I knew I was in trouble when I saw the teeny helicopter flying around the hobby shop. I didnt have any particular reason to be in there in the first place, but I saw the XRB and ooo its a Llama! (my favorite) and it was was electric! and it was RTF! Well, I knew right then I was leaving $340 lighter. I searched through the small mountain of XRBs and found one on the same channel as my Futaba 9C so I can use that transmitter if I want.

This amazing little heli really does fly quite well right out of the box. And I have no experience with helis! I think its just the coolest. Ive gone through a few sets of blades, and Im pretty sure my dogs dont approve, but I can now fly mini recon missions around my living room! Brilliant!

I just had a couple questions if anyone knows?

Top speed of XRB?
Coreless motor = brushless motor? or Whats a coreless motor?
Cargo capacity? Could it carry a six pack?

You sound like me when I got started flying helis with a XRB.
I saw Steve Rojecki flying one in our local gym, and I knew right then I HAD to have one. Ordered one from Tony Stillman at Radio South that night. Two weeks later....

NERRRRRRUUUUOOOOOOOOOO WOPWOPWOPWOPWOPWOP....I was flying a heli.


I still have that heli, and despite multiple offers, Im not selling it. Its one of my favorites.

Top speed??? probably about 15 mph or so.

Coreless motor does not = brushless motor....but it is a vast improvement over brushed motors.

"Major advantages of coreless motors include very low inertia, low mechanical time constant, and high efficiency. Because the core is ironless, its low mass allows more rapid acceleration and deceleration than any other class of dc motor.

Other benefits gained by eliminating the iron core include the absence of magnetic fields acting on the laminations. This interaction in conventional motors appears as torque ripple or cogging plus a resisting torque that decreases motor efficiency. The absence of iron eliminates cogging and the coreless motor operates smoothly, even at low speeds.

Elimination of the iron core dramatically diminishes rotor inductance and resultant arcing. Commutator arcing in conventional motors is caused primarily by the release of stored energy in the armature inductance upon commutation. Excessive arcing produces electrical noise and reduces the life of brushes.

Coreless motors are classified by rotor shapes as cylindrical or disc. Cylindrical rotors are further divided into those containing inside fields or outside fields. The disc types have pancake, printed, or three-coil rotors.

The cylindrical outside-field motor has the smallest mechanical time constant. The stator is a cylindrical permanent magnet surrounded by a mild steel housing. The rotor is a hollow cylindrical coil wound of copper wire and located in the center of the stator. A mechanical time constant of 1 msec is not unusual for this type of motor.

Rotors are typically wound in a skewed or honeycomb pattern (also known as Faulhaber winding) to ensure that all of the core helps produce torque and smooth operation. The flux lines extend radially outward from the permanent-magnet stator through the air gap. The soft iron housing is the flux return path which allows the air gap to be extremely small, producing a high flux density.

The cylindrical inside-field motor is a similar design, but the permanent-magnet stator is located inside the hollow rotor. The motor also features a low moment of inertia, but the mechanical time constant is typically higher than the outside-field motor because of smaller stator magnets.

Coreless motor commutators and brushes are typically small, primarily because they are made of precious metals -- gold, silver, platinum, or palladium. In addition, a smaller commutator has lower peripheral speed, less wear, and accounts for a smaller motor.

Outside-field motors are usually selected for high acceleration. Because of this, the rotor coils must handle a large load torque and dissipate high heat produced by peak currents. To handle the torque, manufacturers strengthen the rotor with glass epoxy. Since the rotor does not have an iron core to act as a heat sink, the housing has ports for forced air cooling.

Recent advances in coreless motor design include the replacement of AlNiCo with samarium-cobalt stator magnets. Also, the mechanical time constant is reduced by as much as two times with aluminum rotor wire instead of copper.

Typical accelerations for these improved motors are 150,000 rad/sec2, but rates up to 1 million rad/sec2 are possible. This greatly exceeds the 30,000 to 50,000 rad/sec2 rates available with iron-core rotor motors. "

Cargo capacity.....probably not much. Definatly not a six-pack, but it will carry a couple of GI-Joes for some heli "rescue missions".

Here's a link to some video of me "turnin&burnin" with the XRB one week after I got it.
http://www.revolutionaircraft.com/IMAGES/HiroboXRB.wmv

Good answer. Thanks.

uhh that hirobo is looking even better, for me I'm either going to get the XRB the MIRCON (with a few less items to lower the price) or the #4

which one would you suggest, I'm a decent flier so the hardness doesn't matter (actually if it was harder it may be better) but I want something I can fly in my room, but if that's not possible it MUST be fun, which seems the XRB is taking the lead, any perticular place to get it? I definatly want it for under $200 and I don't care if it's off Ebay.

I still think the Hirobo XRB is at the top of the stack for a small training heli, or just goofing around in the house. Its just a really good running heli. I lost count of the flights mine has had, I know its over 300 or so. When I first got it I was flying 3-5 flights a day or more everyday for about a month. Ive not had to replace any parts other than the blades. I cut took the tail off of mine and replaced it with a carbon fiber boom, but im probably going to go back to the original tail to take it back to its former scale appearance.

Ive used both the carbon fiber blades and the foam blades that it comes with. For general in the house flying, the foamies are the best. If you go in a gym and want to yank and bank, go with the carbon ones, just be prepared to have to retrim and reset the gyro inbetween the blade changes due to differences in the blades.

