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Balsa Cabin's Ravello Kit Review

By Paul Oliver

This review is intended as a personal review by a modeller that may be of interest for fellow modellers, and therefore comments are the opinions of the reviewer only.

I first came across the Ravello late in 1999 when I witnessed one in use at my local flying club in a club thermal soaring competition. It's performance impressed me sufficiently to start considering this as my next model. Furthermore, a Ravello won the competition. Interest was further fuelled when I learnt that two or three other members (of wise experience in such matters) revealed that they were either constructing, or intending to construct a Ravello. It was these factors that determined that this would be the next model for me. So, having parted with my money I came home with my next project, and cleared my building board.


The Kit

When you see the box, it is not a glossy colour piece of art that you get with many kits nowadays. Personally, while I like to see a picture of the completed model, I don't like to pay for the very nice artwork that some boxes have, only to throw them away. One must also remember that the cost of the box is included in the kit price.

So what do you get when you open the box? A well packed box of wood, a nicely rolled, well drawn plan, a hardware pack, and an A4 size instruction manual. I found the wood in my kit to be of very good quality. Mind you it should be coming from Balsa Cabin. I then spent the next few hours studying the instructions, plan, and parts before starting construction.

The Ravello is definitely a builder's model. Those who are looking for an ARTF need to look elsewhere. Neither, is this a beginner's model for building. However, if you have built a few models using conventional construction methods, you won't have too much trouble. One word of warning, and that is DO READ THE INSTRUCTIONS AND FAMILIARISE YOURSELF WITH THE PARTS BEFORE COMMENCING. I say this primarily with respect to the sheet balsa supplied for the wings. The wood supplied for the wing sheeting is sufficient with little waste, but there are no nice pre-shaped, and cut pieces of sheet that you get in some kits, you have to plan this out yourself with the sheet supplied.


Wing

The polyhedral wing is constructed in four parts - two outer, and two inner panels. The latter are joined to make a centre wing section. The two outer panels slot onto the centre section by means of metal rods in tubes with dowel locators. As additional retention and to smooth over the join self adhesive tape is used (more about this later).

I won't cover the construction in detail, but would stress that the building sequence is followed as per the instructions. Construction is fairly normal, and the design is very sound, resulting in a strong wing. Do check, and double check the fit and squareness of everything. I understand from others who have changed the wing profile during shaping the panels, have resulted in poorer gliding performance to those who have followed the plan.

I made one real departure from the instructions, and that was with regard to the airbrakes. The instructions call for the servo arm to work against a wedge attached to the spoiler to open it, while a rubber band acts as the airbrake return to close it. To me this might call for a lot of setting up, and I was slightly concerned about the load placed on the Union Micro Servos installed in the wing for this function. Instead I epoxied and bandaged some brass tube to the back of the fibreglass airbrake and formed up a brass pushrod that fitted between the tube and the servo arm. The two servos are retained by the use of cable ties wrapped round the servos and adjacent ribs, as per the instructions.

I used a combination of epoxy, white pva, and cyanoacrylate adhesives for the wing construction.

I did find that two pieces of balsa sheet were missing from the kit but made up for this with stock from my balsa box.


Fuselage and Tail

Construction of the wing I would say accounted for about 70% of the total construction time. The fuselage is a basic box construction with plenty of shaping with a razor plane and glass paper to get those nice streamlined curves that you want, but boy does it look good when finished. Apart from reducing drag it also keeps the weight down. This is particularly important for the rear half of the fuselage, to balance the model when completed.

Control of the rudder and elevator is via snakes. I also let a plastic tube into the fuselage to enable me to run the receiver aerial down the inside of the fuselage and out at the tail. This keeps the aerial out of the launcher's way when taking up the bungee tension and holding the model. It also helps to reduce drag slightly. Also, for the radio hatch I elected to use a sprung catch instead of the method recommended in the instructions.

The fin, rudder, and elevators are sheet balsa construction, while the tailplane is built up from strip wood. Nothing untoward here, but one tip I was given, was to fill in around the centre section with sheet wood to the adjacent cross members to strengthen the tail, which could be prone to damage easily. I know of one model to have the tailplane fail while going up on the bungee! Fortunately the model came down without any further damage, and the failure was due to wood giving out rather than poor assembly.

