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Click the mailbox above to send an e-mail to Jason Chan Copyright 2002 by Jason Chan, Hong Kong
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Kyosho Caliber 30
BackgroundYears ago, Kyosho concept line of helicopters were very successful. I'd say most pilots who have been involved in this hobby for over 10 years would have once own a Concept. Later, with the introduction of the Nexus line of helicopter line to replace the Concept line, sales of the Nexus slumped. Kyosho longed for a helicopter line that could lead them to enjoy the past glory of success as they had with the Concept line. On October, 1998, Kyosho introduced to the world the Caliber 60, which was a replacement to their flagship and long outdated Concept 60 SRII. The Caliber 60 featured 23 patented evolutionary degisns which make it a "Ferrari" of helicopters. However, due to the high cost of production, the price tag of the Caliber 60 was very hefty and that prohibited a very good sales of the Caliber 60. Next year Kyosho showed a prototype 50 version of their flagship Caliber 60, the Caliber M50. The Caliber M50 was basically a miniature Caliber 60. However, also due to the high cost of production, the price tag of the Caliber M50 was very hefty and that prohibited a very good sales of the Caliber M50. Not to be left out from the competition, on October 2001 Kyosho introduced the Caliber 30, which was a plastic version of the Caliber main frame design for a 32 size engine. This time, instead of going "No expense spared" liked the Caliber 60 and M50, the Caliber 30 focus on providing as much setup variety in one package while keeping the price low and retain ease of construction and maintenance to serve beginners who buy the Caliber 30 as their first helicopter. The Caliber 30 was designed for the entry level in mind, and very versatile in configuration. Below are some of the features of the Caliber 30:
Liked its brother, the Caliber 30 was once again designed by Mr. Makato Kunii, a well respected helicopter designer in Japan, whom I considered as my mentor in helicopter designs. As usual, Mr. Kunii once again used his talent to push the limit on helicopter design with his talent in Caliber 30, but this time he focus more on saving cost while retaining the best performance possible. The Caliber 30 have plastic main frame, while retaining the drive train design of the Caliber series, where belt are used for power transmission from engine to drive train, and is well known for its silence in operation. It could be configured either in 3 servos 120 degrees ECCPM control, or by regular mixing control, and both configurations would come standard in one kit. Also, the rotor head featured design where the blade grips could be set fore or aft of the blade grip control for the desired delta geometry. As far as I know, the Caliber 30 is the first mass produced design with the most combination of setup and control variety being offered in one box. Mr. Kunii executed this by using a servo tray, where in regular mixing configuration the servo tray would slide fore and aft for pitch change control, and in ECCPM configuration the servo tray would be mounted fix. If using the sliding radio tray for mechanical mixing, four ball bearings would be used to preserve the operation smoothness of pitch control. The plastic swashplate comes standard with mounting points for both mechanical and ECCPM mounting positions. Other cost saving features were plastic clutch bell and lot of plastic molded parts. While the Caliber 30 was very versatile in setup, it also featured some design details that ease beginners' confusion in putting it together. According to Mr. Kunii, he especially used one size of bearing for all mixing controls, and he designed the linkages where they would have stainless steel shafts in 2.3mm and would come pre-built in length that could not be adjusted. Also, Mr. Kunii also designed the control mechanism to use the same length of linkage for both ECCPM and mechanical mix control so that the pre-built, un-adjustable ball links could be used for both configurations. Technical details of the Caliber 30 are as follows: Engine size: 32-38 Gross weight: About 2,900g Rotor diameter: 1,230mm (550mm blades) Tail rotor diameter (With stock tail blades): 240mm Gear ratio (engine:main:tail) : 9.6:1:5.0 With all the above innovative features, at a low price, the Caliber 30 was a dream come true to most. There were two offerings of the Caliber 30, one without engine, and another with OS32SXH engine, and both comes pre-assembled. One special point that I would like to point out was that the Caliber 30 was "Made in Japan". While most might not consider "Made in Japan" a good factor, but I consider this point very important as I have been enjoying the high quality of Japanese made products, and in today's helicopter offering a lot of Japanese brand helicoter kits were not being made in Japan and these usually have quality problems. I got my Caliber 30 through Mr. Kunii right after its release. I also asked Mr. Kunii to send me all upgrade parts of Caliber 30, which was produced by his company Correct. (For you curious minds, yes I have to pay for all this) Let take a look at my Caliber 30, shall we? Assembly (Re-Assembly?)
