Hello everyone.

It is time to take you to Hirobo School. Today you will be learning about the newer style of bell-hiller rotor heads that Hirobo offers. We have a special guest today, Dr. Ben Minor, teaching you about the heads and the different mixing options that you have at your disposable with the purchase of a Hirobo helicopter or Hirobo head.

Let's Begin

The FZ-5 rotor head for the SDX (or can be fitted to the Sceadu) and the SSZ-4 / SSZ-5 rotor head for the Eagle 3, Turbulence D3 and Freya are advertised as the most adjustable tunable heads on the market. They surely are, yet not many know how to tune them to suit their personal flying style.

Note - something to keep in mind while reading this: The FZ-5, SZ-5 and the SSZ-4 rotor heads are essentially the same in terms of head tuning and configuration.

click to enlarge photos      

FZ-5 0412-320

The FZ-5 rotor head comes with Hirobo’s New SDX kit. It is a super rigid head that is meant for 3D. It is very forgiving and inexpensive to repair in case of a crash because it is made up of a fiber infused plastic that makes it stiff but not brittle. Ask any SDX owner about the quality of the head and you will hear the same thing. “It’s the best plastic you can get in the hobby!”


SZ-5 0412-326

The SZ-5 rotor head is an upgrade for the FZ-5 rotor head.
This head is made out of anodized aluminum. Not only does
it have the “Bling” factor but it is even more rigid than the FZ-5 rotor head because of its anodized aluminum. This has the same dimensions as the FZ-5 rotor head.

SSZ-4 0414-455

The SSZ-IV rotor head is the Big Brother of the FZ-5 and SZ-5 rotor heads. This head has larger blade grips for the larger 90 sized helicopters. You would fly this head on a converted Freya or a Turbulence D3

SSZ-5 0414-518

The SSZ-V rotor head was developed for the AOCC 2008 and for the newest F3C rules. This head will be affected less by wind and that’s makes the head perfect for schedule C maneuvers with lots of pirouettes, aerobatics, inverted maneuvers and especially outside loops. The SSZ-5 blade holders are longer that the SSZ-4 rotor head. Also, the lengths between the drag bolts are longer. The rotor diameter is 9mm longer for more stable F3C flights. The pitch arm mixing is also designed for F3C flights.


So now we know what kind of heads are available for different models. In your manuals you have instructions on how to assemble the heads but not necessarily all the information you need to personalize the head to YOUR flying style. So let’s take it to the expert, Ben Minor.


Ben Minor is a Hirobo representative and Hirobo USA team pilot. Ben is into the F3C spectrum of the hobby. He is one of the most thorough people you will encounter. Because of this, his helicopters run like clocks. Ben also has a gift for painting pictures with words.

I have asked Ben Help explain the Mixing options that you will have with your Hirobo model with the new heads mentioned above.

Take it away Dr. Ben……………..

First, let's consider the holes on the flybar carrier or the "Seesaw."

Seesaw 0414-298 0414-464 (aluminum seesaw)

The closer you mount the ball to the center of the flybar carrier, the lower the bell-hiller ratio. There are holes on both sides of the carrier/seesaw so you have even more mixing options.

The model becomes more responsive and less stable in the wind with the ball mounted to the hole(s) closer to the center of the carrier. On the IV/V and SDX heads, you should understand that this is one way to adjust the flybar authority WITHOUT affecting collective or cyclic range. This point is important to understand because the design of these heads generally makes you trade off maximum stability for maximum collective and cyclic pitch range.

Now, the bell mixers...They have a bunch of holes in them.



  Note: If you have a blue anodized aluminum head,

  you will have an aluminum seesaw.


Mixing arm 0414-533

On the side of the mixer whose pushrod goes down to the swash plate, the further you go OUT (IOW mount the ball) on that mixer from its center pivot, the lower the collective and pitch range. In doing so, you'll also be increasing your bell-hiller ratio and flybar authority. The opposite conditions will all hold true the closer you mount the ball to the mixer's center pivot. Now, let's jump to the other side of the mixer. On this side, the further OUT from the center pivot you mount that ball and link that go down to the flybar carrier, the lower the bell-hiller ratio and flybar authority and you'll add to the collective and cyclic ranges. Conversely, if you go IN on this same side of the mixer, you'll accomplish the opposite effect. Again, these rotor heads lose collective and cyclic pitch range the higher you drive the flybar authority when the balls are moved about on the mixers.




