DJI A2 Performance/Build Comparisons

[Droider]

Aye Up Flappy Bird. Welcome to MRF. Glad you are having a generally good experience with your DJI S800. Would be nice to see your fast flying footage as at way lower than the speed quoted I bottle! Where on the planet are you?

Dave

 

[gtranquilla]

A bit more info and background on Futaba FWIW.

Stands to reason that US Military would be looking for a high reliability and nearly failsafe industrial grade field proven solution for wireless control systems and communication protocols and Futaba Industrial has been at it for a long time now.
http://www.futaba.com/products/irc/introduction/
Futaba Industrial makes big money..... and Futaba Hobby division, which makes very little, benefits greatly as a result of ongoing Industrial development and tech spin-off. But once locked in to s.bus hobbyists have to pay mucho deniro to stay with it!
Turns out that Futuba s.bus and DJI d.bus are able to work together such that 14 or more channels can communicate concurrently which means faster data throughput so that the MR FC can control outputs in real time (i.e., no time delays)
http://www.multirotorforums.com/showthread.php?8777-About-DJI-D-Bus-Futaba-S-Bus-and-Can-Bus

Wise choice! There's a reason the U.S. Military uses Futaba for their LOS applications.

 

[Bartman]

interesting!

 

[Droider]

Very.. BUT can you get telemetry down which no one seems to be answering. APM stated on their S1000 video he could see his pack voltage via his futaba what ever it was radio via A2. Can you?

 

[flappybird]

I fly FPV and among other things keeping a close eye on the ground speed via the IOSD I've watched it push over 25m/s many times. To reach these higher speeds I start my sequence at a higher altitude and drop down a gentle flight slope to the altitude I want to be while pushing forward. It doesn't take much of a drop and once the speed is reached it holds nicely aside from the issues stated.

As for Live voltage via futaba and A2 I haven't seen it done but the IOSD performs this function so thats what I use.

 

[Droider]

Nice stuff there.. if you where over this side of the pond you would get slapped for that kind of distance flying and even a bigger slap for FPV but hayho new mexico is probity as big a England anyhow! Fly safe

DAve

 

[flappybird]

Two posts in and already given safety advice Prior to this new system my older WKM based multi has had thousands of flights without a single mishap. Not crashing and safety is explicitly part of the job.

I came here only to help people with the A2 as I have a solid knowledge of the device thats what I'll stick to.

 

[Droider]

Two posts in and already given safety advice Prior to this new system my older WKM based multi has had thousands of flights without a single mishap. Not crashing and safety is explicitly part of the job.

I came here only to help people with the A2 as I have a solid knowledge of the device thats what I'll stick to.

I have to keep things in perspective and just so people in the UK are concerned flying anything over 800 grams FPV is forbidden. AND any FPV flight needs a second to keep line of site. I do not profess to know things about current regulations in the US.

So you are experiencing issues with the A2 yawing when? You stated full yaw spin outs at maximum forward speed with the new FW. Is that 2.1?

Dave

 

[flappybird]

i just uploaded the new firmware last week. I have about 90 minutes of flight on it but haven't went over 15m/s. I'll report back with results after bringing the bird up to top speed. As for the previous spin outs. The experience was almost like having the bird in IOC. It kept flying straight as it preformed the impromptu spin and I just gently let off the elevator to reduce speed. after parking it in a hover for a few moments i proceeded to continue the rest of the flight without incident. My first guess was that in FF flight the amp draw was to much for the A2 to maintain yaw authority but it has happened with the under load voltage close to 22v so thats not it. Arms have been swapped around and I do not believe it is vibration related. I have also flown at top speed or at least well above 20m/s with no issue. So it remains an unresolved topic.

My hope is the new firmware fixed this as the release notes speak of some corrections to the yaw/ Pitch&roll functionality. The yaw with V2.1 is smoother BTW V1 was a lot more abrasive.

... All said and done this kind of speed may just be right at the edge of the machines capabilities.

 

[Droider]

There is an issue of the A2 recording a new POI EVEN IF you do not have it enabled..(well I have it) maybe thats whats happening and the bird is trying to spin round a POI.. That you will not know flying FPV as you cannot see the LED registering to new POI

 

[flappybird]

That is certainly a possibility I can't rule out, but the majority of the flight are close in with the LED visible and I have never seen it act the way you are experiencing. POI does have issues a shame because it works very well on the WKM. With the A2 I can get POI to work 1 time, but if I turn it off and back on the hell violently tilts and rolls like others have described. I typically have IOC and return to home active anyway as I find them to be very useful tools for accomplishing a few specific things. My biggest gripe with POI has always been needing to tune the GPS declination in to perfection each time in order to get a perfectly locked in subject, but when it works its magic and can be used for much more than just flying circles.

 

[flappybird]

View attachment 16100View attachment 16101

A2 just preformed several perfect back to back flights in -5 to -8ish degrees fahrenheit. Used about $50 in hand warmers to keep me and the batteries warm.

 

[fgene]

Hello from a new forum member,

Here are my specs:

1). Flat octo, CF 1000 mm custom frame; T-motor 4014 400kv; T-motor 30A ESC Pro; T-motor 14*4.8 CF props; Pulse 10000 mah 6S battery

2). Graupner MX-20 TX, Graupner HoTT GR-16, PPM sum

3). AVL58, iOSD Mark II, small FPV camera with pitch servo, LEDs for night flying.

