Secrets For Setting Up 120-Degree eCCPM
The MSH Protos is a very high performance 500-class electric helicopter from Italy, and the Protos is now available in hobby shops and from mail order places in the US at a very reasonable price. One of the places that stock Protos in the USA is ReadyHeli. In addition to reviewing the Protos I will explain the basics of setting up a 120-degree eCCPM (electronic cyclic-collective pitch mixing) control system. Use these tips and tricks and you will enjoy superb heli performance.
The original Protos was unveiled two years ago. The Protos was designed by two Italians with their last names starting with M and S, that is why they named their company MSH which stands for MS Helicopter. MSH is located about 15 miles west of Milan, Italy. Before MSH was launched, Mr. M and Mr. S were already famous for making Heli-up branded high quality aftermarket parts for the Align T-Rex 450. When Align switched to all-metal construction for their T-Rex 450 and improved their parts quality, there was no longer a need for aftermarket upgrades, so the two gentlemen formed MSH and designed a new electric helicopter called the Protos. The standard Protos is an excellent value at only around $350 because it comes with a brushless motor and a pair of 430mm SAB carbon blades, made in Italy. The Protos kit alone is under $300. MSHs specialty is injection molding and they have a separate business making injection molded parts for other industries. The quality of the Protos parts is superb.
MSH is also famous for making a nearly indestructible Gorilla landing gear for the Align T-Rex and other models. In 2009, MSH released a version of the Protos with a deluxe carbon side frame. I have built and flown both versions, and they fly equally well. The carbon framed version, of course, has that cooler hi-tech look. Performance wise, the plastic framed Protos flies just as well because all the critical drivetrain and rotor head components are identical, and the motor, ESC, battery pack and blades used are the same.
The flight performance of the Protos is fantastic. Like so many fine Italian products, including Ferraris and Lamborghinis, the Protos is sleek looking and powerful. The Protos is very light, and when powered by Thunder Powers new 45C rated 6S, 2650mAh LiPo battery pack it becomes a rocketship. The Thunder Power 45C pack can dish out 119 amps continuously, and that is much more than needed. I highly recommend this battery pack for the Protos. After a 5-minute 3D flight, the battery is just luke warm! The charger I recommend is the new Thunder Power TP610C AC-DC charger. The TP610C DC charger has been around for three years. The new AC-DC version uses the same charger design, but with the added capability to permit powering it by a 12 volt DC voltage source, or from a 110 volt AC outlet.
Protos high quality injection molded 2-piece frames are strong and facilitate assembly.
The toothed tail rotor drive belt also wraps around the motor pinion to drive the main rotor.
The excellent power-to-weight ratio of the Protos makes it ideal for extreme 3D aerobatics. It is ultra fast in forward flight. Cyclic and collective controls are crisp and precise. With the Protos, all three eCCPM servos are mounted directly to the molded side frames. The servos are spaced to give 120Âº eCCPM control. The swashplate is connected directly to the servos via three straight pushrods, and no intermediate bellcranks are used. Three Hitec digital HS-5245 mini servos are used on my Protos.
MSH protos mechanics left side.
The drive train of the Protos is unique. The tail rotor tooth belt is also used to transfer power from the motor pinion to the main rotor main gear and then the same belt is used to transfer power to drive the tail rotor. This all worked very well and produced a light weight helicopter. The vertical performance and acceleration of the Protos, with all due respect for the fantastic and on some levels revolutionary Align products, is in my personal opinion a bit better than my T-Rex 500, which also runs the same Thunder Power 6S LiPo battery pack. This is a subjective thing as I have not put data loggers on these helis to compare performance; its just my gut feeling.
The Thunder Power 45C 6S Li-Po gives the Protos more power than necessary for the average 3D flight envelope. It is ballistic with the main rotor screaming at 3000 rpm! Although I have not radar gunned it, my impression is that the horizontal speed must exceed 80 mph. For most people, I suggest use the same pinion, but just try a 5S battery pack first because that already gives a very aggressive, sporty performance. Running on 6S is for the pros and really gives an adrenalin rush.