My blood pressure increased when I received the Caliber 30 from courier. On the box there was a very nice photo of the Caliber 30. Upon opening the box I found the main mechanics sitting in the middle of the box, while the completed tail unit was slotted on the side, and the wood main blades on the other side. There was one packet of hardware, instructions, decals, and that's all there is to it! My Caliber 30 came with OS32SXH engine, and it was pre-installed into the main frame. Basically, there was not much left to assemble, since most of the Caliber 30 came fully assembled. All I had to do was to mount the tail belt, mount tail boom, secure boom supports, prepare the canopy, install flight pack, snap on linkage, mount main and tailblades, set up radio and it would be ready to fly. Even the instructions jumped straight to the assembly of the factory assembled portion into a flyable helicopter and did not once mentioned how to assemble the Caliber 30 from the ground up. However, I chose to completely disassemble the Caliber 30 and re-assemble it to check the factory assembled parts so that if there would be any flaw I could let Mr. Kunii know. At the end of the manual were pictures that showed how each part fit together, that gave me clues as to how each part goes together. So here start my assembly/disassembly. Part I - Main frame and drive trainI started with the disassembly and re-assembly of the main frame and drive train. First, I had to drop the engine out of the main frame, which was very easy by loosing six 3mm philips head screws and the whole engine dropped out of the main frame. Before dropping the engine out, I noted that the cooling fan shroud did not cover the engine heat sink at all, and made a mental note to check if the engine tend to heat during flight, and if so then I need to modify the shroud to cover the whole heat sink. The Caliber 30 engine mount design was very clever in that it provide ease of dropping out the engine for maintenance. The TT Raptor was easy to drop the engine off the main frame for assembly too, but the opening of the main frame remains a weak point. The L-shaped metal engine mount of the Caliber 30 reinforce the strength of the whole main frame while offer ease of maintenance. After dropping the engine, I then disassemble the main frame parts. The main frame was constructed by bolting together two pieces of plastic molded servo frames and two pieces of main frames. All the main frame screws were 3mm metal philips heads screws, which I disliked very much, and changed all of them to stainless steel 3mm hex screws. I took care to unscrew all the philips head screws, and found that Kyosho factory assembled them with strong Loctite, and each screw had lots of them applied! This is bad news! The strength of the Loctite resulted some heads of the screws scratched while unscrewing, and two screws even had their heads broke off because they just won't budge! I swore so much while unscrewing them, cause the Loctite used was too strong, and since the whole main frame was in plastic I could not use heat to loosen the Loctite before unscrewing them. A lighter density Loctite should be sufficient. After much effort, the whole main frame was disassembled down to their screws. I took time to take a detailed look of the Caliber 30 drive train. The whole drivetrain was encased inside the plastic main frames, with all bearing blocks molded into the frames. I checked the bearings and did not found any marking on them. As I hated inferior bearings so much, I changed the stock bearings to high quality NSK ones that I had luck with other helicopters. The main shaft was a 10mm diameter solid steel pole, and was quite long compared to the usual 30 size helicopter. The long main shaft of the Caliber 30 should provide very stable hovering characteristics. The shaft holder was fitted against the underside of the upper main mast bearing holder, and was clamp-on style. I was quite surprised to find a clamp-on style main shaft holder on the Caliber 30 because not even most top dollar helicopters were equipped with this. The drive train system provided constant tail driven autorotation mechanism, with no slipper clutch for adjustment. The drive train ran from the clutch pinion, through a belt, to a plastic main belt pulley, then drive the tail belt pulley and the main gear pinion, then to the main gear. The main belt pulley, tail belt pulley and the main gear pinion were all fixed on to the same axle, with a one-way bearing installed inside the plastic main belt pulley to provide autorotation. One set screw was used to secure the main gear pinion to the axle, but there was one 3mm