So, how do you figure out what settings to use? To begin, if you fly more of a contest style set up, the first thing you do is flip the mixer around 180D so the pivot bolt goes through the opposite side of the mixer. Either remove the little standoff that goes through the bearings and put it in from the other side or put a thin shim washer between the mixer and the pitch arm. When you flip the mixer this way, it places the long arm of the mixer on the side going to the swash plate, which better optimizes your choices for stability. Oriented this way, the ball on the side of the mixer going down to the swash will go on the INSIDE of the mixer, and the ball on the flybar carrier side of the mixer will go on he OUTSIDE of the mixer.

You'll go all the way out on the swash plate side of the mixer and one hole out from all the way in on the carrier side of the mixer. Set up this way maximizes stability in the wind while


Here's a photo:

Thanks for the Photo Bob Rapidity      

preserving enough collective and cyclic range. You can't go all the way in on the carrier side of the mixer because you'll lose too much collective and cyclic range. As for the ball on the flybar carrier, you'll choose the hole either furthest out from the center or the intermediate option. Fine tweaking these mixing ratios for optimum stability in the wind is a topic for another dissertation.

For those who fly 3D, the knee jerk reaction might be to max out the ball positions for the ultimate in collective and cyclic range. WAIT!!!

The reason you don't want to do this is:

1) You'll end up with so much collective you'll have to electronically compress the travel and thus torpedo resolution.

2) Your cyclic travel may end up the same way making the model ridiculously touchy to fly, and thus you'll need to compress throw again.

3) You’ll make the model so unstable with little flybar authority that it no longer tracks through maneuvers or a little puff of wind blows it all over the place.

So..........the best thing to do is to start with the suggested settings and fly the model. First, do you have the collective and cyclic range you desire without doing a bunch of funny business in the radio? Remember that with an eCCPM model, you'll want to try to keep the swash AFR's somewhere in the 40 to 60% range to preserve resolution and minimize control interaction. If the head set up is forcing you to really skew the radio numbers one way or the other, then move the balls around on the head to change the geometry and manipulate the collective and pitch range in whatever direction you need.


Tips from the PRO

A bit of philosophy here:

I know the likes of Bobby Watts, Dominik, Nick Maxwell, etc. may fly a really hot set up. This fact does NOT mean you have to fly your model this way. YOU need to figure out exactly how much control range and authority YOU need for the kind of maneuvers the YOU are doing. If you need all the range and authority the head can provide for your style of flying, then that's just fine. BUT, if you're dialing the head back in the radio and otherwise feel as though you have a ball on the end of a needle in flight, then trade back some of the excess control for some flybar authority. The beauty of these new Hirobo heads is that they will pretty much do ANYTHING you want them to do simply by moving the balls around in an informed manner and then playing with blades, paddles, and fly bars. Thus, please do yourself the favor of taking the time to adjust YOUR head to the way YOU want it fly. Your model will fly a lot better for your efforts.

- Dr. Ben -


Now you know how to tune you head, get out there and try before the snow start to fall!

This has been Dr. Ben Minor and Greg Gomes with this edition of Hirobo Happenings.

If you have any questions feel free to contact me:

Call MRC: 732 225 2100

Private message me at, MRC-HIROBO

Or mail me a letter:
Attn: Greg Gomes, MRC, 80 Newfield Ave., Edison, NJ 08837


Hello everyone,

Hope you all are doing well. We have been busy here at MRC working with Hirobo and many of our other product lines.

We have had a long season. I have been traveling around the country and have had a blast meeting new friends.

Many of you know I was out at the AMA headquarters in Muncie Indiana for 18 sun and fun days.
The first part of my trip consisted of the 2009 Worlds FAI F3C competition. MRC helped host the Japan team and I had the opportunity to spend time with some of the best F3C pilots in the world.

