After enduring more than our fair share of delays, attacks of "Murphy's Law", and general snafus, I am pleased to report that the new MkII version of our 2-meter Chrysalis sailplane is finally in full production, as well as the new electric version, and the upgrade option for the 3-piece wing. We had some on backorder, but the last of those should be shipped by Tuesday, and we still have some of the first batch available after that.
The new 2-meter Chrysalis MkII includes a general engineering cleanup of a number of things that we've been wanting to do with it for a while now. The biggest effort was a thorough revision of the instructions, with quite a few clarifications, additions and updates. I even got to add one more "universal glue symbol" to my collection. The Chrysalis 2-meter instructions use little cartoon figures to indicate the recommended type of glue to use for different joints, such as a glue bottle with a rabbit on the label for fast C/A, one with a tortoise for slow C/A, one with a cow on it (including a mouthful of daisies) for white glue, and pairs of bottles with clocks for 5 and 15-minute epoxies.
The new one is an old-fashioned bathtub (complete with a faucet, and little feet on the bottom) with the letters "RTV" on the side, for the RTV silicone rubber bathtub sealer used to mount a little micro servo at each spoiler. This is another of the improvements, replacing the single larger servo at the wing center section with flex cable pushrods out to each spoiler that the old MkI version used. The new version is much easier to build, rig and maintain, and doesn't involve cutting big holes in the center section.
This also makes it easier to add the next improvement, the builder's option of a bolt-on or rubber band wing attachment. The kit includes all parts and instructions for both. We also include a very simple nose hatch attachment, to replace the rubber band that we used on the original version.
Eliminating the spoiler servo in the center section also makes it easier to put things like motor batteries for the electric version in the fuselage compartment under the wing.
We stiffened the wing structure with the addition of diagonal braces between the leading edge and the main spar. This adds torsional stiffness and flutter resistance, without having to resort to the traditional "D-tube" balsa leading edge sheeting that beginners seem to have so much trouble installing smoothly. Of course the MkII still has the original version's corrections in the shapes of the ribs for covering sag, so the airfoil over the vast majority of the wing is correct, without any aerodynamic need for leading edge sheeting. It also has the accurate laser-cut parts, and easy construction, with time saving features such as our unique "Laser-web" shear webbing system for the spars.
For those of you planning to winch launch the sailplane version, we've included instructions for adding carbon to the inboard spar caps and center section joint.
And, for the benefit of the hobby shops who carry our products, we also gave it a new, larger, full-color set of box labels with big photos and more information, to help novice customers get a clearer idea of what they're buying.
We now have an optional add-on kit available for a 3-piece wing. This creates plug-in joints at the polyhedral breaks to allow the outer panels to be unplugged for easier transport and storage. The resulting pieces are no bigger than a 2-piece wing would involve, and avoids the problems with spoiler wiring and center section stress issues that a 2-piece wing would cause.
The bad news is that it's not really practical to add the 3-piece wing option to an already built wing. I'm not saying it can't be done, but it would require some extremely tricky major surgery. The good news is that we do sell separate wing kits.
We also sell separate kits for the sailplane fuselage+tail, and the electric fuselage+tail. Besides helping in the case of major repairs, this also allows you to buy one complete kit plus one fuselage+tail kit, and have both the sailplane and the electric versions available for whichever type of flying you have scheduled for any particular day.
The electric version is designed around a Speed 600 motor for low-cost sport flying, or an outrunner system for higher performance climbs. I prefer the MP Jet 28/20-7 with a 14-9.5 Graupner CAM Precision prop, the one with the aluminum hub and backplate, 42 mm spinner diameter and 5 mm collet. On a 2-series-cell 2000 mah 15C rated Li-poly battery, it pulls about 28.5 amps and 180 watts initially at full throttle, and will climb vertically. Best climb rate occurs at a little less than vertical, about 60-80 degrees from horizontal.
I use a fairly conservative launch for sport flying the electric. I like to launch into a shallow climb at about 1/2 throttle, get my right hand back on the transmitter and check that everything is trimmed and stable, then smoothly open the throttle to full while simultaneously rotating to a max performance climb angle. This gets the model to Hi-start altitudes in about 10 seconds, and to winch-launch heights in about 20-30 seconds. There is theoretically enough juice in the battery for about a dozen climbs like this, although I've never actually succeeded in running the battery completely out in any of my test flights.
Of course both the sailplane and electric versions still have all the parts for the builder's choice of V-tail or two different sizes of conventional tail. It still has the wide root chord for a big "visual footprint" that makes it easier to see at high altitudes and for beginners. It also still has the same great handling and extremely strong dynamic stability, and the long tail moment that helps it display lift so effectively. That long tail also provides novice fliers with plenty of visual cues to help them master the fine art of controlling pitch attitude.
The sailplane version typically weighs 26 to 28 ounces, for a wing loading of 5.18 to 5.58 oz./sq.ft.
without ballast. Low speed performance is excellent as you might expect, but so is range and penetration. One of our customers described it as having "...the same float, but twice the range" of some of its wooden 2-meter competitors.
The electric version is of course heavier, but still lighter than some 2-meter pure sailplanes. My personal prototype, with the MP Jet 28/20-7 outrunner, 14-9.5 CAM prop, CC Phoenix 35 ESC, 2-cell 2000 mah 15C rated Li-poly motor battery and a separate 270 mah NiMH pack to power the radio (it's a good idea to use a separate radio battery on models that are capable of extended soaring flights) only weighs 37 ounces, for a wing loading of only 7.37 ounces per square foot. At that weight it has a very nice blend of low speed thermalling ability and high speed penetration.
We have more details and photos of both versions posted on our website. If you're thinking about trying a 2-meter sailplane and/or electric sailplane, you might do well to take a look.
Don Stackhouse @ DJ Aerotech [EMAIL PROTECTED] http://www.djaerotech.com/
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