The gimbal I use most often was custom made for PJ710V (or other camcorder with similar dimensions), 3-axis stabilized with zoom and camera mode controls, independently operated from a second TX (JR9503). It also has its own 5.8G video transmitter. Apart from using power from the main battery via slip ring in yaw motor, the gimbal is attached to the copter frame only mechanically, by quick release system. All-up weight is 6.8 kg

View attachment 16209

So far it is working very well, flight times are good, position hold is especially impressive. Have been flying full day at mountain ski resort in -18 C to -5 C windy weather with no issues whatsoever. Used styrofoam pads to keep the batteries warm in flight.

Here are my nitpicks (some of them mentioned before):

1. In A2 Assistant software, there's no clear indication of whether failsafe is working/engaged or not.
2. Only 8 channels are available via PPM. To me it looks like an artificial limitation, because I know that Mikrokopter is capable of extracting all 12 channels from the very same RX/TX pair.
3. No easy way to calibrate endpoints on third-party ESCs. I would go with DJI ESCs instead of T-motors because they do not require throttle calibration, but the ones I found only supported 4S max.
4. GPS is sensitive to slightest obstructions. I can sometimes drop the number of satellites from 14 to zero by just leaning over the copter. Because of this behavior, I don't want to risk flying in obstructed environments.
5. No way to set up a dedicated motors on/off switch. It might be a personal issue, but I find DJI system awkward and counterintuitive. More than once I have narrowly escaped damage when, after landing, the motors didn't stop and the copter fell on its side.
6. Inaccurare altitude display via iOSD. Could be off by 2-3 meters. Doesn't affect alt. hold, though.
7. Getting into compass calibration mode is a huge pain, so much that I am thinking of using an Arduino board that could be temporarily plugged in between the receiver and controller, with pre-programmed routine just to get into this mode. Shouldn't be so hard...

Regards,
Gene

 

[Tahoe Ed]

When available, sometime in March the E600 propulsion system will support 6S. Unfortunately not available now.

 

[gtranquilla]

Very nice..... any chance you can provide the AUW and total flight time for your system?
The need for a slip ring caught me off guard... would sure like to see how you did that!

Hello from a new forum member,

Here are my specs:

1). Flat octo, CF 1000 mm custom frame; T-motor 4014 400kv; T-motor 30A ESC Pro; T-motor 14*4.8 CF props; Pulse 10000 mah 6S battery

2). Graupner MX-20 TX, Graupner HoTT GR-16, PPM sum

3). AVL58, iOSD Mark II, small FPV camera with pitch servo, LEDs for night flying.

The gimbal I use most often was custom made for PJ710V (or other camcorder with similar dimensions), 3-axis stabilized with zoom and camera mode controls, independently operated from a second TX (JR9503). It also has its own 5.8G video transmitter. Apart from using power from the main battery via slip ring in yaw motor, the gimbal is attached to the copter frame only mechanically, by quick release system. All-up weight is 6.8 kg

View attachment 20174

So far it is working very well, flight times are good, position hold is especially impressive. Have been flying full day at mountain ski resort in -18 C to -5 C windy weather with no issues whatsoever. Used styrofoam pads to keep the batteries warm in flight.

Here are my nitpicks (some of them mentioned before):

1. In A2 Assistant software, there's no clear indication of whether failsafe is working/engaged or not.
2. Only 8 channels are available via PPM. To me it looks like an artificial limitation, because I know that Mikrokopter is capable of extracting all 12 channels from the very same RX/TX pair.
3. No easy way to calibrate endpoints on third-party ESCs. I would go with DJI ESCs instead of T-motors because they do not require throttle calibration, but the ones I found only supported 4S max.
4. GPS is sensitive to slightest obstructions. I can sometimes drop the number of satellites from 14 to zero by just leaning over the copter. Because of this behavior, I don't want to risk flying in obstructed environments.
5. No way to set up a dedicated motors on/off switch. It might be a personal issue, but I find DJI system awkward and counterintuitive. More than once I have narrowly escaped damage when, after landing, the motors didn't stop and the copter fell on its side.
6. Inaccurare altitude display via iOSD. Could be off by 2-3 meters. Doesn't affect alt. hold, though.
7. Getting into compass calibration mode is a huge pain, so much that I am thinking of using an Arduino board that could be temporarily plugged in between the receiver and controller, with pre-programmed routine just to get into this mode. Shouldn't be so hard...

Regards,
Gene

 

[Bartman]

When available, sometime in March the E600 propulsion system will support 6S. Unfortunately not available now.

what is an E600 propulsion system?

 

[Razzil]

what is an E600 propulsion system?

DJI's E300 and E600 motor and ESC sets

 

[gtranquilla]

Hoping to see more of these including sets to accomodate props up to 16 inch dia or more.

 

[deluge2]

DJI Tuned Propulsion Systems

OLD NEWS, got distracted...

New E300 and E600 "Tuned Propulsion Systems" consisting of ESCs + Motors + Prop sets (each comes in quad and hex quantities), see link below for DJI's description.

The systems were announced in late November 2013. E300 sets, the smaller version for 3S Lipos (4 and 6 arm) are available now. According to Tahoe Ed, E600s are coming in March.

http://www.dji.com/product/tuned-propulsion-system/

Steve

what is an E600 propulsion system?

 

[Tahoe Ed]

See the attached specs:

View attachment 16211

The E300 is good to 4S and the E600 is good for 6S.