General Laser Stabilizer 3D review by mazakari 09-Feb-07

Introduction.

The General Laser Stabilizer 3D is one of the latest 2 axis stabilization systems to enter the market. It is very much in the same mould as the FMA Co-pilot system and aims to achieve the same results. Their advert on their webpage shows an RC helicopter being flown ‘hands off’ with the stabilizer flying the heli, keeping it in a perfect hover. It has been marketed at those that want a stable platform for aerial photography, beginners learning to fly and for advanced pilots who want a ’safety net’ whilst flying.

So how does it work ??

The system utilises IR heat. The sensor has 5 IR sensors on it with one external sensor to be mounted under the helicopter. The sensors read how much IR heat is present at all the sensors. The controller unit then evaluates the IR heat information and adjusts the controls to keep the IR heat values equal for four of the sensors for normal straight-and-level flight. The other two sensors (one on top and one below) allow the controller to know if the helicopter is inverted or not. Infrared heat is a much better source for control input than visible light because IR heat isn’t affected as much by cloud cover.

So what do you actually get ??

Apart from a nice little plastic box, the General Laser system consists of a sensor, a control unit and a set of instructions. The instructions were not written initially in English but, after a couple of reads you should be able to make sense of them.

The Sensor Unit

The control Unit

Neither the control unit or sensor are too big and even the small helicopter would have no trouble lifting them.

Installing the Stablizer system

This system can be used on 90 degree swashplates and 120 degree, so it can be used with almost any type of helicopter control, from true mechanical mixing right through to pure CCPM radio mixed helicopters.
The first stage is to mount the Sensor on to your helicopter. I decided to mount it on the tailboom as this offer an un-obscured view of the world for the IR sensors. I used a bit of Carbon I had and made a little mounting plate, but it would quite happily sit on the horizontal stablizer. The single IR sensor (to be mounted facing down), was mounted on the underside of the mounting plate.

The sensor has two cables coming from it. These plug into the control unit.
The control unit plugs in between the servo’s and the reciever. Your pitch and roll servo’s plug into the unit and the unit plugs into the reciever. There is also an extra lead coming from the control unit that can plug into a spare channel on your reciever. This is for controlling the gain from your transmitter - the same as you can control the gain on your gyro from your Tx eg on the GY401. There is a small pot on the control unit itself so you can adjust the gain on the helicpter.No external power supply is needed for either the sensor or the control unit.
As this is not an installation guide, I’ll leave it at that for now and move on to how it performs.

Flying with the Stabilizer 3D

Right, the platform I chose to mount the stabilizer system to was my TRex 450 (modified) running a JGF 450TH motor, spinning 335 blades just for this test. The weather was sunny and quite mild (for the time of year in the UK). There was a light breeze.
The first thing to do was sit the helicopter on level ground and calibrate the system. This just involves powering up the helicopter and pressing a small button on the sensor. You should then retire to the back of the helicopter - at least 5m away and wait for a few seconds. Once the flashing LED turns steady, you are ready to fly.
At first, I started with the gain set to 0%. This way I could see how my helicopter was flying / hovering without the aid of the stabilizer system.
Next, I increased the gain a little and lifted into the hover. Nothing much happened and the helicopter flew just as before. This is the point I decided to increase the gain a decent ammount to speed things up a little. Big mistake !!! Have you ever had the gain turned up too high on your Gyro ?? You get a tail wag, and it can be annoying to say the least. Now imagine this but in both pitch and roll !!! I thought that was this heli going home in a bin bag, but somehow I managed to get it on the ground in one piece.
The next step was to reduce the gain. Turned it down to between 40 and 50%. This time I lifted into a nice low hover and once happy, lifted the helicopter up to about 4 feet and amazingly, there she sat. There was some drifting because of the wind and I don’t think you could ever put your transmitter down as the TRex helicopter is far too small and light but I was able to take my hand off the cyclic for about 30 seconds before I had to step in and bring the helicopter back. The helicopter stayed level and it was only the wind that took the heli away. On a larger, heavier helicopter that isn’t so troubled by the wind blowing, the stabilizer system would probably work a little better at keeping the heli on the same spot. As for controlling the helicopter, hovering became so easy. It really did reduce the workload your brain has to deal with.

Next I had to try it in flight. I pushed the cyclic forward to gain a little forward speed and went for a circuit. The first thing I noticed was how much stick was needed to make the helicopter move into forward flight. This is proportional to the amount of gain you have set on the control unit of course. Into the first corner and I really had to force the helicopter to turn. Half way through the corner I must have eased off on the cyclic because the helicopter sat bolt upright as if someone had shouted “stay” to an obedient dog. I went for several more circuits, each one getting better as I got used to how the helicopter handled but, at the same time feeling that I didn’t have complete control over my helicopter and I had to force it to do anything at all.

I have still some testing to do and I think that this time I will connect the remote gain to a switch on my transmitter. This way I can have the stabilisation switched on in the hover and off for flight. If the heli gets into difficulty I can hit the stabilizer switch - much like throttle hold, and have the helicopter put itself into a hover - waiting for me to tell it it’s next move. This is something I will do for the next flight tests. Hopefully it will work as I don’t fancy taking my helicopter home in pieces!!

So does it work ??

Ok, you have to remember, these are initial findings and until I have spent some more time flying it and getting it set up how ‘I’ like it I can’t give the definative answer.
So does it work ?? Well, yes but. . . . . . If you strapped it to a Raptor 30, 50 or 90 and put it in a hover - it would sit there as if on a glass table. The TRex is, in the world of RC helicopters, a small helicopter. The system did make the helicopter more stable in the hover but because of the wind, to stay put you are always going to have to ‘fly’ the helicopter. In the UK, you are always going to have a wind vector of some form so hands off flying probably isn’t going to happen.
Flying with the stabilizer. I have to say I didn’t like it at all. It felt like the helicopter was fighting my every move. This can be fixed though by ’switching it off’ when entering flight. You would then have to train yourself to switch it on again when needed - like training yourself to hit throttle hold on the ground or before a crash.

Is it worth the money ??

Money. I haven’t mentioned that yet. I only have the price for this system from General Laser themselves. If Joel stocked this item I don’t know how much he would market it at. All I can say, is from General Laser themselves, this sensor costs more than a lot of the heli’s on this site. Would you strap a sensor worth more than your heli, to your heli ?? Tough call. It does work although I feel it would be suited better to larger helicopters. Anything smaller than a TRex might be pushing it although I am tempted to fit it to my Walkera 4 for a laugh.
Would you be happy with it ?? Depends. If you saw the advert with the guy’s helicopter hovering on it’s own with nobody touching the transmitter then yes, I would say you would be dissapointed. The helicopters on this site at the moment are of the smaller variety and because of the wind vector - you will always have to be flying your helicopter. Don’t get me wrong though. This sensor will make your helicopter easier to hover, no bull. Now, if you bought it thinking that it will make your heli a little easier to hover rather than flying on it’s own, then maybe you would be happy with it. It really just comes down to price. What price would you put on something that makes your helicopter easier to hover, and a safety net when flying around ?? Tough one.

Right. I have some more testing to do with this system (hopefully sometime this week). I’m also going to get some video footage so hopefully you will be able to see the stabilizer in action. I wrote this initial review up as I didn’t want to type the whole lot up in one go. I will add any findings I make to this thread and the final conclusion once the final tests have been done.
Many thanks to Joel (Mr Heliguy) for letting me test this General Laser Stabilizer system. Cheers Joel !!
 

Just to let you know, Mark2.5V6 has now got this sensor fitted to one of his helicopters. Click ,HERE to see what he thinks of it - Part 2 of the review if you will.