KAVAN Cumul 100 - Instruction manual

Precautions

This RC model is not a toy. Use it with care and strictly following the instructions in this manual.

Assemble this model following stricktly these instructions. DO NOT modify or alter the model. Failure to do so, the warranty will lapse automatically. Follow the instructions in order to obtain a safe and solid model at the end of the assembly

Children under the age of 14 must operate the model under the supervision of an adult.

Assure that the model is in perfect conditions before every flight, taking care that all the equipment works correctly and that the model is undamaged in its structure.

Fly only in days with light breeze and in a safe place away from any obstacles.

Caution: This RC model you will build and fly is not a toy! Although it may seem to be light and slow in flight it is capable of serious bodily harm and property damage. It is your responsibility and yours alone to build this model correctly, properly install RC equipment and motor, test the model and fly in accordance with all safety standards (and common sense) as set down in Safety Codes valid in your country. If you are just starting RC modelling, consult your local hobby shop or an experienced modeller in your local RC club to find a good instructor.

You must build the model according to the instructions. Do not alter or modify the model, as doing so may result in an unsafe or unflyable model. Take time to build straight, true and strong. Use proper radio and other equipment that is in first-class condition, properly install all the components and test their correct operation before the first and any further flight. Fly the model only with competent help from a well-experienced modeller if you are not already an experienced RC pilot.

Note: We, as the kit manufacturer, can provide you with a top-quality kit and instructions, but ultimately the quality and flyability of your finished model depends on how you build it; therefore we cannot in any way guarantee the performance of your completed model, and no representations are expressed or implied as to the performance or safety of your completed model.

Specification

Wingspan	2540 mm
Length	1435 mm
All-up weight	750 g
Wing section	AG 40–42
CG position	77–81 mm
Controls	Aileron, flap, rudder, elevator, (motor)

Recommended RC equipment

• Aileron and flap servo: KAVAN GO-1023MG 4×
• Rudder and elevator servo: KAVAN GO-1020MG/GO-1021MG 2×
• Receiver battery: 2S LiPo 800–1000 mAh 7.4 V

Recommender RC equipment (electric)

• Aileron and flap servo: KAVAN GO-1023MG 4×
• Rudder and elevator servo: KAVAN GO-1020MG/GO-1021MG 2×
• Motor: KAVAN C2836-1120, KAVAN PRO 2836-1050 w. 10×6" folding propeller (32 mm spinner)
• ESC: KAVAN R-40SB, KAVAN PRO-30SB, KAVAN PRO-40SB
• Flight battery: 3S LiPo 750–850 mAh 11.1 V

Recommended glues

Unless stated otherwise, use medium cyanoacrylate (CA) glue (KAV56.9952 Power CA Medium). D-box sheeting and wing ribs are better to be glued using a water-resistant white aliphatic resin, like our KAV56.9960 White Glue SUPER (alternatively, you can use this sort of glue for most of the wood- -to-wood joints). The highly loaded parts (wing roots, wing main spars, firewall etc.) should be glued together using 30 minute (or slower) epoxy offering high strength and enough time for the correct positioning.

Tools and accessories

• Very sharp modeller’s knife (e.g. Excel 16001 with no. 11 blades)
• Scissors
• Electric drill with drill bits
• Wire cutter
• Long nose pliers
• Screwdrivers
• Razor saw
• Sandpaper No. 80, 100, 180, 360–400
• Needle files
• Soldering iron and solder
• Clothing pegs
• Modeller’s pins
• Epoxy mixing stick and vessel
• Masking tape, clear sticky tape
• Rubbing alcohol (for cleaning up excessive epoxy)
• Paper tissue or soft cloth (for cleaning up excessive epoxy)
• Straightedge with scale
• Square edge
• Thin clear plastic film (for protecting the building plan)
• Permanent marker
• Modeller’s sealing iron, heat gun (for covering)
• Lightweight balsa filler

Model assembly

The empennage

Everything has been designed extremely light, yet strong enough. The horizontal tailplane is removable for easy transport/storage.