hole on the opposite side that was left void, so I put in another 3mm set screw to provide better security on the pinion. The whole drive train was fixed and had no gear mesh to set, and the stock gears were not very smooth, maybe due to the molded gears used. I guess later on there should be upgrade parts for these. The fuel tank was molded in clear plastic, and was quite big for a 30 size helicopter. I took out the fuel line inside the tank to check, only to find the fuel tubing that ran inside the fuel tank was short and not flexible enough, so I changed that to better ones from IM. Since my Caliber comes with engine, it also came with all fuel lines being hooked up. However, the inner dimension of the stock fuel lines were too small (1.8mm I guess), and I changed them to 2.5mm inner hole ones from Tettra for better fuel flow. The fuel tank was located right underneath the main gear, which was the best CG position for a fuel tank. I used stainless steel hex screws to put the main frame back together. When bolting together these frames, I used stainless steel 3mm locknuts on the screws that goes through the whole main frame for better security. While assembling the frame, I tried aligning the frame on a flat piece of glass with an angled rule, and found alignment of the frame to be true. Adding the two pieces servo frame to the front of the main frame structure completed the assembly of the whole main frame. The landing gear was mounted to the main frames through four 3mm hex screws. The stock landing gears were very strong, and had a sleek shape. I put in some rubber grommets on the struts to prevent the helicopter from slipping around during takeoff.
The engine that came stock with my Caliber 30 was pre-installed into the main frame. This engine was fitted with a different carburetor, the 20C, instead of the better 3H that comes with OS32SXH when you buy them off the shelves. The 20C carb was much restrictive than the 3H, a look at the fuel outlet on the bottom of the carb would tell you that. I think the 20C carb was mainly due to cost savings. A dig through my parts bin had me one of the 3H carb from an old OS32 engine, and I exchange that with the 20C. With my 3H carb installed, I also put in a Tobee Craft air filter to prevent foreign particles from sucking into the carb. The muffler that came with my Caliber 30 was sized ok for a 32 engine, which was quite good for a stock muffler when compared to others at the same price level. However, I used a K&S HN-30 muffler for its much better performance. Next up was engine installation. An adapter shaped like a very thick axle was to be screwed first onto the crankshaft with the clutch, and this design did not require any dial indicating for the clutch to sit true onto the crankshaft. The stock clutch was a metal unit which was quite big for a 30 size helicopter. While fastening the start shaft adapter, its best to use the OS piston locking tool, and to put some loctite on the thread of the main shaft. Then the clutch bell was to go onto the adapter, supported by two bearings, and the whole clutch assembly was to be held secure by a cooling fan on the top with two 3mm hex screws. The whole assembly was very clean. The stock clutch bell was in plastic, and I opt to use a metal one from Correct. I learned a lot of lessons with the plastic clutch bell back in the days when I had the Concepts, they were very flimsy, and whenever the helicopter crashed with the engine in high rev the clutch shoes would always broke loose from the clutch and tore the plastic clutch bell apart, which was very dangerous. The metal clutch bell from Correct provided much better security, and should be a "must have" item for the Caliber 30. As to cooling, the cooling fan of the Caliber 30 was a more traditional type, where it sat on the same axle of the crankshaft. Gone were the designs of the Caliber 60 and M50s, where a free rolling fan would be located on top of the engine's heatsink inside a straight fan shroud, and the fan would be powered through an O-ring that connects the fan to the clutch, where this design has been a problem with Caliber 60 and M50 for overheating. The stock Caliber 30 fan incorporated a 6mm hex start adapter onto the top of the fan, and a start shaft with one way bearing should be used. I opt to use a metal fan from Correct with my Caliber 30. The engine, with the clutch assembly, was then sit on to the engine mount. The engine mount was two pieces of L-shaped aluminum that was to be bolted onto the main frame, and loosing six screws would had the whole engine assembly dropped out of the helicopter, which was very convenient for maintenance.
