Wig-Wag Monocopter

Ascent position










Descent position [almost]

The Wig-Wag is yet another monocopter with an adjustable pitch wing. Like the two Campitch MC's the wing automatically adjusts from ascent pitch to descending autorotative pitch.

The Wig-Wag employs a weighted arm mounted to the hub and a wire loop mounted to the underside of the wing leading edge which goes around the weightbar. Before ignition, the weightbar dangles down holding the wing down with it. As rpm increases centrifigal force swings the weightbar outward, thus upward, until it's horizontal, pulling the wing up to ascent angle. After motor burn out, as rpm decreases, the weightbar sags downward again, bringing the wing down into autorotation mode. Unlike the Campitch MC's, this pitch control system is more responsive in flight and doubtless more tunable on the ground since it's controlled by the mass [and length] of the weightbar alone rather than the interaction of wing weight and spring strength. This actually works like the weight ball governor on old steam engines [and some early petrol engines], particularly stationary units. So like them, at peak performance, the Wig-wag monocopter is literally running ball[s]-out.

While the Campitch MC's would've been difficult to design without serious drafting, preferably CAD, the Wig-Wag was cobbed together a part at a time with no drafting of any sort. It aint perfect, but it's a good first attempt and entirely functional from first flight on.
The wing and hub are used parts resurrected from the remains of the CP-1. This makes for a wing that is too small and heavy but it does turn in fair flights on C motors. The weightbar is made from an RC pushrod clevis and a piece of 2-56 all-thread with a lead fishing weight nutted on. My biggest conceptual stumbling block was coming up with a suitable weightbar pivot mount on the hub. Installation of an upright piece of G10 fiberglass was easy enough with my bandsaw followed by grinding access for the flybar with a moto-tool. What was actually more difficult was bending a suitable wire loop for the wing and then mounting it in the best spot. I bent two loops and then punched three pairs of holes in the wing before I was reasonably satisfied. I was glad to be utilizing used parts as I had no concern for cosmetic issues.

So far the Wig-Wag has made three flights. First on a C6, then on a D5, followed by a D12. While the two Estes motors were fine, the Quest D5 suffered a case burnthrough. While this is no big surprise anytime you spin one, that recycled undersized wing makes matters worse. This led to replacement of the motor mount tube.

After puzzling for quite a while over a name, I settled on Wig-Wag due to the resemblance between the weightbar and a wig-wag railroad crossing signal.

Upgraded PC At Last

Hooraw!
My friend Steve recently replaced my PC tower with a much newer one. Not precisely cutting edge as it was assembled from hand-me-down components, but it's a lot more advanced than my old one which I had for over 11 years.

There's a helluva lot of work to do yet, software and tools to transfer or download, and gigs of folders to transfer. Wherever practical, I'm downloading fresh copies or newer versions of software and tools just to be sure they're clean and up to date. Normally I cringe and start to break out in hives every time I'm faced with "Updated" or "Improved" software. Most of the time it has compatability issues or unresolved glitches, or will no longer do what I needed it to do beforehand [Quicktime comes to mind on that score]. Naturally, I totally object to automated updates and block them always. The learning curve is pretty steep, principally changing from Win 98 to XP, and Bobcad 17 to 21.xx. After using dialup all those years, having a hi-speed internet connection sure is nice too.

Steve is a computer professional and I cannot recommend him enough. You can reach him through the following link; pcmaverick.org
Thanks Steve.

A Really Big Pair

I finished making these 2 nozzles for longtime rocket buddy, Don C., a few days ago.  They aren't the biggest nozzles I've worked on, I once helped design and produce a 2 piece nozzle that was 8" dia., but these are the biggest that I've CAD designed myself and turned on my own lathe.
Eureka! ZZakk's Lab has produced monsters!  Bwa-ha-ha-haaa!!!  

Ahem, in the lower pic they're posed with one of the Cesaroni Pro98 motor cases that they were made for, and the fabulously expensive spanner tool that Cesaroni now sells for installing the retainer rings.  Actually, just about anything you need or want for 4" rocket motors is fabulously expensive. The Cesaroni cases are designed and licensed [fabu dinero, I'm sure] to operate with Aerotech reloads as well as Cesaroni reloads.  This is a good thing since it increases the versatility of the hardware.  My friend however, is currently making his own Moonburn reloads for the cases, and using RCS/Aerotech supplies in the process.  The RCS 98mm nozzles are $44 each for a single use, and in the case of the 5/8" throat on the right, would still need to be custom bored anyway.  My graphite nozzles are completely reusable, and if need be, I can remachine the throats later if they get too crusty, chipped, or a larger throat is desired.  Some internal fuel volume is sacrificed but I added a much better expansion ratio, between 5:1 & 6:1 instead of only 2:1.

Last year, I looked long and hard at the costs of larger motors.  I decided to go with 3" hardware since it costs less than 4" every step of the way, despite the longer length needed for the same power.  Plus, being a hybrid flyer, a 3" combustion chamber is plenty big enough, AND, I'm already used to building rockets that take relatively long motors.

More recently, I rescued a belled 3" case from another friends recycling pile. Thanks RK!  
I trimmed the ends off, but still need to cut new snap-ring grooves.  It's kinda short, but I'm on my way!  When I get around to buying new 3" motor cases, I'm gonna give the
Cesaroni hardware another good look.