LavaRocks

i found this on helihobby and wanted to know if anybody knows anything about it

ive seen conversions of the xrb llama to r/c, but they didnt fly so good

anybody?

http://www.helihobby.com/html/minidr...elicopter.html

cutlassglsracer

The dual rotor helis appear to be more complicated, so reliability would probably suffer. Also because there are 2 rotors there is higher chance of damage in a crash.
As a plus there isn't a tail motor to burn out. Yaw movement is controlled by varying the speed differential of the 2 rotors, torque moment will then yaw the airframe. Of course as I said before this system is more complicated and could prove to be just as troublesome as the cheap tail rotor motors.

IMHO I would go with a good quality FP(or CP if you could afford it) like a hummingbird or a MS hornet. Also it seems that people generally like their JABA IIs and their esky honeybees.

LavaRocks

well the wired xrb llama works just fine with the dual rotor design

cutlassglsracer

That may be, but the wireless heli will have added weight because of the rx(none needed in the wired ver.)/mixer and the battery. All those things were probably contained in the control unit on the wired one.
To keep weight down in the wireless version they might resort to using weaker lighter materials, and thats were the reliability issues could come up.

But who knows, it might turn out to be a good heli. I just wouldn't take the chance on it.

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cutlassglsracer

well thats good to hear.

ger87410

I love it! Works great, but everything has to be perfect.

JohnY2004

A canopy at hellihobby looks much better. I wonder where can I get that canopy.

LavaRocks

do you have one of these things?

JohnY2004

No, I don't have one yet but have been wanting to buy one. There has been a discussion of a group buy of this helicopter. Do a reach, you'll be able to find a link.

gargoyle7

Just got one of these little puppies, I must say the stability is rock solid, very easy to hover indoors with little practice, anyone with the least amount of experience with a Piccolo/Hummingbird/etc should have a blast. Motor life does worry me, but the rotor & blade system is very well designed, breaks apart on crash much like a Pic, just pop blades back on & go. About 10-12 mins hover time on a pack.

Shame on helihobby though, $275 + shipping is too high, they bumped it from $199, I found mine on ebay for $155 SHIPPED (seller 'egrandbuy')

JohnY2004

If it's hovering about 2 ft, the ground effect is still a little bit too much for this little heli to handle. In order to acheive stable hovering, it must stay at 4ft or above. In forward flight, the horizontal stabilizer on the tail must need to be adjusted with a little positive angle of attack (15~30 degree) to keep it from flaring or it might behave as if it has CG problem.

warren52nz

I have a lot of experience with these models, I have 2 of them. Although it's my first chopper so I have nothing to compare it to. I've flown it in front of several guys who fly model choppers and they say it's surprising how well it survives crashes!

I think I've learned just about everything there is to know about these now. I even make my own blades out of styrene which makes for very cheap but labor intensive blades.

I can buy them directly from China as I have a contact there but I have to buy them 6 at a time. I could probably sell them for around US$275 + shipping each if anyone's interested.

It took very little time to learn how to fly this thing and, because I'm a first timer, I suppose it must be easier than most.

There's a place on the Net where you can get carbon fibre blades for these. They're really good but break if they hit anything too hard whereas the stock styrene ones can take a bit of abuse.

Anyway, I can organise a group buy if there are enough people interested.

For those of you who already have one and have any questions, you can get me directly on:

[email protected]

Cheers
Warren

R-Rudder

I wish some one would come up with the alumium blade holders for both upper and lower sections. The B section blade holder is extremely fagile, it'll break beyong repair if the B blades hit the ground or minor crash.

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FlyingFish

My Feedback: (17)

I've seen these Helis demonstrated at the 2004 Hobby Vision trade show, It works very well, I just recently purchased one on ebay, but haven't received it yet. I even got to meet that guy from DIY show Chris cantenelli............

warren52nz

I've had a bit of trouble with the blade holders but not much considering the hundreds of times it's crashed into things. I actually made a lower blade holder out of copper and it worked although it was quite heavy! I'm wondering if your blade holders are the same as mine. I can tell you that the upper blade holder on the tethered Lama is a bit different in that it has individual pitch controls whereas mine doesn't. Looks identical otherwise.

gargoyle7

I've had some time to really put this thing through its paces, & must say overall it is very durable & adequately built - really holds up under many minor crashes. The dual motors are a plus as well for longevity. This thing flies EXACTLY like the lama, in fact I wonder if the Korean company producing them has ties to the manufacturer for Lama parts, 90% of the engineering/production is identical. I've managed some VERY controlled spot landings & some nice stable hovers, I reccomend using some model tubing to deactivate the ratchet mechanism on the throttle to get better hover control. The crappy TX is an issue, but its so-so quality.

