Olympic 650

The packaging was good and delivery took just 10 days from the USA

There has been a serious gap in the model glider kit market for real balsa bashers but thankfully Aerosphere in the USA bought the rights to produce a whole range of classic model aircraft that were once manufactured by Dream Catcher Hobby. Perhaps only us cauliflower heads remember classics like the Aquila, Sagitta and Olympic 650? - models that were all winners in their day. These models appeal to those that do not want to shell out hundreds of pounds for a 'glass' ship but desire the thrill of building their own model. Bill Warren of Aerosphere has now released a thoroughly updated kit of laser cut parts with accurate plans for the Olympic 650.

I was fortunate to find Aerosphere’s website and get one of the first kits across the Atlantic. I’m glad to say Bill Warren ships the kits double boxed and the outer box defies any mail service to smash it up. This, by the way is not a challenge! Should we feel guilty about not supporting local model shops? Well, the fact is that by cutting out the middle-man and only selling direct, Aerosphere is able to ship stoutly boxed kits across the pond in very fast time and at reasonable cost. Mine took just ten days.

The kit included quality hardware from Sullivan and a first class plan that gave options for an electric version/Cox glow, but I wanted to see if it would be suitable for a building and soaring novice yet have a thrilling performance for those who enjoy thermal hunting.

First steps in construction

You’ve read it a thousand times but for goodness sake, even if you are an experienced builder, read the comprehensive instruction booklet and study the excellent photographs in it. Build your confidence first by identifying the wood and sheet parts in the box.

The 650 is a simple slab-sider but I can assure you it is more easily built if you follow each stage as suggested in the instructions. All the flying surfaces, wings, tailplane and rudder are simple ‘pin down’ jobs but I admit that I tend to use scrap steel blocks that I salvaged from an engineering scrap dealer to hold strip balsa down so that the build is held perfectly flat. I do use pins but ensure they are never stuck through the wood to weaken and disfigure it. Keep the plastic bags the parts come in and slit them open lengthwise as laying them over the parts of the plan that you are building will prevent glue wrecking the plan.

The finished bones look great, pity to cover 'em!

I know Aerosphere have taken a lot of time in perfecting the laser-cut parts and believe me, they are the best I have ever come across and drop into place on the plan after only a very slight application of sandpaper to rid them of the laser burnt edges. The only tools I used during construction were a balsa knife, hand drill and bits, 140 grade glass paper stuck on scrap plywood and some G-clamps and set squares. I used ordinary white woodworking glue and 12-minute epoxy throughout the major parts of the construction.

The Fuselage

This is a simple box section fuselage with ply sides. The left and right sides are clearly etched to avoid building two left or right-hand sides. Spruce stiffeners are glued to the ply at the nose and to help to locate the main bulkhead just ahead of the leading edge of where the wing sits.

A common mistake a novice makes when building a slab sided and square fuselage is that it somehow gets a twist so that it comes out anything but symmetrical around the centre line. It will then have bitter and twisted flying characteristics! The 650 will defy this kind of disaster as the main bulkheads are epoxy glued onto the flat ply/balsa base of the fuselage and are checked with a set-square to ensure they are perfectly upright while the hardwood nose block is the gauge for the angled first former.

A dry run with sides dropped over the base will ensure that the G-clamps can be positioned in the right place to draw the sides to the base and that the sides go right down to the building board and the bottom fits snugly between them. Use scrap ply between the clamps and wooden sides of the fuselage so as not to damage the ply. This is where the slow setting epoxy is used as it allows plenty of time to spread the glue in the right places, clamp up the model and double check that the sides are still perfectly upright and square.

When finished, you'll find that this is a tough fuselage that does not require reinforcing. However I would prefer to carry a bit of epoxy/glass ahead of the wings as reinforcement and ballast rather than the dead weight of lead. I used a light glass cloth with epoxy resin to glass the inside of the fuselage from the nose back to the fourth bulkhead. When completed I usually line the bottom and sides of the battery and RX compartments with a dense foam rubber to give some protection to these components. One other modification made to the fuselage was to substitute a captive nut in place of the wood screw that is shown to hold the hatch down. The snakes are installed for rudder and elevator rods prior to checking over the aft section of the fuselage. Two standard servos and the captive nut for the tow hook just about finished the fuselage.

