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Oct 24, 2019, 03:52 AM
jofro
Thread OP
Gallery

"Mini Twin Widow" - "LFA"".


I have never build anything smaller than few twin 55mm EDF jets, but always had a craving to go smaller. Unfortunately couldn't get hands on 20mm set of power units, so started on the slightly larger set of 30mm fans to power mini replica of one of my 8Kw giant "Twin Widow" (pic)
Using some 3.3 formula it is slowly coming along with few minor mods.
Last edited by jofro; Sep 07, 2021 at 05:26 AM.
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Oct 25, 2019, 02:54 AM
jofro
Thread OP
Great news, the model seem to be lot lighter than expected, despite using lot of balsa and epoxy for a quick set.
Started playing with my favored tool, the paint brush.
Oct 27, 2019, 04:22 AM
jofro
Thread OP
Coming along nicely bit by bit, started on power unit mounts, thrust tubes and 3D printed air intake bell mouth to get the best out of the units.
Oct 28, 2019, 02:46 AM
jofro
Thread OP
Finito with the frame.
Nov 03, 2019, 06:10 PM
jofro
Thread OP
Cute little piddlies arrived, 3/D printing new air intakes, thrust tube roll outs and mounting flanges is next.
Nov 05, 2019, 04:15 AM
jofro
Thread OP
After some reinforcement of the power units, the mount brackets were added with the first thrust tube roll out.
3D printing of the miniature bell intakes will be little bit more complex but on its way.
Nov 06, 2019, 03:38 AM
jofro
Thread OP
After the first static test run I have found bad surging at 3/4 of the stick due to the horrible "black wire" oxidation on the brand new 20 A speedos power leads. It was only matter of luck, while shortening the power leads!
Back to the vendor for replacement!
Tomorrow I'll hook up another new set of speedos to see if the same occurs.
Nov 07, 2019, 05:24 AM
jofro
Thread OP
After new set of speedos fitted all works fine but it took me good part of the day to re-program the set for smooth run, playing with the timing, frequency, cut of voltage and numerous other settings while using various batteries capacity.
At 400 grams AUW it seem to hold its own weight after static tests.
Also had to replace receiver after constant re-bind when initial hook up.
Nov 07, 2019, 08:01 PM
EDF all the way!
bruff's Avatar
Awesome looking! Good luck with 1st flight.
Bob
Nov 08, 2019, 03:29 AM
jofro
Thread OP
Thanks Body, it's just about fully complete after adding small support to the rear of the thrust tubes, took it out today to do the range check after receiver replacement, all good.
Seem to have just about one to one thrust after further static tests, not sure if I should fly it as it is or wait till I get the new 3D bell intakes printed.
I make sure I get someone to hand launch it for me the first flight to get a quick thumps response if CG or thrust line is not correct.
Nov 08, 2019, 11:06 PM
jofro
Thread OP
Just about ready for action.
2019 1109 194311 042 (1 min 0 sec)
(Mini TW static test run)
Nov 13, 2019, 03:21 AM
jofro
Thread OP
Next to her big sister.
Nov 18, 2019, 08:59 PM
jofro
Thread OP
Instead waiting for the 3D print of bell mouth intakes I decided to test fly it with out them.
Couple of hand launch test flights this morn with modeler friend launching it for me in dead calm but very smoke hazy conditions.
Lot livelier and faster than expected, extremely quiet even on full stick.
Few more control travel adjustments required but also very smooth thumps touch, being such a small and rather responsive model.
Tiny 4.5 gram servos are not returning to precise Neut position which made the first run slightly of a roller coaster run after launch but soon after settled with softer touch.
Next flight I'll have a go on my own to get used to it.
Nov 19, 2019, 03:28 AM
jofro
Thread OP
Few more test flights today, after some bench re-set of throws, I had first go launching it on my own, resulting in two bad ones and two so so!
It will take lot more prax to sort it out to perfection.
Nov 25, 2019, 01:29 AM
jofro
Thread OP
Latest upgrade, the new bell ring air intakes.


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