The biggest weakness of the build is the use of a shoddy PCB as the guts, not sure whats onboard, but obviously an Rx, gyro, speed control.

Definitely a good deal for what they are going for on ebay, they seem to be inching up in price though. Demand maybe.

Also interesting that Helihobby stopped selling them - perhaps because replacement parts are difficult to stock, OR they may have a heads up from Hirobo that the Korean 'Dragonfly' is an illegal knockoff, & that a true Hirobo product will be released soon. JUST SPECULATION on my part.

warren52nz

Very nice to hear from someone else who's had some considerable experience with these!

I can add some more observations:

If you hold it in your hand while revving it, it will start to shudder after a few seconds, presumably because the gyro (which is an angular velocity type) can't sense any response to its subtle yaw commands and goes berserk trying. This can cause the pinion gears to loosen on the motor shaft after awhile. Symptoms of this are the chopper suddenly starting to spin rapidly on its yaw axis. Other things that can cause this are loose main gears (the big ones) and damaged tail boom. The latter causes vibration in the body, I think, which confuses the gyro. Super glue on the motor shaft will help hold the pinion but be SUPER careful not to get it on the motor bearing!

Also, I have found no good way to hang the antenna lead from the chopper in a way that doesn't end up with it wrapped around the turning bits which can rip it out of the circuit board. If this happens, you need to open up the box and re-solder it... a bit of a mission.

But, the way you wrap the antenna wire can have a profound effect on the receive signal. When I first got my 2nd one, I had a lot of trouble getting the transmitter to "talk" to the chopper. I eventually found that leaving a little half loop in the wire just before it goes into the box and wrapping the rest around the skids (all the way around the outside of both skids in a square works OK. It's probably only that little loop that's getting the signal. The wrapped wire is a significant inductor at 40 MHz (my 1st was 27 and this one's 40) and probably doesn't do much to help the reception. I also put a bit of epoxy on the wire where it enters the body to do a bit of strain relief.

I've had a few instances where the lower rotor assembly has slipped up or down on the hollow shaft and started slipping. Symptoms are rapid rotation (yaw) to the right and loss of lift. I just put a bit of super glue on the shaft and quickly pushed the collar over the spline on the shaft. With super glue, you've got to get it right first time! You could use epoxy instead but you'll have to wait a day before flying again.

Don't lubricate the gears... they'll start to slip.

Both of my choppers wanted to yaw left even on full right trim. On my 2nd one, I've opened up the transmitter and rotated the yaw potentiometer a bit to give it a new centre point which works very well but you need to drill a small hole for the pot locating pin to do this.

Oh, I also changed mine from Mode 1 to Mode 2 by swapping over pots inside the transmitter and the little metal lever that keeps the throttle in the same position if you take your hands off it. But, as Gargoyle says, you could just take it off altogether. Mode 2 puts the "cyclic" on the right stick which makes sense to me.

That's all I can think of right now. Anyone wants any advice just let me know.

R-Rudder

The transmitter consumes very little power. I've been using the same 8 AAs batteries for almost 3 weeks, they still provide enough power to control the x-heli but not enough to power a digital camera.

warren52nz

Yeah but I think the range is very limited too although, as I said, I have the receive antenna wrapped around the skids. On mine, when the batteries finally start to give up, the "turn throttle down" control was the first to go! So watch it!

rcxm

jabo 2 is better , it had 4in1 board, i got one from www.xmseller.com

FlyingFish

My Feedback: (17)

VERY VERY VERY SLUGISH AND POOR CONTROLS !!!!!!!!!! and when the battery dies it just shuts off and drops like a dead bird[X(]

R-Rudder

Just need some practice before finding the sweet spots on the tx. once you find them, you can hear the 4 blades start singing and making some unique pitch sound. Then, you can hover without looking for couple seconds.