Recent Updates
Feb 04 - added a page on elevator and rudder controls installation
Jan 04 - added
--- page on setting the fin,
-- added to the existing 'Sheeting the Wings' showing the first wing covered
with Monokote.
-- Added a page not yet complete about cowl and bellypan mounting.
Added a page about
'Keeping the Dust Down' - a dust collector filter for the shop -
Building a Hybrid Pattern Plane
It's a hybrid since it's a balsa/ glass composite fuselage
from a 'DELITE' and wings from an EMC2.
This will document the construction of a 2-meter pattern plane for a local Masters- class flyer. It'll take about 6-10 weeks of spare time to build. When complete it will be 2 meters long, 2 meters in wingspan (thus the name '2 meter plane'), weigh under 10 lbs., be able to go about 120 mph in level flight, and will have unlimited vertical performance
I received the fuselage about complete - horizontal stab mounted and aligned, wing socket installed. I'll have to move the fuselage anti-rotation pin locations - I HOPE the wings will align correctly with the socket where it is- don't want to cut THAT out.
Then I'll have to figger out mounting the landing gear - fuselage mounted. Probably carbon fiber - dunno yet.
This page shows the construction of the plane's wings. They're Styrofoam cores, and will be sheeted with 1/16 light contest balsa... after all the internal parts and structure are installed.
Note: As with anything, the techniques shown are a mixture of stuff I've read, been shown by others, and a very little bit I've thought up myself (not much of that - I'm still earning this stuff!)
This
is an overall view of the wings cores as they came. The manufacturer cut them
from foam blocks with a hot wire, and drilled the holes in them for the wing
tube that will function as a spar and join them to the fuselage. I've drawn
basic layout lines on the cores to help me visualize the work I'll need to do.
The owner directed that I shorten the wings by two inches at each tip, so that's
marked on the cores too.
This
is a close-up of the wings. The lines show where the wing tube sleeve will go,
where the servos and mounting rails will go. and where the ailerons will be cut
off. The ailerons are at the back of wing (top of the picture). I'll cut them
off, face the cut edges with balsa wood for strength and to give the hinges a
place to live, and then temporarily rejoin them to the wing so I can sheet the
wings with 1/16 balsa wood. We're looking at the bottom of the wings in
these pics - the tops will be completely smooth.
This
is the glue I'll use in this step - it's a water soluble acrylic copolymer glue
(don't ask me what that means, but it works to glue wood to plastic or
fiberglass) that dries flexible but VERY firm. Great for gluing these spruce
rails into the foam wing cores.
Here
are the aileron servos mounted to the spruce rails that'll be glued into the
wings. I used the servo/rail assemblies as templates for cutting the foam.
--The channels I cut the channels with a high speed cutter on my Dremel tool (-
it could also have been done with a soldering gun/ iron tip.) When using the
Dremel on foam I recommend keeping the vacuum running at the cut- otherwise
everything gets covered with little foam particles...
--The servo well itself goes all the way through the foam core. When the wing is
sheeted you'll be able to see the top sheeting at the bottom of the servo
well .
** A note on weight - the lightening holes in the spruce rails saved 2 grams on each wing.
The
rails glued in place with Glu-it-2-it. Now to wait for the glue to dry....
This
is the full-depth rib in the middle of the wing 1/8 lite ply - it
will
-- support the wing tube socket
-- tie the servo rails to some structure
-- serve as the wing cap for the aileron cutout
It'll be capped with soft balsa to be flush with the foam - therefore it'll tie
in with the top and bottom sheeting.
** A note on weight - these intermediate ribs weighed 25g together before the lightening holes- 17g afterwards - a savings of 1/3 ounce - plus the adhesive that won't be on the whole rib. Nice payoff for 20 min with drill press and jigsaw...
The
full depth rib fitted in place on an outboard wing panel. It's not glued in yet
- I'll glue it all together when I mount the inner panel on the wing tube
socket. -- apply the glue (epoxy and GluIt2It, I think) to all pieces, push it
all together, and align the set in the wing shucks, and weight it some to
make sure a straight wing panel results.
Nov 19 -- Drilled the aileron servo channel (with sharpened brass tubing) and
capped the servo rails with scrap foam.
-- Test
fitted the wing root sections to the rest of the wing - looks like they'll
work fine.
Nov
23 - The pic shows the wing components ready to rejoin. The lite
ply rib is glued to the outer panel now. Here's what 's been done -
- Filled scrap foam over the servo rails
- Cut the ailerons off,
- Capped the aileron cutouts and the aileron leading edges
- Installed the intermediate rib onto the wing.
- They're back together now, and so we're waiting for the glue to dry again.
The balsa wing skins are assembled - 2 need final sanding and two are ready to
apply now- 39 g each, ready to go. Not bad, I think.
Nov
24 - First time all the parts have ever been this close together
-- NOTHING's aligned yet, and the wing tube sockets both need to be trimmed
flush, and... and... and....
But it's starting to look like an airplane - sometimes a builder just needs that.
Next is to
Adding the wing mounting system
Start setting up the fuse - install wing adjusters, match the root rib to fuse
side, etc
This is done!! -- and documented at
Root Rib Prep and Mounting
Jan 11'03- The wings are sheeted now -
documented at
Sheeting_The_Wings
Dec 13 '03 -CG,
Landing Gear and Fin Mounting-- Initial CG check, Landing Gear support /
mount, Fin mounting
Mounting the Cowl and Bellypan
(under construction as of Jan 28 04)
Elevator and Rudder linkages
- showing servo mounts and linkages at the tail
Back to:
Planes I've Known
Thought for the day:
Pattern flying is just a hobby... .like neurosurgery is just a job...
