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Old Nov 22, 2012, 01:32 PM
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tupelo's Avatar
Helsinki, Finland
Joined Feb 2008
293 Posts
Could someone post an image with the FY-31AP powered with two separate BECs. One for the AP and one for the servos.

I would like to have this arrangement as I plan to mount the 31AP into a 1/4 scale Piper Cub and I am not sure a single BEC connected to the receiver can provide enough juice for both the servos and the AP.

Thanks!
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Old Nov 22, 2012, 01:42 PM
uavservices on MRF
saabguyspg's Avatar
Calgary Canada
Joined Jun 2006
4,970 Posts
hi guys, here is some info on the throttle with 31AP

First off we must understand that there is no airspeed sensor on board and thus the plane can not know it's airpseed, only ground speed via gps.

Because of the above fact the autopilot can not know if it is about to stall the plane even when maintinaing ground speed.

Any stabilized airplane once entered into a stall without control over the throttle taken over by airspeed WILL stall your airplane if you go too slow. The plane will try to maintain altitude and attitude and this is the worst thing to do in a stall.

If your plane stalls you must take manual control, point the nose down and increase throttle to get out of the stall. I highly recommend this is done in manual mode as stabilization will only cause the recovery process to be either slower or to fail completely.

Now onto 31AP's throttle control. The throttle is controlled either with a percentage or throttle or with a minimun ground speed set in the GCS. I did not play with this much as I recall I set the throttle speed that worked for me. It's been a while since I let 31AP control throttle though so please just take a look at the options for you in the GCS and play with them.

Lack of an airspeed sensor means you still need to fly this plane with some common sense.

I fly with throttle manually controlled by my RC TX and set to over half in a fail safe situation.

Check your wind direction priror to flight, know that while the plane is going down wind you should be throttleing up to maintain a good airspeed. Watch the plane on the GCS and you can control throttle manually as she flies.

Get to know your planes charateristics really well and you will never stall it. I have never stalled mine excpet just to see what would happen.

That brings me to my next point. If you set up your plane a little on the nose heavy side I have found that with throttle off and circling at the home point the plane will circle and do a minor stall then recovery as it goes around and around. However this will take some tweaking to achieve and most people will know that having your plane too nose heavy is inefficient so it's a balancing act.

Anyway at the end of the day a stabilized plane will be harder to get out of a stall than one wiht no stabilization so there is nothing wrong with the 31AP. Switch to manual in the event of any stall charateristics to recover and there are options for throttle control in the menu so play with them. have some fun and you will figure out what works best for you.

WARNING if you select auto launch and are allowing the AP to contol throttle the motor will start as soon as you hit auto launch!!! so be careful! it's for this reason I decided to take full throttle control on my airplane. Other than that it was controling my throttle just fine in the air as I recall.

Hope this helps clarify some things.

Steve
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Old Nov 22, 2012, 01:59 PM
Registered User
Banff Alberta Canada
Joined Nov 2004
569 Posts
Quote:
Originally Posted by tupelo View Post
Could someone post an image with the FY-31AP powered with two separate BECs. One for the AP and one for the servos.

I would like to have this arrangement as I plan to mount the 31AP into a 1/4 scale Piper Cub and I am not sure a single BEC connected to the receiver can provide enough juice for both the servos and the AP.

Thanks!
31 ap on a quarter scale cub ...... Nice!
Good idea on having a separate. BEC. On the. servos
I will make make a diagram in a couple of hours.
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Old Nov 22, 2012, 02:05 PM
uavservices on MRF
saabguyspg's Avatar
Calgary Canada
Joined Jun 2006
4,970 Posts
The 31AP does not have separate rails for + and - on the servo output side like the Panda does so the wiring is a tiny bit more complex.

Here is a simple sketch with two servo's, hope this helps.

Stevd
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Old Nov 22, 2012, 07:37 PM
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Joined Oct 2009
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FY 31AP and GPS UAV unit - AutoDrop

I finaly had time to make these two units cooperate.
When testing I was surprised how precisely the 31AP can follow the track.
See the detailed picture vith more info here:
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Old Nov 22, 2012, 09:16 PM
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Banff Alberta Canada
Joined Nov 2004
569 Posts
Quote:
Originally Posted by tupelo View Post
Could someone post an image with the FY-31AP powered with two separate BECs. One for the AP and one for the servos.