• Trial fit the parts of the horizontal stabilizer, elevator, fin and rudder – no glue yet! Sand as necessary to obtain perfect fit. Bevel the leading edged of the rudder and elevator to allow the control surface travel as indicated on the building plan.
• Epoxy the T8 and T9 plywood inserts into the T10 stabilizer centre part. Glue together all the parts using medium cyano or white glue. (Fig. 1+2)
• Put the tail feathers aside for now. They will be finished after covering, once the tailplane seat is installed to the tail boom.

Wing

Wing centre section

• Cut out all the CNC milled ribs using a sharp modeller’s knife or jigsaw, check them with the plan and mark the numbers on them with a soft pencil or marker. Sand as necessary to fit all spars easily.
• Assemble the main spar shear webbing. Epoxy the W30 wing joiner bays to the W29 balsa parts. Enclose the bays; epoxy the W31 plywood plates (front side of the shear webbing) and W32 (rear side). Prevent the epoxy from hardening inside the bays. Put the parts together with the carbon joiner inserted, then immediately remove the joiner (do not forget cleaning the joiner using a paper tissue and rubbing alcohol before the glue sets). (Det. B, Fig. 3)
• Bind the joiner bays with the provided Kevlar® thread and soak with medium CA or epoxy. Epoxy together both two shear webbing halves reinforcing the joint with the plywood joiners W27 (short one, front side) and W28 (long one, rear side). (Det. B, Fig. 3+4+5)
• Epoxy together the wing central ribs W1 and W2. Insert 3 mm beech dowels into the holes in order to obtain correct match. Note: Make a left and right pair of ribs.
• Epoxy the plywood wing bolt plates W15 and W18 between the W1/W2 ribs. Glue the balsa blocks W16 and W17 onto them (trim the W17 first to match the outline of the W1 ribs). Sand the W16 flush with the edge of W2 ribs. (Fig. 6)
• Glue the W26 flap servo trays between the W5 ribs.
  
  Note: Make a left and right pair of assemblies.
• You can use medium cyano for gluing most of the wing centre section parts. In that case you are supposed to put together most of the wing without glue at first. Once checked for the correct alignment, the cyano is applies to the joints from the outside. Or you can use white glue. In that case the wing is assembled step by step pinned down on the building plan protected by a thin clear plastic film. Start with pinning down the W9 bottom main spar. The W11, W12, W14 and W38 parts are to be glued after the wing is removed from the building board.
• Assembling the wing using cyano: Insert all ribs and riblets into the respective notches, slide on the W13/W19 trailing edge. Cyano the W6 ribs to the shear webbing using the 7 deg dihedral jig (the W7 outer ribs are to be glued later - after the wing centre section has been paired with the wing panels).
• Insert, but not glue, the W11 auxiliary spar (5 mm balsa) and the W12 flap leading edge (7 mm balsa). Align the top edge of these parts flush with the top edge of the ribs (you will trim the protruding part at the bottom later, once glued in place).
• Cyano the W25 flap horn blocks in place.
• Double check the correct position of all ribs and spars. Lay the wing on the building plan. Once satisfied, apply cyano to all joints.
  
