Jason Chan with Freya and friend James Yuen
Taken on ready box in Hirobo Cup Finals 2000
Kasaoka, Japan
I have been with my two Freyas for over half a year already, and both logged over a hundred flights each. I fly with them almost every time when I am at the fields. Since I am a F3C pilot, I need to practice the F3C schedule in order to be well prepared for upcoming contests. The Freyas provide me a very economical way for me to have a quality machine to practice. Through my experience accumulated with my Freyas, I would like to share with you here some experience. I will begin with showing how my two Freyas have evolved up to date, the pitfalls of the Freya, and what will be coming for the Freya.
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New stickers for Freya |
Optional sticker scheme 1 of Freya |
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Optional sticker scheme 2 of Freya |
Shaft tail drive conversion for Freya |
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Shaft drive tail gearbox of Freya |
CCPM conversion set for Freya |
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Graphite main frames and upgraded drive train |
Freya with all upgrade parts installed |
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Left
side of Freya CCPM
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Right
side of Freya CCPM
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In fact, at the end of the day, I have tried almost all of the above items except the shaft tail drive conversion because I liked the belt's ease of maintenance. If you are interested in knowing more of the above parts application, refer to the Grade up Option List in Hirobo's website for more detail explanation.
My Two Freyas
In my Freya page, you know that I have two Freyas. Basically they start off as the same machine with almost the same setup. However, down the road I evolved them into very different machine one to another. I will call them Freya 1 and Freya 2.
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| Mechanics of second Freya | Mechanics of second Freya |
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| Two Freyas | Two Freyas |
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Freya 1 |
Freya 1 with Nova 3 fuselage |
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The Freya 1 has been my primary training machine for over 200 flights. As to the life of this Freya, gradually, I've add upgrade it with parts list below:
YS61 ST2 engine
The Freya 1 start off as a mule for breaking in my OS 61 RX-WC engine for my Hirobo Dauphin. Later on, I changed the engine into a YS61ST-2, which I use exclusively for all my machines. The YS61ST-2 have enormous torque and silky smoothness that tops any OS61 engine. Coupled with a Hattori 661 muffler for the YS, it is an engine a pilot would want besides factory custom build engine.
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YS61 ST2 |
Hatori muffler |
SSR-V rotor head (Hirobo #0404-810)
The SSR-V rotor head, first seen in Poland World Championship in Hashimoto's machine, is installed in the Freya 1. The SSR-V rotor head offers more precision on aerobatics, but lacks the hovering stability of the FFZ-II rotor head of the original Freya. Coupled with a set of Hi-Products PG-60 main blade, the aerobatics of the Freya became more precise, and flight speed significantly higher. However, due to the heavy weight, it still lack the flight speed of my other Eagle EXs.
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SSR-V rotor head (Hirobo #0404-810) |
SSR-V rotor head (Hirobo #0404-810) |
WC Flybar paddles (Hirobo #0404-710)
These paddles are extra sitting inside my parts bin for a while, so I might as well put them onto the Freya to test if there is any difference. These paddles weights 45 grams, which is 5 grams heavier than stock paddles.
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WC Flybar paddles (Hirobo #0404-710) |
Special airfoil tail blades (K&S #843)
These blades are designed to produce less noise and more tail power during flight.
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Special airfoil tail blades (K&S #843) |
UG tail servo mount (Hirobo #0404-736)
Once again another part from my parts bin. Changing to this part just for cosmetic purposes.
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UG tail servo mount (Hirobo #0404-736) |
EX Elevator arms assembly (Hirobo #0404-122)
Stock elevator arms are made in plastic and after about 30 flights it began to develop some slop. I changed to the metal set of Eagle EX which provided much better precision.
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EX Elevator arms assembly (Hirobo #0404-122) |
HG lower gear (Hirobo #0414-154)
This is a part from Hirobo in which the middle hub was machined in aluminum, while the gear part in delrin. This lower gear replaces the stock molded plastic one and makes operation smoother while reinforces the whole drive train.
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HG lower gear (Hirobo #0414-154) |
UG slider and mixer set (K&S #592), Aluminum swashplate (Hirobo #0404-121)
These part are machined in hard aluminum, and gives less slop.
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SSR-V flybar control brackets (Hirobo #0404-817)
The stock brackets are molded in plastic and will wrap even at modest pressure. Changing to these parts gives better flybar control. The SSR-V rotor head comes stock with these brackets.
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SSR-V flybar control brackets (Hirobo #0404-817) |
Machined delrin tail pinion gear (Hirobo #0414-169)
This gear replaces the stock gear and provides much more smoothness in operation.