I would like to have this arrangement as I plan to mount the 31AP into a 1/4 scale Piper Cub and I am not sure a single BEC connected to the receiver can provide enough juice for both the servos and the AP.

Thanks!
The attached diagram shows my setup for using a separate BEC to power up the servos.
I am using the same colour coding as the FY -31 APs hookup to the receiver connections..I use coloured heat shrink to mark the wires.
Rather than using 3 servo extensions, I am using only 2 female servo connectors and 3 male servo connections mainly because I have a shortage of female connectors and an ample supply of male connectors.
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Old Nov 23, 2012, 12:07 AM
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Calgary Canada
Joined Jun 2006
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good stuff!! PistaJ

love your plane btw.

Steve
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Old Nov 23, 2012, 06:23 AM
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Joined Oct 2009
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The plane is called SEXY
People want me to start a thread about it. It is the best plane I have ever built.
Fast, transportable,spacious.
If I have time I will start the thread about it.
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Old Nov 23, 2012, 06:57 PM
When a hobby gets a passion
Thailand, Chon Buri, Pattaya
Joined Sep 2012
762 Posts
Quote:
Originally Posted by saabguyspg View Post
hi guys, here is some info on the throttle with 31AP

First off we must understand that there is no airspeed sensor on board and thus the plane can not know it's airpseed, only ground speed via gps.

Because of the above fact the autopilot can not know if it is about to stall the plane even when maintinaing ground speed.

Steve
Dear Steve,

I am flying with the throttle connected to the AP from the beginning and it has long time been my concern. But I haven't had any problems sofar. I am flying long distances and I am always doing this:

- Set the failsafe throttle to 60%
- Fly early morning or late afternoon when the wind calms down
- Ground speed 60Km/Hr
- Climb and descend rate 20%

The stall speed of my Raptor is less then 30Km/Hr. I think it is important to know your stall speed.so you know at what wind speed you shouldn't fly. But I also noticed, due to the failsafe of 60% throttle (about 11A motor current), the AP never throttles down to zero. My motor current will go down to 7 or 8, but not less. So that means I will always have enough airspeed. I noticed this is correct, as the ground speed in some cases goes up to 90Km/Hr.

But the same is true for throtteling up. It seems the AP only throttles up to about 18A, so that is why I programmed climb and descend rate of 20%. When climbing, my speed goes down to about 35KM/Hr. If I would climb faster, the AP cannot give enough power to the motor.

So from my experience sofar, the FY31AP only affects the throttle within a certain range, in my case from 7 to 18A, with an average of 11A.

I had 1 occasion where I changed my receiver and forgot to set the failsafe while binding, which resulted in a stall and a landing in a lake. Since then, I always do as follows: My first 2 waypoints are control waypoints where I can still see and control my plane. I bring my plane up, and switch on NAV. At reaching waypoint 1, I switch off my transmitter and observe my plane reaching waypoint 2. Then I know all is OK and enjoy my flight. If there is any strange behavior up to waypoint 2, I take back control and land.

This is what happens if you forget to set the failsafe:

Ditched FPV in Lake (6 min 0 sec)


and this is one of my last very nice flights:

19112012_Wat_Yansangwararam.avi (7 min 44 sec)


Many things I had to learn the hard way, as here in Thailand FPV is still relatively unknown and only forums like this can help me to sort out things.

I just recently bought a good onboard camera and can now enjoy HD recordings:

19112012_Wat_Yansangwararam.avi (6 min 19 sec)


Thanks for this thread and all the inputs.

Anthony.
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Old Nov 24, 2012, 09:25 AM
I love my HammerHead wing...
sgrouts's Avatar
Joined Jun 2012
663 Posts
first of all I would also like to thank everyone for this thread.

But my FY is just a dissapointment for me...
I tried everything,
I installed 2.0 and 1.2 firmware.
I resetted the gyros.
I located the GPS sensor out on the wing to give space from every other electronic.
I recorded neutral position in flight many many times over.
The plane flies fine on stabilized mode.
But,
in ACM it just does random circles, and sometimes it gets really far and I have to disengage to save my raptor.
in RTL it doesn't return home just goes to a random direction and does circles.
The FY before take off is double flashing the red led as it should.
I don't know, I feel like I threw my money out of the window....