Wings and tail feathers

The wings and tail feathers could hardly be simpler to build. The wing has one big central section and two shorter steel-dowel plug-in wingtips. Most damage to gliders is caused when a wing tip catches the ground on landing and cartwheels the model. With this configuration it is usual for only one wing tip section to be damaged. Another advantage is that this model is easily transportable and if the option of removable tail feathers is taken, it will fit into a box only 40” long by 14” wide and 4” deep.

These parts are all pin-down jobs, and little needs to be added to the text and the excellent photographs illustrating construction. Once the bottom main spar is pinned in place, do a dry run to check that the ribs are a good push fit onto the trailing edge and leading edge spar - no filling in gaps with glue!

Do make certain that you have pinned the partially shaped spruce leading edge the correct way up as shown on the plan. Take extra care when gluing up the brass wing joiner tubes as you must have both wing tip sections at precisely the same dihedral of 4 7/8” The laser-cut holes are accurate but use clothes pegs on the inner and outer 1/4” balsa ribs to get a snug fit. I still use electricians tape to cover the joint to prevent them parting company in flight.

The 650 can only produce a high performance if you sand the model to perfection so that ends of ribs are flush with the trailing edge and the leading edge is sanded to the correct rounded profile.

I spray painted the fuselage, note the essential fume extraction tube!

Painting and Covering

I enjoy spray painting a model and the all-wood fuselage of the Olympic 650 just asks to be sprayed but you can do this job just as well with iron-on film. As no engine fuel will go anywhere near the model you can use any type of paint from ordinary enamels to the British Airways full sized spray paint system that I just happened to have in the workshop, I had no room for the rest of the 747!

All paints need an undercoat to fill the grain, especially the sheet balsa parts. Folks worry about the weight of paint on a model but the fact is that if you let all coats thoroughly dry and then use wet and dry paper to cut them back almost to the original wood surface, then you will be left with little added weight – just a super smooth surface ready for the final gloss coat.

The 650 is a simple model so I used a simple colour scheme. It is worth noting that when a glider is climbing in a thermal the best colour for visibility is red and so wooden under surfaces of the fuselage were painted red and red Profilm used for the under surfaces of the tail feathers and wings. I like Profilm as if a mistake is made or a model needs to be repaired then it is easily removed with a hot covering iron that does not leave the colour stain behind.

She handles beautifully

Preflight workshop checks

The hardwood nose block is supplied hollowed out and there is already a hole cut in Bulkhead No.1 to fill with lead to get the C of G right on the rear edge of the wing spar. The flying surfaces are very rigid when covered but check for warps (twists) in them. If you find anything out of true, then place the offender back on the building board and use bits of balsa to slightly over twist the surface in the opposite direction to the warp. Then re-heat the covering film so that as it tightens, the warp should be eradicated. Judging the amount of opposite twist is a matter of practice but what you don’t want to do is over-heat the film so that there is no more shrinkage in it.

Flying

Geoff Bell had finished shooting tigers in India (with a film unit I must add) so I commandeered him as test pilot while I did the flying shots. All I would say is do not do as we did but do as we say. Choose a calm day for hand launch test flights. An easterly force 5/6 (17m.p.h. gusting to 27m.p.h) greeted us down on the Devon coast but just holding the plane aloft in it told us she really wanted to go even if she could make little headway. In fact she simply flew out of the hand and soared aloft with out the slightest trace of any nasty attributes.

Whilst only an rudder/elevator soarer, there is plenty of rudder authority that will see her safely up the tow line and in a howling wind allow her to keep her head up and cross soar to climb out quite respectably. I have no doubt that she will take some ballast but our test flights proved she is a first class design that will give hours of pleasure to builders.

Datafile

  • Name - Olympic 650
  • Manufacturer - www.aerosphereonline.com
  • Wing span - 72"
  • Wing area - 650 sq. in.
  • Wing loading - Approx 8.4 oz/sq ft
  • All-up weight - 1078 gm (38 oz)
  • Control functions - Rudder and elevator
  • Approximate cost (£1 =US$ 1.90) - Kit £42, P&P £15.52




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