RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
INTRODUCTION 4
ASSEMBLY RECOMMENDATIONS 4
MINIMUM REQUIRED TOOLS 5
OPTIONAL TOOLS 5
OTHER COMPONENTS REQUIRED 5
MAIN CHASSIS ASSEMBLY 6 TAIL PINION BEARING BLOCK (1-1) 6 MOTOR BLOCK (1-2) 7 SWASH CONTROL LEVERS (1-3) 8 TAIL CONTROL LEVER (1-4) 10 ESC SUPPORT (1-6) 10 CONTROL LEVERS AND CABIN SUPPORT INSTALLATION (2-1) 11 MAIN MAST BEARING BLOCKS AND ELEVATOR LEVER INSTALLATION (2-2) 13 BATTERY TRAY SUPPORTS INSTALLATION (2-3) 15 SKID SUPPORTS INSTALLATION (2-4) 16 ESC SUPPORT INSTALLATION (2-5) 16 ELECTRONICS TRAY INSTALLATION (2-7) 17 SKID SUPPORTS REINFORCEMENT AND VIBRATION DAMPERS INSTALLATION (2-8, 2-9) 17 MAIN GEAR AND AUTOROTATION BLOCK ASSEMBLY (3-1) 18 TAIL GEAR ASSEMBLY (3-2) 19 TAIL PINION BEARING BLOCK AND TAIL BOOM SUPPORT INSTALLATION (3-3) 20 MOTOR BLOCK INSTALLATION (3-4) 21 MAIN MAST AND GEARS INSTALLATION (3-5, 3-6) 21
MAIN ROTOR ASSEMBLY 23 SWASHPLATE ASSEMBLY (4-1) 23 PHASE ARM ASSEMBLY (4-2) 24 CENTER HUB ASSEMBLY (4-4) 25 BLADE HOLDER ASSEMBLY (4-6) 25 SPINDLE SHAFT AND BLADE HOLDERS INSTALLATION (4-5, 4-7) 26 MAIN ROTOR INSTALLATION (4-4) 27
TAIL ASSEMBLY 28 TAIL PULLEY ASSEMBLY (5-1) 28
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL CASE ASSEMBLY (5-2, 5-3, 5-4) 29 TAIL SLIDER ASSEMBLY (5-5) 30 TAIL PITCH LEVER ASSEMBLY AND INSTALLATION (5-6) 31 TAIL ROTOR ASSEMBLY AND INSTALLATION (5-7) 32 TAIL BOOM BRACES ASSEMBLY AND INSTALLATION (6-2) 34
SERVOS 35 SERVO INSTALLATION (7-1, 7-2, 7-3) 35 TAIL SERVO CONTROL RODS (7-4) 39 TAIL CONTROL ROD INSTALLATION (7-6) 40
PINION SELECTION 41
MAINTENANCE RECOMMENDATIONS 41
ASSEMBLY DIAGRAMS 42
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
INTRODUCTION RVE is committed to using technology and innovation to bring new feeling to helicopter aerobatics. The company regards "Refined Victory Equipment" as its main idea, strives to become a leading brand in the field of remote control model helicopter competition, and redefines the precise flight connotation of F3C with first-class technology and exquisite craft. Since its establishment, RVE has always adhered to the spirit of "seeking quality and sincerity, stimulating innovation". Always practice the concept and value of "precise, precise and exquisite" products, and penetrate the outstanding innovative ideas into every detail of products, showing the infinite possibility of flight. The company's flagship aircraft is the MERAK 750 F3C competitive aircraft, which has been verified and tested for a long time before finalization and mass production.