Part II - Rotor head and cyclic control mechanismThe rotor head of the Caliber 30 came pre-built. One of the special points of the Caliber 30 was that owners could choose different rotor head mixing mechanisms-namely positive or negative deltas. (Referred to as FRS and RRS resepctively in the manual) Since the manual did not elaborate as to the difference between the two, I would try to explain this in simple here just for your information. (For you gurus, please correct me if I am wrong). Positive delta in mixing means the rotor head would have mechanical mixing dialed in so that negative pitch would be dialed in to the flapping. For example, the rotor blades were constantly rotating to provide lift power for our helicopters. Let's say during hovering wind blows towards one direction that made the blade towards the wind blows flap up, a positive delta mixing would dial in negative pitch towards this side of the blade grip, which would in effect automatically correct to stablize the helicopter and made hovering in windy condition much easier. However, during aerobatics the automatic correction mechanism would work against our input and made cyclic control a bit less sensitive. On the other hand, a negative delta mixing would dial in positve pitch towards the flap up side of the blade grip, which would in effect magnify the effect of the wind and would requires much more correction input to stablize the helicopter. However, during aerobatics a negative delta rotor head would work for our input and made cyclic control more sensitive which would be good for aerobatics. Usually most helicopter had already set either positive or negative delta mixings designed into the rotor head right out of the factory and would not be choosable between the two. However, the Caliber 30 let owners choose bwtween the two. Choosing in between positive or negative deltas are to one's preference, cause both had their goods and bads. Out of the factory, the Caliber 30 had its linkage fixed at positive delta setting, but all it takes would be to change four links, two ball positions to switch, and rotating the blade grips with their pitch arms either towards the front of the blade for positive delta or to the rear of the blade for negative delta. Personally I liked positive deltas more, and use such in my Caliber 30. Aside from the choosable delta mixing, the stock Caliber head featured a floating sprindle shaft design, using rubber dampers to provide the damping. The sprindle shaft was 6mm diameter, which was very strong for a 32 size helicopter. For the moment only one type of damper is available, but in the future I think there would be optional dampers with different hardness available for Caliber 30 owners to fine tune cyclic response to their likings. The stock rotor head was constructed with mostly plastic, with the rotor hub in aluminum. Each main blade grip had two bearings and one thrust bearing to ensure smoothness in operation. Blade bolt is 4mm and are long shank ones, which was not seen in most economical line of helicopters. I am glad to see the Caliber tend to tiny details like these as Mr. Kunii obviously was very careful to details about putting the Caliber 30 together. Correct also had a pair of optional blade shims that would allow the Caliber 30 stock rotor head to accept blades that use 3mm blade bolt, but in my opinion for today's high performance 32 engines 4mm blade bolts should be standard. Two linkage balls were mounted onto the pitch arms of the plastic blade grips by self tapping screws. These screws were too short to provide secure mounting to the linkage balls. I changed them to longer self tapping screws and used Zap to glue these screws and balls onto position to provide better security as if these screws were loosen during flight control precision would be lost, and in worst case if the linkage balls break loose during flight it would lead to lost of control, which would be very very dangerous. All rotation points on the rotor head were equipped with bearings. I re-assembled the rotor head to install a set of metal mixers and flybar control brackets from Correct, which should provide better control precision. While assembling the rotor head I found that the seesaw had a bit of play, and I used some 3mm shims at 0.1mm thickness to take out the play. Stock rotor head came with a plastic dome on the top for ease of stopping by hand, while I had a metal dome from Correct to replace the stock plastic one, I opt to use a much bigger metal dome found in my parts bin. As with other parts of the Caliber 30, the rotor head used metal philips head screws, and I changed them to stainless steel hex screws. The flybar was a 3mm black metal one that goes through the seesaw unit, and the flybar paddles were then screwed on to the flybar. The flybar looks kind of long for a 32 class helicopter. The Caliber 30 paddles were new design where lead weight could be added/taken out to tune cyclic response. The airfoil of the paddles were very thin, and with edges razor sharp. The tailing edge of the Caliber 30 paddles were so sharp that I had several cuts on the leg by the paddles. After completed assembly of the rotor head, I put it on a high point balancer to make sure the head balanced. Another point to praise was that the Caliber 30 used a long shank 3mm bolt to secure the rotor head onto the main shaft, which was a tiny but important feature that was usually neglected by other manufacturers. The stock swashplate was molded in plastic and comes pre-assembled with linkage balls. The plastic swashplate comes standard