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I've been working on a new helicopter platform the last few months. Based on an MSH Protos heli which I chose because it's an extremely light weight platform, weighing in at only ~1200g without battery. It has a full belt drive which I much prefer to gears as it's quieter, lower vibration and more reliable. I've had a few problems with it because the belt drive makes a really awesome Van deGraaf generator... not a good thing on a UAV. But I solved that, and am conducting test flights now.


The flight controller is a modified PX4v1. I replaced the switching regulator with a MIC29300, so that I can run it on 2S direct with the servos. Main motor power is 4S 5000, typically this heli would run on 6S 3300. Using the MSH stretch kit and 465mm Spinblade Asymmetric blades. In otherwise standard form, this heli flew for 17 minutes on an old crusty battery, in -10C temperatures.

I have now added a subframe to hold an extra battery, FPV gear with a camera in the nose, and a vibration damped NADIR camera mount to be used for aerial mapping. The idea is to develop a mapping UAV that is superior to a multirotor, offering a valid alternative to a fixed wing for short to medium range missions. The VTOL capabilities would eliminate all the nastiness of catapults, and controlled-crash landings with onboard cameras in rugged areas.  Even the price is attractive at about $400 for the basic kit with motor and ESC (no servos).

Specifications show the advantage of a heli platform. This machine has an AUW including the batteries and camera of only ~3kg. It is 80m long, and about 15cm wide not including the extended legs, and 30cm high. The blades fold for easy transport, without requiring any lose wires or vibration-prone electrical connectors as a folding multirotor does. It actually looks much bigger on the table than it really is. This seems to be very good compared to multirotors I've seen with the same performance. (payload and duration)

Vibrations are always a problem with helis, but manageable with the right design and construction techniques.

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Arducopter really makes helis worthwhile. You could buy two entire heli systems including a Tx for the price of a single DJI Ace One non-waypoint controller.  Or 7 for the cost of a single Ace One waypoint enabled controller.  I strongly prefer the PX4 controller over the APM and Pixhawk, because it offers 32-bit performance in a small package that is easier to mount in a heli frame.

So does it work? I took it up for it's first photo tests yesterday, and it worked beautifully. Better than 80% photos are usable. It flies for 20 minutes in a hover with old, cold batteries (-5C). I'm hoping for closer to 30 minutes while actually moving (helis are more efficient moving than hovering), in warmer weather with new batteries.  It should have an easy cruising speed of 15 m/s with little or no reduction in flight time.  At 20 minutes, this would offer an 18km range, and 27 if it can do 30 minutes.  If you wanted to do FPV and not mapping, you could configure it with a 3rd battery in place of the SX260 and fly for... 30-45 minutes, and a range of up to 36km.  Top airspeed is still TBD, but probably 20-25 m/s.  

Wind penetration and stability is excellent compared to both multirotors and fixed-wing.  You could do a mapping mission in winds up to 40 km/h with little effect on stability or duration.

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If the success continues, I'm going to consider building a large gasser heli.  This would allow flight times up to 2 hours, or payloads on the order of 10 lbs for 30 minutes.  So you could map large areas, or even perform light duty spraying operations.  I'm thinking about local application of a herbicide for things like Giant Hogweed elimination, that sort of thing. Such a large heli does pose significant danger and should only be used in industrial, agricultural or remote areas.

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  • been published in the apm thread on rcg.

    it is a log analizer.

    http://www.rcgroups.com/forums/showatt.php?attachmentid=6701452&amp...

    http://www.rcgroups.com/forums/showatt.php?attachmentid=6701452&d=1398109743
  • Ok. Looksllike only blades are destroyd. I was luck. 

    Tested today hover and eight shape with only rx .. No auto pilot and stab.

    Ready to rock n roll.

  • Thank you robert ..

    But now i will need to wait for the parts to get here .. As the hk sites have an avg shipping time of 5 weeks ... I think a lot will happen until i will try again..

    Thanks.

  • Guy, I try to answer all the questions on ardupilot.com daily as much as possible, but you caught me at a bad time.  I'll try to have a look at your situation tomorrow.

    I had a great weekend flying the helis.  Finally some decent weather.  Got a sunburn.  Flew all 3 helis several times.  Hit 30 m/s on my mapping heli, flying FPV to almost the range of the 200 mW 5.8GHz transmitter.  I was actually pretty surprised at the speed I hit, though I might have been pushed by a tail wind.  I hit 25 many times.  It's way easier to get up to speed flying FPV as you have more time to build speed.  I really wasn't trying to set any speed records.  Just push the nose down in Alt Hold and it just goes and goes.

    Acro flips and rolls with my little heli, lots of Stabilize mode bail-outs, all working fantastic.

    Ready to put the Nex back on my big heli and go for it.

  • i found the full param list ... it appears to be collapsed ...

  • i posted it there .. but never got an answer on that forum.

    :(

  • Guy,  I don't know how to read your log.  Put it on the other forum and I think you will get help.  I did notice however that you have your RATE FF all set to zero.  That's probably not good.  Especially if the heli has not been trimmed yet.  Keep in mind today is Easter so you can't expect any answers on the traditional helicopter forum for a bit.

    Regards,

    David R. Boulanger

  • https://www.dropbox.com/s/35xj5xr0ckod9ut/2014-04-19%2022-04-33.log

    Dropbox - Error
    Dropbox is a free service that lets you bring your photos, docs, and videos anywhere and share them easily. Never email yourself a file again!
  • yes .. i did check the fix for stabilization ..

    it worked even when not armed. in fact everything worked when not armed but the motor.

    i am not sure if there is a new firm ware or what but i never found something like i have in my mp in the wiki nor on the web...

    i can upload the logs .. but there is not a living soul in the traditional helicopter forum of d.i.y

    about the heli .. hu .. i am ok with that .. crashed it many times .. ( but this is defiantly the shortest flight ever :) ) 

  • Guy.  Sorry you had problems. Is the swash moving in the proper direction with the transmitter sticks?  If you arm the heli and roll it by hand in stabilize does the swash move in the proper direction to counteract the roll?  Can you post your x,y,z, vibration graph.  You may want to move this over to the other Traditional Helicopter forum.  The experts will want you to post your flight log.  Then most likely they will have an answer to what the problem is.

    Regards,

    David R. Boulanger

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