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The boom is permanantly attached to the boom joint
pad. The front of the boom slides into the spar doubler and sticks out
about 1/8" in front. The two aluminum elbows stick out the front of the
boom end and connect to the servo arms. The aluminum elbows (1/16 aluminum tubing bent into an elbow and CA'd to the .030 carbon rods) should be long enough to still be inside the boom when the servos are in their forward position. This prevents the ends of the elbows from catching on the front edge of the boom. The entire glider can be disassembled into three pieces after it is built. The nose pod, the wing assembly, and the boom/tail assembly. (OK, 4 pieces if you count taking the T-tail elevator off by undoing the plastic bolt.) The nose pod and the tail boom are connected to the spar doubler using plastic bolts. The top of the bolt is ground down to leave just an arm sticking out from the side. (Think of a 1" dowel with half a tongue depressor glued to the top.) These are screwed down to hold the boom in place. The pod has keyed holes in it. After the screws are tightened down, loosen them enough for the remaining screw head arm to pass through the keyed slot, then turn about 3/4 turn to lock the pod in place. This allows the pod to pivot up to allow access to the battery connectors and other electronics. At the field, connect the battery, rotate the bod back into position, lock the bolt head, and go flying. Hope this helps with some of the details that are left to your imagination on the drawings. The web site construction details were supposed to show these little details. Where did I put my digital camera? |
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The wing foam seems to be glued to the spar using
either 3M-77 or white glue. The foam is held firmly in contact with the
spar using the packing tape to compress it all together. The stab is connected to the fin with a semicircle of balsa on each side. This gives the stab torsional stability while allowing it to pivot on the plastic bolt/hinge. The balsa semicircles have been treated with CA and the fin has been glassed with 1.5oz glass cloth so there is very little friction. Only one balsa semicircle has a hole in it for the end of the pushrod. The aluminum elbow goes thru the hole, thru the slot in the fin, and is held in place by the torsion of the carbon pushrod. Hope this helps. |
| I forgot to measure the tail. Scott will forward this on later. I was taking pictures in the pouring down rain and had blocked somebody out of their car so I got a little distracted. Here are the photos I did manage to take and the highlights I noticed: |
| General impressions - It's light! I hadn't
really paid attention to the spec's yet, but I was amazed how fragile
it seems. Scott's has many miles on it, but still flies very well. I can't
imagine it has enough inertia to damage itself in a crash. Does make
you wonder how well it penetrates a headwind... |
| Tail - Actually feathered more than plan shows
on the TE. Notice that the boom is let into the vertical stab until it
almost shows through. The tail boom is chamfered at a 20-30 degree angle
at the end to allow the rudder rod end to clear on hard right turns. The
rudder rod goes down the tube the entire way while the elevator exits through
the slot shown on the plans. The boom is removable by removing the screws
holding the plate to the 1/4 balsa. The wing is actually split for
the last 1/3 of the chord and just taped together on the bottom. The nylon
hinge bolt is threaded into the far side control horn. No nut is used. I'd
also venture that the horns are 1/32, not 1/64 as indicated on the plan. |
| Wing - I couldn't get a measurement of the
wing thickness, but it was less than 1/2 inch. It tapers to a razor thin
trailing edge. The top and bottom layers of tape are the last 1/8 inch
of the wing at the TE. The thumb pad is on the bottom of the left
wing and let in so that it is flush with the surface. I'm not sure how
it was cut so smoothly at only 16th deep. I'm thinking of using my small
router and a 1/4 straight bit prior to laminating to the spar for this
job. Scott cautions that this is a "wing launch" not a "discus launch" plane.
It's pretty much a gentle back swing like a bowling swing (thumb on bottom,
fingers on top) with a very easy transition from back to forward at the apex,
no jerking. This is followed by a forward arc releasing at the top. He says
he can match the composite ships for launch height easily. I could see some
hint of carbon in the spar, but got no details from looking at it. Also
note that the hole in the dihedral brace in the center is large enough
to allow the rod ends to slip through. It is not a tight fit. |
| Gear - The servos were mounted with a combination of the foil tape on the top that ran over onto the wing core and silicone glue attaching them to the cut out. The receiver in Scott's is an Extreme 5, but he indicated that it had an AM when it came from Harold. The wires are soldered, but Scott has seen later models with the connectors still on, but plugged into an RX with end pins. The battery is 2 Lithium photo cells made into a pack. They are non-rechargeable. Get this, the antenna is folded into a bundle with about the last foot down the carbon shaft. This goes against all rules I've learned about antennas and carbon. Scott has literally spec'd it out with no troubles. Both battery and RX are loose inside the pod. |
| Pod - The pod looks even more complex in person. I'd love to get a tutorial on how it's done. The mounting screws are nylon with most of the head removed as in Silver's description. It's pretty amazing. |
| The tape starts with general footage of various
planes flying at 60 Acres. They spot the Nipper flying and then it's
all focused there. Amazing launches and maneuverability. The end shows
Harold explaining some details. He defines "treated" as swabbing polyurethane
on with a rag, letting it soak briefly and then rubbing/blotting up the
excess with a paper towel. One coat only. The edges are treated with CA
for durability (he does not say before or after poly treating). He grabs
the elevator and gives it a twist that makes you cringe as he's explaining
that this method infuses the poly into the balsa fibers and plasticizes them. Amazing. Also note that the thumb pad is on the bottom left for a right handed Nipper and vice-versa. The plans weren't clear if it was top or bottom. Also note that the "someone's nipper" photos show a left handed model and Scott's is right handed. Follow the drawing for tail placement. He also recommends "good, light" balsa, but not contest grade for the tail. |
| One other note - Scott's has a piece of strapping
tape spanning the servo cut-out onto the wing and Harold explains that
this is experimental. It is intended to keep the wing halves from separating
at the dihedral joint on launch and is working well. After seeing that
the wing is joined mainly at the spar only, I can see his point. Hard 1/4"
balsa is crucial for the pod/boom mount to allow forces to transfer from the tail to the spar in flight and from the pod to the structure on nose in's. There are also nylon nut inserts into the hard balsa to receive the bolts (they show as a hexagon on the plan). |
| Later notes: The boom has been shortened to 13" on later versions. The strapping tape in the photos across the servo cut-outs has been replaced by an adhesive backed foil tape to prevent the wings from trying to separate on launch. |
