KAVAN Orion A3 glider kit 930mm - Instruction manual

Introduction

The Orion A3 glider is a great entry-level kit for any modeller who has already gained some skills in classic balsa bashing and dope & tissue covering. You will need some basic modeller‘s tools, glues and dopes – you will find these handy for any of your future projects as well. Please make yourself familiar with the building plans and this manual BEFORE you actually start the assembly.

Specification

Wingspan	930 mm
Length	740 mm
All-up weight	min. 150 g

Before you start

Glue: You can use solvent-based modeller's glue (UHU® Hart etc.), water-resistant white glue (KAVAN White Glue, BISON® Super Wood etc.) or medium cyano (KAV56.9952).

Dope: KAVAN STANDARD line Adhesive dope, Shrinking dope, Top gloss dope and Thinner are the must for the dope and tissue covering, indeed. You can use any of the KAVAN Color shrinking dopes as well.

Tools and accessories: You will need a perfectly flat building board (at least 300×700 mm), precision knife (KAV66.770), jigsaw, sanding blocks with 180 and 360–400 grit sandpaper, model hobby pins, scissors, sharp model hobby knife, flat and round fine file, soft flat (1/4"–3/8") brush, thin clear plastic film to protect the building plan (a large PE bag cut in half will work).

Precautions

The model you build and fly is not a toy! Although it may seem light and slow in flight, it is capable of causing injury or other damage if mistreated. It is up to you whether you build the model properly, fly properly and continue to fly in accordance with common practice and rules (and common sense). If you are just getting started with aircraft models, ask for advice from your model shop or an experienced modeller at your local modelling club to find a good instructor.

Before construction: Build the model exactly as instructed. Do not change or modify the model. If you do, you risk that the model may be unsafe or unable to fly. Take the time to build everything firmly and reliably. Use appropriate tools, accessories and other equipment that is in top condition. Correctly install all parts of the model and check the model before the first and every subsequent flight.

Note: We, as a kit manufacturer, can guarantee you a premium quality kit with detailed instructions, but flight characteristics and performance depend entirely on how you complete the model. Since we have no control over how you complete and operate the model, we cannot (and cannot be assumed) assume any responsibility for any damage caused or related to the operation of your completed model.

Assembly

• Lay the wing building plan on the building board and put a sheet of a thin clear plastic film to protect the building plan. If you have just a small building board, you can carefully cut the building plan into sections – wing section, horizontal tailplane section etc.
• Before you apply the glue, please, always double-check the correct size, shape and alignment of the particular part.
• Balsa and spruce sticks are intentionally supplied oversized in the kit. Pin the stick to the plan overlapping at both ends – you will cut/sand them to the correct length/shape once the assembly of the particular part has been finished.

Wing centre section

• The wing features an under-cambered wing section; it is to be built in two steps. At first, you are going to glue together the ribs, mains spar and leading edge on a flat working surface - and then you will add the trailing edge using the supplied jig in order to get everything right.
• Pin down the bottom main spar 2 (6x2 mm spruce stick) laid over the supporting 5×1.5 mm balsa stick 1 on the building plan protected by a clear plastic film - refer to Det. A. Glue all the ribs 3 to the bottom spar as well as the outer ribs 6L and 6R - the bevelled side outwards (refer to Det. F-F).

Note: The centre ribs 9 will be glued later.

• Glue together the 6×2mm spruce stick 4 and 6×4mm balsa stick 5 so that their sides match as well as possible (Det. G). Once the glue has cured, sand this side perfectly flat using No. 180 sandpaper.
• Glue the prepared leading edge to the front of 3 and 6L/6R ribs.
• Glue the 6×2 mm spruce top spar 10 into the notches in the ribs 3.
• Remove the wing frame from the building plan and put glue into the notches in the left trailing edge 17L (we recommend using white wood glue as it gives you longer working time to set the trailing edge right and true). Attach the trailing edge to the ribs so the bottom of the trailing edge matches the bottom edge of the ribs. Before the glue sets; check the correct position of the trailing edge using the supplied jig 14 (Det. B).
• Glue the right half of the trailing edge 17R in place in the same manner; finally, glue it to the left half 17L.
• (If you are using cyano: Attach the trailing edge to the ribs, set it into the correct position using the jig 14 and only then apply the cyano to the joints.)
• Lay down the wing centre section over the building plan and check if it is straight and true; before the glue sets you can carefully pin it down to the building board. In order to prevent any unwanted change of the wing profile, support the ribs with the balsa stick 1 near the trailing edge.
• Glue the front bottom balsa sheeting 7 between the leading edge and the bottom spar 2; glue the rear bottom sheeting 8 between the main spar 2 and the trailing edge 17 (Det. G).
• Glue two centre ribs 9 onto the bottom sheeting and then the top sheeting 11 and 12 over them (Det. G).
• Cut the triangular gussets 13 from 1.5×8mm balsa stick and glue them into the corners.
• Cut and sand flush to the bevelled end ribs 6L/6R the overlapping spars, leading and trailing edges 4+5, 2, 10, 17.