The F3C Hirobo pilots from aruond the world


The second part of my stay was for IRCHA, the world’s largest RC helicopter event. This year’s IRCHA Jamboree was the biggest it has ever been. It was my first time attending this event and I must say it was almost overwhelming. Luckily, I had great support from my MRC-HIROBO team and the HIROBO-JAPAN team.

At the Golden Hour, the HIROBO presence were felt, for sure.

Dominic Haegele and his father Hans attended IRCHA after Dominic came in FIRST just a few weeks before at the 3D master’s championships in Spain. At IRCHA, Dominic pushed his Turbulence to the limit and showed us why he is the Champion. You can see the Video of his flight here: Dominic's Demo

Mark Schneider and Rod “Dr. Thumbs” Wagner accompanied me and were a great help. I owe them a world of thanks. One highlight of the demo flights was the tandem flight by these two gentlemen. Mark put together a very funny music montage featuring some of the theme songs from the cartoons we watched when we were growing up. Somehow, Rob managed to fly so low he was not cutting grass, he was cutting dirt!! Frankly, I though he was trying to fly it underground. See Rob’s dust cloud here: Mark Schneider and Rob Wagner Demo

The Former F3C world champion Mr. Hashimoto put on a stunning unexpected demo with his prize F3C model. He piro-flipped, tic-tocked and hurricaned his helicopter with only 9° of pitch, YIKES!!!

If you ever wanted to see someone uncomfortable, you should have looked at his mechanic, Mr. Kurokawa, as he watched Mr. Hashimoto 3D a Hirobo EAGLE-3 AOCC with a $1500 Black Shark Fuselage.

Mr. Hashimoto's Black Shark
Mr. Hashimoto and his spotter after a successful flight


Hirobo Team News

We also have a few new additions to the HIROBO TEAM

Andrew Merlino - pilot & his father Bob from Boston

Rick Cotte from PA outside of Philly

Tim Tripoli from Central PA

Andy Kim from Seattle, WA

Stanly Kopreski, our resident Scale Master! From Albany, NY

Give me a call if you have any questions about your HIROBO. I might be able to link you up with a HIROBO representative in your area.

iHobby Expo

In October, the HMA held the annual IHOBBY show in Chicago. I had a blast meeting new people and seeing the sights at the show. MRC had special guests that visited, Mr. Tamura and Mr. Kimura from HIROBO Japan. They brought goodies with them for me to showcase at the trade show. MRC-HIROBO has new optional parts for the S.R.B. Quark and the New SDX .50 sized helicopter.

NEW Quark Optional parts (click each image to enlarge):

0302-036 Carbon Fiber Tail Boom
0302-038 Metal Swashplate
0302-039 Metal Rotor Head
0302-037 Double Bearing Tail Drive Shaft Assembly


NEW SDX Parts (click each image to enlarge):

These parts are nice and very well machined. I have yet to put them on my helicopter. When I do get a chance to put them on and test them out I will be sure to let you all know how they do.

0412-326 SZ-5 Rotor Head
0412-327 SZ-5 Blade Holder
0412-328 SZ-5 Pitch Arm
0412-334 SDX-G Radius Stay

0412-331SZ-5 Stabilizer Control Arm
0412-335 SDX-G Auto Rotation Case
0412-332 SDX-G SWM Elevator Lever
0412-336 SDX-G High Torque Auto Rotation Case
0412-333 SDX-G SWM Lever Stay
0412-338 Shroud Extension
0412-337 Pink Decal



Hirobo has also sent me an email regarding the new, more powerful engines that are now out such as the OS .55 and the YS.56. HIROBO has a few safety tips that they would like you to be aware of before slapping a new engine in and flying. These topics are common issues that a responsible pilot would do for any helicopter.


■ Notice for using OS 55HZ Hyper and YS 56 SR engines

Both OS and YS are releasing new engines 55HZ Hyper and 56SR. These engines are much more powerful than current 50 size engines. To prevent accidents or crushes, if
you are planning to use these engines on Hirobo SDX, read following notice before
using those engines.

1. Using Hardened drag bolt (2532-044) is recommended.

2. Do not use main blades that do not come with metal collars. We recommend using Hirobo main blades.

3. Using upgrade main gear 0412-169 (87T) or 0412-291 (89T) is recommended.

4. Pitch up (collective or CCPM) servos should have more than 9kg torque. (This is subjective requirement, if you are going to be flying sport you are good with normal servos. Are you looking to extreme 3D the mess out of this helicopter? If you are, I would say grab Servos with a good amount of torque, maybe 7 to 9kgs. That will give you a nice ridged machine.)

