GT5500

If you are familiar with car engines you will know they are timed so the spark comes at the right time if you ran the engine backwards the spark would come too late. Its similar with electric motors, the brushes are timed to make contact at the right time if the motor runs backwards the timing will out and power will be lost, so a reversed timed motor will work better.

dimadee

Hi flybilly,

Basically, a timed motor is optimized for rotation in one direction. A forward timed motor will spin faster running forwards then backwards.

As the motor is mounted facing backwards (pusher) on a Mugi, to get the prop to spin in the correct direction, you need the motor to spin backwards (don't forget to mount the prop facing forwards!)

The QRP speed 400s from Aircraft World are the best I have used.

dck102

why do you say stay away from big servos ?
i have thrown away many 9gram servos because of stripped gears , yes cheap chinese ones but big ones have lasted longer ! is there a technical reason as to not using larger 3 or 4 kg servos

babylon5

Hi, the bigger servos are not a problem for the mugi. This mugi of mine with a 800mm wingspan can fly and still glide pretty well at 750grams . I use twin ducted EDF with a single 3S 2200mah lipos.

If you are using a speed 400size motor a 2 bigger standard servos will not be a problem for a 800mm wingspan mugi as the combine weight with batt and RTF is no where near 750grams.

However, you need to be careful that the horn do not get bind or rub against
the ceiling of the corrugated materials since standard servos are a lot thicker and bigger than the 9g servos.

cheers

flymess

Hi, just finished a Mugi with 9gm servos, Brushless outrunner and 7"x5" prop. Trouble is after setting the wing tail mix as per instructions on my Spektrum DX6i, the elevator (up/down stick) runs the airelons, and the airelon (side to side stick) activates the elevator. Any ideas out there about what I've done wrong and how do I fix it? Dying to give it a go.

babylon5

Try the following:-

Made sure your Dx6 is set to delta mode

1) Reverse the aileron servo
2) reverse the elevator servo
3) unplugged the aileron cable and swap the cable with the elevator servo cable.
4) After step 3 repeat step 1 & 2 again. Should be able to get it right.

Once you get it right, mark and note which side servo should be at the elevator and aileron for future elevon setup.

Cheers

flymess

Thanks babylon5, tried that but didn't fix the prob. tried a few things and found that reversing just the elevator did the trick. all in order now

babylon5

Hi to all Mugi lovers. I have built many Mugi from 700mm wingspan to 1.1metre .
Some are pusher and others are EDF. The range from single ,twin to triple blow job. Just visit youtube Starsreamer47 at your own pleasure. I have pose several videos of the mugi in action together with some other e-flight aircraft.
The most wonderful thing about the Mugi on corroplast, is they are tough and the last a long time.

here is the link
http://www.youtube.com/results?searc...creamer47&aq=f

Feel free to comment on the site so that I can improve my future built.
Thanks

Cheers

flymess

Nice vids bab. Film of a dot in the sky can get a little "samo" tho. Would love to see some close-ups of the plane, better yet the build. That would help others. Like how do ensure a straight motor mount for brushless. what method do you use to keep TE together?, mine come apart using hot glue. do you mold your aerofoil before glueing or just go with natural shape that fold makes? what size battery do you go with and where's your CG? Keep us informed. I'll post some picks when I learn how it"s done

babylon5

Hi Flymess, regarding the fold, just score the folding line before folding.
Folding lines must be nearly perpendicular to the flute lines.
Regarding motor mount. Its difficult to tell which mount is the best. Outrunner with rotating case are more difficult to mount. They need special metal brackets for mounting. When i have the time I will show you some method of mounting.

Related to the corroplast mugi go to this thread http://www.wattflyer.com/forums/showthread.php?t=58196

It will show you how to fold the corroplast wing.

Cheers

flymess

I made a motor mount by bending a piece of aluminium and bolting it to the mugi with another piece as a doubler. trouble is it was not a perfect bend and is slightly skewed. the elevons are too light (3mm coro) and flex, i'll try 5mm ( they're the only options I can get) and the TE keeps coming apart (hot glue just doesn't do it). It's all accademic anyway because I haven't got the skill to fly it here are some pics

babylon5

I saw your picture and here are my comment:

1)I think aluminum bracket plate area is too small. Two screw to hold and keep the bracket to the corroplast body from rocking is just inadequate. i use four small screws, also has larger surface area for the base of the L plate shape bracket.

2) Hot melt is not good for places where there is constant impact or jarring force like hard landing or crashes. After a while the hot melt will become loose.

3) You may want to insert a 3mm thick plywood base plate sandwich between the corroplast ,glue down with with contact cement prior to holding the AL bracket down.

All the best & take care

babylon5

Hi, I dont have the time to post the various method to mount the motor to the Mugi but here is the link to my first twin EDF mugi using a standard 3mm thick c.p material with a wing span of 800mm. This Mugi weights about 750grams ready to launch. It was my first Mugi ( built by a mutual friend)

[media]http://www.youtube.com/watch?v=fHQNqdhHFSU[/media]

From this flight one will realize how much lift this delta wing is capable.
After the first taste of the mugi, I started building my own and now have a fleet of mugi's.


Cheers

babylon5

I made mine using Al plate and bend. I did not use addition wood base as my mugi is 3mm thick corroplast. This one uses a 180grams 35 to 36 mm diameter motor on a 7-6 propeller on 3S lipo. KV is 1.7Kv/V.

Cheers

babylon5

Oops I forgot to mention, the mugi that uses the 180grams motor is 1.1metre wingspan.

Cheers

babylon5

I have overhaul and re-modified my little mugi.
It is make up of 2mm thick coroplastic material.
Only 24 inches WS.

If you want to know what's the difference watch this video.

[media]http://www.youtube.com/watch?v=zyatO2sd_ro&feature=channel_video_title[/media]



Cheers