RADIO CONTROL HELICOPTERS
Ray Stacy 15 W. Main St., Webster NY 14580 E-mail: [email protected]
Introduction
At roughly this time of year we begin to look for things to do indoors. Christmas has passed, winter has finally set in, and cabin fever isn’t too far off. I think I have found the perfect machine to play with during the times when the weather stops us from going outside: Model Rectifier Corporation’s (MRC’s) new RTF Hirobo Electric XRB Sky Robo R/C Mini Lama helicopter. It gives you true RC, tether-free flying in the comfort of your home. There are no cords to knot up or break!
What’s in the box
Inside the Sky Robo box you will find a complete micro helicopter with:
- A four-channel FM transmitter
- Receiver and two servos
- A 720 mAh Li-Poly battery and wall charger
No work or modifications are necessary. Just charge and fly!
Design and controls
The XRB Sky Robo R/C Mini Lama is the follow-on to the successful tethered version of the same machine. This Lama uses two sets of counter-rotating main blades to provide directional control, yaw, and lift — that’s right; no tail rotor is needed. The bottom set of blades is attached to a swashplate that is controlled by two servos and provides fore/aft and left/right directional control. The top set of blades has a flybar for stability and works in conjunction with the bottom blades to control yaw by speeding up or slowing down to produce left or right yaw. For a left rotation, the top blades speed up and the bottom blades slow down; the opposite happens for a right rotation. Yaw control using this process is amazingly effective.
Blades and motors
The XRB uses four lightweight foam blades. If the Lama’s blades come into contact with an immovable object, they break off and seldom cause additional damage to the model or the object they hit. It takes a few minutes to install new blades, and then you are off and flying again. Spare blades come in a box of 10 for approximately $10. The RC version uses the same blades as the tethered version.
The XRB has two coreless motors—one for each set of blades. The motors have proven to be reliable, and the new metal pinions are perfect for giving many hours of flight time. We average about 15–20 minutes on a charge. Recharging takes roughly an hour. Extra Li-Poly packs are available from MRC.
First impressions and flight stability
I first saw the XRB at a fun-fly last year. Jeff Green from MRC brought the wireless version. After making sure his frequency was clear, he turned on the transmitter and then the helicopter, and while holding it in his hand he brought the rotors up to speed and gave the Lama a little push. It just hovered! Jeff handed me the transmitter, and I spent a few minutes playing before I had to give the radio to the next person.
The XRB’s stability is amazing. The onboard gyro does an excellent job of controlling yaw as well as providing predictable yaw control. It was nothing but fun!
Not for outdoor use (unless modified)
This is not an outdoor helicopter. Those small blades and servos do not have what it takes to penetrate even the slightest breeze. I have been thinking about laminating the foam blades with some fiberglass tape to see if it helps with control while outside.
Caveat about imitations
Being the impatient person that I am, I decided to buy one of the imitations on eBay. I strongly recommend that you don't do this! It was terrible and completely unflyable. It was nothing like the one Jeff had. The seller was convinced the problem was me and would only give me a partial refund. After my experience, I read about a few others who had done the same thing and had the same results. Stay away from the imitations — there is nothing like the Hirobo version.
Training and maneuvers
My son and I really like the original XRB. It was a great tool for teaching a new pilot the various helicopter controls and helping the experienced pilot with maneuvers such as nose-in and backward flight. The cord on the tethered model was always an issue: in time it begins to knot, and sooner or later you want to go beyond the umbilical cord.
As much as we liked the original XRB, the RC version is many times better than any tethered machine out there today. Not only is it a great way to spend some flying time indoors, but it makes a great training tool. Backward figure eights, pirouetting circles, and nose-in are just a few of the many things this micro-marvel can do.
Try to resist flying the Lama before reading the instructions. They are well written and contain great tips about blade tracking, blade balancing, and trimming the helicopter.
Setup tips and support
I noticed that after changing all four blades I could not get the helicopter to stop spinning; I was certain I had broken something. A quick call to Jeff Green revealed that it is common to have to adjust the pitch of the top set of blades after replacing a complete set. Thanks, Jeff! MRC's support is second to none.
The manual even instructs you how to use your JR, Futaba, or Sanwa transmitter. I didn't try this because the supplied transmitter works great.
You may notice some control interaction when flying the Lama, but don't worry about it. I have found that it is a characteristic of the machine that you quickly become comfortable with and even forget about.
The Lama even has an "Advanced Pilot" configuration that increases the sensitivity of response. Changing flybar authority ratio and swapping out the heavier stabilizer weights for the smaller, lighter flybar paddles does this. We found that we prefer the flying characteristics of the paddles to the flybar weights that come installed on the helicopter.
Video and club events
Check out the video of my 9-year-old son Kyle flying his Lama in our shop. He was quickly able to learn pirouetting circles, and it didn't even cost us a blade! You can access that video at: http://64.41.102.82/lama.htm
The local RC club—the Rochester Aero Modeling Society (www.rcplane.com)—sponsors indoor fun-fly events during the winter months. Fellow modeler Don Geldof coordinates the events for us. There were five RC XRB Lamas at the last fun-fly!
Longtime RAMS member and RC airplane pilot Rod Curtis took me up on my offer to fly our Lama awhile back, and sure enough, there he was at the fun-fly with his own Lama. I was impressed by how well he was doing. I guess I forgot to let him know that nose-in was difficult because there he was, out there doing it like a pro!
Where to get one
If you are looking for a way to keep your skills up during bad weather or just looking for a little relaxing entertainment, check out the Hirobo XRB Lama. For more information, contact MRC at:
- Model Rectifier Corporation (MRC)
- 80 Newfield Ave., Edison NJ 08818
- Tel.: (732) 225-2100
- Web site: www.modelrectifier.com
Other news
While putting this column together I received the new Toki two-stroke helicopter engine from MRC/Altech. The Toki-40H is a 40-size engine in a 30-size case. It looks like it will be the perfect way to breathe new life into your 30-size helicopter. You can purchase it with or without the tuned muffler. Check back to see how it performs in the Goheen Stinger 30.
Closing notes
Thanks for all the e-mail. Remember that Cobra I asked about in my first column? In no time at all I had made contact with more than 10 people who either had one or knew where one was. Thank you to everyone who replied.
If you sent me a message and I did not reply, please accept my apology. I use a spam filter, and it works so well that sometimes I even miss real mail. If you did not get a reply from me, chances are your message got hung up in my spam filter and was eventually deleted. Putting the words "Model Aviation" in the subject line will help get my attention.
MA
Transcribed from original scans by AI. Minor OCR errors may remain.