Wing panels

Note: The outer wing panels are to be built in the same manner as the wing centre section; just the top spar is to be glued later, once the washout has been set (see later). You can build both panels at once.

• Pin down the bottom main spar 16 (6×2mm spruce stick) laid over the supporting 5×1.5mm balsa stick 1 on the building plan protected by a clear plastic film - refer to Det. A. Glue all the ribs 3 to the bottom spar as well as the root ribs 18L and 18R - the bevelled side outwards (refer to Det. H-H).
• Glue together the 6×2mm spruce stick 19 and 6×4mm balsa stick 20 to form the leading edge as you did before.
• Glue the leading edge to the front of 3 and 18L/18R ribs.
• Remove the wing panel frames from the building plan, put glue into the notches in the left trailing edge 21L/21R and attach it to the ribs so the bottom of the trailing edge matches the bottom edge of the ribs. Before the glue sets; check the correct position of the trailing edge using the supplied jig 14 (Det. B).
• Before the glue has cured, lay down the wing panels over the building plan, support the root ribs 18L/18R with the balsa stick 1 near the trailing edge - so you can pin the frame down without any change to the wing profile. Pin the wing panels down at the ends of the leading edges and at the root of the trailing edge. Support the tip end of the trailing edge (where the wing tip 23 will be attached later) with a 5mm scrap of balsa or spruce stick to form the washout - it improves the stability of the model significantly. The washout of both two wing panels has to be the same.
• Glue the 6×2mm spruce top spar 22 into the notches in the ribs 3.
• Cut the triangular gussets 13 from 1.5x8mm balsa stick and glue them into the corners.
• Cut and sand the overlapping spars, leading and trailing edges 19+20, 16, 22, 21 flush to the bevelled root ribs 18L/18R.
• Glue the wing tips 23 in place and round their outer edges (Det. H-H).
• Sand the leading edge of the wing centre section and wing panels to shape (Det. G).

Joining the wing

• Trial fit the wing centre section and wing panels – if attached together the wing panel dihedral must be 90 mm (Det. E, measured at the leading edge). Apply a generous amount of glue to the wing centre section end ribs and wing panel root ribs and attach the wing panels to the wing centre section. Lay the wing centre section down on the building board; secure it with a couple of magazines wrapped in a plastic bag serving as a weight. Align the wing panels so their tips are 90 mm (at the leading edge) above the building board (you can use a couple of books or a wooden block). Let the glue cure thoroughly, and then sand the entire wing frame with fine sandpaper.

Horizontal tailplane

The horizontal tailplane is to be built directly on the plan protected with a clear plastic film in a similar manner as the wing.

• Pin down the balsa bottom main spar 25 (4×1.5 mm balsa) and 4x4mm balsa leading edge 28 on the building plan protected by a clear plastic film; glue all the ribs 26 and the centre rib 27 to them.
• Glue the trailing edge 29 and the 4×1.5mm balsa top spar 30 to the ribs.
• Cut the triangular gussets 32 from 1.5×8mm balsa stick and glue them into the corners.
• Cut and sand the overlapping spars, leading and trailing edges 28, 25, 30, 29 flush to the outer ribs. Glue the tip ribs 31 in place and round their outer edges slightly.
• Sand the leading edge to the shape of the tip ribs 31 (Det. K).
• Use a 2.5mm drill bit to create a groove for the dethermalizer pin 33 in the centre ribs 27; the pin will be glued in place after covering.

Fuselage and fin

The fuselage consists of the tail boom made of spruce sticks and balsa blocks and the front fuselage block made of Ceiba plywood with veneer side covers offering enough space for the ballast and timer (if you decide to install one).