with mounting points for both mechanical and ECCPM mounting positions. The washout arm assembly consists of two control arms that pivot on to a base. The washout base was unusual in that there were two guiding pins that sticks from the base, and those pins go through a plastic washout fixer. This design gives bigger pitch window without the pins hitting the swashplate. I exchanged items both to metal ones from Correct that should give less slop. The Correct metal swasplate for Caliber 30 was in disc type like those from K&S that allows hookup points at 120 degree for ECCPM, or at 90 degrees for regular mixing. Of special notice was that this Correct swashplate had two more holes on the inner ring of the swashplate, which was for Correct's 3 blade metal head for 3D (More on that later). Another special point of the Caliber 30 would be that owners could choose to control the helicopter either by 120degree ECCPM or through regular mixing. The difference in between the two would be using a different servo mount, mounting bellcranks on different position, and using different ball links. No matter what mixing the owner choose for cyclic control, the 12 o'clock control point would be the same, which consist of a plastic arm that was mounted on an axle to control the 12 o'clock point of the swashplate through a ball link. This axle was located just on top of the hex start adapter, with the middle part slimmed down to clear the start shaft. During engine starting the start shaft could hit this axle and bent it, so care must be needed during engine start, and the use of a start shaft with a one-way bearing would be a must. The other two swashplate control bell cranks were L-shaped plastic arms that were mounted on both sides of the frame at positions depending on whether the owner chooses ECCPM or regular mixing control. For all plastic bellcranks, linkage balls were secured onto them by self tapping screws, and I used slow Zap to glue the screws so that they would not be coming off too easily. Next was the fitting of various pushrods to the mixers and bellcranks. These pushrods were stainless steel 2.3mm type. I was surprised to find these links were very smooth out of the box.
Part III - TailThe whole tail came pre-asssembled by the factory. Originally, all I would need to do would be just to hook up the tail belt and slot the boom into the main frame to complete the assembly. However, I opt to disassemble the whole tail and re-assemble it myself. The tail boom was in 20mm diameter, which was a bit small compared to other makes. The horizontal and vertical fins were installed by the factory on the tail assembly. The tail hub was a machined aluminum part, which was quite hefty for a 30 size helicopter, with blade grips in plastic. The tail blade grips were supported with two ball bearing on each side. Mr. Kunii had send a set of metal blade grips for me to test, but I opt to use that later. The tail pitch slider was another plastic part and was supported by ball bearings, which was hooked up to a tail pitch change arm that went through an opening slot on the plastic tail gearbox to the other side to connect to a push rod for tail pitch changes. I played with the tail pitch lever and found that it was not working smoothly, mainly due to the opening slot was not wide enough and that the arm touched the top and bottom of the slot. I had to disasseble the whole tail gearbox to modify the slot so that the tail pitch arm would not touch on the slot. After disassembly of the tail gear box, I found the tail shaft and the tail pinion inside the tail gear box. Once nice thing was that the tail belt pinion was secured onto the tail shaft by 3mm set screws, not by punch pin that was usually seen in other helicopters. Using set screws instead of puch pins make changing tail shaft a lot easier. After modifying the slots, I put the tail gearbox back together, exchanging all the philips head screws with hex screws and locknut. After this modification, the tail pitch change became smooth operation. The tail pitch change arm was secured onto the tail gear box by a self tapping screw through a bearing. I noticed this self tapping screw did not go all the way through the mount on the tail gear box and prolonged flight might risk this screw coming loose. As a result, I used a 3mm hex screw to replace the self tapping screw, and the hex screw went all the way to the other side of the mount, and was secured by a 3mm locknut. With this modification the tail pitch change mechanism became bulletproof. Before mounting the tail boom to the main frame, I installed the plastic tail servo mounts on to the boom. I found that this plastic tail servo mount had differnt design than others in that instead of just hanging the tail servo under the boom, this mount would set the servo so that the servo horn would sit on the center line of the boom, and made the tail pitch control rod straight, another brilliant design. The whole tail was then secured onto the main frame by four hex screws. After fastened the tail boom to the main frame, I found that the tail boom slips easily on the grip, and even with plastic tapes wrapped on the end of the boom the boom would still slipped. As a result, I setup the tail boom at the required tail belt tension, drilled and thread a 3mm hole on the tail boom grip and the tail boom, and used a 3X6 hex screw to hold everything in place. The tail boom supports were in aluminum with caps on the end for mounting, and were secured to the tail boom through a two piece grip which also was the horizontal tail fin mount.
