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.
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.
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.
Human Danger is many times what makes projects down, the problen with Helos is the expensive crashes compared to Multi.
Yamaha have been building and flying RMAXes commercially in Japan since the nineties. I'd say they know what they're doing with trad helis now. I find the quoted payload and engine power surprisingly good compared to other helicopters of a similar size.
One of the things that takes some getting used to when filming with a Heli is the way they all hover with a side tilt. That is because the tail rotor is generally below the main rotor and causes a roll input when it pushes against the torque. I think some experimentation is due with some degree of vertical offset in the tail rotor alignment. I see some military stuff is going that way. I did notice that this tilt was more noticeable with the very heavy and wide cord Spin Asymmetric Blades. Although it flew OK at around 1200 head speed it was much firmer at 1500. with two MaxAmps 11,000 batteries I got around 30 mins. depending on the weight of the camera.
See, when you say "Not serious," I hear "challenge" ;P I was looking for a final project ;P In all seriousness though, it honestly has potential to be more safe than having someone cropdust a field. A) you wouldn't have a person flying fast at low level to dust the field, B) you have much less devastation and danger in the event of a failure, and C) the number of safety rules and regulations, as well as the environment it would be operated in, put the system on track to have a stellar safety record. Assuming you're smart enough to not stand right next to the blades while it's flying, that is ;)
Mr R, I have just finished reading this topic and your right on the money. I've just started to learn how to fly my new toy, an Align 450L and there's no doubt they are far more difficult to fly, a real challenge but thoroughly enjoyable. The other issue is maintenance, if you don't like pulling things apart stay with the multi, the Align factory recommends a head strip down and main shaft bearing check every 20 flights, and I love doing this stuff. One thing you never get with a multi is autorotation, in the right hands it can save your heli, and as long as your flying in the right place you should be able to keep your house.
I agree,that's great practical product but 3m props....hm,not near me...once I was near when 600 clas heli lost tail prop,pilot had years of experience..I just do not trust them...I came to great stupid idea;maybe balloon can carry sprying equipment and rover on the ground can move him around(this is joke not serious proposal.)
Emin, if you fly where it is designed to fly the dangers are far, far less than you flying you multi rotor in your back yard, don't quote me but I read that it's MTOW is close to 100kg. The impact on rural Australia will be huge, the biggest bonus is nil soil compaction, and selective spraying.
Emin, that is an agricultural implement. No more dangerous than a Combine, I'd say.
wow...this looks more dangers than any other flying object I saw before....no wonder pilot licence is a must....
Mr R, I don't know if you have seen the Yamaha RMAX industrial helicopter or not, but these are available in Australia for commercial operation, I believe there are only 2 in the country at the moment involved mainly with seeding and spraying rice crops, but obviously the uses are endless.
You can not purchase these out right, they are lease only and come with a full maintenance program, training for a setup cost of over AUD$120,000.00. They have full autonomous capabilities, but CASA regs only permit line of sight flying to a max of 400ft, (non visual by application) a 246cc 20hp horizontally opposed twin cylinder gas engine, the main rotor is over 3 meters in diameter, and has a load carrying capacity of 28kgs (62lbs). The pilot is required to hold a Controller Certificate, and the Company requires a Operators Certificate.
Very impressive, and I suppose if you look at buying a tractor and spray unit etc it probably a competively priced system.
I just thought you might be interested.