• Start with the tail boom: On a flat working surface protected by a clear plastic film, glue together the balsa blocks 35 and 36. Glue the spruce sticks 38 and 37 to the top and bottom of the balsa block 35+36 with their ends flush with the narrower end of the block as well as matching the edges of the block along its entire length. Double-check the tail boom is straight (not bent up/down, left/right) laying it down on your workbench.
• Glue the spruce reinforcement 39 into the gap between 35 and 38.
• If you are considering installing a timer (either mechanic or electronic) and dethermalizer, now it is time to trim the openings in the fuselage block 40 as needed. Do not forget to cut an appropriate opening in one of the side covers (42) as well.
• On a flat working surface, glue together the assembled tail boom and the front part of the fuselage 40.
• Glue the ballast 41 into the opening in 40 and glue both two side covers 42 in place.
• Glue the plastic horizontal tailplane support 43 to the top of the fuselage and - spaced to match the width of the horizontal tailplane - the front horizontal tailplane seat 44.
• Use the tip of a pointy modeller’s knife to cut slots for the brass tin rudder hinges 47 into the fin 45 and rudder 46. Cyano the hinges into the rudder and then into the fin leaving a small (0.5mm) gap between the fin and rudder.
• Glue the fin 45 to the fuselage in front of the horizontal tailplane seat 44; align it exactly along the longitudinal axis of the fuselage and square to the horizontal tailplane attached to its seats 44+43 and fastened by a rubber loop.
• Glue two wing dowels 49 into the fuselage.
• Lay down the plywood wing seat 48 onto the fuselage and put the wing over it securing it by a rubber loop to the fuselage. Looking from the tail and nose, check if the trailing edge of the wing centre section is parallel to the horizontal tailplane. Trim the top of the fuselage under the wing seat if necessary; once satisfied, glue the wing seat in place. Before the glue has cured check the correct alignment of the wing respective to the horizontal tailplane once more.
• Drill a 2.5mm hole for the horizontal tailplane pin 50 in the tail end of the fuselage and glue the pin in place.
• Glue the skid 51 in place.

Doping and tissue covering

Lightly sand the entire airframe with fine sandpaper. Before the frames are covered, all EXTERNAL surfaces MUST be primed with the adhesive dope (diluted at least 1:1 with the thinner; the dope must have the viscosity of water - never use the dope unthinned!). Use a soft flat brush to apply the dope and, when dry, lightly sand all doped surfaces with the fine sandpaper. Apply the second coat and sand lightly again.

Sheets of the Vlies covering tissue are supplied in the kit. You can glue it to the airframe using water-thinned white glue or clear dope. Always align the „grain“ of the tissue the long way - from tip to tip of the wing or horizontal tailplane.

Horizontal tailplane: If you are new to the dope and tissue business, you should start with the horizontal tailplane to gain the skills on a smaller part of your model featuring no curves. Cut a 10mm piece of the tissue oversized all around the outline of the horizontal tailplane. Apply the thinned white glue or adhesive dope around the external edges of the lower side of the tailplane and to the diagonal ribs and centre plate; IMMEDIATELY set the tissue in position and smooth the edges with finger tips before it has a chance to dry. Cut the tissue all around the outline of the tailplane leaving it 4–5 mm over size. Bend and glue with thinned white glue or clear dope the overlapping tissue around the entire tailplane.

Cover the upper side of the tailplane in the same manner – apply thinned white glue/adhesive dope to the trailing and leading edges, main spar, centre plates and tips. Do not apply the glue to the diagonal ribs!

Wing: Cut four or six pieces (a skilled builder could cover the entire bottom side of the wing using just one long strip of tissue; the upper side of the wing centre section and wing panels are to be covered by separate strips) of the tissue 10 mm oversized all around the outline (do not forget the upper sheets have to be wider due to the airfoil camber). Again, start with the bottom side of the wing – apply the glue/dope to the leading and trailing edges and all ribs, attach the tissue and smooth the edges with your fingertips. Cut the tissue all around the outline of the wing leaving it 4–5 mm over size. Bend and glue with thinned white glue or adhesive dope the overlapping tissue around the edges of the entire wing. You will have to cut the tissue against the wing panel joints and in short 4–8mm portions around the wing tip in order to follow the curve of the tip.

Note: Covering the bottom side of the wing requires a little bit of skills, care and thoroughness. Take care to glue the covering tissue thoroughly to the entire wing frame; let the glue/adhesive dope cure at least 24 hours prior to shrinking. Using a different glue/dope than the dope used for shrinking is essential (you can glue the tissue to the wing using a diluted white glue or adhesive dope, but you cannot expect any success using a shrinking dope both for attaching the tissue to the wing and shrinking it); otherwise you are risking the tissue will tear off when treated with the shrinking dope.

