Airsight 4: A Strong Shouldered Quad

[stevemaller]

I am a Cinestar/Octo guy, and committed to the heavy lift platform I spent more than a year designing, building, testing and flying. And when it's time, it'll be a real moneymaker for me.

But I've found over the last year that I miss having a smaller copter that's less complicated to put in the air, represents a smaller investment/risk, and would be fine to keep at home for fun weekend flying. Rick Chen of Air Sight in Taiwan and I discussed, and he has come up with a big quad frame that met my needs. I don't want the extreme capabilities of the TBS Disco or the high agility of some of the other copters out there. But I wanted the ability to fly anything from a GoPro to a small mirrorless camera like my NEX-5n. So, here I go...

My copter is (at this point) going to outfitted thusly:

• Airsight 4 carbon fiber frame
• Famous Hobby motor mounts
• Avroto 3515 motors
• KDE Direct 35A ESCs
• Naza M V2
• Spektrum AR8000
• no name eBay power distro board with onboard 5V and 12V BECs

To be determined:

• Props (likely 14" or 15")
• FPV kit
• Gimbal(s)

So today I started wiring things up. Naza motor test was successful, but I have a lot of work to do to get all the parts to fit the frame snugly.

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[antims]

Well done. looks good!

 

[stevemaller]

Airframe is all together now, electronics are installed and configured, and it's time for a checkout ride!
I got everything together as per my list above, and ended up using a set of 14" Xoar PJN props I had sitting around. Didn't balance them, but didn't care that much, either.
I ran motor tests and configured things with default settings in the Naza software.
I got a couple things wrong.
For one, the yaw was backwards! :frog: Good thing I wasn't too ambitious about this first test flight.
But more seriously, I have to move the throttle up to about 50% on the DX8 before the motors go above idle. Obviously that's wrong. Is that a gain thing? Again, I've started from default settings on everything.
Here's some photos of her all put together, and a video of her first trip outside.
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[FlyACG]

Steve - does your Naza unit have the bluetooth module? If so, you can quickly adjust settings from your iPhone in the field to test gains. Much easier than hauling the laptop around...

 

[stevemaller]

Steve - does your Naza unit have the bluetooth module? If so, you can quickly adjust settings from your iPhone in the field to test gains. Much easier than hauling the laptop around...

I didn't get the BTU, but I think I'm going to order one. Seems useful, plus the mission planner thing is a nice toy.

 

[FlyACG]

I use the BTU on a DJI Wookong system we have and it has been very useful. As if we don't lug around enough expensive equipment - the Retina Macbook Pro is something I prefer to leave at home.

 

[stevemaller]

I got the Feiyu Tech gimbal MacGyver'd onto the copter today. Did a quickie flight with it, and it seems to work well. No noticeable wobbling, although I'm used to flying a MōVI M5 and I miss having that 3rd axis. The quad yaws quite abruptly! Oh, and I have to reconfigure my legs...they are in the GoPro's visual field. Do'oh!

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[sk8brd]

steve, the above 50% throttle in atti and gps modes when taking off is normal, i believe they call it "auto take off" after you lift in atti/gps the throttle will act normal. you could also take off in manual mode which will be normal throttle response. when you switch to manual on the ground there can be a jump in throttle for a second so don't be alarmed. 50% throttle in atti/gps is not really 50% the fc is adjusting the throttle input so the craft hovers at same height at mid stick. there can be a difference when switching into manual mode as far as hover point goes depending on the builds true hover point. what seems to be mid stick in atti/gps can be true 40% throttle, 70% or whatever the craft actually hovers at. Sometimes people get suprised when they flip into manual mode as the craft can rise or drop depending on the true manual hover point- just something to be aware of with dji stuff. manual mode turns off self leveling so be ready if you ever try it. I would recommend enabling manual mode on your mode switch so if the gps wigs out or your crafts starts acting funny like leaning for no reason manual mode usually will snap it out any issues if caught early, witnessed it myself one day, rare but happens.

 

[stevemaller]

steve, the above 50% throttle in atti and gps modes when taking off is normal, i believe they call it "auto take off" after you lift in atti/gps the throttle will act normal. you could also take off in manual mode which will be normal throttle response. when you switch to manual on the ground there can be a jump in throttle for a second so don't be alarmed. 50% throttle in atti/gps is not really 50% the fc is adjusting the throttle input so the craft hovers at same height at mid stick. there can be a difference when switching into manual mode as far as hover point goes depending on the builds true hover point. what seems to be mid stick in atti/gps can be true 40% throttle, 70% or whatever the craft actually hovers at. Sometimes people get suprised when they flip into manual mode as the craft can rise or drop depending on the true manual hover point- just something to be aware of with dji stuff. manual mode turns off self leveling so be ready if you ever try it. I would recommend enabling manual mode on your mode switch so if the gps wigs out or your crafts starts acting funny like leaning for no reason manual mode usually will snap it out any issues if caught early, witnessed it myself one day, rare but happens.

