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Posted by Mac50L | Oct 21, 2015 @ 10:15 PM | 1,541 Views
The U/C is made using the HK parts. They are actually designed for a tail-dragger. For trike fitting it might be expected that they'd be inserted into the foam of the fuselage but to avoid stress I've fitted mine as a unit on the outside.

Both parts of the U/C are mounted on a strip of light ply and a similar strip inside the fuselage, sandwiching the foam of the fuselage and spreading the load. The bolt-heads (2) are sunk into to the inside ply piece so the battery rests on top with no bits to damage the battery in a heavy landing (crash).

Excuses - the 2 long bolts seen holding the aft U/C part are to be cut or replaced now I've proved the concept. Actually another one or two to fit to stop the plastic part of the unit twisting are needed. The front wheel unit has wooden blocks each side of the plastic wire-U/C-holder. That plastic bit is actually meant to go vertically into the fuselage, usually aft when a tail-dragger.

The servo cover is off (IMG_8938) so air can flow from the front airscoops, through the fuselage. There are bits of Velcro on the underside of the wing for stores mounting. Note the sockets for the aileron wiring and stores release. The wings are held on by 2 strips of Velcro from wing to wing on the under side. No bolts holding the wings on.
Posted by Mac50L | Jun 08, 2015 @ 08:02 PM | 1,620 Views
A list of, at present, 80+ biplanes, their URLs, builder/designers and other information. This is version 3 (an arbitrary number) and will, if kept up to date, keep changing.

Criteria - mostly foam construction, plans free, website(s) open to view.
Posted by Mac50L | May 28, 2015 @ 07:34 AM | 1,966 Views
Taking Chara's Bipie -

Reducing the size a little and giving it a full fuselage, the Mk VII. Why 7? Sounds a good number.

NOTE - Construction Notes V9 (17 July 2015) now mounted below.

Span: 545 mm (21.5")
Length: 530 mm
Weight net: 220 grm, 296 grm with U/C
Motor: 19 grm AX 1806N 2500kv
ESC: 12 Amp Blue Series
Battery: 850 mAh 3S
Servos: 2 x 5 grm, 1 x 9 grm
Prop: 6x4

Pictures -

#6 The parts with tailplane and rudder in place.

# 8 This shows the linkage between ailerons. The linkage stoppers are fitted to CD horns. Credit cards pieces were used instead of CD plastic, on the second one.

#11 The motor vent tube looking like a P&W PT-6 exhaust.

#12 Both Bipies, second one on the left.

#13 is the second Bipie.

#15 shows the pilot and the struts to hold the upper wing. These are bamboo kebab sticks and go down into the fuselage to the mid point.

#16, the instrument panel and in the cockpit, the fore and aft bamboo strengtheners are visible, glued to the inside of the sides.

#17 The pilot sitting on the cockpit floor. The pilot is an orange tennis table ball and a bit of foam block (but don't tell him that).

#18 The strengthening bamboo piece for the fin to fuselage. With the large rudder, the glue join takes a lot of stress.

#19 Close-up of the strengthener.

#20 Underside view of the cockpit area, rudder and elevator servos plus Rx mounted on the side under the cockpit floor and above the lower...Continue Reading
Posted by Mac50L | Apr 11, 2014 @ 06:36 AM | 3,285 Views
The plywood motor mount is retained by two screws. The plywood visible is there to load spread the screws.

The motor cowl has a screw into the pillar and a magnet at the bottom of the hole the cowl pillar goes into.

Posted by Mac50L | Apr 01, 2014 @ 08:14 PM | 3,130 Views
I've noted which end of the bottom servo hatch is the end to lift off (magnet end).

A picture of one of the hinges on the tailplane plus the clevis replaced with a linkage stopper due to the push rod being too long. The alternative fix is to put in a new Z bend at the servo end. The tailplane and elevator have been slit to allow fitting of the hinge. The 4 dots are kebab stick pushed through and glued with PVA glue.

Having been asked how I now fit the wings on, attached, a picture. There are 2 strips of Velcro running under the wing, attaching to 4 pads, 2 each sided. The upper one (aft one) in the picture has the cross-the-plane Velcro peeled off (my thumb in the picture holding it).

