600N Upgrade Engine Fan Comparison

Written by Tony Chaveiro Monday, 22 October 2007 00:00

Fans

Introduction

When I began thinking about testing all the aftermarket fans that were available for the new 600N, I thought this would be a fairly easy job to accomplish. There had to be one fan that would do its job better than any other. After my initial tests, I soon discovered this wouldn't be as easy as I thought initially as all fans both have their weaknesses and strengths. The fans that were used in these test are the G-Force HeV2 (High Efficiency), the 3DX Fan from 3Dx, the G-Force SHO (Super High Output) and the new QuickUk fan. I didn't bother testing extensively the stock align fan as the question for most 600N owners isn't if the aftermarket fans are better than the stock one (no question about that) but what third party fan is the best. At the time I started the tests, the metal align fan wasn't available yet.

Test Methodology

To try to be as accurate as possible during testing, all fans were tried out for four flights during three consecutive days to assure ambient conditions would be as close as possible. The best of all four flights was used as comparison and the others discarded to avoid confusing as I was constantly adjusting the engine needles for each particular fan. As a recording device, I used an Eagletree Systems USB Micrologger which was set to a capture rate of one frame per second to assure there would be enough memory to adequately record all four flights. The data that was to be recorded included: engine rpm, Rx voltage, instant amperage consumption, cumulative amperage and, of course, engine temperature. The idea behind all those sensors was to not only give an idea of the engine performance but to cross reference the data with servo load (instant amperage draw) and engine power (rpms) during a set of maneuvers. This would assure that I didn’t cheat and fly softly with one fan and trashed the machine around with another. The servo load during a temperature “high peak” and an rpm “low peak” states that a hard maneuver was performed. Just as an example, imagine a back flip. The servo load is higher during the initial and transitional collective bump and much lower during the disc unload phase (vertical nose up and vertical nose down). The same applies for engine temperature although the engine rpm curve will state the opposite i.e. low servo load equals unloaded rotor disc which should reveal a higher rpm. The governor used in these tests was a CSM Revlock 20 with the gain setup at maximum without engine hunting. The power was supplied by a 2600mAh Fromeco Pack and Arizona Regulator. The temperature sensor was the standard Eagletree system’s one and I made a patch to use the existing rpm sensor on the machine for the logger. At the time, CSM was about to release an electronic unit that would be able to tune the main needle of the engine according to the head’s temperature. This device would had probably allow me to show much more consistently and accurately engine performance but even after contacting CSM, I was unable to acquire a unit as it still was in a “beta-testing” stage. Maybe next time I will get the opportunity of using one of those fantastic devices. The helicopter used was a T-Rex 600N pro with Futaba S9351 servos on collective, a Futaba S9254 on throttle, a Logictech 6100T Gyro/tail servo combo and a Futaba 5114 G3 Receiver in 2048 mode. The engine used was an O.S. Hyper 50 with a Hatori #522 muffler.

Flight Report & Results

After all the field tests I can say that all fans were a major improvement over the stock align fan. Not only in terms of performance but also in every other aspect like noise level and ease of installation. It’s much easier to detect a metal fan rubbing inside the fan shroud than it is with a plastic unit. For clarity purposes I decided to divide the results so instead of comparing directly each fan to the all others, I’ll list the data and the pros and contras of each one.