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Stock and delrin pinion |
Delrin pinion installed |
EX belt tail gearbox assembly (Hirobo #0404-668)
On one occasion I damaged the plastic tail gear box of this Freya. Instead of getting the plastic gearbox as replacement I installed the metal tail gearbox for belt of Eagle EX just to see if tail control precision would improved. Later on, I found that with the EX belt tail gear box the tail became "soft" on control, but with more precision. Its due to the fact that the belt gear that comes with the metal gear box was bigger in dimension than the Freya plastic belt gear, so in effect the tail rotor now spin at a slower RPM. Gone were the little jerkiness of the tail after fast pirouettes.
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EX belt tail gearbox assembly (Hirobo #0404-668) |
EX belt tail gearbox assembly (Hirobo #0404-668) |
Nova 3 fuselage (Hirobo #0404-973)
At one point, I put on a Nova 3 fuselage on this Freya. My Nova 3 fuselage was factory painted by Hirobo, a limited edition one, and had been left gathering dust for some time before I put it on the Freya. With the Nova 3, straight line flight speed and tracking improved, but later on I took it off so as not to destroy it.
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Nova 3 fuselage (Hirobo #0404-973) |
Nova 3 fuselage (Hirobo #0404-973) |
With all the above parts installed, the Freya exhibit flight characteristics that make it near to the precision of the Eagle EXs. While some flying buddies commented that my Freya, with all the upgrades installed, rivaled the cost of owning a Eagle EX. I compared and found that my Freya still have some control "softness", and I contribute that to the plastic frame that lacks the frame stiffness of the EX carbon frames, also the single point pitch control might lack control precision on small collective pitch adjustment that is frequently needed in hovering. Throughout its over 200 flight lifespan, it survived through 5 minor crashes, and one major crash totaled the whole thing.
On my second Freya, I also used upgrade parts liked the first Freya that I had, and tried to match both settings to the same. However, with this Freya I used OS 61 SX-WC engine instead of a YS engine, and still retain the FFZ-II plastic rotor head. Gradually down the road this Freya was not as lucky as the first one, and it crashed more often than the first one. As a result, I had further upgrade this Freya to the point that at one time it has a carbon lower frame of the Eagle EX installed. With the carbon lower frame installed, there was not much difference in control feelings, but the weight did shaved. Later on, after about 100 flights, this Freya also encountered a major crash that nearly totaled it. So at the end I ended up with two totaled Freyas, and their remains scattered in my parts bin, what should I do with them. Hmm.... After some thoughts, I've decided to merge the remains of my two Freyas to became one, and install a Hirobo SWM Conversion Kit for Freya on it to see the difference.
Basically, the Freya CCPM was based on the CCPM conversion kit of Hirobo (Hirobo part #0414-181). This kit comes with all necessary parts to convert either the Freya or the Freya EX to 120 degree 3 servos CCPM operation. The CCPM kit install on pre-drilled positions on the plastic main frame, so there was no need to take out a drill and a hacksaw for installation. As to this moment, Hirobo did not have a package of Freya CCPM, so the only route to own a Freya CCPM was through getting the Freya kit and the Freya SWM conversion kit.
I started off with a plastic Freya main frame. At this moment, the collective pitch control, elevator arms and other mixers should be taken off from the main frame. The CCPM instructions provided very clear steps to install the kit, assembly was straight forward without any pitfall. I changed the stock plastic swashplate guide to a metal one for better precision, and other than that all components of the SWM conversion kit were used. CCPM controls were all push-pull controls, and I used Futaba 9252 digital servos for cyclic. For other components they were basically like my Freyas in the past, except that I used the FFZ-II plastic head because the SSR-V head was damaged.
In flight, the Freya CCPM showed very different flight characteristics compared to the regular mixing Freya. Cyclic with the CCPM became very sensitive and powerful so I had to dial in a lot of exponentials. Hovering became on the sensitive side. On aerobatics control feelings became very direct. Overall, the Freya CCPM suits 3D very much, but might not be a very good choice for F3C.
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Hirobo SWM Conversion Kit for Freya |
Hirobo Freya main frame |
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Close-up
of swashplate and guide
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Close-up
of swashplate and guide
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Metal swashplate and mixers |
CCPM mixers |
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CCPM mixers |
Metal
swashplate and mixers
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Metal swashplate guide |
EX belt tail gearbox assembly (Hirobo #0404-668) |
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Drive train |
Push pull controls on all cyclic |
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Rebuilt FFZ-II rotor head |
FFZ-II rotor head installed |
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OS61SX-WC |
Left side of the Freya CCPM |
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Right side of the Freya CCPM |
Freya CCPM |
According to Hirobo officials, they would like to develop the Freya as an entry level machine as start, and gradually upgrade it to be a true contest grade machine. However, right after the introduction of the Freya, Hashimoto was seen in Japan using a special edition Freya, equipped with a OS91 engine, to compete in the Japanese championships.