My XRB has been crashed....and hard. But so far no serious damage. Usually all that happens is the blades pop, and the flybar unclips itself. Just snap the flybar back into the top of the head, replace the blades, pop a new battery in there and go flying again.

I will mention this. DONT fly battery after battery after battery through the XRB. Give it a chance to cool down between flights. The coreless motors get really hot after a 15-20min flight, and you need to let them cool down before flying again. If you dont, you can either burn up a motor....or the most common problem is fracturing the pinion gear. If you just get the battery that comes with the XRB, you can let it cool down while the battery is charging, thats what I do.


The XRB is really easy to fly, and fun. Its just so simple in design and flight charectoristics. Its not a aerobatic powerhouse, but its not designed to be either. Its designed to just hover and putz around. Think of it as the Piper Cub of Helicopters.

The XRB is still the best I have over 2500 flight hours on mine and all I have broken was some rotor blades and a tail boom(Dumb Thumb) and the motors are running fine.I made a couple of heat sinks for mine and I run three 1000mah battery packs that I made for it one after another and I only get up to 100 degrees on the motor when finished.If you really get into it forget the stock battery's make your own the ones I made are great they fly for around 15 to18 minutes and have plenty of power.I used the wire and plugs off of my three old stock battery packs and so they still can be charged with the stock charger,balancer that came with the heli.

Hello,
I want to buy an electro helicopter and that's why I've been reading posts these days. I've read bdavison's review on Hirobo XRB Lama and that's why I searched on ebay to see the price of it. I found it with 300 Euros.
I also found it's half brother Hirobo XRB Shuttle with 250 Euros. I looked for reviews on it on the forum but haven't found any. Which is better?

I also found the Syma Dragonfly with 30 Euros. What's with this huge price difference?
An advantage of Dragonfly is that you can use it outdoors comparing to the indoor Hirobo XRBs.

Regards,
Alex

The hirobo shuttle is identical to the XRB, just has a different shell. Either would be a good choice.

How about Syma Dragonfly, which is 10 times cheaper? Is it 10 times worse than Hirobo XRB? What do you think are the problems with Syma Dragonfly?

I want to equip the helicopter with a controller and a lens. Can Hirobo XRB sustain more weight? How heavy are the removable shell and tail? Can it fly without them?

Thank you

I have not been impressed with the cheap knockoffs. You have to understand that Hirobo makes some of the finest quality heli's out there. Their stuff is ROCK solid, well designed and built to last. Unfortunatly many of the knockoff's are not, and are not worth even considering. Ive never flown the Syma one, but I have flown the Esky one.

Do yourself a favor and get the Hirobo. I know its expensive, but you honestly pay for what you get. The XRB is better than the BladeCX in my opinion. Follow the well written instructions to fine tune the heli, and it will last forever. I dont even know how many flights mine has now...Im guessing well into 1000 flights. The only repairs so far, is replaced the lipo, quite a few sets of blades, and a flybar pitch link (it popped off in a crash and I couldnt find it).

The heli will fly without the canopy, but not without the tail. The CG is too far off, and it acts funny without the tail, not to mention the fact that you cant tell which way is which if the heli yaws.
You might be able to equip the heli with a wireless camera, but it would have to be a very VERY small camera, Im thinking payload maybe 40g total weight would be reasonable, and dont expect much performance from the heli if you load it down. If you get the carbonfiber blades, you might be able to get a little more payload on it.

You have been very helpful.
Are those 40g paylod with the canopy on?
If yes, what is the weight of the canopy?
I have found on ebay only replaceble foam blades for Hirobo XRB. Does any carbon fiber blades work, or must they be specialy designed for the Hirobo XRB?

The canopy is just molded acetate, it really doesnt weigh much at all. Im saying stock right out of the box, with canopy, and tail ready to fly....you could add 40g to the helicopter is probably a fair estimate at what you could carry with it and still have reasonable control. Im guessing max payload is probably somewhere around 123g before it just wont fly anymore. Think one 9V battery, and the really tiny pinhole camera would probably be the most you could put on it and still be able to max performance. Anything more than that, and it would start affecting performance.

As far as the carbon blades, I think helihobby.com has them. I got mine from a company in canada, but I cant remember who or where they are. They aren't cheap though, as a matter of fact...they are downright rediculasly expensive. $50 for a set last time I checked.

If you stick with the foam ones. Cover them with clear packing tape. It will make them a little more durable.
If you are running a heavy payload, check them around the root of the blade every 10 flights or so. The foam will weaken eventually around the blade grip, especially under loads or aggresive flying. Just pop another set on and your ready to go again. Blades are pretty cheap(at least the foam ones) Normally its about 20 bucks for 6? sets of the foamy blades.

Hello again,
I received the heli without the remote control.
It says the remote control should be at 35Mhz, channel 72. What's channel 72?

Is the following remote control suitable?

Graupner X-412 UNIT 35 MHZ GR.-NO. 4713
Micro-computer radio control system with 6 control functions. X-412 COMPUTER SYSTEM 6-channel FM radio control system. 35 MHz band.

Regards,
Alex

Dancu:

You can get the carbon fiber blades for the XRB at Canadian$ 45 from Star Flight (www.jutstar.com). They are efficient and ship the items out quickly as soon as they confirm payment thru PAYPAL or by credit card.

I hope you are enjoying your Hirobo as much as I do mine. In fact, I bought another XRB, the Lama (I have the Shuttle with a painted shark face canopy and United States Marine Corp insignias.

Joey [8D]