Tuesday, May 13, 2008

Esky Lama V4 Helicopter Review

The Esky Lama V4 is an inexpensive indoor electric helicopter. For less than $100 USD online, you get a completely assembled and ready-to-fly helicopter, four channel transmitter, LiPo battery, charger, and a spare set of blades. The Lama does not come with training gear or an instructional video like similar models from Tower Hobbies and Horizon Hobbies, but it only costs half as much.





The first thing you'll notice is the two main 13" rotors, each of which has its own 180-sized motor. This coaxial design cancels out the torque of the blades without the need for a tail rotor. This supposedly makes the helicopter more stable and easier to fly for beginners. Turning the nose left and right (i.e. yaw) is accomplished by changing the relative speeds of the top and bottom rotors. While this works quite well, there is a drawback in that turning changes your total downward thrust, so moving the rudder stick can change your altitude. Forward/backward motion as well as left/right roll are determined by two servos which tilt the swashplate. The stock battery is a 7.4V, 800 mah LiPo pack which is good for about 10 minutes of flight. It takes about an hour to charge with the supplied charger/balancer. I was happy to see that this two cell pack has a balancing connector for charging, rather than using the main discharge lead and potentially leaving the cells uneven.





The transmitter is a very basic four channel FM model. It has mechanical trims, servo reverse switches, and a trainer jack on the back. It's serviceable but cheaply made - the battery compartment cover on mine barely stays on. Unfortunately the throttle stick is ratcheted instead of moving smoothly for fine throttle control. See our tutorial for how to remove the ratchet . The good news is that this is a standard 72 MHz setup, so you should be able to swap the receiver crystal and use your own transmitter on your preferred frequency. Flying for the first time was straight forward. There's no assembly involved at all - just charge the battery. It wasn't clear whether the factory had trimmed the controls, so I set them all to neutral and turned on the transmitter. After plugging in the battery, the gyroscope took a few seconds to stabilize, and then lit up solid green. It's important to bring the throttle up slowly to avoid stripping the gears. I was happy to see the Lama come up off the floor easily and seem to be pretty stable. Rather than taking a chance, I took note of which way it was drifting, then landed and adjusted the trims. After a few tries, I was able to get it pretty well dialed in, with the exception of yaw. I found that even with the rudder trimmed fully to the right, the heli would still turn slowly to the left and needed constant correction. An open basement with seven foot ceilings was enough space to learn how to fly, but more height would have been better. Spending a few hours on a simulator before the first flight also helped a lot in terms of orientation and anticipating what the controls would do. It only took a couple months to go from a first-time heli pilot to having a good feel for what the Lama V4 can do. It can easily fly tight circles forwards and backwards indoors, and it's maneuverable enough to land on a small table top. Forward flight seems somewhat limited, but it does move backward pretty well. In very calm weather the Lama can be flown outside, but even a slight breeze will make it impossible to hover even with full cyclic. If you're feeling adventurous, you can lengthen the servo arms in order to give the swashplate a bigger range of motion, but you'll need to upgrade to a longer main shaft to further separate the top and bottom blades. Flying the Lama V4 is really addictive. It's a very easy helicopter to learn on, and it's remarkably tough. It's endured more crashes than I can count, and the only things that have broken are the rotor blades and one side of the landing gear. The flybar has a resilient design which causes it to pop out undamaged in a crash, which is a great feature. It's important when reattaching it to make sure that the upper blades pivot freely, which largely determines how stably the heli will hover. The black plastic blades that come with the helicopter are pretty fragile, cracking and splitting after a few crashes. The Lama will still fly with some imperfections in the blades, but this tends to create vibration throughout the body. I decided to try the Xtreme replacement blades which are popular on RC Groups . These white blades have proven dramatically better in terms of toughness, and don't show any signs of damage after repeated crashes. Several times I've experienced blade clashes, where the top and bottom rotors touch during aggressive flying, but the blades were unharmed. These are well worth the money ($8-10 for the entire set) and should be your first upgrade. I also bought the "indestructible" landing gear for the Blade CX which fit the Lama without modifications. They happened to arrive the day I broke the right factory skid. The new ones are visibly thicker than the standard ones, and so far have held up without any problems. There are many other upgrade parts available, including aluminum replacements for most of the head. It's not clear whether these improve flight performance, and a complete set costs as much as the helicopter itself. Overall I'm very impressed with the Esky Lama V4. This four channel helicopter is a huge step up over the two and three channel toys out there, and is not much more expensive. When properly set up, it can hold its own with similar models from Blade and Heli-Max that cost more. The Lama is a huge amount of fun and is easy enough for someone with only airplane experience to fly.

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