Bryan,

it looks like you got some replies on the A60 before I got a chance. Indeed, DW, drafted up the A60 in CAD very nicely but felt his plan was not complete. I may agree, but the bulk of the engineering effort was done and very well - as usual. In any event, I have started to work on his drafts to bring the plan into a more complete state such that the design can be laser cut (or scratch built) and the CAD plans used for construction. While I don't intend to touch the design at all (Undoubtedly Naruke knew a fair bit more than I do as far as pattern design goes... [:-]), I was considering, after having discussed with Jeff (Bootalini) his electric plug-in wing A60, the idea of reducing the weight of the fuse. I am thinking that the fuse sides as well as the doubler can be either reduced in stock size or, in some other way lightened. Seeing and handling Jeff's A60 first hand gave me the distinct impression that the wings were super light while the fuse was on the heavier side.

I am considering re-working the fuse sides to 3/8" (down from 1/2"), possibly in 2 layers (1/4" core plus 1/8" skin) and the doubler to 1/32" (down from 1/16") or simply lightening the 1/16" doubler where appropriate. In order to keep the former design untouched (much less work), I may just go the latter route on the doubler. The fuse would build to 1/8" less width on either side but perhaps this isn't altering the design substantially. An alternative would be to widen the formers correspondingly.

In any event, these changes basically amount to wood stock specification on a laser cut layout sheet without really affecting much else.

As far as the Beetle goes (and Tarquin, I hope you don't mind this little detour from your build here - we're working toward survival of these beautiful models), I would be very careful with altering things like airfoil on such a design. I don't really consider world class models such as the Aurora or Beetle "bash platforms" for experimental design. Take a Kaos or even a Curare if you will for design altering fun since those models are what I would consider "brutes". A refined design such as the Beetle on the other hand, I'd be leery to "design-in" such flight altering behavior such as LE airfoil changes. The shape and span-wise thickness of the LE on a wing is a critical aspect of its design and has a significant effect on the flight performance of the model.

As far as ease of building, these wings don't build easily as far as I'm concerned. To my mind, many of these MK Japanese designs could benefit from dual 1/4" center holes along the rib chord centerline in order to permit a jig to be used to frame up the panels. Using tabs on tapered and swept wings quickly gets tedious and having a jig to align the ribs and spars makes for a straight wing which can be sheeted while still in the jig. Inexpensive jigs are available from Tower for $24 or one can be built if so inclined.

Last but not least, as far as a repro kit from Don goes, I envision the kit being a glass/foam model so that what Don may need for a fast wing build consists of the root and tip airfoils along with the core planform. Building a framed up wing isn't going to help to "make a mold" of it. The critical thing to know is whether the tip rib is indeed centered along its chord axis on the root rib for a longitudinally symmetrical wing about a constant chord axis. I haven't studied the plans in detail enough to know if that's the case but I believe it is. With those four pieces if information, Don should be able to set up wing templates for Beetle cores.

Finally, an optional and firth piece of information, is the idea of making these models as plug-in wing designs in the glass/foam kits - much like how Jeff built his scratched Aurora (even if it was wood). As far as the fuse molding goes, this seems to make more sense as only a fuse and a bottom pan would need to be molded and produced. It also makes for a much easier fuse to work with since most of the space taken up by the wing in the fuse is now available. The approach that strikes me as the most graceful in terms of the glass/foam version would be to design the model around plug-in wing panels which have root chords that are at 90 degrees to a reference spar perpendicular to the ribs (the spar doesn't actually exist in the framed up wing). This allows the plug-in system to be simpler and also makes for easier wing construction although foam cores don't pose a complication even with angled root ribs. The wing fairings on the fuse would then be built onto the wood fuse with "wing stub" extensions setting the wing panel mating to the fuse to also be at 90 degrees to the fuse centerline. This is a way to mold these compound curves into the glass fuse and keep a simple wing tube mount as well as a simpler two piece glass fuse (no wing belly pan required). In summary, this would require altering the wood fuse plug construction as well as how the wing cores are ultimately cut.

Bryan, Don, Tarquin, Paul, others - thoughts?

David.

P.S. Tarquin, if this is taking your Beetle build too off topic, just let us know and we'll take this discussion somewhere else.