There is another pad running between them, there for a bomb-drop attachment. The socket for that control had not been fitted at that point. Now there are 2 sockets on each side.

To make fitting and attaching of the aileron servos wires easy, there is a socket on each side, glued to the fuselage (done after the previous picture showing the Velcro). Once the wing is fitted the aileron wires are plugged in.
Posted by Mac50L | Jan 02, 2014 @ 03:56 AM | 3,651 Views
After building and flying a J-Bug, getting "taken-out" by a Vapour one indoor flying night, it seemed that something needed to be done.

This resulted in the AOP1 (Air Observation Plane). If it had military markings it would be an Army Observation Plane. The first picture before the motor cowling (3 small bits of foam) was fitted.

While it was being built, the wings were on the bench in the low wing position. Interesting.

That meant that the next plane would be a low wing version. It was fitted with the same 10 grm motor and obviously under powered. A 19 grm motor sorted that out but control was lacking. Fitting ailerons fixed that but there was wild wing flapping under power in a dive. The cambered wing was filled in making a monocoupe constructed wing with lots of stiffness and now something that could be thrown around and stay together.

The low wing version, Kea, is shown with a foam canopy from a Dart-XS sitting on it for effect and the other pictures, open where there is access to the battery. A cover goes over this hole and either a couple of windscreens and pilots or a single clear canopy with pilot. The later is made and still needs to be fitted. The first pictures don't show the ailerons which were fitted as extras and increased the wing area as seen in the last picture. This also includes the side of a plastic bottle for the canopy and a pilot. Hopefully he will make the flying a bit better.
Posted by Mac50L | Apr 06, 2013 @ 04:57 AM | 4,086 Views
I delivered a new Dart (#3) to its owner last night and he did a quick test flight. I advised less throttle and launched it. Within 10 seconds (his words) he was hooked on it. This is someone who has been flying for over a year, Bixler, SBach 342, etc.

We had indoor flying later that evening so a quick outdoor flight by both of us to "calibrate" fingers and then inside. I'd built the first Dart just for the indoor flying nights and was flying my #2 (#2, that's another story). The indoor is just a basketball court size and I've found a UM T-28 a bit of a handful in there (poor pilot?). The Dart, off the floor with a kick on the throttle vertical for ~10 feet and then lazy circuits. Square circuits - this thing turns on a sixpence (OK a dime).

So my #2. Made a mistake measuring the wings and has an extra ~3" span and a little less chord. Flight difference? Can't see any, maybe glides further.

Modifications - the body is 15 mm longer, sticking out ahead of the front edge of the wing. This allows the battery to be fitted further back near the CoG. The body is wide enough to fit a 460 - 500 mAh, 3S battery in. The vertical walls of the fuselage bend from the front of the tailplane back and meet at a point at the back of the tailplane where the elevator meets it. The wings have a Western Red Cedar internal spar which saves fitting a kebab skewer (or CF spar) across the wing. A plywood firewall with ~60 mm long ply panels inside from it, glued to the internal...Continue Reading
Posted by Mac50L | Nov 05, 2012 @ 05:18 PM | 4,385 Views
I find it difficult to find the size of horns for control surfaces that I actually want. So, make them (green because that's the colour of the caps for container of the type of milk we buy) -
Posted by Mac50L | Jul 23, 2012 @ 08:36 PM | 4,780 Views
We have a problem, these things are breeding and there's another one or two on the way!
Posted by Mac50L | Jul 23, 2012 @ 08:16 PM | 4,973 Views
A closeup of the 3M hook with the wire and rubber band retainer. The "70" is the mm distance from the wing's leading edge. There is also a "60" (out of picture). These are for CoG checking.

A link-stopper replacing a clevis. Note the wire on the horn for security. Also visible under the pushrod is another copper wire through the wing. This is one of the hinge retainers. The hinges aren't actually glued into the wing, just retained with copper wire.
Posted by Mac50L | Jun 11, 2012 @ 03:52 AM | 5,081 Views
The airscoop and undercarriage fitted to a Bixler and a more reliable wing retainer using a wire with a rubber band to stop it unclipping. The wire runs across from hook to hook and has a reverse bend at its ends for the rubber band to hook over.

This is all replaced with Velcro on the V1.1 which replaced the V1 which ended up with more glue than foam.