  Note: Be sure not to glue the W11 and W12 parts to each other, just to the ribs.
• Insert and cyano the W10 rear spar (6×3 mm pine stick).
• Pin down the wing centre section to your building board. Butt joint the W9 main spar (10×2 mm pine) to the edge of the W39 top D-box sheeting (1.5 mm balsa). Apply white glue to the top of the ribs, riblets and the main spar shear webbing. Insert the W9 main spar into the notches in all ribs and pin it down. Then step by step pin down the W39 balsa sheeting to the ribs.
• Once the glue has cured, remove the wing from your building board. Glue the W14 support spar in place as well as the W9 bottom main spar. Use white glue to secure the W38 bottom D-box sheeting in place. (Fig. 7)
• Sand the front edge of the W39 and W38 balsa sheeting flush with the front edge of the ribs and glue the W8 leading edge in place.
• Glue the W24 bottom cover plates of the flap servo bays between the W5 ribs. Glue the W33 flap root ribs in place.
• Sheet the space between W2 ribs from the bottom and top with W20a, W20b (with the W40 connector reinforcement plate glued on top), W21, W22 and W23. (Det. C)
• Sand the sheeting flush with the edges of W2 ribs. Drill the hole for the front wing bolt through the W39 top sheeting. Taper the top edges of the wing bolt holes to match the supplied countersunk screws. Soak the tapered area with thin cyano to reinforce it.
• Glue the W47 gussets in place.
• Fine sand the entire wing centre section, pay attention to the leading edge, sand the W6 ribs flush. Trial fit the flap servos. Prepare the aileron and flap extension cables. To allow threading the cables after the wing has been covered, you should put a thread through the holes in ribs secured by strips of sticky tape. Or you can glue 6 mm plastic tubes (not included in the kit). See the dotted lines on the building plan. There is a pair of the MPX8 8-pin connectors supplied in the kit suitable for the cable connection of aileron and flap servos and your receiver. The male part (with pins) is to be secured by screws into the fuselage, the female part into the wing. (Fig. 11+21)
• Solder the extension cables with (+) and (-) pins shared, the remaining pins are for the servo signal leads. You can use regular servo connectors between the wing centre section and outer panels, but the sturdier MR30 connectors (KAV36.131 - not supplied in the kit) are more suitable for the task. If you are going to use them, install the male part (with pins) of the connector into the wing centre section. It is probably for the best installing all the cables before the wing is covered. Do not forget double-check the correct polarity and connection first! The connectors are to be cyanoed to the wing after the covering.
• Use a fine razor saw to cut the root part of flaps through the W13/W19 trailing edges and between W33 and W2 ribs. Cut through the ribs between the W11 auxiliary spar and W12 flap leading edge with a sharp modeller’s knife or razor saw and remove the flaps. Bevel the leading edge in 27 degrees angle, allowing the up deflection of the flaps (flaps are hinged on the bottom side of the wing). (Fig. 8)
• Trial fit the carbon wing joiners into the respective bays. There should be a tight fit, no play. If there was a significant play, put some epoxy to the appropriate area of the joiner and sand as necessary once the glue hardens. Trial fit the W7 liteply outer ribs - do not glue yet.

Wing outer panels

• The wing outer panels are to be assembled in one piece. The winglets will be cut off subsequently. Build the wing panel on a flat building board. The trailing edge has to be supported so the wing tip was be 2 mm above the building board creating the required washout (the railing edge lays flat on the working surface at the W50 root rib, then it is supported in at lest three points sot it was 2 mm above the building board at the W74 end rib).
• Assemble the main spar shear webbing. Epoxy the W37 wing joiner bays to the W34 balsa parts. Enclose the bays. Epoxy the W36 plywood plates (front side of the shear webbing) and W35 (rear side). Bind the joiner bays with the provided Kevlar® thread and soak with medium CA or epoxy.
  