5. Keep main rotor rpm less than 2,000rpm.

6. If there is any vibration caused by parts getting loose, stop flying immediately to check or replace parts.

Before each flight, make sure to check the machines carefully.

From the guys at HIROBO and folks here at MRC, we want to remind you all to fly safe and smart no matter what brand you are flying.


Winter is almost here and that means spring is just around the corner. As I wrap up this flying season, I will be starting to take requests for next season. We already have some dates set for Fun Flies that we will be attending next season. If you are having a good ole’ helicopter “shindig” and you would like me and Hirobo Reps to attend, feel free to drop me a line.

Call MRC:
732 225 2100

Private message me at

Or mail me a letter:
Attn: Greg Gomes

80 Newfield Ave.
Edison, NJ 08837



From Greg Gomes, your heli guy:

With two more Fun Flys under our belt, Hirobo is getting out there in style. From June 5th through the 7th, the Hirobo team could be found in Maryland for the MHA Fun Fly. The rain held off for us and we had some great days of flying. The SDX presence is being felt as we see more appearing at the fun flys.

“Dr. Thumbs”, Rob Wagner, had a great smack down flight over/in a corn field. He flew down between the rows and pulled a disappearing act on more than one occasion. You know he laid it down when the whole helicopter is green at the end of the flight from all of the grass and corn stains. Check out the video link.

click to enlarge images

The following weekend, June 13th, was time for a local SRW (Seaview Rotary Wings) spring spool up. The Fun Fly was held at the club’s beautiful location right across the river in New York City. With the Verrazano Bridge in the background, Dr. Thumbs and I got some great shots of our SDXs.

This SDX is getting better and better. I learned that the SDX can take a hit. I smacked my helicopter into the ground and though it was done for. After close examination, I saw that I didn't have a scratch on it. HIROBO did a great job engineering the new frame so that it could withstand a bigger beating.


click to enlarge images

Come join us at our next Fun Fly June 26th through the 28th as we travel out to the motor city, Detroit,
for the Mid America Fun Fly. Get you tickets ready because we will be raffling off an SDX!


click to enlarge images

From Greg Gomes, your heli guy:

The flying season is in high gear, so Mark Schneider and I took a road trip to the second annual “Helifun” in Hurlock, MD,  sponsored by The Eastern Shore Aeromodelers Club. The rain held off and we began by demonstrating some scale Hirobo ‘copters. The Scale Tow Cobra got oohs and aahs before I even lifted off. Mark guided the MD 500 trough its paces, including some mild 3D maneuvers.

This was the very first time we showcased the new SDX .50, a totally new design. And as advertised, it performed flawlessly. The SDX showed phenomenal agility in rolls, piros and collective punch. Mark did a great job shepherding the SDX all over the skies and ended up cutting grass on an inverted hover. A real crowd pleaser. We also pulled off great “spotlight” night flights without a light kit.  You have to see it to believe it.

The turnout for Helifun was excellent, and our are hats are off to Brent Stock for running a great event. We’ve already made plans for next year.

If you’d like to see why the SDX is being touted as the most competitive, most tunable .50 Hirobo has ever developed for beginners through 3D pilots, visit with us at the MHA funfly, June 5th to June 7th in Maryland. We’ll be there.




From Our Heli Guy Greg Gomes:

Hello Everyone,

The 55th Annual Weak Signals show was a great success. We had a fabulous turn out at the MRC booth and the show in general. For those of you who made the trip, Thank you! We truly appreciate the support.

As many of you know, it was the debut of Hirobo's new .50 size nitro helicopter, the "SDX". Hirobo has really done their homework with this helicopter. With the addition of the new head with the 30 degree pitch throw and 9 degrees cyclic deflection, it flies just like the Turbulence D3. The SDX will not only suit the beginner getting started but the hard 3D enthusiast as well. This heli will take you from learning how to hover to amazing 3D maneuvers all in one kit! We were told by many, the SDX was the highlight of the show.