ASSEMBLY RECOMMENDATIONS All the machined parts such axes and steel pinions should be carefully cleaned using Isopropyl alcohol or universal spray lubricant (WD-40, Triflow...). Remove any shaving left after the machining process.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MINIMUM REQUIRED TOOLS ● Allen screwdriver: 1.5 mm, 2 mm, 2.5 mm, 3 mm and 4 mm ● Hex nut screwdriver: 5.5 mm and 7 mm ● Small Phillips screwdriver ● Wrench: 5.5 mm and 13 mm ● One-way wrench: 6 mm ● Universal ball link driver ● Drill: 3 mm ● Nose pliers ● Universal ball link pliers ● Scissors ● Small file ● Epoxy glue ● Universal spray lubricant ● Threadlocker: soft and medium ● Thrust bearing grease ● Silicon grease ● Light oil ● 2 mm pin bars ● Digital pitch gauge ● Caliper ● Solder equipment
OPTIONAL TOOLS ● Torque screwdriver with required bits ● Ball link caliper adapter
OTHER COMPONENTS REQUIRED ● 3 Cyclic servos ● 1 Tail rotor servo ● 6 ch. RC system ● Flybarless controller ● Electric motor, 440-560KV, 6 mm shaft, maximum 70 mm diameter ● ESC according to the selected motor ● RC power system, if not integrated within the ESC ● 12s 5000-6000 mAh LiPo battery ( 2 x 6s packs) ● Battery plugs (male/female) ● Motor plugs, if not included with the motor (male/female)
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MAIN CHASSIS ASSEMBLY TAIL PINION BEARING BLOCK (1-1)
Both bearing blocks are identical. Please pay attention to the chamfer for a correct bearing block orientation. While inserting the pulley, press it against the pinion and tighten the two M3 x 3 mm set screws using soft threadlocker. Insert the second bearing block and then secure it with the M3 x 6 mm screw and flanged washer. Optionally, lower bearing inner race can be fixed to the helical gear axis with soft threadlocker.
***Recommended tightening torque:
0.8 Nm for the M3 x 3 mm set screws 1 Nm for the M3 x 6 mm screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MOTOR BLOCK (1-2)
The motor block is designed with an integrated third bearing and a special helical pinion. Only motors using 6mm shaft are compatible. Several pinions, 10t, 11t and 12t are available. Follow the recommendations from Pinion Selection chapter in order to choose the correct pinion. Insert first the selected pinion into the motor block bearing and lock the pinion nut using medium threadlocker. Optionally, bearing inner race can be fixed to the helical gear with medium threadlocker. Install the engine into the motor block, fixing it with the two M4 x 10 mm button head screws, using soft threadlocker. Align the motor shaft flat surface with one of the pinion threaded holes and use the two M4 x 4 mm set screws to secure it. If the motor doesn’t have a flat surface, it can be done with its center at approx. 10mm from motor mounting surface.
***Recommended tightening torque:
2 Nm for the M4 x 10 mm button head screws 1.2 Nm for the M4 x 4 mm set screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
SWASH CONTROL LEVERS (1-3)
Bearings are fixed to both elevator arm and aileron levers using medium threadlocker. Apply little threadlocker on the outer bearing race, avoiding the threadlocker to touch the shield. Then insert the bearing on its place. Be careful to not forget to put the brass spacers into the inner part of aileron levers. Long M3 threaded balls are installed using medium threadlocker into the aileron levers’s long arm as shown in the pictures.
***Recommended tightening torque:
1 Nm for the M3 threaded balls
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
Insert the ball link into the elevator arm securing it with the phillips screw. It may be needed to sand a bit the ball link’s cylindrical part in order to insert it into the elevator arm. Use a little amount of medium threadlocker on the screw part in contact with the aluminum elevator arm. Previous to install the elevator arm into the elevator lever (red part) place the flanged spacers in the internal part of the elevator arm as shown. Secure both parts together with the M3 button head screws, do not overtighten them. The elevator mechanism should move freely.
***Recommended tightening torque:
0.6 Nm for the M3 x 8 mm button head screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL CONTROL LEVER (1-4)
There’s a short and a long threaded ball. Install them as shown on the pictures using medium threadlocker. Secure the tail control lever to its support with the M3 x 14 mm screw and medium threadlocker. Do not forget the brass spacer (washer) to assure good contact between the bearing’s inner race and the support. Do not overtighten the mechanism, it should move freely.
ESC SUPPORT (1-6)
The carbon fiber ESC plate is secured two the aluminium supports with M3 x 8 mm flat head screws using soft threadlocker. The kit includes XT150 connector brackets that can be optionally used. Secure the brackets to the aluminium supports with the M2.5 x 8mm screws and soft threadlocker.