Cover the upper side of the wing centre section in the same manner (the tissue overlapping over the wing panel root ribs 18) – apply thinned white glue/adhesive dope to the trailing and leading edges, main spar and ribs.

Cover the wing panels with separate strips of tissue; attach the tissue to the rib, using a pencil and steel ruler or a piece of flexible plastic draw the line marking the joint of 6 and 18 ribs on the tissue. Trim the tissue to the line and glue it in place in the usual manner. You will have to cut the tissue in short 4-8 mm portions around the wing tip in order to follow the curve of the tip.

You can cover the tail boom as well (apply 4 slightly overlapping strips to the bottom of both sides and finally to the top of the boom) to add some extra strength; there is no need to cover the nose.

Now you can apply several coats of thinned shrinking dope in order to shrink the tissue and protect it from moisture. Once the tissue is nice and smooth without wrinkles (after 1–2 coats) you can apply the colour tissue trim – and continue applying the shrinking dope.

Only apply the dope in a dry and well-ventilated area at room temperature (over 20 °C; low temperature/high humidity may cause „fogging“ of some dopes turning them milky white instead of clear – if that happens you can usually cure it by taking the model to a dry and warm place and applying just the fresh thinner with a brush to the „fogged“ part). Apply 3–5 coats of thinned dope to the entire model (use the top gloss dope for the fuselage and the last coat for the wing and horizontal tailplane). Lightly sand all doped surfaces with fine sandpaper between each coat.

Apply the colour tissue trim (if any) to the fuselage before the last coat of dope (use the top gloss dope for the final coat). The stickers are to be applied only after the final coat!

Let the model dry thoroughly after each coat (2–3 days). Check for any warping of the wing centre section or horizontal tailplane (the wing panel washout has remained the same). If that happens, you have to lay the wing and/or tailplane down to a flat surface protected with a plastic film and weigh it down (a couple of magazines in a plastic bag to the rescue again) after each coat. Let it dry thoroughly.

Final assembly, centre of gravity (CG)

Glue the dethermalizer pin 33 into the horizontal tailplane.

Secure the side tow hook 52 to the left side of the fuselage using two screws 53 – refer to the building plan. The tow hook is adjustable – you can move it forward on a windy day or backwards on a calm day in order to achieve nice and steady climbing during the hi-start.

Tie the wing and horizontal tailplane to the dowels on the fuselage using several loops of the supplied rubber thread. Please note – one loop is never enough!

Drill a 5mm access hole into the additional ballast compartment in the fuselage (refer to the building plan). Support the wing of the model with your fingertips in the centre of gravity position (the point marked by an arrow on the fuselage plan). The fuselage should be level - if the nose pitches up, put in as much additional ballast (not supplied in the kit) as necessary (you can use pellets, small screws etc.) Once satisfied, cover the hole with a strip of clear sticky tape. The correct balancing is essential; an incorrectly balanced model will be difficult to set up or unable to fly at all!

Flying

Once again check the correct position of the centre of gravity and check for any excessive warping of the wing centre section, tailplane and fuselage. Check the wing panel washouts are the same. Choose a nice calm day for the first flight.

The model must be launched into the wind every time. Throw grass into the air to observe the wind direction.

Hold your model with the wing and fuselage level. Launch your model with a gentle push straight with the nose pointing slightly down. Do not throw your model with the nose up or at a greater angle than 10 degrees down. The model must have a certain minimum speed from the very start to stay airborne. It is not enough to just place your model in the air. It is better to land in tall grass in order to prevent any damage to your model during initial trimming.

If everything is OK (correct wing and tailplane alignment, correct CG position) ORION will fly with the wings level in a nice glide with her nose pointing slightly down. If the model glides straight down to the earth a few paces in front of you, check the CG position again. If OK, add a thin piece of balsa or plywood under the trailing edge of the horizontal tailplane until the model glides in a nice flat and straight path.

Once satisfied, bend the rudder 46 slightly (about 2 mm) to the left (looking from the tail to the nose). Now the model should glide in large left (counter clockwise) turns; whilst under tow, the off-centre tow hook would force your ORION right - resulting in straight flight. Elementary!

Once trimmed out you can try your first hi-start with your ORION using a 25m towline (a fishing line). You can purchase a towline set in your local model hobby shop or you can make your own from scratch. Get a towline (any fishing line strong enough to hold a 5kg fish is OK), tie a key ring to one end (a bowline knot is the best) and a flag (a piece of red cloth) 20–30 cm from the end. The flag makes the towline visible in the air as well as on the ground. Find a suitable spool to keep the towline on. Hook the ring at the tow hook and ask a friend to hold (and launch later) your model. Unwind the towline walking into the wind keeping it slightly stretched. The launch position of the model: wings level, nose very slightly up, directly into the wind.

