Strykass




The Retracts are a Carl Goldberg design that have been out of production for well over ten years. I still have a set of the main gear (wing) retracts should I ever decide to build another Crusader II. You can find them on E-bay from time to time.

I originally ran all three gear with one retract servo and I constantly had problems with the nose gear. the nose gear was operated by a golden rod running from the servo between the two main gear retracts. The push rod always had too much flex to make the nose gear work properly all the time. I ended up putting a second servo in the nose to operate the nose retract.

The prop I was running if I remember correctly was a 10x8 Zinger wood propeller. when I built this plane there wasn't a lot of choices in pusher props.

If you notice in the picture the engine in mine was mounted straight up and ran a std (modified) muffler. I did this for several reasons.
First it did away with everything on the bottom of the plane and if you needed to make an emergency gear up landing you could put it down in the grass with out any damage to the plane.
Second, I didn't like the tuned pipe set-up the plans called for and with the exhaust exit point midway up the plane it would alway be an oily mess on the bottom of the plane. Plus sooner or latter that oily mess would start migrating under the monokote, saturating the wood and destroy the plane.
Third, with the engine canted over at 130 degrees it would be hard to get to the glow plug and service the top of the engine.
Forth, weight saving , no lower or upper fairing.
5th, better cooling to the motor.

Modified muffler, I used the standard Webra muffler and modified it by plugging the exhaust hole (pointed forward) and drilled two 5/16" holes in the top outed edge of the front of the muffler and and install two 5/16 in brass tubes that ran to near the back of the muffler and stuck out the front of the muffler a 1/4". With this the exhaust was blown straight through the prop and kept the plane very clean.

The modification I made are probably why I had a problem with the CG the lack of all the extra wood work and no tune pipe changed a lot of the planes weight around. Also Delta wings a very sensitive to CG location, even a slightly aft CG will turn the plane into a handful. Also the control surfaces are very effective on a delta wing, it does not take a lot of deflection for the plane to respond.

If I were building the same plane today I would do a lot of things different.

First, air operated retracts, a lot less headache, more dependable and I would use a set that were spring loaded down. In other words if you have a air system failure the landing gear come down and lock.
Second, Micro Digital servos, Small Digital Servo today have the power to run all the functions on this plane at half the weight, better centering. This would reduce the weight of the plane by several ounces.
Third. I would look very hard and converting to electric power. All the problems with the engine, tuned pipe and fuel system are gone. the possibility of a engine flame out on a plane that has the glide ratio of an SR-71 Blackbird is also gone.

With todays motor and battery technology and micro servos this plane could be a pound lighter, which equates to more speed, slower take-off and landing speeds and a better flying airplane.

One other area I would look at (and this would not be for the builder that was faint of heart) Convert to electric ducted fan or even duel ducted fans.

What would Steven Ellzey do if he was designing this plane today with what he would have available to him now.

I may have to build another one of these![>:]