Part IV - Radio installation and final bits and piecesI used Futaba 9Z WCII with DS8201 digital servos for cyclic controls. At this moment, I have to decide whether to choose 120 degree for ECCPM or regular mixing for cyclic control, since both would require different assembly. Since I am not a fan of ECCPM, I chose regular mixing. The difference between 120 degree for ECCPM or regular mixing for cyclic control would be that different servo mount platform and ball link placement would be used. In regular mixing configuration the servo tray would slide fore and aft inside the box shaped platform on the main frame for pitch change control. The sliding radio tray would be used for mechanical mixing, while for ECCPM configuration the servo tray would be mounted fix. There were four ball bearings used on the regular mixing servo sliding platform to preserve the operation smoothness of pitch control. When I mounted the collective control servos onto the platform I used JR servo reinforcement brackets on all collective servos to further secure the servo mountings. The self tapping screws for servo mounting were only long enough for Futaba servos, and since I used JR servos I had to change to longer screws. After all collective control servos were mounted the whole platform, together with four bearings, was to be seated onto the "box" shaped platform on the front of the main frame. When I put on the servo platform, I found that there was quite a bit of lateral freeplay on the sliding tray, which was not good. I left it as is for the moment, and made a mental note to see if these play would cause significant control slop. The linkages of the Caliber 30 were another special features, in that they all came pre-built in 2.3mm stainless steel which was very strong, but the most special was that they were NOT adjustable. i.e. all links were fixed length. Mr. Kunii designed the control mechanism to use the same set of linkage for both ECCPM and mechanical mix control so that the pre-built, un-adjustable ball links could be used for both configurations. This was very brilliant design. As to the ball links, they were very high quality, and in fact the ball links in the Caliber 30 were the smoothest ball link that I have yet to see todate. With all my other helicopters, I would always substitute the ball links with my favorite Pioneer links for their smoothness, but I'd say the Caliber 30 ball links tops the Pionner links! Too bad the links of the Caliber 30 did not come by themselves, or I would switch to these links for all my other helicopters! After all linkages were installed, I checked and found that most collective control linkages would pass over the cooling fan, near the hex start adapter. Extra care had to be taken while starting up the engine cause if the start shaft hit on any of the linkages it might bend the linkages. On the first page of the instruction, there were "FOR ADVANCED FLIERS" printed in bold....Shouldn't the Caliber 30 aim for beginners too? Anyway, throughout the manual there was virtually no data given as to what servo should be reversed or what were the ATV settings. Also, Kyosho clearly showed their alliance with Futaba, as in the manual all servo horn shown were Futaba ones. The only setup data provided were for pitch settings, and that's all there is to it! Like the Raptor, the Caliber 30 had markings on the plastic swash guide to indicate pitch setting at different level of swashplate position, but I found this useless cause even though all control links were fixed length the two pitch links could still be adjustable and throw off the pitch setting set at the factory. I setup my Caliber 30 according to my experience without any reference to the data in the manual, but I guess Kyosho should provide a very detailed setup sheet for most radio in the market so that a beginner could follow that to setup his Caliber 30. In this respect, Hirobo did very well in that all of their helicopters, including top of the line Freya WC, would include detailed setup data for the owners to follow. The throttle servo was installed