  Note: Make a left and right pair.
  (Det. A, Fig. 3+9+5)
• Assemble the wing panels without glue at first. Insert all ribs and riblets into the respective notches in the shear webbing. There are two 5 mm ribs W66 and W67 dividing the outer panel and the winglet (you can glue both two ribs square to the shear webbing and bevel both at 4 degrees angle once the winglet has been cut off, or you can one of them - preferably W67) glue in 8 degrees angle using the supplied 8 deg dihedral jig).
• Slide on the W83/W84 trailing edges onto the ribs. Cyano the W50 root ribs to the shear webbing using the 7 deg dihedral jig (the W49 outer ribs are to be glued later - after the wing panels have been paired with the wing centre section).
• Insert, but not glue, the W79 auxiliary spar (5 mm balsa) and the W80 aileron leading edge (7 mm balsa).
• Cyano the W46 aileron horn blocks between the W56 and W58 ribs (not to the W80 yet).
• Double check the correct position of all ribs and spars; lay the wing on the building plan. Once satisfied, pin down the wing outer panel to your building board with the trailing edge supported as described above. Apply medium cyano to all joints (do not glue the W79 and W80 parts yet). Insert and cyano the W78 wing panel rear spar (6×3 mm pine stick) and the W85 winglet rear spar (4×2 mm pine).
• Butt joint the W77 main spar (10×2 mm pine) to the edge of the W89 top D-box sheeting (1.5 mm balsa). Apply white glue to the top of the ribs, riblets and the main spar shear webbing. Insert the W89 main spar into the notches in all ribs and pin it down. Then step by step pin down the W89 balsa sheeting to the ribs.
• Butt joint the W91 winglet main spar (8×2 mm balsa) to the edge of the W88 top D-box sheeting (1.5 mm balsa). Apply white glue to the top of the ribs, riblets and the main spar shear webbing. Insert the W91 main spar into the notches in all ribs and pin it down. Then step by step pin down the W88 balsa sheeting to the ribs.
• Once the glue has cured, remove the outer wing panel from your building board. Align the top edge of the W79 and W80 flush with the top edge of the ribs and glue them to the ribs, not to each other. Trim the protruding part at the bottom side of the wing. Put the wing panel down onto your building board to check the trailing edge is straight and elevated by 2 mm at the wing tip.
• Glue the W43 wing tip in place.
• Glue the W90 support spar in place as well as the W77 and W91 bottom main spar. Use white glue to secure the W87 and W86 bottom D-box sheeting in place.
• Sand the front edge of the W87/W89 and W86/W88 balsa sheeting flush with the front edge of the ribs and glue the W75 and W76 leading edges in place.
• Glue the W48 winglet gussets in place. Glue the W44 bottom cover plates of the aileron servo bays between the W56 and W58 ribs.
• Sand the W50 root ribs flush. Trial fit the carbon wing joiners into the respective bays. There should be a tight fit, no play. Trial fit the W49 liteply outer ribs - do not glue yet.
• Slide the wing panel onto the carbon wing joiner together with the W49 and W7 liteply ribs. Slide on the wing centre section as well. Check how the ribs and wing parts are matching. Trim them as necessary to achieve a perfect fit. Once satisfied, epoxy the W7 and W49 ribs in place.
• Fine sand the entire wing panels, pay attention to the leading edge.
• Cut off the winglets. Use a fine razor saw to cut through (from the bottom) between the W66 and W67 ribs. If you have glued the ribs square to the main spar, now bevel both at 4 deg angle in order to achieve the required 8 degrees winglet dihedral.
• Cut through the ribs between the W79 auxiliary spar and W80 aileron leading edge with a sharp modeller’s knife or razor saw and remove the flaps. Bevel the leading edge in 28 degrees angle allowing the down deflection of the ailerons (ailerons are hinged on the top side of the wing).
• Glue the winglets to the wing panel (the butt joint protects the wing as there is a good chance the winglet breaks of in an accident - whilst the rest of the wing will remain undamaged).
• Glue the W103 aluminium alignment pins into holes in W49/W50 ribs. (Fig. 13)
• Trial fit the aileron servos. Prepare their extension cables. To allow threading the cables after the wing has been covered you should put a thread through the holes in ribs secured by strips of sticky tape. Or you can glue 6 mm plastic tubes (not included in the kit) - see the dotted lines on the building plan. You can use regular servo connectors between the wing centre section and outer panels, but the sturdier MR30 connectors (KAV36.131 - not supplied in the kit) are more suitable for the task. If you are going to use them, install the female part (with sockets) of the connector into the wing panels. It is probably for the best installing all the cables before the wing is covered. Do not forget double check the correct polarity and connection first! The connectors are to be cyanoed to the wing after the covering.

Covering

• Thoroughly sand the surface of all parts with No. 360–400 sandpaper and carefully vacuum all the dust (the iron-on film does not stick well to a dusty surface; the dust also contains hard grains released off the sandpaper capable to ruin the smooth coating of your sealing iron quickly).
• Use as light iron-on film as you can get (transparent KAVAN film, Oracover®, Oralight® etc. – not supplied in the kit). Follow the instruction manual supplied with the covering film of your choice please.

Hinging the control surfaces

• Use strips of a high quality hinging tape (available in hobby shops) or strips of the same iron-on film you used for the covering. Remember to apply the tape with the control surface deflected to the limit in order to get free movement of the particular control surface.