***Recommended tightening torque: 1 Nm for the M3 threaded balls 0.6 Nm for the M3 x 14 mm screw 0.8 Nm for the M3 x 8 mm flat head and M2.5 x 8 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
CONTROL LEVERS AND CABIN SUPPORT INSTALLATION (2-1)
Plastic servo supports are used for aileron servos (left and right). Use the M2.5 x 4 mm button head screws to fix the plastic servo supports to the carbon fiber chassis. The supports allow small position adjustment in order to use different brand servos, do not completely tighten the servo supports at this point, it will be done later while installing servos.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
The aileron lever is fixed to the chassis with a M3 x 15 mm screw and a nylon lock-nut. Do not forget the brass spacer (washer) to assure good contact between the bearing’s inner race and the carbon fiber chassis. Do not overtighten the mechanism, it should move freely. Long cabin supports are installed at the front of the carbon fiber chassis with M3 x 8 mm button head screws and soft threadlocker Rear support holes are slotted to allow adjusting its position vertically. Short cabin supports are installed at the rear of the carbon fiber chassis with M3 x 8 mm screws and soft threadlocker.
Check for the tail lever orientation while installing it on the chassis. The short threaded ball should be placed inside and pointing down, the long threaded ball outside and pointing up. Use M2.5 x 6 mm screws with soft threadlocker.
***Recommended tightening torque:
0.4 NM for the M2.5 x 4 mm button head screws 0.6 Nm for the M3 x 15 mm screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
0.8 Nm for the M2.5 x 6 mm, M3 x 8 mm button head and M3 x 8 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MAIN MAST BEARING BLOCKS AND ELEVATOR LEVER INSTALLATION (2-2)
Three similar bearing blocks are used for the main mast. Check for the correct orientation for each of them following the images below. The two upper bearing blocks are secured to the carbon chassis with M3 x 8 mm screws with aluminium washers, using soft threadlocker. The lower bearing block is secured with two M3 x 8mm screws with aluminium washers and two M3 x 30 mm with aluminium washers and aluminium spacers, using soft threadlocker. It is recommended to install the three bearing blocks without fully tightening their fixing screws and then insert the main mast to guarantee a perfect bearing block alignment. All the fixing screws will be finally tighten with the main mast inserted into the bearing blocks.
***Recommended tightening torque:
1 Nm for the M3 x 8 mm and M3 x 30 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
The elevator mechanism is installed by means of he elevator shaft into the bearings pre-glued to the carbon fiber chassis. Two M4 set screws with soft threadlocker are used to fix the elevator mechanism to the shaft. Then the elevator push-pull arm is installed on the chassis side with two M4 set screws with soft threadlocker. Use two 2 mm pin bars to fix in neutral position both elevator lever mechanism and elevator push-pull arm before tightening the push-pull arm set screws.
***Recommended tightening torque:
1.2 Nm for the M4 x 4 mm set screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
BATTERY TRAY SUPPORTS INSTALLATION (2-3)
The aluminium battery tray supports are installed on each side of the carbon fiber chassis with M3 x 6 mm screws with aluminium washers using soft threadlocker.
***Recommended tightening torque:
0.8 Nm for the M3 x 6 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
SKID SUPPORTS INSTALLATION (2-4)
The skid supports are mounted into the carbon fiber chassis with M2.5 screws using soft threadlocker.
ESC SUPPORT INSTALLATION (2-5)
The ESC support has mounting holes for ESCs such Kontronik Kosmik and Hobbywing Platinum series. The ESC support is mounted into the carbon fiber chassis with M3 screws and aluminium washers, using soft threadlocker. Its position on the chassis is vertically adjustable.
***Recommended tightening torque:
0.8 Nm for the M2.5 x 6mm and M3 x 6 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
ELECTRONICS TRAY INSTALLATION (2-7)
This tray is optional and can be used to harbor different electronic devices such receiver and its battery. It is pre-glued and manufactured in carbon fiber sheet. It can be mounted to the carbon fiber chassis by means of M3 screws with aluminium washers and nylon lock-nuts.
SKID SUPPORTS REINFORCEMENT AND VIBRATION DAMPERS INSTALLATION (2-8, 2-9)
Two carbon fiber sheet reinforcements are used joining together front and back skid supports. Vibration dampers with soft threadlocker are used to fix them to the skid supports, helping isolating possible vibrations from the hanging skids. Skid’s fixing M3 screws and washers are included in this step, use them later.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MAIN GEAR AND AUTOROTATION BLOCK ASSEMBLY (3-1)
The autorotation bearing block is secured to the red aluminium core with M3 x 5 mm screws with soft threadlocker as shown. Double-check the orientation of the bearing block before tightening. Use star-pattern tightening sequence, increasing gradually the torque till the recommended one. This assures a perfect assembly with no deformations.
