Conference vmszoo::rc

    
    I'd like to add some supporting comments to your description of
    Scratchbuilding.
    
    I'm not a Master Builder by any means, but have mangled enough
    kits so that a typical set of plans can be somewhat comprehensible.
    
    I totally agree with you Al, that if you've worked a few kits you'll
    have little problem creating your own.  I think this is particularly
    true if you start out by sticking to good old fashioned basics.
    
    As an example, I am building, from a single sheet plan (John Pond)
    of the old Berkeley Buccaneer (Free flight design).  Everything
    you'd need is there by way of information.  Sure, there's a lot
    of tracing, cutting, shaping, sanding, etc. - but it's gratifying.
    
    In addition, you can easily modify as you go along to suit you
    particular needs, i.e., Beefing up, Lightening up, addition of
    control surfaces for radio assist (as needed).  My ship is not
    finished yet, but it is framed up - and it looks so pretty setting
    there that I hesitate to cover it. (Silk & Dope, of course)
    
    GO FOR IT !
    
    
    John Nataloni  (Spell that- "Old Timer")

    
    Hi,
    The plan are from a book called "MODEL PLANE BUILDING from A to Z"
    published in 1965. I have build kit airplanes before with good success.
    I whas looking for a simple enough airplane I could build for my .049
    engines which I don't know what to do with. I had a Falcon junior last year
    with an .049 rudder and elevator. It flew great and aldo demanded more
    concentration then my bigger airplanes I just love it for it size.
    I found this plans for an AERONCA for a .049 with rudder only as
    control and decided to try and make two of them with ailerons, rudder,
    elevator and engine. I might fixe the rudder if the extra weight for
    an extra servo appears to much. I have half a dozen .049's with the
    tank attach behind, which gives an autonomy of about 5 to 7 minutes. I have
    succeded with my Falcon junior to modify the .049 and add a extra gaz
    tank which gave me a 20 minutes autonomy. I'm planning to try to modify
    them further adding some king of speed control. If that works good, I
    have plans in the same book for a biplane Babcock Mark III and a 
    Fokker D-7.  both run out of .049's. I know small plane are harder to
    fly but that is one more reason I like them. The Aeronca will be my
    firts scratche build airplane and is a small investissement ( another
    reason I like small airplane, I can also have 10 airplanes that size
    before I run out of room ). I am usually laft at the field when I bring
    my Falcon junior but it ends when it is in the air and they can see
    what it can do. Thank you for your input, it helps a lot. If you have
    more, don't be shy.
    
    
                Jacques
    
    
                  

As I just found out when my P-38 plans arrived, RCM will send the text of the 
construction article along with the plans when you order them.

No pictures but it's better than giving up ;^)

    The F3E sailplane I am constructing around a kevlar fuselage is
    progressing slowly.  I am seeing that you get more with a kit
    than originally meets the eye.
    
    The last two "kits" I built were the Robbe Calibra and Arcus.
    These kits come with presheeted wings and all the "hardware"
    necessary to get the plane in the air.  Last but not least
    all the dimensions(wing area, planform, stab area, incidence, etc)
    and engineering has been done.
    
    Almost no time is spent thinking when constructing a kit.  Granted
    you might make small changes if you really don't like the way something
    is done, but overall you just assemble the thing.
    
    I have spent a lot of time thinking about spar structure and how to
    bolt the wing to the fuselage while still leaving room for 27
    batteries.  What seemd like a relatively simple project is turning
    into a long, drawn out affair waiting for parts and paying numerous
    $5 shipping fees from various suppliers(Soarcraft-Teflon tape, CST-
    carbon fiber, fiberglass, Tower-wing holdown bolts, etc).
    
    In the end I hope to save about $150-$300 over a similar commercially
    available offering(Calibra Pro-$270 or Freudenthaler Surprise II-$399)
    
    The biggest problem besides the protracted construction time is - THE
    PLANE MIGHT NOT FLY WELL, OR WORSE IT MIGHT CRASH!  Hopefully, I have
    done my homework and the wing will stay on the fuse and will not fold
    and the dimensions and incidences are correct, etc,etc.  ALL these
    factors have been decided and hopefully debugged by a reputable
    manufacturer when you purchase a kit.
    
    The only good things I can see at this point is I have a foam cutting
    rig in place and a wing press for "future projects".  Also, it will be
    satisfying if the plane flys well to be able to say that the ship -
    "is my own design".  We'll see.
    
    At this point the Calibra Pro sure looks like a good deal.
    
    
    
                                                    Regards,
    
                                                    Jim  

Jim,

Good luck with your project! Sounds like you're having *fun* with it. I would
suggest copying the setups(incidence, stab area, etc...) from an existing(and 
known good) design. 

The foam cutter and wing press will always come in handy on future projects. I
know I cringe at the thought of scratch building another balsa wing! 


Just my .02 cents,

-Lamar

    re: -2
    
    Lamar,
    
         Believe me, I am liberally borrowing from other designs.  My
    current engineering dilemna is where to locate and what to construct
    the wing holdown blocks from in the foam wing.  The must be able to
    withstand wrenching high G turns and speeds of maybe 150 mph.
    
    I have no examples to go by.  I am thinking of epoxying vertical
    grain balsa capped with ply/kevlar to the main spar.  1/4" nylon
    holdown bolts would be used to hold the wing to the fuse.
    
    There are many of these considerations to be dealt with.
    
    
                                                      Thanks,
    
                                                      Jim

Jim,

On page 9 of the June RC Soaring Digest, they show the wing hold down for the
Synergy III. It's not clear from the picture if any wood is used, but you can 
see some type of cloth(glass or kevlar??) is used in the layup. The setup appears
to have a T-nut encased in an epoxy layup. 

Whoops! I just reread your note and saw you were looking for a setup inside the
wing itself. For the wing, a layup of carbon fiber and kevlar over the hold down
area might help. My 2 meter Alcyone wing hold down bolt pass through the wing
(a one piece wing) just in front of the spar. A basswood block is epoxyed in
whe the two wing halves are joined. Then a band of 6 ounce cloth(2" wide) is
wrapped around the joint. With the basswood block glued to the spar, it helps
spread the load out over the wing.

Hope this helps!

-Lamar