Forum 400 - October 1999 [Archive]

Pat Mattes

Oct 01, 1999, 12:00 AM

<big>Culprit Identified!</big>

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<a href="/articles/ezonemag/1999/oct/forum400/Dcp01279.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/Dcp01279_small.jpg" alt="Dcp01279.jpg (15340 bytes)" WIDTH="78" HEIGHT="100"></a>
Thanks to all who responded to my question "what is this?" in last
month’s column. The gearbox in question seems to be unanimously identified as a Union
gearbox. Turns out there used to be a number of airplanes sold by Union, such as the
Challenger, the P-51, and the Tsunami. The identifications of the gearbox ranged from
descriptions such as: Union, Union Turbo, Union RC180, and most responses stated that the
300 was the motor that went behind the whole works, and also stated cell limits in the 5-6
range. That stands to reason if it is a 300, since it has a fairly high Kv. Props for this
gearbox were identified as 7x6’s. Looks to me like they knew what they were doing
when they developed this box! A neat, light, little power unit that could pull a small
model around with some good authority. Two other responses identified the gearbox as a
Nikko 28BB. That could very well be, considering how so many companies buy and sell and
re-brand the same product under different sales markets. It was also stated that the
present day Hobbico SkyRunner either owes its heritage to the Union models, or is a
re-tooled version of it. Thanks again to all who identified it!
 
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<big>Reader Contributions</big>

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I’m always interested in seeing what projects people come up with for the 280
through 480 motor range. I love to experiment, and the cheapness and availability of this
range of motors allows you to do ACTUAL testing relatively cheaply. But there’s a
limit to the amount of time I have to devote to experimentation, and can’t possibly
hit all variations of planes, motors, batteries, etc., that are available. That is why I
welcome E-zone readers to send me their pictures or stories of what they are doing. Even
if it’s a simple 7 cell Speed 400 power system, it’s great just to see all the
wonderful aircraft that can be built around it! Please continue to send me your comments,
suggestions, stories, pictures, etc. I won’t guarantee it will ever get published in
the column, so please don’t feel offended if it doesn’t. It’s more a matter
of timing and material. "Forum 400" is usually where I open up my brain-valve
and empty the contents of my gray matter into the computer for a month. Sometimes the
column gets too long before I’m done, and I don’t get around to putting in
reader contributions. I’ve been a little short on flying and modeling in September,
so I found myself shy on brain-drain material for October’s column. Sounds like a
good time to institute my OPP plan ( Other People’s Projects! ).
 
SkyRider
First off, there’s a neat foam glider conversion that’s been sitting in my
computer since June that deserves first billing. The idea and execution of this electric
conversion comes from John Digby of England. 
<a href="/articles/ezonemag/1999/oct/forum400/skypic4.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/skypic4_small.jpg" alt="skypic4.jpg (54651 bytes)" WIDTH="169" HEIGHT="100"></a>
It started life as a "five dollar foamie"called the SkyRider. It uses two
Speed 280 motors in parallel on 7 cells (600AE’s) and draws 8 amps total for a total
of 56 watts. All-up weight ends up being 16 oz, so the power loading is pretty
respectable. He uses Gunther 5x4.5 props on it, and says the glider cruises around
extremely well at reduced power settings on calm summer nights. Best flight was over 12
minutes!
John has additional pictures and a well written account of the development and
conversion of this glider. To view it, click here <a href="/articles/ezonemag/1999/oct/forum400/skyrider/skyride.htm">skyrider/skyride.htm</a>
, but remember to come back to Forum 400 when you’re done!
 