120 VS 140 ECCPM
Some eCCPM models permit choosing 120Âº or 140Âº eCCPM control by changing the length of two steel ball studs on the swashplate. In reality, during flight, it is difficult to feel differences between 120Âº and 140Âº eCCPM. I have tried both 120Âº and 140Âº eCCPM on my JR Vibe 50 and 90, and the bottom line is: when high speed servos are used, it almost makes no difference whether using 120Âº or 140Âº eCCPM. For example, on the Vibe 90, I have tried different digital servos, including both high speed/high voltage servos, and simply good digital servos. My conclusion is that as long as one uses high quality, newer digital servos (and servos have been improving at a remarkable pace) with zero dead band and zero gear freeplay, then you will enjoy excellent handling. The secret with any eCCPM controlled RC helicopter is simple: use modern high grade servos and never use low grade servos.
MSH Protos mechanics right side.
With many eCCPM helicopters, especially electric models, such as the Protos, to save weight, the swashplate is connected directly to the three eCCPM servos by using a direct pushrod link between the servo and the swashplate. In this case, the advantage is it saves weight and reduces complexity. But the drawback is all vibratory and steady loads from the main rotor blades can transfer directly to the servo gear train. In a crash, the shock of the blades could cause plain nylon servo gears to break teeth.
Larger models usually use a push-pull lever in between the servo and the swashplate. The advantage of using a push-pull lever is that it reduces direct feedback loading from the blades to the servos, because the loads must go through the bellcrank. The disadvantage is extra complexity and weight, but with medium to large size helicopters it is desirable to have a push-pull linkage. Small electric helicopters typically skip push-pull to save weight and complexity. With either direct drive or with a bellcrank, it is still necessary to use highest quality servos to ensure zero free play in the control system: only then can we be assured that the helicopter will obey every tiny input we tell the model to do.
When the Idle-Up switch is turned on, and the throttle collective stick is at the center, the servo arms for all three eCCPM control servos should sit horizontal, and the main rotor blade pitch angle should be at zero degrees.
SETTING UP ECCPM
The Bell-Hiller mixing arm for the Protos is mounted on the blade pitch control arm. Since the pivoting point of the Bell-Hiller mixing arm is in line with the main rotor shaft, and directly above the flybar, it has a zero degree Delta-3 angle. Zero Delta-3 provides no pitch-flap coupling, and some designers and pilots prefer keeping the rotor geometry at a pure zero coupling angle to give uncoupled kinematics. And yet some other designers prefer tweaking the layout to fine tune handling. I suggest leaving the helicopter as is and do not modify anything because the designers and the engineers who manufacture these products should have tested their machine to optimize the model already. Please see the photo to see exactly what zero Delta-3 means.
Here we see how the Bell-Hiller mixing arm is mounted to the main rotor blade pitch control arm and the Bell-Hiller mixing arm is connected to the flybar seesaw.
This shows the main rotor and the eCCPM swashplate. 120 degree eCCPM means that the three control input pints on the swashplate are located 120 degrees apart. When all three servos move in unison the swashplate rises or lowers to change collective pitch.
The pictures also show where to mount the steel balls on the Bell-Hiller mixing arm. On the Protos, the Bell-Hiller mixing arms has two hole choices for mounting the steel ball for the pushrod connecting to the swashplate. I recommend using the inner hole because this reduces the control sensitivity to the collective and it will still easily provide +11 to -11 degrees of collective travel range.
