Windsurfer 100 (oz5681)

About this Plan

Windsurfer 100. Radio control sailplane model. Wing area 790 sq in. Plan # 582.

Direct submission to Outerzone.

Update 09/08/2018:Added kit review from MAN August 1984, thanks to RFJ.

Quote: "Field & Bench Review: Windsurfer 100. A Joe Bridi design for silent sensations. By Ralph Boehm.

The Windsurfer 100 is a Standard Class sailplane designed by Joe Bridi and manufactured by Kraft Systems. The basic construction is of the finest quality machine-cut balsa.

Included in the kit are a clear canopy, assorted hardware, full-size plans and a very comprehensive instruction booklet. If there was anything missing, I certainly couldn't find it.

When I opened the box I was amazed at the compact arrangement of the wood. It was obviously an exercise in efficiency! Not a square inch of room was unused. This makes for minimal damage in shipping, as well as giving you the feeling that you are getting what you paid for, which is refreshing.

I selected this particular design for many reasons. I wanted a good flying model, and one that would not take forever to build. Above all, I wanted something that was competitive. I can honestly say that I was more than pleased on all counts.

The Windsurfer 100 is a majestic flying machine. It seems to have eyes for thermals. Like a giant eagle, it seeks out and preys upon lifting air. It is unlike any other sailplane I've ever had. This beautiful bird stalks and tracks and rises in an uncanny fashion, almost as if it had a mind of its own. Perhaps Joe Bridi put something into it that only he knows about. Whatever it is, it's magic. But then, all of Joe Bridi's designs are magic, aren't they?

CONSTRUCTION: The construction of the Windsurfer 100 is as delightful as the performance. It has a well-thought-out design, one in which all the pieces fit like they should. I was never confronted with a head-scratching situation where I didn't know what to do next. The building sequence was conventional and straight-forward, and even the novice builder shouldn't have any problem completing this model.

The fuselage and stab construction, like I've said, are straightforward. The instructions provided are easy to follow. The basic framework of the body contains so few pieces that at first I thought there had to be some pieces missing. Not at all. It is very simple, yet strong. Certainly sailplanes must have integral strength to withstand the abuse of nose-down landings. I have witnessed many such occurrences and have also observed the snapping off of the fuselage toward the tail section. Not so with the Windsurfer 100.

The stab section is designed for a 'plug-in' type of arrangement, which makes it easy to transport, particularly in a small auto. The horizontal stab is of the 'flying' style, and the pivot and actuator setup is well-engineered for minimal slop. The vertical stab is generous in area and very effective. Since the horizontal stab is raised above the base-line of the fuselage, it is free of the vortex coming from the wing. Again, the parts count here was minimal, yet everything was very sturdy once assembled.

The wing design is also a plug-in configuration and is equipped with spoilers. Note: If you use a super powerful winch or launch in extremely windy conditions, I would recommend adding a dihedral brace to the poly-section on the outer panels. The reason I say this is because I cracked mine on a monster winch launch which required repair to the wing. It may not be necessary under normal conditions, but just for added insurance I would suggest that you do it. Construction again is very uncomplicated and goes together so fast you'll be amazed. Make sure that both wing halves are exactly the same size and weight.

I prefer using transparent Super MonoKote on the wing and stab. It is both asthetically pleasing and functional, since the sun shining through makes this bird easily seen from below. I chose Super MonoKote for a number of reasons. It's a very strong film for one, and is extremely manageable. It shrinks evenly and predictably without fuss.

To prepare the model for covering, simply sand the daylights out of the wood until it almost shines. Vacuum off the dust residue and commence covering. A sharp knife and a straightedge are essential tools. When you apply the Super MonoKote, tack it down with your iron at about 6-inch intervals. Pull out any wrinkles and then seal the edges to the wood. Shrink it completely, using your heat gun. Be sure to keep it moving so you don't burn a hole in the material.

Like all sailplanes, the fuselage is narrow, so care must be taken to insure room for your servos, receiver, and battery. There is adequate room, however, and once everything was installed, little ballast was necessary to achieve proper balance. I used a Kraft radio in the Windsurfer 100 and I'm very pleased with the results.

FLYING: It was very windy and bitterly cold on the day of the initial flight test. My determination to see this bird fly, however, could not have been quenched even if a tornado was on the loose!

I set the release hook, hit the winch, and the Windsurfer 100 shot up like a rocket, almost vertical. I realized almost before it happened that this was too much strain on any wing. And then I heard a slight cracking sound. I got off the winch immediately and landed. The outer panel at the dihedral brace had a slight twist in it, and upon examination I found that the dihedral brace had cracked.

I cut a slit in the Super MonoKote, applied some Zap, and it seemed strong enough. I re-rigged it again for launch and this time it went up at a normal angle with no difficulty. Release was right on the money and even with the windy conditions I had little trouble keeping it near. It was a fitting culmination of a fine ship.

Subsequent flights on the Windsurfer 100 have proven to be a joy to behold. The kit is extremely nice to build and the competitive potential of the design is obvious. It is an attractive model that you will be proud to fly and to own. It is just that kind of ship."

Update 01/06/2020: Added kit instructions, thanks to StevenMills.

Quote: "Hi; I have just came across the build instructions for the Windsurfer 100 (oz5681). Please find the pdf attached so others can enjoy also."

Supplementary file notes

Review.
Instructions.

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