Finally you may find it necessary to add a little more ballast to the nose. Most people I have spoken to seem to add an extra 2-3 ounces to the 3-4 stated in the instructions, so try to make as much space in the nose block as possible and start with 4 ounces of lead. I started with 3 and added another 2.5 behind the nose block.


Covering and Finishing

The instructions recommend various methods of covering. I opted for good old Solarfilm with a scheme of yellow fuselage, tail, and wing centre section, with red outer panels. This actually seems to work quite well in aiding orientation and locating the model in the sky.

One tip in the instructions I liked was the use of clear self adhesive tape on the wing where the outer and centre panels were joined to prevent damage to the film. Then when the wing panels are joined another piece of tape is laid on top of these pieces on the panels. I used Sellotape Diamond tape, as this has excellent properties. Not only is it nearly invisible, but it is strong with good adhesion properties. I took this method slightly further in that instead of applying tape up to the edge of the panel, I folded this over on to the side of the end ribs to help prevent the tape lifting when peeling off the top layer of tape. Having a layer of tape underneath the top layer also makes it easier to peel it off.

I also elected to use Diamond tape to hinge the rudder, elevator, and airbrakes. This tape is extremely good for this purpose, and I have used it to hinge a number of my electric models without the need to replace the tape after a year or so, as some tapes necessitate.

After fitting a Futaba 131S servo for the rudder, and a 148 servo for the elevator, I fitted a GWS 8 channel receiver and a Sanyo 600mAh nicad pack. After setting the throws as recommended, and checking the C of G, my Ravello was ready to fly.


Flying

Having finished the model just in time for a club competition, I was hoping to get the opportunity to test fly the model beforehand. No such luck, the day for the competition dawned with an as yet unflown Ravello. The weather was not ideal for mid September. The decision to cancel the competition due to inclement weather was almost made. However, what rain there had been early in the morning stopped, and we were left with a dry if overcast morning, with a light breeze, with very limited lift about.

Trial hand launched glides before the start of the competition revealed that only a very little up elevator adjustment was needed to the trim to produce a nice stable flat glide. The tow hook had been fitted as per the plan. My turn to launch came and with reasonable tension on the bungee my launcher released the model on command and I watched as the model went up the line straight as a die, with me holding in some up to help. The model pinged off the line nicely for the conditions and I settled down in to a nice gentle flat glide while desperately looking for lift. Inspite of the less than perfect conditions the model glided nicely, and very little height was lost in flat turns. I was starting to get to enjoying the model when time came for me to land. A rectangular approach was made and the model landed gracefully. The flight was over too soon for my liking but my first impressions of the model were very favourable.

I had two further flights in the competition, and these confirmed my initial impressions. I found that the model would respond well to any lift around. I decided that the model had great potential, and with very little fine tuning from myself, other than my familiarisation with the model, it would not only make a good club level competition model, but one suitable for national competition. I know this to be correct, as Ravello's have been used in both regional and national competition with some success.


Summary

This is a model that has clearly had a great deal of development put into it. This is evident from the fact that if built true, and to the plan i.e. wing shaping, balance etc, it will require very little adjustment required by the builder to be competitive. If you just want a glider that will give you immense pleasure on a sunny summer's afternoon, the Ravello fits that category too.

In terms of value, I would say that for money it is fairly competitively priced. If you wanted an ARTF you would probably have to add at least 100.00 to the 60.00 of the Ravello kit. Value in terms of flying performance is extremely good, while value for enjoyment is also good.

Likes:
  • Wood quality was excellent.
  • Structural strength provided by the design.
  • Flying performance.
  • Some of the tips provided within the instructions.
  • Wing rib set already cut out.
Dislikes:
  • Lack of pre cut balsa sheeting for the wings.
  • Airbrake actuating design (personal view).
  • Lack of provision of a receiver aerial tube in the kit.

Would I recommend this model to anyone else? The answer to this would be an emphatic YES!

At the time of writing I have as yet to fly the model again. The weather and other commitments have prevented this, but if anything new arises I will add a post script.