Radio Control Helicopters - 2010/03

Radio Control Helicopters

Mark Fadely [[email protected]]

The indoor storage of outdoor helicopters

Hello again, helicopter people. I hope you are doing well as this late winter/early spring issue hits your mailbox. Yep, the winter that most of us have suffered through is almost over.

This year has been an even better one for indoor electric-powered models. I just got my hands on an Align T-Rex 250SE. Jeff Green at HeliWholesaler sent me one to try. After the machine was assembled, I discovered what all the hype over this little helicopter was about. Keep reading; I will write more about the 250.

It is prudent to take time right now to make sure your outdoor nitro-powered models are ready for the upcoming season.

Many nitro-flying pilots have only a background in electric flight. They may not be aware of some important things to look for when storing nitro helicopters during the winter. Nitros have additional issues of concern when you revive them for their spring flights.

Following are some things you should check before you hit the flying fields.

1. Fuel lines can become damaged and crack during inactive periods. It is smart to replace the fuel line each season.

1. Take apart and inspect your fuel filter for debris that may have accumulated during the previous flying season. If you use muffler pressure to the tank and have a fuel magnet pickup, this is especially important.

1. Remove the muffler and inspect the cylinder, piston/ring, and liner for carbon buildup, scratches, or other damage. If damage is present, install a new ring and liner before starting the engine.

1. The bearings inside the engine usually become worn during the season and tend to hold raw fuel that can gum up during the winter. It never hurts to replace them. An engine with new bearings runs much smoother, with more power.

1. Change the glow plug and start the new season with a clean one.

1. Check all the ball links on the model for fit. Some will be too loose and some may even be too tight. If you can easily pull a link off the ball with your fingers, chances are that it is too loose.

Ball links wear rapidly on 3-D machines. The tail-rotor ball link is notorious for becoming too loose and surprising pilots when tail control is lost during flight. Sometimes loose links on the swashplate will pop off during hard 3-D maneuvers. That is never pretty.

1. Look closely at all the wiring that runs to every device on your helicopter. Pay special attention to areas where wires go around edges of the framework. It is common for wires to chafe against the frame edges. You don't often see the hidden area of chafing until the helicopter starts to glitch or worse.

1. I change my receiver batteries every year, because batteries lose performance in time. You may be able to get a few years on a pack, but with all the vibrations involved with our machines, it makes sense to start every season with a fresh pack.

1. Check the condition of dampers in the rotor head. These rubbery parts keep the rotor disk stable and in track. In the worst case, with worn dampers you may have a midair tailboom strike that can destroy your entire helicopter in a split second. Ask me how I know that—ha ha!

1. Pull the tailboom off of your helicopter and do a critical inspection of the torque-tube/belt-drive system. There is much stress on this area of the model, and you can often find cracks, tears, or other areas of wear that can be hidden inside the tailboom.

1. Check all gears for mesh and broken teeth.

1. Inspect all of the frame members and twist things slightly to see if you find cracks anywhere. Fatigue cracks can show up in the frame anytime. These can cause radio interference and wire chafing if not identified.

Some pilots don't take helicopter maintenance seriously. These are usually the people you see having unexplained crashes and problems at the field.

We invest a lot of time, money, and effort in our beloved hobby, so please don't be lazy about servicing your machines. Keep them in top flying form for your own sake and the safety of everyone.

As I write this, there is still a lot of indoor flying activity occurring. Let's continue the discussion about the little 200-size helicopters.

The 200 class of micro helicopters is heating up. Several models can 3-D the same as their bigger 450-size brothers. The parts of the 200-size helicopters are amazingly small, but modern machining tolerances and manufacturing techniques allow them to fit precisely, which makes the models fly better and last longer.

The T-Rex 250SE

The T-Rex 250 I received is the SE version. It came with everything needed to fly except receiver and battery.

For testing, I installed an Align 3S 850 mAh pack. I had to make two new canopy holes to accommodate the large battery I installed. I thank Andy Panoncillo, Ben Parrott, and Jason Russell for their expert help in getting the model set up properly.

The included heading-hold gyro has a single button that you push to set the parameters. When the 250SE was spooled up for the first time, it had a tail-wag issue. There are two sets of tail rotor blades included with the kit, and the problem went away when the long ones were replaced with the short ones.

Normally I don't get too crazy when flying a new helicopter, but this 250 felt so good that I had to flip it over into an inverted hover on its first flight. We were flying in a tiny space where the model's diminutive size helped with the comfort level.

Surprisingly, the micro T-Rex can gain speed fast, enabling it to fly over as large an area as a 450. It can be maneuvered more tightly as well.

Pirouetting flips or Tic-Tocs can be performed in confined spaces. Basically any 3-D flight with the 250SE can be done in roughly half the area in which a 450 can do it. That makes it nice for pilots who have small indoor venues in which to fly.

The T-Rex's disk loading is higher, so some maneuvers are not as crisp as you might be used to when flying a larger helicopter. The vertical performance and thrust produced is actually shocking. When I pulled the helicopter up into a vertical position and jammed in some collective for a long Rainbow, I think a few pilots at the venue were surprised by its capabilities.

The tail control felt good; however, you can overdrive the tail-holding capabilities by throwing too much collective pitch at it. Because of the higher disk loading, the tail has to work much harder than on larger models. This does not cause a problem; it is just something you have to get used to when transitioning to a smaller-framed helicopter.

If you have thought of trying a micro-size machine, I highly recommend the T-Rex 250SE. It may be tiny, but it's huge on 3-D capability.

I was pleasantly surprised to learn how good the model had become. It is astounding how far the micro electric side of our hobby has come. Thanks go to Jason Krause for designing such a fine machine.

That will be all for this month. I hope you are getting some useful information here each time. It has been a couple of years since I took on this column-writing job and I still get excited about doing it.

Thanks for checking in, and I will be back here next month.

Sources

• HeliWholesaler — (877) 454-9757 — www.heliwholesaler.com
• International Radio Control Helicopter Association — www.ircha.org

Transcribed from original scans by AI. Minor OCR errors may remain.