next. I carefully set up the middle position so that full throttle range can be covered with 100% throttle ATV. I did not use the stock fixed length ball link here because I would rather want to adjust the throttle linkage by myself. The tail servo was the last servo to be installed. I was forced to use an Arcamax Pi w/2700G gyro with a JR 2700G servo combination because the gyro mounting position was too small to take anything bigger than a GY401. Locally GY401 were out of stock, and at first I wanted to use GY502, but there was just no extra space on the main frame to take the amp of the GY502. Later on I would fit in a GY401 when they became available, but for the time being I would have to settle for an Arcamax because its the only gyro that I had which was small enough to fit in the gyro mount of the Caliber 30 without touching the canopy. Routing of the tail servo wire was held by molded wire holders on the Caliber 30 main frame. The tail pushrod was a 2.3mm stainless steel type with one end threaded for 2.3mm ball links, and the other end a Z-bend. The pushrod was a high quality one, smooth and strong, but why trash the goodness of this link with a Z-bend? Adding one more ball link to replace the Z-bend should not cost a lot of money for Kyosho....Anyway, I am using the stock rod for the moment, but would later change to a carbon rod with ball joints on both ends. After all servos were hooked up, its time to settle the receiver, battery pack and the power switch. The power switch position of the Caliber 30 was hidden quite high underneath the servo tray, and I presume this switch position would post a problem for finger access after putting on the canopy. There were two very tiny space for the receiver and battery pack. The receiver opening could only fit in the receiver covered with 2mm thickness foam, and the battery opening would only take a small 1,100 pack with thin foam. So if you want ot use a big battery pack, heavy padding, an engine govenor, or a gyro that have its amp and sensor in two pieces....tough luck! The Caliber 30 could not take any of them! In fact, spaces on the Caliber 30 main frame was so tight that there was no place to take a glow plug extension or a heading tank without modification on the main frame. The main rotor head accepts main blades with length up to 550mm. Stock package came with a pair of wood blades, and while these wood blades were I guess the best quality wood blades that ever come with a helicopter package they were immediately headed to my trash can. I used Funkey 5535 semi-symmetrical blades first for their very good performance and second I still have over 30 sets of these fresh inside their boxes..... The canopy of the Caliber 30 was in my opinion the worst canopy design ever, period! The look of the canopy was ugly, to say the least! I remembered when I first see the Caliber 30 canopy in the 2001 Tokyo Show I commented to Mr. Kunii that the canopy looked like " a Raptor canopy with a mouth and no teeth". Who needs a Raptor with a mouth and no teeth anyway? Aside from the look, the functions of the Caliber 30 canopy had the worst design of all. The Caliber 30 canopy was to be fixed onto the main frame by four mounting positions with thumb screws, but after putting on the canopy all access to battery switches, fuel lines and mixture needles were being covered. Also, since the canopy was designed as tight fit onto the main frame, if the owner opt to use a bigger muffler the whole left under side of the canopy had to be gone to clear the muffler. For my canopy, since I used a K&S muffler, I had to cut out the whole left underside to clear the muffler, and I had to extend the "mouth" part to the underside of the tip of the canopy just for me to reach the power switch. I was so frustrated with the Caliber 30 canopy that I was designing a FRP canopy for the Caliber 30 that would look better, could take a bigger muffler, and retains ease of access to switches. I had confidence that my canopy would look much better than the original, cause I think the original look was really hard to beat!