Aileron and flap servo installation

• If not done before covering, insert the aileron and flap servo extension cables in place. Install the aileron and flap servos with arm set to neutral with your radio on (to allow for the max. travels it is recommended setting the aileron servo arms offset by 15–20 degrees forward and flap servo arms by 15–20 degrees back). Cyano the W100 flap horns (longer fibreglass arms without triangular opening) into the W25 blocks and the W101 aileron horns (shorter fibreglass arms without triangular opening) into W46 blocks. Make the servo linkage: cyano one all-plastic quick link and one quick link with metal pin to the ends of Ø2 mm carbon rods (the all-plastic quick link is a sort of safety device protecting the servos on a rough landing or other mishaps). (Fig. 10)
• Double check the correct operation of aileron and flap servos. Once satisfied, cyano the MPX8 and MR30 (if used) connectors in place. (Fig. 11+12 +13)
• Secure the W41 and W42 servo covers with strips of thin double sided sticky tape.

Fuselage

• The fuselage consists of the F2 carbon reinforced fibreglass part and the F1 carbon tail boom with milled slots for the fin and horizontal tailplane pylon.
• Horizontal tailplane pylon: Epoxy the aluminium captive nuts M4 and M3 into the F9 liteply horizontal stabilizer pylon matching the openings in the F10 horizontal tailplane seat that is to be epoxied square onto the top of the pylon. Glue the F11 balsa blocks on the sides of the F9 pylon. Sand the blocks to match the outline of F9 and F10. Trial fit the pylon into the slot in the F1 tail boom. Trim the bottom of the F11 blocks until the F9 connects with the bottom of the tail boom and the balsa blocks are matching the surface of the boom. Round the leading and trailing edges of the pylon and cover it with your favourite iron-on film - now it is prepared for the final assembly. (Fig. 14)
• Drill and cut 2 mm slots for the rudder (right side) and elevator (left side) push rod exits - refer to Fig. 16+17. Insert the elevator and rudder push rod sleeves into the F1 tail boom threading them out through the respective exit slots. Epoxy the horizontal tailplane pylon in place. (Fig. 15 + 16 + 17)
• Slide the smallest of the three push rod plywood holders (packed in the bag. no. 1) onto the push rod sleeves and push inside the tail boom using a suitable hardwood stick. Secure it with a small amount of epoxy or cyano.
• Attach the horizontal tailplane to the pylon and secure with screws; remove the covering film from the fin-tail boom contact area and insert the fin into the slot in the tail boom. Trim as necessary; double check the fin was square to the horizontal tailplane. Once satisfied, epoxy the fin in place. Epoxy the F6 tail skid in place as well.
• Insert and glue the two remaining plywood push rod holders into the tail boom.
• Tow hook (glider): Disassemble the supplied tow hook, use the F8 plate as a template to drill the openings for the M3 screws and 4.5–5 mm slot for the F7 hook and its setting screw (assuming the CG position is 77–81 mm behind the leading edge of the wing, the tow hook is to be positioned 4–10 mm in front the CG depending on the wind). Install the tow hook into the fuselage. (Fig. 18)
• Firewall (electric): Glue together the liteply nose cutting jig (32 mm spinner is assumed). Mark the cutting line with a soft pencil; cut the nose with a razor saw and sand flush. Epoxy the F3 firewall in place (check whether your motor matches the firewall first. Trim if necessary or make a new firewall of 3 mm plywood or fibreglass plate). (Fig. 19)
• Trim the servo tray F4E to match your servos if necessary and insert it into the fuselage (the long cut-out for your flight pack towards the tail). The tray is to be glued in place only after you have checked the correct CG position with your motor, ESC, servos and flight pack (3S LiPo 750–850 mAh for the contest flying. Anything 3S that will fit the fuselage for Sunday flying) installed. (Fig. 20)
• Aileron and flap servos connector: A pair of the MPX8 8-pin connectors is supplied in the kit suitable for the cable connection of aileron and flap servos and your receiver. The male part (with pins) is to be secured by screws into the fuselage, the female part into the wing. Solder the extension cables with (+) and (-) pins shared, the remaining pins are for the servo signal leads. (Fig. 21)
• Servo tray (glider): The servo tray F4 supplied in the kit is tailored to KAVAN GO-1020MG/GO-1021MG servos or similar. The servos are to be secured using the supplied fibreglass stoppers. If you are going to use different servos, trim the tray as necessary or make a new one to match your servos. Insert the servo tray into the fuselage allowing the clearance for your receiver battery in the nose. Once satisfied, epoxy the tray in place. (Fig. 22)