The POM helical main gear is secured to the red aluminium core with M2.5 x 6 mm screws using soft threadlocker. Check the position and alignment of the reinforcement ring before inserting the screws. As with the previous step, use star-pattern tightening sequence, increasing gradually the torque till the recommended one.
***Recommended tightening torque:
1 Nm for the M2.5 x 6 mm screws 1.2 Nm for the M3 x 5 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL GEAR ASSEMBLY (3-2)
The POM helical tail gear is secured to the red aluminium core with M3 x 6 mm flat screws using soft threadlocker. Use star-pattern tightening sequence, increasing gradually the torque till the recommended one. This assures a perfect assembly with no deformations.
***Recommended tightening torque:
1 Nm for the M3 x 6 mm flat screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL PINION BEARING BLOCK AND TAIL BOOM SUPPORT INSTALLATION (3-3)
Slide the tail drive belt through the tail boom supports as shown in the pictures. The M3 x 40 mm screws and nylon lock-nuts are tightened in step 5-7 to fix the tail boom in place. Insert the tail pinion bearing block assembly using M3 x 8 mm screws to temporarily secure it. Use aluminium washers only for the upper screws. The slotted holes allow to set the gear backlash for the tail pinion once the tail gear assembly is installed.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MOTOR BLOCK INSTALLATION (3-4)
Insert the motor block assembly using M3 x 10 mm screws and M4 x 10 mm button head screws to temporarily secure it. In order. Use the provided carbon fibre mounting plates. The slotted holes allow to set the gear backlash for the motor pinion once the main gear assembly is installed.
MAIN MAST AND GEARS INSTALLATION (3-5, 3-6)
First clean with alcohol the autorotation bearing sleeve before installing it. The autorotation bearing sleeve should be inserted from below into the autorotation block. Then insert the tail gear assembly aligning the aluminium core hole with the sleeve’s hole.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
Put the gear assembly in place and insert the main mast through it aligning their holes. Use the M4 x 25 mm screw and the nylon lock-nut to fix both parts together. Insert the hex head screw and its washer from below, fixing it with soft threadlocker. Pull the main mast end, pushing down the collar and fixing the M3 set screws with soft threadlocker.
Once the main mast and gears are installed, both tail pinion and motor pinion backlash can be adjusted, allowing a little bit of play (an excess of play can prematurely damage the gears). Use soft threadlocker for securing the motor and tail pinion bearing block screws.
***Recommended tightening torque:
1.6 Nm for the M4 x 25 mm screw 1 Nm for the M3 x 3 mm set screws 1.2 Nm for the M3 x 10mm screws 2.5 Nm for the M4 x 10 button head screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MAIN ROTOR ASSEMBLY
SWASHPLATE ASSEMBLY (4-1)
All the threaded balls for the swashplate have the same length. Use soft threadlocker to secure all the M3 threaded balls.
***Recommended tightening torque:
1 Nm for the M3 threaded balls
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
PHASE ARM ASSEMBLY (4-2)
Pins with circlips are used to secure the plastic ball link arms. Insert a circlip on the pin, mount the plastic ball link arm on the aluminium lever and insert the pin through, securing the assembly with the second circlip. For additional security, block the pin with the M3 x 3 mm set screw using soft threadlocker.
***Recommended tightening torque:
0.5 Nm for the M3 x 3 mm set screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
CENTER HUB ASSEMBLY (4-4)
Use the M3 flat head screw with soft threadlocker to secure the head button to the center hub.
BLADE HOLDER ASSEMBLY (4-6)
M3 x 8 mm and M3 x 12 mm screws with soft threadlocker are used to mount the pitch arms into the blade holders. Outer hole from the pitch arms should be used in order to assemble the M3 threaded balls.