Sakis
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Last edited by sgrouts; Nov 24, 2012 at 11:49 AM. Reason: typos
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Old Nov 24, 2012, 10:53 AM
Registered User
Banff Alberta Canada
Joined Nov 2004
569 Posts
Quote:
Originally Posted by Pattaya01 View Post




and this is one of my last very nice flights:

http://www.youtube.com/watch?v=_vMNj...&feature=g-upl

Many things I had to learn the hard way, as here in Thailand FPV is still relatively unknown and only forums like this can help me to sort out things.

I just recently bought a good onboard camera and can now enjoy HD recordings:

http://www.youtube.com/watch?v=r3HOX...&feature=g-upl

Thanks for this thread and all the inputs.

Anthony.
Thanks for posting the HD video . I really liked the part where your drone flew over the Wat Yansangwararam temple. It gave me flash backs of when I flew over some temples in an ultralight when I was in Chiang Mai a few years ago.
I noticed on the picture that you posted of your plane that you are using an cloverleaf antenna that is enclosed.
According to IBCrazy the enclosure affects the range . I was wondering if you ever tried a cloverleaf antenna that isn't enclosed to see if there is any difference.


Larry
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Last edited by larry baraniuk; Nov 24, 2012 at 11:13 AM.
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Old Nov 24, 2012, 12:26 PM
When a hobby gets a passion
Thailand, Chon Buri, Pattaya
Joined Sep 2012
762 Posts
Quote:
Originally Posted by larry baraniuk View Post
Thanks for posting the HD video . I really liked the part where your drone flew over the Wat Yansangwararam temple. It gave me flash backs of when I flew over some temples in an ultralight when I was in Chiang Mai a few years ago.
I noticed on the picture that you posted of your plane that you are using an cloverleaf antenna that is enclosed.
According to IBCrazy the enclosure affects the range . I was wondering if you ever tried a cloverleaf antenna that isn't enclosed to see if there is any difference.


Larry
The enclosure would affect the range if the antenna was designed without enclosure and then put an enclosure around it. The enclosure affects the center frequency and as a result, the range. But if you design an antenna with enclosure right from the start, the result does not affect the range at all. In fact, I have tried many self made cloverleafs following IBCrazy's design, this one which I bought from HK, gives the best result. It is available as a set, a CL and a SP. Looks like they did a very good job in designing and tuning.

I know this because I was RF engineer before I retired a few years ago and know a few things about antenna design.
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Old Nov 24, 2012, 12:51 PM
Registered User
Banff Alberta Canada
Joined Nov 2004
569 Posts
Quote:
Originally Posted by Pattaya01 View Post
The enclosure would affect the range if the antenna was designed without enclosure and then put an enclosure around it. The enclosure affects the center frequency and as a result, the range. But if you design an antenna with enclosure right from the start, the result does not affect the range at all. In fact, I have tried many self made cloverleafs following IBCrazy's design, this one which I bought from HK, gives the best result. It is available as a set, a CL and a SP. Looks like they did a very good job in designing and tuning.

I know this because I was RF engineer before I retired a few years ago and know a few things about antenna design.
Good to hear.
I'm sold!
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Old Nov 24, 2012, 04:03 PM
uavservices on MRF
saabguyspg's Avatar
Calgary Canada
Joined Jun 2006
4,970 Posts
sorry to hear this, so do you have an OSD?

if stabilized mode works then I must assume it is a GPS problem.

Are you losing satellites when up in the air I wondeR?

have you tried moving the gps to another location?

what video frequencey are you using?

Steve

Quote:
Originally Posted by sgrouts View Post
first of all I would also like to thank everyone for this thread.

But my FY is just a dissapointment for me...
I tried everything,
I installed 2.0 and 1.2 firmware.
I resetted the gyros.
I located the GPS sensor out on the wing to give space from every other electronic.
I recorded neutral position in flight many many times over.
The plane flies fine on stabilized mode.
But,
in ACM it just does random circles, and sometimes it gets really far and I have to disengage to save my raptor.
in RTL it doesn't return home just goes to a random direction and does circles.
The FY before take off is double flashing the red led as it should.
I don't know, I feel like I threw my money out of the window....

Sakis
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Old Nov 24, 2012, 06:26 PM
When a hobby gets a passion
Thailand, Chon Buri, Pattaya
Joined Sep 2012
762 Posts
Quote:
Originally Posted by larry baraniuk View Post
Good to hear.
I'm sold!
Something not clear in the HK description: they both come with SMA Male connectors. This was not good for the transmitter I am using which also had a male. So I had to change the CL to female SMA.
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