Page Two.
The Black Rainbow, Black surfer.
The
flying clog.
24'th July 2006. |
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The
new servo was mounted on a bridge made from scrap CF board and
scrap CF sandwich left over from the main fin. The CF is glued
and well as screwed so it will be a little difficult if I have to
pull it apart. |
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I don't think a plastic chute would have survived
today's mishaps. |
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Camera payload module. A carbon fibre payload module was fabricated and more info can be found in my vacuum infusion pages. I made a wax replica of the camera top so I could make a carbon cover for it which I mounted a micro servo on. This can hit either the “on” or “shutter” button. I would like more clearance between the servo arm and the buttons but there wasn't enough servo travel to use the servo arms which were at 180 degrees and there wasn't time to make a custom servo wheel. This arrangement did work on the ground. I went to Nimbin and attempted to test fly the new payload module. It was a little windy but I gave it a try. I had 1800mah battery because my 2200mah one died so it was a little lighter. The empty payload module weighs about the same as the original one so all up it was a little bit lighter. At this weigh control was very poor during launch but not to bad on descent. I had some bad takeoffs and crashes. On my last flight the chute inflated well and it staggered up to maybe 20 meters. I progressively reduced power till I had more or less level flight and reasonable steering. Then the motor seemed to glitch and then stopped. The solder on the esc had melted and 3
wire had come off. I later discovered a chip was missing –
the solder had obviously melted and it had come off. The winding
on the motor looked cooked. |
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Here is the burnt out stator. The insulation under the wire was also fried so I didn't reuse this stator core. |
Fortunately I had a spare stator core lying around at home which I wound to match the original. I used coloured “newbie” wire. Not wound as neatly as the original but it is my first attempt. The colours make the three phases obvious. This is wound with 16 turns on each pole. |
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Clearly I have to be more careful with airflow to the motor for cooling. I've put a lot more holes in the motor tube and I may have to move the ESC to stop it shielding the motor from the breeze. I also ordered a double stator motor kit today from gobrushless in case I need to upgrade the motor. I had already made the motor tube with enough room for the larger motor. |
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A
kit built double stator motor. |
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Murphy strikes again. Easter
2007. After upgrading the motor, the black rainbow suffered a series of bad crashes on or shortly after take-off. This is I believe closely related to problems experienced by myself and others with sky-surfers (clones). The symptoms are different using the kite versus the plastic chute. |
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The kite will inflate and fly only using low power – just enough the climb slowly. Even a small increase will cause the gondola to spin and wind the lines up (if it doesn't hit the ground first). You can see I've used lots of plastic packing tape to make it more crash worthy and I've taped a soup spoon to the front to increase the weight. |
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The
surfer chute doesn't have the problem of the gondola spinning.
Instead the whole thing rolls on it's side. Out of the box my
surfer clone launched ok but it had very little power and could
not climb. As soon as I changed the battery to Li-Po, I had more
power but also a serious roll problem. Even when the chute is
flown on my home made gondola, the tendency to roll is still
there. |
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Black surfer (BS). The only successful flights for the carbon creation lately have been using the plastic chute from the surfer clone. It has survived far more crashes than I'd ever expected but is now in need of repair/replacement. I hate the waste of buying a complete model just for the chute but this seems to be the only option. |
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The surfer uses a 4 line rig – most models use two lines. Two line is usually referred to as “weight shift” steering but I'm not sure this is accurate. Anyway in order to fly a surfer style chute on my contrivance I had to figure out how to convert it to two lines. After some guessing and test flying the rig shown here works. It may still need some tweaking but it flies. If the rear line extender (the plastic bit) is folded in half it is still a little but too long. So it is shortened more by clipping the clip a little higher on the pink lines and zip tied in place. |
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The Easter Saturday black surfer flights went moderately well. There is a little instability and the steering is very touchy compared to the surfer. I'm not sure if this is due to the two line rig or because the servos are much faster. I don't have as much servo travel here as on the surfer but it still seems to be too much. I had a very brief flight+crash on Monday. The wind was gusty and I'm not quite sure exactly what happened. I flew with some ballast in the middle (instead of front) and I had the impression it flew better till the wind and most likely pilot error (I panicked as it neared a tree) terminated the flight.
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Thanks to Mike Van Emmerik for pointing the cameras for me. |
Cheers Eddie.M.
My models page is here and my home page is here.