***Recommended tightening torque:
1 Nm for the M3 threaded balls, M3 x 8 mm flat head and M3 x 8 mm screws 1.2 Nm for the M3 x 12 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
SPINDLE SHAFT AND BLADE HOLDERS INSTALLATION (4-5, 4-7)
Install the dampers into the center hub using silicon grease. It allows an easier assembly but also helps maintaining the damper’s flexibility and a good operation. Clean properly the spindle shaft with isopropyl alcohol and install one of the M6 x 10 mm screws with its washer using medium threadlocker. A one-way wrench can optionally be used to tighten the first installed M6 x 10 mm screw. The blade holder’s thrust bearings are pre-installed with thrust bearing grease. Introduce the spindle shaft into the blade holder. Then a flanged washer should be installed with the lower diameter side in contact with the blade holder’s bearing inner race. Then one or more spindle shim washers should be used. Insert the spindle shaft with an installed blade holder into the center hub and replicate the flanged washer/spindle shim washer setup symmetrically. Insert the second blade holder and complete the assembly with the M5 screw and its washer, taking care of using also medium threadlocker on it. During the first assembly, install only one spindle shim washer on each side and complete the rotor assembly. The blade holders should move freely but a certain pressure should be guaranteed to just keep them in place. If the blade holders fall by their own weight or a little play is observed, please add an additional spindle shim washer on each side. It may happen that the initial spindle shim washer setup works well and after 20-30 flights a little play appears. If this happens, add one additional spindle shim washer on each side.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
MAIN ROTOR INSTALLATION (4-4)
Insert the main rotor assembly into the main mast. A M4 x 25 mm screw with a nylon lock-nut is used to join through the main rotor and the main shaft. Tighten it lightly and the install the phase arms without fully tighten their M3 x 22 mm button head screws, using soft threadlocker. The M3 button head screws should be gradually tighten in order to obtain a symmetrical assembly. Once the M3 button head screws are fully tighten, finish with the M4 screw tightening.
***Recommended tightening torque:
0.6 Nm for the M3 x 22 mm button head screws 1.6 Nm for the M4 x 25 mm screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL ASSEMBLY TAIL PULLEY ASSEMBLY (5-1)
Align the tail pulley threaded hole with the tail shaft notch using the showed orientation. Tighten the M4 set screw using soft threadlocker.
***Recommended tightening torque:
1 Nm for the M4 x 4 mm set screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL CASE ASSEMBLY (5-2, 5-3, 5-4)
Mount the left side plate to the tail case main block. The left side plate is the wider one. Mount also the red cylindrical spacer. Use for both operations M3 x 6 mm button head screws with soft threadlocker. Insert the tail boom brace clamp first (then the support sponge if a fuselage is to be installed), then the tail case clamp and finally the previously assembled tail case. Place the tail shaft in the case and mount the right side plate with the tail pitch lever support using M3 x 8 mm button head screws. Check the tail shaft side play, adding shim washers if needed. Remember to insert the o-ring on the tail shaft. Fix the tail case to the carbon tail tube. First insert the M3 x 3 mm set screw till touching the carbon tube, then screw half additional turn. Then tighten the tail case clamp M3 x 8 mm screw using soft threadlocker. Tightening torque is not provided for the M3 x 8 mm screw, tighten it till the assembly is correctly secured.
***Recommended tightening torque:
1 Nm for the M3 x 6 mm and M3 x 8 mm button head screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL SLIDER ASSEMBLY (5-5)
Insert the tail slider sleeve through the bearing ring, locking the tail pitch arm with soft threadlock. Pay attention to not overtighten the assembly to avoid damaging the bearing. Don’t worry about the assembly getting loose, the tail slider sleeve is opposite threaded. Tail ball links are marked with a dot indicating the side that goes into the ball. Install the ball links as shown in the pictures, locking them in place with the circlip secured pins. For additional security use the provided set M2 x 2 mm set screws with a very little amount of soft threadlocker to block the pin.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL PITCH LEVER ASSEMBLY AND INSTALLATION (5-6)
The tail pitch lever carbon plate is fixed to the aluminium tail pitch lever with two M2.5 x 6 mm screws as shown in the pictures. The control ball is secured to the carbon plate with a phillips head screw with a nylon lock-nut. Threaded guiding pins are installed in the aluminium tail pitch lever with soft threadlocker. Glue the two flanged bearings in the aluminium tail pitch lever with medium threadlocker. Install the tail pitch lever assembly in the tail pitch lever support with the provided aluminium bushings, then secure it with the M3 x 8 mm button head screws using soft threadlocker. Slide the tail slider assembly into the tail shaft first, then slide the tail pitch lever pins into plastic bearing ring groove.
