RADIO CONTROL HELICOPTERS
Eric Hawkinson
319 Yellowstone Ave., Billings MT 59101 E-mail: eric@heliproz.com
It's another great month to be enjoying the sport of radio control (RC) helicopters! If all is well in the world, this issue will come out at roughly the time many of you have just started on new projects you received from Santa, some of which will be first-time helicopter projects for experienced airplane fliers. I'll have some info for that group shortly. First, I have some updates on products I mentioned in the last column.
Raptor 30 V2 and engine notes
My new Thunder Tiger Raptor 30 V2 (short for Version 2) I wrote about last month now has much more time on it, with me as pilot and my flying pal and co-worker Kurt Kreiger. The more we fly it, the more we like it. The helicopter is trouble-free to date and, for reasons we are not sure of, actually flies better and smoother than the original version. Not hugely so, but noticeably better. Our guess is that the smoother handling is caused by the larger bearing and spindle. Whatever the cause, it flies very nicely.
The other part of the "new helicopter" equation that is turning out to be a pleasant surprise is the new engine. As you'll recall, I installed the new Thunder Tiger .39 Pro helicopter engine in the Raptor and promised to report on it as we got some fuel burned. After almost two cases of Cool Power 30% helicopter fuel, the engine has shown good handling and good power. You won't mistake the power for an O.S. .50, but you certainly will see a marked increase in power compared to the venerable O.S. .32 SX-H.
The TT39 starts easily and runs smoothly throughout the range. It is a ringed engine and is pretty tight during break-in. I was very glad that I had installed the Venom onboard thermometer prior to flying because even after a gallon of fuel, it was easy to see overly hot temperatures even when the engine was producing plenty of smoke. I ended up leaving the needle at least as rich as the recommended break-in settings long after a normal break-in period. Be cautious with the needle for at least the first case of fuel with this engine.
The muffler supplied with the Raptor 30 V2 (if you buy the engine and helicopter as a package) is a new-style cast-aluminum part that runs fairly well. I replaced mine with the Mavrikk muffler after the first gallon and saw only a small improvement in running. I mostly just changed it because my past experiences with cast mufflers have been mixed. Beginners should just go ahead and run the stock one.
While writing this column I received the official announcement from Ace Hobby Distributors (the U.S. importer and distributor) that the Raptor 50 had been discontinued. Strangely enough, there was no concurrent word on the release of the new Raptor 50 V2, which is no doubt due out soon. I expect that the Raptor 50 V2 will be much the same as the 30 V2 except for the upgrades and changes that are required for the 50-class engines. I'll give more details when I have the new kit in my hands.
Tips for airplane pilots starting helicopter projects
As promised, I have some notes for the airplane pilot who is starting (or planning to start) a helicopter project. We talk to a fair number of these people at the shop where I work, and it is usually about how much added equipment they will need for helicopters. Not all airplane pilots have the same flight-support equipment and tools, but they usually have a pretty good chunk of the things they would need to buy if they had no prior involvement in the hobby. All of the propeller wrenches, glow-plug wrenches, glow-plug lighters, fueling equipment, and electric starters are equally applicable to helicopter use. The same metric hex drivers that many of you have for working on engines will suffice for helicopter use, although you will want something better than the cheap "L" wrenches if you are going to be involved with helicopters for any length of time.
However, even the better-equipped airplane pilot will need a few tools that will be new to their arsenal. They are as follows.
Tools and equipment (recommended)
- Ball-link pliers: Available in several brands with various differences. All of the good ones look like a pair of needle-nose pliers with a peculiar tip. You need these to install and remove the plastic links from the metal link balls that make up dozens of the connections on your helicopter's control system. Prices range from $13 to $30.
- Starter adapter: Most helicopters now use a 6mm hex receiver cup that you insert a starting probe into. These starting probes come in many versions, and you need to order the type that fits into the system on your model. Some helicopter clutches use a one-way bearing on the clutch, in which case you want a start shaft that includes a one-way bearing. Depending on brand and whether you need a bearing, cost will be $9–$39. For 30-size helicopters, most airplane electric starters will do fine to drive the start shaft.
- Pitch gauge: This gauge is used to check the main blade pitch angle at the various throttle/collective stick positions. Yes, you need one. Price ranges from $26 to $40. I prefer the Heli-Max unit. It's not perfectly accurate at high angles, but it is the easiest to read with a bright-red body and white markings. I generally dislike the types of gauges that use bubble levels; they are far more complicated to use and are harder to read accurately.
- Blade balancer: You can cobble up various ways to balance your blades spanwise and blade-to-blade, but it's far quicker and easier to use a blade balancer. KSJ sells a good working unit for roughly $40 that is simple to use. The "deluxe" balancer is the Koll Rotor Pro; it's more accurate and can also do chordwise balancing checks. The Koll sells for approximately $80.
- Hardened hex drivers: The cheap L wrenches will do in a pinch, but you will want a good set of metric hex drivers for all of the metric bolts on your helicopter. You should be able to get a good basic set for $20–$30.
- JIS screwdrivers: Most of the non-hex fasteners you'll find on helicopters appear to be Phillips-head screws, but they are usually Japanese Industrial Standard (JIS). You should be able to get a set of high-quality JIS screwdrivers for roughly $20.
- Foam blade holder: For $3–$5, this simple item allows you to fold the main blades back over the boom and stow them for storage and transport.
Other recommended items (not absolutely required)
- High point balancer: You may already have one for balancing propellers. On helicopters there are many things that really should be checked and fixed for balance: clutches, flywheels, tail-rotor assembly, main grip assembly, and so on.
- Thermometers: You can't run up a helicopter engine and pinch the fuel line to see if the needle is set right because the main blades will whack you in the head. The only way to accurately assess the needle setting is to check the engine temperature. The two best methods are the Raytek infrared thermometer (a handheld tool for $79–$99) and an onboard thermometer that has a high-temperature recall. I use both of those. The Raytek is handy for lots of other jobs and is an accurate device. The Venom onboard thermometer is accurate enough and is easy to use; you just read the LCD. These are available for $28–$32. With either, you then adjust the needle—richen it if the temperature is too low and lean it if the temperature is too high.
- Remote glow-plug adapter: On many helicopters, you'll need to remove the canopy every time you want to start the engine if you do not use a remote glow-plug adapter. For $5–$9 each, there are many versions of remote adapters available that make life easier.
- Paddle-alignment gauges: For $7–$15 you can make the difficult job of getting the flybar paddles aligned much easier. As with the pitch gauge, you visually align the straight line.
I'm stretching my space allotment, so that will have to do it for now. Until next time, fly safely and happy motoring!
- EH
Transcribed from original scans by AI. Minor OCR errors may remain.