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<blockquote>
SEFSD Activity
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<blockquote>
The next series of neat projects come to us from Bruce Cronkhite of SEFSD, which stands
for Silent Electric Flyers of San Diego. 
Bruce sent me pictures of an old timer that they are using in a pylon race! It’s a
Thrush Mite, built from Model Builder plans (available also from Bill Northrop). 
<a href="/articles/ezonemag/1999/oct/forum400/BlueMite.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/Blue_Mite_small.jpg" alt="Blue Mite.jpg (24030 bytes)" WIDTH="183" HEIGHT="100"></a>
The only restrictions for racing are that it has to use a Speed 400 motor and 7 cells,
but the prop, gearing, and battery selection are all up for grabs. They use a 200 foot
course like the normal S400 pylon course, but I’m sure the lap times are a bit
different! 
Next up are two neat small-scale planes, Fred Harris’s Curtiss Robin and John
McKinney’s Farman 400.
<a href="/articles/ezonemag/1999/oct/forum400/FredRobin.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/FredRobin_small.jpg" alt="FredRobin.jpg (24006 bytes)" WIDTH="267" HEIGHT="100"></a>   <a href="/articles/ezonemag/1999/oct/forum400/Farman400.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/Farman400_small.jpg" alt="Farman400.jpg (21249 bytes)" WIDTH="235" HEIGHT="100"></a>
Both are beautifully done, and it’s hard to believe they are Speed 400 airplanes.
Regardless of the motor size, it just goes to show you what can be accomplished on a small
scale. 
Bruce goes on to tell about their club’s entrance into the Speed 400 F5B
competition. Shown here are Bruce’s Hot Petrel and Don Wemple’s Flicker. 
<a href="/articles/ezonemag/1999/oct/forum400/HotPetrel.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/HotPetrel_small.jpg" alt="HotPetrel.jpg (49259 bytes)" WIDTH="179" HEIGHT="100"></a>   <a href="/articles/ezonemag/1999/oct/forum400/WempleFlick.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/WempleFlick_small.jpg" alt="WempleFlick.jpg (31483 bytes)" WIDTH="133" HEIGHT="100"></a>
Again, both great looking birds, and fast looking as well. Bruce currently has his Hot
Petrel powered by a 4.8 volt motor on a 4:1 gearbox swinging a 10x8 prop. He states about
1.7 minutes of run time at full throttle, so it appears motor current is close to 18-19
amps static. Yea, I bet the Petrel does get a little Hot! 
The final contribution is his flying wing, the Flattie. 
<a href="/articles/ezonemag/1999/oct/forum400/JRFlattie.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/JRFlattie_small.jpg" alt="JRFlattie.jpg (20967 bytes)" WIDTH="182" HEIGHT="100"></a>
I’m a real flying wing nut, so I really checked this one out. If you don’t
believe me, notice he’s got it propped up on an AstroFlight charger box! 
Bruce welcomes people to check out the rules for F5B 400 at the SEFSD web site <a HREF="http://www.SEFSD.org/">www.SEFSD.org</a> While you’re there, check out some of
the other activities they’ve got going on. 
 
DAW Staudacher
Bob Kreutzer sends me 3 shots of his completed EPP Staudacher from Dave’s Aircraft
Works. 
<a href="/articles/ezonemag/1999/oct/forum400/PIC00002.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/PIC00002_small.jpg" alt="PIC00002.jpg (17433 bytes)" WIDTH="156" HEIGHT="100"></a>   <a href="/articles/ezonemag/1999/oct/forum400/PIC00010.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/PIC00010_small.jpg" alt="PIC00010.jpg (12590 bytes)" WIDTH="188" HEIGHT="100"></a>   <a href="/articles/ezonemag/1999/oct/forum400/PIC00011.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/PIC00011_small.jpg" alt="PIC00011.jpg (17042 bytes)" WIDTH="157" HEIGHT="100"></a>
Looking at Bob’s pictures, I can’t help but think I need to spend less time
writing columns and more time perfecting my covering skills! The nice thing about EPP
aircraft is you can devote your time to doing covering jobs like this and not have to
worry about messing it up in a crash.
 
Patton Aircraft
Peter Ford included some shots of his Patton Aircraft EPP mini-warbirds, the P-51 and
the FW-152. 
<a href="/articles/ezonemag/1999/oct/forum400/pf-p51.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/pf-p51_small.jpg" alt="pf-p51.jpg (25598 bytes)" WIDTH="182" HEIGHT="100"></a>   <a href="/articles/ezonemag/1999/oct/forum400/pf-FW-152.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/pf-FW-152_small.jpg" alt="pf-FW-152.jpg (19331 bytes)" WIDTH="127" HEIGHT="100"></a>
Peter mentioned he had all three of the Patton Aircraft mini-birds, but when I went to
find his picture file on the P-40 I didn’t have it. Sorry about that! So, I pulled
this shot off of Patton’s homepage.
<a href="/articles/ezonemag/1999/oct/forum400/PA-P40.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/PA-P40_small.jpg" alt="PA-P40.jpg (37763 bytes)" WIDTH="107" HEIGHT="100"></a>
Patton Aircraft can be viewed on the web at: <a href="http://home.earthlink.net/~pattonacft/theminis.htm">http://home.earthlink.net/~pattonacft/theminis.htm</a>

 
Wait, there’s more!
As exciting as it is to see a picture or spec listing of someone’s latest project,
it’s even more fulfilling to see some of these special projects actually fly! And
there’s nothing like a good Electric meet that provides this opportunity. Most
recently attended was Azarr’s "Non-Event" electric gathering on September
18th in Donnelsville, OH. The Springfield Model Aircraft Club (SMAC) sponsored this
gathering, and it definitely was "the place to be" that day. Fantastic weather,
a great turnout, and a wonderful field. What more could you ask for? Well, I suppose we
could have done without the dust devils that were shedding the leaves off the cornstalks,
but they were pretty neat to watch and ended up feeding some killer thermals! 
Although not representative of ALL the great aircraft present that day, I borrowed a
few pictures from Steve’s digi-cam that reflected "Pat’s Picks". No
special criteria existed for selection, just that they had to be powered by 280 through
480 motors (This is Forum 400 ya know…) and had to be a creation that was far off the
beaten path. I always love it when someone strays farther off the path than I do! 
 