***Recommended tightening torque:
0.6 Nm for the M3 x 8 mm button head screws 0.8 Nm for the M2.5 x 6 mm screws and threaded guiding pins
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL ROTOR ASSEMBLY AND INSTALLATION (5-7)
Install the tail blade holders shafts into the hub with soft threadlocker. Use a 6 mm one-way wrench for tightening them.
Install the M3 threaded ball in each blade holder. Complete the assembly as shown in the picture. The thrust bearing must be greased, then assembled with its bigger id bearing race inside and the shorter one outside. Fix it with the M3 x 8 mm screw using soft threadlocker.
***Recommended tightening torque:
0.8 Nm for the M3 threaded balls 1.2 Nm for the M3 x 8 mm screws
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
Slide the tail rotor into the tail shaft, fixing it with the M4 x 4 mm set screw using soft threadlocker. The tail shaft is grooved to allow a secure assembly, please check to align both parts before tightening the M4 x 4 mm set screw. Carefully insert then each tail blade holder ball into the ball links. Once the tail rotor assembly is completed, the belt tension and tail rotor alignment should be performed. The tail belt tension is sensitive, if it is too loose power to the tail rotor will not be correctly transferred, if it is too tight premature wear in pulleys and bearings may appear. A good belt tension is achieved when the belt flexes a bit without touching both ends when force in the tail belt is applied with two fingers on the tail box near the tail pulley. Use a digital pitch gauge or a bubble level for a correct alignment. Secure the tail boom at the desired position by tightening M3 x 40 mm screws and nylon lock-nuts from main chassis tail boom supports. As with the tail case, tightening torque is not provided for the M3 x 40 mm screws, tighten them till the assembly is correctly secured.
Finally install the tail rotor blades, fixing them with the M3 x 14 mm screws and nylon lock-nuts. Adjust the tightening torque as desired depending on your prefered firmness.
***Recommended tightening torque:
1.2 Nm for the M4 x 4 mm set screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL BOOM BRACES ASSEMBLY AND INSTALLATION (6-2)
Carbon fibre boom braces are delivered pre-sanded in order to guarantee the best glue adherence and thus strength. Use epoxy glue to glue the aluminium terminals to the carbon fibre boom braces. For additional strength, drill a 2 mm hole through the carbon fibre boom brace and secure both parts together with the provided M2 screws and nylon lock-nuts.
Front part of tail boom braces is secured with M3 x 10 mm screws and nylon lock-nuts. Fix the boom braces with a M3 x 40 mm screw and nylon lock-nut through the tail boom brace clamp.
***Recommended tightening torque: 0.8 Nm for the M3 x 10 mm set screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
SERVOS SERVO INSTALLATION (7-1, 7-2, 7-3)
Left and right aileron servos are fixed to the chassis using the previously installed servo supports. Fix the servos as shown in the images using the provided self tapping screws and reinforcement plates.
Elevator and tail servos are directly installed to the chassis. Mount first the plastic inserts in the rear part of the servos. Then fix the servos in place as shown in the images, using the self tapping screws. In order to better arrange servo cables, each servo cable may be attached to its servo using tape, guiding all servo cables to the front part of the helicopter.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
First install the M3 threaded balls in the servo horns using medium threadlocker. Each servo is to be equipped with a inner bushing servo horn, fixing it with the servo horn screws provided with the servos. Inner bushings are only available for Futaba 25t standard spline servos. Each servo horn is clamped to its inner bushing by means of a M2.5 x 6 mm screw with medium threadlocker, but not right now. In order to guarantee a perfect servo setup, servos and swash control levers need to be centered. Center the servos connecting them to a receiver or servo tester. If you do it through a Flybarless controller, remember to disable gyros first. Additionally, insert the provided pins to set the elevator and aileron levers in neutral position. Adjust the connecting rods length and install them. Finally fix each servo horn with the M2.5 x 6 mm screws.
***Recommended tightening torque:
0.8 Nm for the M2.5 x 6 mm set screw
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
Servo connecting rod lengths are not provided as the position of the servos can differ slightly depending on the specific servo brand/model. In order to figure out the correct length for the swashplate servos connecting rods, measure the distance between each servo axis and its corresponding lever axis as showed.