Below is a Freya seen in Hirobo factory in 2000, which was in fact the prototype of the Freya EX. Due to a promise to Hirobo officials, I cannot reveal all the details about this Freya before its release.
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This prototype was later released as the Freya EX. For further details, please refer to my Freya EX review page.
After the Freya was introduced into the market, some people e-mailed me about problems with their Freya. I provided suggestions to these people and helped them solve their problems, and I would share few of the most common problems I helped solved here.
Question-The tail belt is loosing tension after a few flights, why?
This is because the tail boom is slipping inside the main frame, causing belt to loose tension. For all my Freyas, I would first set the right tension on the bench, and drill a 3mm hole that goes from the top side of the main frame part that hold the boom all the way to the boom. I then use a 3mm hex screw to fix the boom position. This would prevent the boom from slipping.
3mm screw used to secure boom to the frame
Question-My Freya have shakes on the tail. I balanced the main rotor head and the tail rotor already, and still the shake. Why?
I received a lot of messages from Freya owners around the world about having minor shakes on their Freya, and most of the times the shake are evident on the tail, especially on idle ups. According to my experience in helping fellow pilots taking this shake out, provided that if you have balanced everything, and all shafts are straight, most of the time a Freya would show minor shake on is caused by one of the following:
Tail boom not securely mounted -
Linkage balls not securely fastened onto the blade grips -
Rotor head not assembled properly - This shake is because the Freya head is very stiff, and since it sits relatively high up on the main shaft, even very very minor unbalance that did not affect flight performance would show a shake. To cure this shake, first, make sure that when assembling the FFZ-II rotor head you have glued the two metal spacers onto the plastic yoke. I found that in some case the owner, while assembling their Freya rotor head, would just slot the two metal spacers into the plastic yoke and did not use glue because they think the sitting is very tight already. With this case, during flight the yoke would be deformed and lead to shakes. In addition, even if you glued the spacers onto the yoke, check to see your spindle would slide freely and smoothly on the yoke, and make sure that you do not use too many shims to take out the space between the yoke and the blade grip. There should be a little free play between the blade grip and yoke, and the spindle should slide smoothly on the yoke for a smooth operation. Most of the times with the above steps the shake would go away.
Care must be taken on rotor head assembly to ensure smooth operation
Question-My Freya was crashed due to mid flight pitch or elevator servo burn. Before crash, during aerobatics pitch or elevator control was lost, and lead to crash. Post mortal check revealed pitch or elevator servo burn out during flight and lead to lost of control.
Provided that good and high torque servos are used:
Elevator servo - One common assembly mistake that I see frequently on Freyas in that owners would connect the X-shaped mixer upside down. If this is so, at the extreme position the servo would be bind by the linkages. Prolonged binding would cause servo to burn pre-maturely, and lead to crash. Make sure the X-shaped lever is connected the right side up, or to check at swashplate extreme position whether any servo is being bind.
Pitch servo - Since the pitch connection is through a single push rod in the Freya, tremendous stress is enacted on the pitch servo during aerobatics. If the other cyclic servos are not set up properly that lead to binding at the extreme position, extreme force would be enacted onto the pitch servo, causing it to burn out. Make sure that all cyclic connections are operating smoothly at all positions to lessen the possibility of pre-mature servo burn outs.
Ensure all cyclic control servos are operating smoothly to prevent premature servo burn outs.
Actually what I learnt from Hirobo factory pilots is that if you exercise high care and attention into assembling and taking cafe of your Freya. it would award you with a very high performance helicopter. I actually saw, touched and test flew some box stock Freya with no upgrade parts assembled and setup by Hirobo factory pilots, and I found these Freya's performance rivals to my Freya that was upgraded to the max. I asked Hirobo pilots what secrets did they put on to their box stock Freya, and their answer was simply take care and attention on assembly. To prove the point, I had the privilege to see a Hirobo factory pilot assemble a Freya for test, and I witnessed and helped the assembly from the ground up, and found what he said was true. He asked me to pick one box of Freya from production, and followed strictly according to the manual for assembly, adding ample grease and lubricants to mechanical parts to make sure they operated smoothly. The end result was a Freya that was completely different than what I had, with the smoothness and precision that I would not expect from a plastic helicopter. From this lesson, what I learned was that with due care in assembly a box stock Freya would fly very good.
The Freya had been giving me good service as an entry level F3C trainer. Due to its ease on maintenance, cheap to operate, good flight performance out of the box, extremely good parts supply, the Freya makes for a very good 60 size helicopter for any pilots who would want to step up to a 60 class machine