiver by connecting Ch.1 on the primary to Ch.8 on the secondary. A bit weird that, but it all works...

 

[Louis O'Dwyer]

Try it on a switch just connected to a normal channel.
A good idea is to map it to a knob rather than a switch, because it is harder to accidentally switch a knob!
When you are testing it make sure to take the weight off the machine, so there is no chance of it collapsing.
I think it will give a red light if the switch is the "wrong" way at power-up, but once you get the green light those legs will retract if you flip the switch...

 

[econfly]

Hi flipfoto,

Why is your receiver in mode D, is it a second receiver? Otherwise I would have thought it should be in mode B for S-Bus/.
In mode D, the physical connection 1 should be mapped to channel 9 on the transmitter, 2 to 10, 3 to 11, etc. Channel 8 looks like it's reserved for S-Bus.

For my config, I use a Futaba T14SG with two receivers, the primary one in mode B and the secondary one in mode C.
I then use the primary one (with S-Bus) for the Wookong stuff and the secondary one gives me 6 channels (mapped to 9-14 on the TX), one of which I use for the retract.
The secondary receiver gets it's power from the primary receiver by connecting Ch.1 on the primary to Ch.8 on the secondary. A bit weird that, but it all works...

A T14SG with an R7008Sb is all you need. In mode D you have channels 9-15 running over the 1-7 ports with sbus on port 8 (and sbus 2 -- the low horizontal port). In that mode just plug the sbus port into the WKM (which will pick up 1-7). You can run 9 to the landing gear (plugged into port 1 on the receiver).

 

[Louis O'Dwyer]

A T14SG with an R7008Sb is all you need. In mode D you have channels 9-15 running over the 1-7 ports with sbus on port 8 (and sbus 2 -- the low horizontal port). In that mode just plug the sbus port into the WKM (which will pick up 1-7). You can run 9 to the landing gear (plugged into port 1 on the receiver).

That sounds great, if it all works.. I could then use channels 10-15 for the Zenmuse 15, instead of having to use two transmitters...
I'll give it a go! Thanks...........

 

[flipfoto]

well that sounds nice.... S-bus2 connector of the R7008SB to the wookong, al the others are free.... so, port 1 on the receiver will become 9, port 2 will become 10, etc. .... but will i need S-bus - programmable servos then? Don't know what kind of servo's the landing gear is using. But I will try and figure that out, this night. Thanks for the advice. Gives me something to work with...

 

[econfly]

well that sounds nice.... S-bus2 connector of the R7008SB to the wookong, al the others are free.... so, port 1 on the receiver will become 9, port 2 will become 10, etc. .... but will i need S-bus - programmable servos then? Don't know what kind of servo's the landing gear is using. But I will try and figure that out, this night. Thanks for the advice. Gives me something to work with...

My setup is pretty much just that: Futaba 14sg, R7008SB in mode D, the WKM is connected via S-Bus2 (the low horizontal port in the receiver), and the gear on the Evo are controlled by the single connection on channel 9 (which in mode D is mapped to port 1 on the receiver). So, two connections to the receiver (one to the WKM, another to the gear) plus I also have a voltage cable connected for telemetry. The gear on the Evo works just fine out of the box this way. That's it for flight control / gear on mine so I can't say how any other servos might work, but given that you can connect them individually to unused channels 10 or higher (2, 3, 4, ... on the receiver) I would have to think they would work just as well (or not) as anything else connected to a single Futaba channel. Apart from this, I have the Zenmuse on a separate receiver -- an R6208SB -- linked to another radio and connected via a single S-Bus cable itself.

 

[flipfoto]

Dear econfly, I hope that you're a beautifull woman.... I could kiss you :nevreness:....IT WORKS ! and was real simple, the way you explaned it. Finaly, everything is working as it was expected to be. I'm over the moon! thanks a lot!!

 

[econfly]

Dear econfly, I hope that you're a beautifull woman.... I could kiss you :nevreness:....IT WORKS ! and was real simple, the way you explaned it. Finaly, everything is working as it was expected to be. I'm over the moon! thanks a lot!!

Sorry, pretty much the opposite of that, but glad to help!