Screw the ball links to each rod, adjusting roughly its length to the previously measured one. Check for the correct orientation of the ball links, RVE engravement from the ball links should always point out of the threaded balls. At this point it is helpful to use ball link adapters installed in a caliper to precisely set the connecting rod length. It is key that both connecting rods for each servo have the same length. To check that the connecting rod length is correct, install one connecting rod between the servo arm and its lever and one end from the second connecting rod. Then try to place the leaving end from the second connection rod over its ball, its length may be correct, long or short. If short, enlarge both connecting rods the same length till obtaining a perfect setup. Do it similarly if the connecting rod is long but shortening the connecting rods. The same procedure is to be followed for all swashplate servos. With the pins locking elevator and aileron levers and the servos in their center position, secure each servo arm M2.5 x 6 mm screw using medium threadlocker.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
For the connecting rods between the aileron levers and the swashplate, as the elevator arm length is fix, aileron connecting rods should fit elevator arm length. With the provided pins locking both elevator and aileron arms/levers, use a swashplate leveler tool to adjust the aileron connecting rods length, obtaining a perfectly leveled setup. As always check for the correct orientation of the ball links, RVE engravement from the ball links should point out of the threaded balls.
For the rods connecting the swashplate with the bladeholder’s pitch arm, follow your flybarless controller instructions in order to set the correct length. Some flybarless controller systems ask to have zero degrees for collective pitch in the swashplate center position (this position can be obtained by locking elevator and aileron arms/levers with the provided pins). Then it will be possible to asymmetrically set the maximum range for maximum collective pitch and negative collective pitch. Other flybarless controller systems ask to perform a symmetrical setup having in a certain amount of pitch in the middle of the swashplate range. In order to identify the specific collective pitch to have, the center of the desired collective pitch range should be found. For example, if the maximum collective pitch we need to achieve is +12º and the minimum -10º (taking in account all the different flight modes), the center of the collective pitch should be set to 12º-(12º+10º)/2 = 12º-22º/2 = 12º-11º = 1º
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL SERVO CONTROL RODS (7-4)
Tail servo rod aluminium ends need to be glued first to the carbon fibre tube. In order to guarantee the best glue adherence use a small file to cut some notches. Then use epoxy glue to attach the aluminium ends to the carbon fibre tubes. Threaded rods are fixed to aluminium ends using medium/hard threadlocker. Let enough time for the threadlocker to cure before inserting the ball links
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
TAIL CONTROL ROD INSTALLATION (7-6)
Tail control rod guide needs to be installed on the middle position +/- 2 cm. The tail control rod guide is clamp-style so it is fixed with a self tapping screw. Check to not overtighten it. Align the tail control rod guide on its longitudinal axis, allowing a smooth movement of the rod on the full servo range. Choose the right position avoiding the tail control rod to bent. The tail control rod length should be adjusted till having a perfect squared position of the tail pitch lever, with the tail servo and thus the tail lever on its center position.
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RVE MERAK E750 - ASSEMBLY INSTRUCTIONS
PINION SELECTION Check the pinion recommendations in the following table, based on a 12s LiPo setup. Use this information as a reference.
Motor rpms Pinion
500-540KV 10t
480-520KV 11t
450-490KV 12t
MAINTENANCE RECOMMENDATIONS RVE uses only high quality raw materials, components and high level quality checks on his helicopters. That translates in a low maintenance helicopter having only to check as follows:
● For a new machine, after the first 50 flights check the main rotor blade holders play, adding a shim washer on each side if necessary.
● The rotor head dampers and spindle shaft should be regularly greased, specially under hot temperatures.
● Thrust bearings for main and tail rotor blade holders should be cleaned and greased back every 100 flights. Each time thrust bearings are greased, check for wear and replace them if necessary.
● Check regularly for unwanted dust on the drive-train area coming from gears due to a wrongly adjusted backlash between the motor and the main gear or between the tail gear and the tail pinion. Special attention for the backlash adjustment should be paid under hot temperatures due to thermal expansion on the main and tail gears.
● Check regularly the ball links, replacing them if necessary. This check is recommended to be performed during each flight pre-fight checks.
● Every season perform a full platform check, replacing parts with excessive wear when neccesary.
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ASSEMBLY DIAGRAMS
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