The following setup procedures are for intermediate level pilots who are using the Idle- Up feature. First, program the transmitter throttle and pitch curves according to the Throttle and Pitch Curve Setup article I published in issue two of RC Heli Pilot. Once the transmitter throttle and pitch curve values have been programmed, then turn on Idle- Up, and move the throttle-collective control stick to the center. The servo arms should be exactly horizontal. If the servo arms are not horizontal then remove the servo arm screws and rotate the servo arm by one or two spline tooth increments until the arms become close to horizontal. Then, use the subtrim feature in your transmitter to make sure each one of the three servo arms is horizontal. Please check the direction of the cyclic controls to ensure left cyclic command tilts the swashplate to the left and a forward cyclic command on the transmitter tilts the swashplate forward. Raising the throttle-collective stick should raise the swashplate and increases blade pitch angle.
The yellow imaginary line shows that the pivoting point of the Bell-Hiller mixing arm is in the middle of the rotor hub and this means there is zero Delta-3 angle.
Some optional metal parts for the Protos. They include washout arms, Bell-Hiller mixing arms, metal pulleys for the tail rotor drive belt, metal mount for the tail rotor control servo, metal seesaw and motor mount.
Next, bring the throttle-collective stick back to center. Next adjust the three pushrods from the three servo arms linked to the swashplate until the swashplate is perfectly level. There is an aftermarket gadget designed and produced by Mike Fortune that uses a bubble level to check if the swashplate is level. At this time, the swashplate should be approximately in the middle of the total vertical travel range, if not, then adjust the pushrod lengths for all three pushrods.
In this picture the pushrod from the swashplate is connected to the inner hole on the Bell-Hiller mixing arm.n This means that for a given amount of swashplate vertical movement, there will be more blade pitch angle change. This gives more Bell action and less Hiller action.
The pushrod from the swashplate is connected to the outer hole on the Bell-Hiller mixing arm, this means for a given amount of swashplate vertical movement, there will be less blade pitch angle change. This gives less Bell action and more Hiller action.
BLADE PITCH EXTREMES
Next move the throttle/collective stick from high to low, and use a pitch gauge to measure the blade angle at full positive and full negative positions. In general, I like to set up all my 3D helicopters, such as the Protos, at +11 to -11 degrees of total collective travel. If you do not get the necessary travel range, then go to the CCPM swashplate menu and adjust the pitch travel value. Normally, the factory preset value for Pitch in the Swashplate Menu is 60. I recommend using a value between 60 and 75. If the value is lower than 60, then it means the servo arm is not rotating very much, and you are not taking full advantage of the resolution of the servo rotational movement.
Bottom side of Protos tail rotor showing the tail pitch control bellcrank.
Note the simple and functional tail rotor design along with precision pitch change mechanism on the Protos.
Ideally, for eCCPM helicopters, when a pitch value of 60 to 70 is used then the servo arms rotate approximately +30 and “30 degrees. If the value is greater than 75, then the servo arm is rotating too much (it would be rotating +40 to -40 degrees). That is not desirable because two roll servos moving opposite each other to give roll cyclic control can start to introduce unwanted coupling between cyclic and collective motion.
SERVO ARM LENGTH
If you can not get the desired +11 to -11 degrees collective travel range with the Swashplate Menu pitch value between 60 and 75, then change the servo arm to a longer one. On the Protos and most 120 degree eCCPM helicopters, a servo arm of around 14 to 16 mm is needed. In the Swashplate Menu you will also notice there are settings for roll cyclic and fore/aft cyclic. In JR transmitters, they are labeled as Aileron and Elevator. In the photos, I used 70 for Aileron, 70 for Elevator, and 75 for Collective Pitch.
This is the deluxe carbon frame version of the MSH Protos. All Protos come with a painted, light weight fiberglass canopy.
END POINT ADJUSTMENT
Travel Adjustment or End-point adjustment (EPA) is used to set how much movement the servo arm can swing in each direction. On most radios, the left and right movements of the servo arm can be individually set from 0 to 150% of the maximum throw. The End-Point Adjustment is used to control the servo total travel range. I suggest leaving them at as close to 100% as possible.