Sage advice! Thanks. I did change the switch to enable manual mode instead of making it do RTH. I am still flying with 100% default gains, so I was a little uneasy about flying manual, but it actually handles really nicely. I think it's going to move like a bat out of hell, as it's way overpowered for its weight. It is about 8 lbs AUW, and is flying with 4 Avroto 3515 motors and (for now) 14" Xoar props. According to eCalc, it's hovering at about 23% throttle. That's what I call power in reserve!

 

[stevemaller]

Endurance test: almost 20 minutes...no problemo!

After running some calculations in eCalc, I decided to test eCalc's assertion that I could get 20+ minutes of flight time with my current config (8 lbs AUW with 14" props).
Sure enough, got 19 minutes easy just now. Low voltage light was blinking (I have it set to 22.1VDC), but based on my experience and the relatively low current draw this copter's putting on the battery, I probably could have gone another 5 minutes before hitting 21VDC, which is probably the critical point for these batteries I'm using (Zippy 8000 6S).

 

[macc]

Nice frame there Steve, is it available to buy? would you have a link.?

 

[stevemaller]

Nice frame there Steve, is it available to buy? would you have a link.?

It's pretty cool, but it's a prototype that I'm evaluating. Not sure if it's as good as it looks. But that's why it's a prototype. ;-)

 

[macc]

Looks cool, I spose as long as its rigid... I wouldn't mind evaluating it ..lol

 

[sk8brd]

nice, looks good and really effecient! 23% hover point- you could fly at idle speed..ha.

 

[stevemaller]

nice, looks good and really effecient! 23% hover point- you could fly at idle speed..ha.

Yes, good call. That's the issue. There's a lot of joints in this thing, and it's not clear it needs them. That's one of my issues. I'm used to the Cinestar build, which is a beast and super solid and tough. I may end up building a smaller Cinestar-type body as a quad.

 

[jfro]

I have a similar setup and I love it. I made a 650mm frame with aluminum arms. Rock solid.
Used the avroto 3515's to test, and then put them on an x8 at 850mm as I bought 8 of them.

Now have KDE 3520's on the 650 quad. I flew it for a month with the Naza V2/GPS and now have the xAircraft SuperX on it. I think I liked the Naza better, but it is now on my x8.

I'm able to fly my gh2 and gh3/gh4 using a light weight modified 2axis Gotheli v2 gimbal. Get about 14-15 minutes of video slow flying on 1 8000 mah 6s battery. Get much better times with gopro 3 axis, but didn't time it. Best guess is 20 min or so.

Not sure, but think I"m using 14" right now, but might have the 15" cf props on. Not home, so can't check.

Either way, I agree with you on the fun part of flying. I do notice it's more fun to play with the gopro then the heavier gh4 just from a stress standpoint. I did start my experimenting with 550mm but went to the 650mm for bigger props and heavier camera.

 

[sk8brd]

i seen some cinestar quad on quadrocopters video's a while back. i think it was someone that worked their but it looked pretty awesome. l i'll' try to find the vid. here it is https://vimeo.com/91771759. seen your other heavy lift builds-nice! if you have spare frames/booms around a cinestar quad would be pretty slick.

 

[stevemaller]

And now better with FPV...and goats and sheep! The copter is behaving very nicely, and now with the DJI miniOSD I can do a better job of monitoring the vitals (especially power!). This was a fun 13 minute flight at about 1/4 mile. The 1.3 gHz downlink was very solid, although I've got a IBCrazy skew planar antenna and notch filter coming for it (it has a janky old whip on it now) to match the RHCP antenna on the receiver. Now I have to figure out how to monitor RSSI on the Spektrum so I don't wander out of its range!

 

[stevemaller]

OK, did a 180°, so to speak, and decided to go back to a familiar frame type. The frame I was using was interesting, but a little too unsteady. So I went with clone parts with which I'm way more familiar. It was pretty easy to transfer everything over to the new frame, and it all flew brilliantly the first time out. Did a 12+ minute FPV flight out to 500m and had a ball. I'm loving this project!

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[sk8brd]

yes!. want it-lol. do you know the auw before battery is added. always liked cinestar frames.