Lanier’s U2 Free Flight glider
<a href="/articles/ezonemag/1999/oct/forum400/lanier6.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/lanier6_small.jpg" alt="lanier6.jpg (31320 bytes)" WIDTH="173" HEIGHT="100"></a>
Now this was cool! There’s nothing like taking a $30 foamie and turning it into
this. Glen Stucker brought this multi-motor project along. It uses 6 Speed 280’s
powered by 16 cells (500AR’s) and are wired in such a fashion that there are 3 sets
of 2 motors wired in series. The 3 paired sets are then parallel wired into a final
junction. If that’s confusing, look at it this way: Each one of the three
"pairs" of 280’s will see the voltage of 16 cells. Since each
"pair" is series wired, each motor sees 8 cells, which is just perfect for the
280’s. The U2 comes in at 50 ounces with this configuration.
Glen says it uses 10.6 amps in flight, for a total power of 175 watts. That equates to
56 watts per pound and a wing loading of about 11.5 ounces per sq. ft. That big 74"
wing sports 624 square inches of area!
 
Prairie Bird
<a href="/articles/ezonemag/1999/oct/forum400/trimotor.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/trimotor_small.jpg" alt="trimotor.jpg (47088 bytes)" WIDTH="137" HEIGHT="100"></a>
This neat little critter also from Glen is a Prairie Bird powered by three 6 volt Speed
400’s in parallel wiring. He’s got it set up to run on 7-cell packs of
1700’s and 2000’s. It pulls just a tad over 30 amps, and climbs like a rocket.
It easily does loops from level flight, and will roll and spin well yet retains a nice
degree of stability.
 
Chirp-Chirp-Chirp?
<a href="/articles/ezonemag/1999/oct/forum400/cricket.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/cricket_small.jpg" alt="cricket.jpg (32179 bytes)" WIDTH="138" HEIGHT="100"></a>
Undoubtedly deserving the honor of "most unusual aircraft" was Ted Biggs
"Cricket". It uses two 7.2 volt Speed 400 motors spinning 6x4 props, all driven
by 16 cells (600AE) in series. An Astroflight 217D controller is used to keep all the
electrons well behaved, and the Cricket flies at a 40 ounce all-up-weight.
The wing is 50" span, and with a 6" chord gives 300 square inches of wing
area. Crunching these numbers through my calculator gives a wing loading of 19.2 oz/sq.ft
and a power loading of approximately 68 watts/pound (my estimate with MotoCalc, I forgot
to ask Ted!). It flew well!
 
And the Second Runner Up is…..
<a href="/articles/ezonemag/1999/oct/forum400/azarrfoam.jpg"><img src="http://static.rcgroups.com/articles/ezonemag/1999/oct/forum400/azarrfoam_small.jpg" alt="azarrfoam.jpg (38461 bytes)" WIDTH="122" HEIGHT="100"></a>
Truly a plane after my own heart (since it uses Blue Foamie wings!) is Azarr’s
"Widow Maker". You can’t see it very well from the photo, but those little
circles on the wings with lines running through them contain names of people he was going
to "kill" in the Combat session at our August 7th Fort Wayne Electri-Fly. As you
can surmise by the fact the plane is still in one piece, he fared well with it despite the
heat of the battles that day. 
The WidowMaker uses a carbon fiber shaft for a fuselage, Blue Foamie wings to carry it
aloft, and uses a 6 volt Speed 400 powered by seven 500AR’s. It comes in at a very
light 13 ounces, and uses a very positive pull-pull cable system for rudder and elevator
control. I flew it during the meet, and it will loop and spin like crazy yet slow down
enough to perform a hand-catch with it. The benefit of having your battery out in the air
stream was very evident, as even after a full throttle flight the battery was cool enough
to throw the pack right back on the charger! A neat little plane that fits nicely in the
car trunk, just begging to be wrung out during lunch hour.
That’s it for October… Many thanks to all who contributed their time and
effort to write up their projects and send pictures to me. It’s greatly appreciated.
Till next time,
Pat
<a href="http://rcgroups.com/shared/nospam.php?u=Pat-Ingrid-Mattes&d=Juno.com">Pat-Ingrid-Mattes(at)Juno.com</a> 
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