APM 2.5 alt hold mode

I have 2 quads which I fly FPV both are TBS disco frames, one has a Naza M (my first multirotor), and I have recently built one with the APM 2.5, which I have test flown and has worked brilliantly, :smiley: I have tuned nothing and have used stabilize, loiter, and alt hold. really pleased and surprised that it is stable with no tweaking. In stabilize, I would say it is crisper than the Naza, with less drift after pushing and releasing the sticks. Loiter with the ublox GPS is also very solid.

The one problem I have is; the Naza is great is that it controls the altitude but still lets you adjust the throttle quickly. This is very good for flying under and over things quickly and up/down hills ect. The APM in alt hold is very stable, but the dead band on the throttle is hard to work with; you canā€™t make quick changes in height, and stabilize is really difficult, as the constant throttle adjustments are very hard when you want to fly close to the ground.

Is there a way to make alt hold more like the Naza?

New to APM 2.5 and would also like to see if and how this can be achieved.

I have sorted out my problem: I simply changed to a 4s battery instead of 3s and that gave it the power it needed to fly the way I wanted in stabilize mode. Also on the 3s battery I struggled to pull out of fast descents.

So I am really happy with the way it performs now, it seem very responsive and agile. Iā€™m really enjoying flying FPV with it, here is a short bit of video as I put it through its paces:

https://www.youtube.com/watch?feature=player_detailpage&v=1RChanVYC4o

great flight! yeah I have my machine running on 4s also and itā€™s doing great on the stabilize flight mode which was used to fly in this video www.youtube.com/watch?v=hbCKLDXWNVo

What a unbelievable flights, guys. Your videos really made me want go FPV. Please share your quad specs with usā€¦ Please!

Thanks! This is what Iā€™m running:

SPECS:
HK 450 Dead Cat frame moded to fit Flamewheel F450 Arms
power distribution board
4x simon k 30A ESCā€™s
4x DJI 920kv motor
9x4.7 Gemfan props
4s 3300mah nanotech main flight pack
3s 1300mah nanotech for VTX/camera using UBEC 5v
APM 2.5 with arducopter 3.0.1
ublox GPS
Fatshark Aviator goggles tethered to tripod 3s 1800mah to power VRX
5.8ghz Boscam 200mw VTX with 305 VRX
CP cloverleaf antennas
GoPro 2 for recording and FPV
moongel for dampening
AR600 RX
DX8 TX

Nice flying r0beert0, and a really good and big location, I like it when you were following the paths and flying in between the trees and goal posts , a lot smoother than my flying, I think my stabilize pids need backing off a bit.

milani my setup is as follows:

Frame: TBS discovery
flight controller: APM2.5 (mounted on silicon dampeners) with Ublox GPS
ESC: Ipeak SimonK
Motors: MT2216/12 900KV
Battery: 4S 4600mah (whole thing really came alive when I switched from 3s)
Props: DJI 10-3.8 (they withstand hedge trimming well!)
video TX: Immersion RC 5.8 600w TX
FPV camera: CMQ1993X (security camera2000) with 5-12volt step up
OSD: Minim OSD
Recording camera: Gopro hero 3 black (mounted in its protective case, upside down)
Goggles: Fatshark attitude
Reciever: immersion RC EZUHF 8CH
Transmitter: Futaba T8J with Immersion RC EZUHF (cumbersome setup!)

Thatā€™s nice. Now I have 2 guidelines for my next projects. I had a iFly Quad from hobbyking, but it turned out to be limited, not open-source, not very reliable, weak ESCs plus the control board do not work with regular ESCs, etc. I got tired, rapped everything out and bought APM. Now I am completely satisfied with the control, but the motors are weak, and its frame does not accept other motors.

I will follow something like your specs.
How long does the 4S 3300 ~ 3600 mAh batteries takes to run out? Isnā€™t it a little heavy?

Thanks!

Thanks Rob, while the standard X config works great I did slightly dial down the roll rate, your rates may vary but these seem to be working for my setup.

Stabilize Roll: 4.3500 (from 4.5000 default)
Rate Roll: 0.1350 (from 0.1500 default)

milani, the weight of the 4s 3300 is fine (keep in mind that Iā€™m using an additional 3s 1300 pack to power the VTX and camera) and itā€™s not impacting performance. Iā€™m getting 7 minute flights and coming down @ 35% (or 3.86 per cell) could probably get 8 minutes out of it and still be within 20% though really depends on the style of flying/state of the pack.

hobbyking.com/hobbyking/stor ā€¦ duct=20463

you should be fine going in to the 3600 range while using an additional lipo for VTX. sounds like Rob is powering all components from the main flight pack and heā€™s using a larger 4600 pack.

Thanks r0beert0 I have tweaked the rates a bit when I tuned it, but it still needs a little work. although its not great for filming it is great for racing!

I also have a Naza on the same frame, but it just doesnā€™t seem as agile, in fact I end up crashing it because I canā€™t pull round the corners. It is running DJI 920Kv motors and DJI 30A ESC. I did try it on 4s but it made no difference. Is the Naza just less agile?

With regard to the battery, when the 4S 4600 pack arrived I did think this is going to be too heavy, and it will struggle with it, but I was really surprised, it flys well, and I regularly get flight times of 10-12mins sometimes longer(I rely on the OSD battery warning). With the 3s 4200 pack I was getting around 6-7mins.

Hi Rob, good to know the TBS can handle large 4600 packsā€¦ Iā€™m using the 3X 3300 packs because I already had them from another model, theyā€™re still holding strong though when the time comes to replace Iā€™ll probably go for the larger capacity packs.

Regarding the Naza agility, I also have an F550 ship running a wookong FC I always fly that on GPS mode as itā€™s my photo/video platform though on ATI mode sheā€™s a lot more agile so you might want to try that and see how it feelsā€¦ of course there is always manual mode too if you really want to be agile with it :slight_smile:

-Roberto

[quote]
Regarding the Naza agility, I also have an F550 ship running a wookong FC I always fly that on GPS mode as itā€™s my photo/video platform though on ATI mode sheā€™s a lot more agile so you might want to try that and see how it feelsā€¦ of course there is always manual mode too if you really want to be agile with it :slight_smile: [/quote]

Hi Roberto,

Yes with the Naza, I only use GPS mode for position hold, I mostly fly in attitude mode, but its just not agile like the APM. I did try manual mode ages ago, and crashed, perhaps I need to try that again. The trouble is now I am used to flying the APM, so when I change to the Naza, I end up crashing as I canā€™t get it to bank and ā€˜pullā€™ round the corners.

Rob

[quote=ā€œmultirotorrobā€]

Hi Roberto,

Yes with the Naza, I only use GPS mode for position hold, I mostly fly in attitude mode, but its just not agile like the APM. I did try manual mode ages ago, and crashed, perhaps I need to try that again. The trouble is now I am used to flying the APM, so when I change to the Naza, I end up crashing as I canā€™t get it to bank and ā€˜pullā€™ round the corners.

Rob[/quote]

Sounds like itā€™s just a matter of tuning both systems to what feels right for you.