I must say I had fantastic introduction to the RC community for my first tradeshow since joining MRC. It was a real eye opening experience. I enjoyed meeting everyone and already look forward to next year.

In closing, MRC would like to congratulate Robert Lyttle for winning the first production model of the SDX in the U.S! If you're considering an SDX, get together with your local hobby shop now as the first shipment is almost sold out. The SDX should be hitting their shelves by May 11th. Reserve
yours today.

Until next time, fly safe!

-Greg Gomes-



From Our Heli Guy Greg Gomes:

"I just received the SDX from Japan a few days ago and was able to get  it up in the air on Sunday, March 15th 2009.  I took it down to the Atlantic City field and Jeff Green took a turn at the controls. We had a good time in spite of the weather.  I could feel an immediate change from my previous Hirobo 50.   With the addition of the new downsized  Turbulence FZ-5 rotor head the helicopter took everything I threw at it. The tick tocks were solid and quick and I didn't have to fight the helicopter because this new 120/135 swash eliminated all the interaction. It was a BLAST to fly.  I look forward to the up coming weekends when its get a bit warmer."

Greg Gomes MRC


MRC Is Excited About The Release Of  The New .50 Size Hirobo SDX

The Turbulence D3 based .50 SDX’s maneuverability, stability and performance will make pilots think they’re flying something really special? Can the entirely new .50 size SDX be minutely adjusted for a wide range of performance levels, from beginner to 3D or F3C expert… You bet!

Not sitting on their laurels for winning the '07 3D Masters and '08 XFC championships with the .90 Turbulence D3, Hirobo decided to make the most competitive 3D .50 size heli available anywhere... the new SDX!.

Not another upgrade, this "from-the-ground-up" design contains the new FZ-5 Rotor Head that's based on the SSZ-4 used in the Turbulence D3. The pilot now has the most precise control ever developed for a .50 size ship. The new design 90/120/135 swash plate allows about 60% more aileron/elevator movement and eliminates interaction when difficult 3D maneuvers are flown. A host of new designs abound, from fuselage to tail blades and everything in between. The SDX is "THE .50" for the 21st century.  



  • FZ-5 Rotor head - Maximum 30º pitch stroke possible for 3D
  • Spindle is same size as .90 SSZ-4 (Turbulence D3) head
  • Spindle diameter increased from 6mm to 8mm
  • 2 pcs plastic yoke is same size as SSZ-4 yoke
  • Metal SSZ-4 yoke can be used as optional item
  • New design blade holder with 8mm thrust bearing
  • Aluminum center hub is same size as SSZ-4
  • Blue anodized SSZ-4 center hub can be used as optional item
  • SSZ-4 seesaw, mixing arm, and slide block can be used as optional items
  • Tail housing and tail blade holder straight from the Turbulence
  • Stronger, thicker main frame designed for 120º and 135º SWM
  • New design, lightweight, low height skid
  • New servo mount layouts (as Turbulence) and control layouts
  • Rudder servo can be mounted on front of frame
  • New design aileron lever, elevator lever and lever stays
  • Holes added to main frame for optional header tank
  • Beautiful-, Hirobo “family look” fuselage

ITEM # 0403955 - $489.00

                 (Street Price)

For more than six decades Model Rectifier Corporation of Edison, New Jersey has built a bold and dynamic reputation for quality products and technical achievement within the hobby industry. Today, MRC is the exclusive distributor for some of the world's most respected hobby products as well as the creators and manufacturers of prominent proprietary lines. The Hirobo SDX continues this path of hobby excellence.

11.19.08 AMA Park Pilot Program Approved!

Earlier this year the AMA announced a new membership program geared towards the burgeoning park flyer class of R/C aircraft. This new program offers many of the AMA benefits that traditional AMA members are afforded, but at a reduced cost. This program has also set about a new means of assisting pilots with identifying models that are accepted as part of this program.