FlightThe first few flights of my Caliber 30 was to set up the helicopter and break-in the engine. I hovered the Caliber to set the trims, checked for tracking, and set the head speed. I set the head speed on around 1,450rpm for hovering. There were no apparent shakes, wobbles or vibrations. However, I just could not get the cyclic trimmed. That day was "Turbine Day" for me, so I did not take much time to set up the Caliber 30....leaving more time for my favorite turbine jets... Since these first flights were in very windy condition I thought its the wind that throw off all trimming effort.The second day I tried hovering the Caliber 30 in no wind condition. Still I could not get it trimmed! Careful examination revealed that the free play on the sliding servo tray gave too much play that equals to at least three clicks for cyclics and about 2 degress in collective pitch movement, which was a lot! I ended the day just by hovering the Caliber 30 to break in the engine.After the second day of flight, I tore down the servo tray and tried to find a way to take out the play so that the Caliber would have much better cyclic precision. The free play was due to the fact that the sliding platform had irregular width from both ends to the middle, so that when the servo platform slide fore and aft most of the times only two bearings were touching the side of the platform, and the other two bearings were left banging left and right. This problem would be eliminated if using 120 degree ECCPM control because the ECCPM platform was to be set fixed on the main frame, but I don't want to avoid this problem by changing to ECCPM, I wanted to fix it for regular mixing. I was scratching my heads trying to think of a way to take out the play, while drinking a can of Coke...lightning striked! I finished up the can of Coke, and cut two pieces of 94mm by 4mm pieces from the Coke can, slip them into the sliding tray in between the bearings and the platform, and voila! all freeplay were gone! I then used thin doube sided tape to fix the "Coke can spacers" on the platform, and checked to make sure the sliding was smooth. With the "Coke can spacers" installed, I could not rock the sliding platform sideways anymore, and that should solve the problem. While at it, I also found that the stock plastic washout guide had a bit of free play too, and jusk by luck I located a metal washout guide in my parts bin that was taken off from the Caliber 60. I modified that to use on the Caliber 30 and now the washout unit was smooth and precise.
On the third day I took the Caliber 30 to the field, only to find out my modifications worked like magic! Now hovering could be trimmed. Then I started to do some hovering maneuvers. Hovering was rock solid with precision and control like a very refined machine. In fact, I felt the control precision of Caliber 30 to rival that of my Shuttle RG, which I think is the best 30 class helicopter that money could buy. My Sceadu, with all the modifications installed, could not top my Caliber 30 in mild wind conditions. I guess the extraordinary long main shaft of the Caliber 30 did the trick. During hovering, the Caliber 30 was very silent, mainly due to various belt driven drive train. I forgot to mention that for all these flights I had the canopy off because its with a friend of mine in the process of making a FRP canopy, so I would only hover the Caliber 30 for the moment till I had the canopy back. I don't think I would fly the Caliber 30 without canopy cause that would make orientation hard. As a result, I would update this page to include the Caliber 30's aerobatics capabilities later.More upgrade parts from CorrectOn the package that Mr. Kunii sent to me, there were two metal rotor heads for Caliber 30 that I yet to install. There was a metal head that featured the same design like the plastic Caliber 30 head, but made in A2017 alloy which was very hard and light. All moving points on this rotor head were silky smooth without any slop, which should provide much better precision to the Caliber.Another metal rotor head that Mr. Kunii sent me was a three bladed rotor head for the Caliber 30. No its not for scale, but for 3D! So what's the logic behind a three bladed 3D head? Mr. Kunii revealed his plan of making a three bladed rotor head for 3D to me when I met him in 2001 Shizuoka show. According to him, for 3D maneuvers cyclic throws would be so extreme that the flybar paddles were in fact deflected at a rate that they became brakes to stall the main rotors. His idea behind the three bladed rotor head for 3D was that by doing away with the flybar paddles the main blades could work at their max. Later on, Correct introduced a three bladed 3D rotor head for 60 class helicopter. My Japanese friends actually tried the three bladed 3D head with their Caliber 60s and foudn them to have very good results. I would definitely try this head later, but I would need to take time to find three 550mm blades that were balanced to each other to use this head. Stay tuned for more of this revolutionary new rotor head design!
Final ThoughtsFor its price, the Caliber 30 provided a good choice to new comers into this hobby. Mr. Kunii had used his talent in designing the Caliber 30 to offer different setup characteristics, which was not usually seen in other helicopters in the market. Copyright 2002 by Jason Chan of Hong Kong. All rights reserved. Unauthorized duplication of all or any part of this page is prohibited.
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