This shows the transmitter swashplate menu for the 120 degree eCCPM. Regardless of which brand of radio used, it is better to keep the values for the cyclic and collective pitch travel volume at between 60 and 75.
Try to keep all Subtrims at zero. But sometimes one has to use Subtrim to make the servo arms horizontal at a zero degree collective pitch angle. Here channels 2 and 6 require 20% subtrim. As a good practice try to keep Travel Endpoints Try to keep all Subtrims at zero. But sometimes one has to use Subtrim to make the servo arms horizontal at a zero degree collective pitch angle. Here channels 2 and 6 require 20% subtrim.
As a good practice try to keep Travel Endpoints at 100% on both ends. Occasionally, it is required to use a value between 90 and 110 to fine tune the control sensitivity.
Usually, if the above mechanical and radio setup tips are followed, then the helicopter should fly almost hands-off and will require minimal trim changes on the maiden flight. I recommend spending time setting up the model mechanically as best as you can, and then you should rely minimally on the transmitters electronic features. The electronic features of a modern helicopter transmitter should be used only to assist in fine tuning the mechanics to make the helicopter perfect.
The author recommends the Thunder Power 2650 mAh 6S 45C Li-Po battery for experienced 3D fliers and the 5S for sport fliers.
In the future, I plan to publish an article discussing the different types of undesirable control cross couplings that can cause problems for your helis optimal performance, and I will also use an entry level 3D helicopter to explain how to set up eCCPM for the first time 3D pilot. An example: in general, for a beginner, it is better to use only a small amount of negative pitch at low throttle on the collective stick; for example just -2 degrees. But it is still recommended that the beginner use +10 or +11 degrees at maximum positive collective pitch. I highly recommend that you get a copy of the previous issue of RC Heli Pilot in which I explained setting up the pitch travel and pitch curves. The Blade SR model that I reviewed in Issue 3 is an excellent example of a beginner level 120Âº eCCPM helicopter, but the Blade SR comes fully assembled and even test flown at the factory, so one does not have to worry about setting it up.
The Protos is easy to build and is well engineered.
Please check out the MSH Protos, it is a very high performance 500-class electric model and it is a great value. Either the plastic or the carbon version will provide ballistic flight performance. For sport fliers, I recommend trying a 5S Thunder Power 2650mAh 45C LiPo pack. For experienced 3D pilots, the Thunder Power 6S 2650mAh Li-Po will give you an unbelievable ride. I recommend buying the Protos with the motor and ESC/blade packaged in because that takes the guess work out. See you next issue!
HELICOPTER: MSH Protos
MANUFACTURER: MSHeli (MSH)
TYPE: 500-size electric helicopter
FOR: Intermediate to advanced
FLYING WEIGHT: 3.5 lb.
MAIN GEAR RATIO: 4.65:1 (Variable);
MAIN GEAR: 93 teeth
BLADES: 425 mm
ROTOR SPAN: 965 mm
TAIL ROTOR DIAMETER: 192 mm
LENGTH WITHOUT BLADES: 892 mm.
HEIGHT: 282 mm
POWER SYSTEM: MSH brushless motor, MSH ESC, Thunder Power 45C 6S 2650 mAh LiPo
BATTERY/CHARGER: Thunder Power 610C AC-DC
RADIO: Spektrum 2.4 GHz DX7, Spektrum AR7000 receiver, ECCPM servos: Hitec HS-5245 MGs; Gyro: JR770
High quality parts, already painted canopy, extremely light weight helicopter, easy to build and a great 3D flyer. Ball links required some fine tuning. Excellent value for the money, and we recommend the combo version with motor, ESC and blades. The Protos comes with a beautifully painted canopy. In the hands of experts, this helicopter can do every 3D maneuver in the book.
Fortune Model Products, www.fortunemodelproducts.com, (901) 568-6200
MSHeli, www.readyheli.com, (888) 739-4354
Thunder Power RC, www.thunderpowerrc.com , (702) 228-8883