Several of Hirobo's models met the specifications outlined by the AMA as "Legal Aircraft" and have been approved. The approved models include the Lepton EX, the XRB and the SRB series. Look for models that have this approval and are adorned with the official AMA Park Pilot Program Legal Aircraft logo shown above.
Park Pilot Program Information

10.16-19.08 iHobby Expo, Rosemont, IL

This year's iHobby was bigger then ever! We had on display: Turbulence D3, Sceadu EVO 50 EX, Sceadu EVO 50, Lepton EX, SRB Quark, XRB Shuttle, XRB Bell 222, XRB Lama, SSZ-IV Turbulence Rotor Head Conversion for the Freya, Turbulence D3 Carbon Fiber Option parts, Lama SA-315B, Tow Cobra and CH-47 Chinook RAF. Everyone was drawn to the helicopters, particularly the Turbulence and scale machines. The consumer days were jammed from opening to close. We hope everyone had a great time, we sure did!

9.5-7.08 The Big Gathering VI, Mays Landing, NJ

Despite threatening rain, MRC/Hirobo attended this event. Mark Schneider showed off the new Turbulence D3. We also piloted a Sceadu Evo 50 with Hughes MD500E fuselage, even pulled off a loop and roll! Turnout was rather low, but everyone who did show up had a good time!


8.14-17.08 IRCHA Jamboree, Muncie, Indiana

780 registered pilots, nearly 5000 attendees, several dozen vendors: The largest RC event on the planet! Our Team built and test flew the first Hirobo Turbulence D3 on American soil, Dominik Haegele put on a 3D-Ripping show along with a stellar team flight with Andy Rummer of Team Mikado piloting our Freya EVO with SSR-4 head. Mark Schneider slung our EVO 50 EX around for the crowd and also demonstrated the new head on the Freya EVO for Mark Ryder's cameras. Special thanks to all the team guys: Chris Berardi, John Russman, Terry Moore, Ben Minor, Jeff Butler, Mario Spina, George Matthews, Randy Kubacki, Mark Schneider, Doug Trent, Dominik Haegele, Hansi Haegele, Albert Fruth and Andy Rummer of Team Mikado and the AMA!


6.20-22.08 2008 Hirobo Cup Grand Event, LaSalle, Michigan

MRC and Hirobo would like to thank the Toledo Weak Signals Club, Rider's Hobby of Toledo, the full scale pilots and all 82 registered model helicopter pilots for taking part in a fantastic event!


6.18.08: 2008 Xtreme Flight Championships, Muncie, Indiana

MRC & Hirobo Ltd. are extremely excited to announce that Dominik Haegele, flying the "soon to be released" Hirobo Turbulence D3, won the prestigious Futaba International Extreme Flight Championships (XFC) that took place June 13, 14, and 15 at the AMA National Flying site in Muncie, Indiana.

Hirobo concentrated on developing and competing in the F3C world, with many triumphs over the last 20-years. In 2007, due to many requests, they started a project to develop a .90 size machine wholly dedicated to 3D competition. Dominik Haegele of Germany piloted the first proto-type machine to win at the most prominent and popular of 3D competitions, the 2007 3D Masters.

Hirobo's popular Eagle series has been the top model for F3C, and the Turbulence D3 will be introduced as the top machine for 3D. Hirobo wanted to develop a machine with the ultimate level of performance capability, so together with 3D Masters champion Dominik Haegele and other world-class 3D pilots from around the world, a new machine was born, solely aimed at competition or expert level 3D flight.

The Turbulence D3 was designed to incorporate the absolute latest in 3D design technology, combined with affordable pricing, which could replace the Freya line. However, as development and testing progressed, Hirobo felt if they wanted to sit on top of 3D world, then there should be no compromise on performance. The Turbulence D3 will be the pinnacle of our 3D line of products and the Freya line will continue uninterrupted.

The excitement generated at MRC and throughout Hirobo with 3D Masters champion Dominik Haegele's win at the XFC is overwhelming, considering it was the Turbulence D3's first competitive flight in the USA! Dominik will pilot it again as defending Champion at the 2008 3D Masters competition in the UK at the end of July.

The Turbulence D3 is designed and manufactured in Japan to the same high quality that customers have come to expect from Hirobo. MRC and Hirobo deeply appreciate the input and extensive testing from the many 3D pilots from around the world.

Hirobo's customers asked for a RC model helicopter that would set the bar for quality and performance for the 21st century. The entire RC helicopter world now knows it's called Turbulence D3.