Give a signal to your friend holding your model; both of you will start running into the wind and the assistant will launch the model after a few paces. Continue running into the wind paying attention to the tension of the towline and checking the model over your shoulder. Run as fast as necessary to achieve a steady climbing rate of your model – the model should climb straight forward, at a steady rate, in a nice arc. The stronger the wind, the slower you might run. If the towline tension decreases, your model climbs slowly (and yaws to a side) you should run faster. If the towline tension increases and the model turns violently to a side, you have to slow down and wait until the model returns to the original straight path. Hi-start requires some skills; especially on a windy day running too fast might even end in the destruction of your model. Once the mode climbs almost over your head, it should start turning slightly left – this is the moment to stop. Let the model fly in front of you and release the towline. For the initial high start, set the tow hook to the forward position. Based on the ORION´s behaviour, you can move it back/adjust later. If your model hesitates to climb, move it back; if pitches the nose up and veers to the side, move it forward. Adjust the rudder to achieve large flat left turns; tight banked turns kill the altitude! Usually, just a 2mm left offset is OK. Contest flyers would want to install the dethermalizer with a timer that kicks the horizontal tailplane up (about 45°) once the set time has elapsed; the model will land in large „hoops“ then.

Have a ball, enjoy your Orion.

Parts list

The kit contents
Part	Building plan no.	Quantity
Fuselage block (8mm Ceiba plywood)	40	1
Side cover (1mm veneer)	42	2
Building plan		1
Instruction manual		1
Vlies tissue sheet		1
Sandpaper		1
Sticker sheet		1
Stick bundle A
Wing centre section main spar (spruce 2×6×560 mm)	2, 10	2
Wing leading edge- centre section (spruce 2×6×560 mm)	4	1
Fuselage stick (spruce 2×8×498 mm)	37, 38	2
Wing leading edge- Centre Section (balsa 4×6×560 mm)	5	1
Stick bundle B
Wing panel main spar (spruce 2×6×200 mm)	16, 19, 22	6
Wing panel trailing edge (balsa 3×12×200 mm)	21L, 21R	1+1
Wing panel leading edge (balsa 4×6×200 mm)	20	2
Wing and horizontal tailplane gussets (balsa 1.5×8×198 mm)	13, 32	2
Stick bundle C
Horizontal tailplane main spar (balsa 2×4×300 mm)	25, 30	2
Horizontal tailplane trailing edge (balsa 2.8×10×300 mm)	29	1
Horizontal tailplane leading edge (balsa 4×4×300 mm)	28	1
Wing centre section trailing edge (balsa 3×12×290 mm)	17L, 17R	1+1
Fuselage block (balsa 8 mm)	35, 36	1+1
Bag A
Wing rib (balsa 2 mm)	3	24
Bag B
Wing centre sheeting (balsa 1.5×33 mm)	7, 8, 11, 12	3
Wing jig	14	1
Wing centre rib (balsa 2 mm)	9	2
Wing tip (balsa 4 mm)	23	2
Wing centre section outer rib (bevelled) (balsa 6 mm)	6L, 6R	1+1
Wing panel root rib (bevelled) (balsa 6 mm)	18L, 18R	1+1
Bag C
Horizontal tailplane centre rib (balsa 5 mm)	27	2
Horizontal tailplane tip rib (balsa 3 mm)	31	2
Horizontal tailplane rib (balsa 1.5 mm)	26	10
Dethermalizer pin (bamboo Ø2.5×40 mm)	33	1
Bag D
Fin (balsa 3 mm)	45	1
Rudder (balsa 3 mm)	46	1
Rudder Hinge (brass tin)	47	2
Wing Seat (plywood 1,5x32x107 mm)	48	1
Fuselage Reinforcement (spruce 3x8x90 mm)	39	1
Wing Dowel (beech Ø3x32 mm)	49	2
Horizontal tailplane pin (bamboo Ø2.5x25 mm)	50	1
Skid (balsa 3 mm)	51	1
Horizontal tailplane seat (plastic)	44	1
Horizontal tailplane support (plastic)	43	1
Tow hook (fibreglass 1.5 mm)	52	1
Tow hook screw (steel Ø2×8 mm)	53	2
Ballast (steel Ø20×8 mm)	41	1