840mg square 2.75 - RC Groups
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May 17, 2007, 01:33 PM
Your ruler, in part...
Angry_Monk's Avatar

840mg square 2.75

With this sub gram plane i wanted to focus on small size as opposed to low weight. i still tried to get a light plane, but i wanted a plane so small that even i would think it was small. i ended up taking the plans for the the square 5.5 and scaling them down 50%. the airframe was a little on the heavy side but it wasnt something to worry about. i soldered the RX together w/o the circuit board and through massive sanding of the IR sensor i was able to get a 65mg receiver. i took apart some quartz watches to get the wire for the actuator, which measured about 65 ohms/meter. the biggest problem i had was the motor. i had a nice 155mg lightened Shicoh but it didnt produce enough thrust w/ my props to fly this plane, even in mono wing form (that version of this plane was only 695mg!). i spent a day trying to rebuild another motor w/ flux ring but didnt get anywhere. finally i just put on a stock Shicoh and added the second wing and flew it like that. i was aiming for a .7XXg plane but i'm happy with what i got. i can improve the weights on the RX and AF for my next plane, and with some new tech that will come out shortly i think i'll be able to jump the .7g range all together.

I have to say, for its size and weight, this plane flys very well. After some tweaking i got it to fly relatively slow, and have a turning radius of about 3ft. It does have a natural counter clockwise tendency which i may or may not fix. it is not bad but all i would have to do is add left thrust for straight flight. it is also worth saying that this plane has a lot of power! my props are not perfect but if they were this plane could get close to 800mg of thrust. with some changes it would be possible to have the first sub gram plane with a 1:1 thrust to weight ratio. that would be interesting.

Weight Breakdown:
Airframe + act: 75mg
IR RX: 65mg
3.2mm motor, stock: 275mg
Prop: 10mg
10mah cell: 395mg
misc: 20mg

Total: 840mg

Video: https://www.rcgroups.com/forums/showthread.php?t=688363
Last edited by Angry_Monk; May 20, 2007 at 02:21 PM.
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May 17, 2007, 02:00 PM
Zlin Flier
Rick McWilliams's Avatar
Very nice compact model. It would be even cuter with landing gear. The ROG would be such fun.
May 17, 2007, 02:02 PM
did it flied?
Electronick's Avatar
That is some nice work there Mr Monk
Even a Rocket Scientist would have a tough time building something like this..
May 18, 2007, 12:08 AM
Registered User
sideburn's Avatar
very very nice work.
I want one.

(i can barely solder the actuator,motor, and battery wires on my Aerosoarer rx without my hands shaking so bad that i knock the plane off the table)
May 18, 2007, 02:26 AM
Registered User
peter frostick's Avatar
Excellent work as ever; a bipe seems a very successful way to lower wing loading without much structural weight/size gain.
Anyone heard any news of Billy Stiltner who inspired the design????

May 18, 2007, 03:12 AM
Registered User
Hello angry Monk,

what a nice little plane!
What about adding a third channel and an additional actuator? Just exchange the PIC10 by a Cygnal F300. I just sanded one down to equal weight (14mg). It has 8 instead of 4 I/O pins giving more output channels. If you have a transmitter with more channels and if you have a source for the transmitted protocol I can program an F300 for you. You can even add a 4th channel and make a 3d version!
The power seems to be almost adequate.

May 18, 2007, 03:33 AM
Registered User
Fantastic model - congratulations!

All you need now is a lighter cell

May 18, 2007, 07:30 AM
Senior to who? Member
crossup's Avatar
Unfortunately Billy Stiltner apparently has not posted since Nov of last year
I hope he is well and flying
May 18, 2007, 11:07 AM
Your ruler, in part...
Angry_Monk's Avatar
thanks for the kind comments everyone.

i have thought about making a sub gram 3d plane. it is possible as long as the weight is kept below 800mg max. but as of now i dont plan to go in that direction because i prefer 2 ch control over 3 ch. i would also have to make a new tx to handle the third channel, which i something i dont want to do right now. i am focusing on ever lighter sub gram planes. like AtomicWorkshop said, i need lighter cells. but eventually i think i will attempt a 3d sub gram flier, or at least one w/ an elevator.

I dont know what happened to billy. i have checked and he really hasn't posted since November. i have talked briefly with others and no one really knows what happened. it seems he just dropped off the map. i hope he is ok.
Last edited by Angry_Monk; Jun 10, 2007 at 12:42 AM.
May 18, 2007, 02:23 PM
The ceiling is the limit!
micromad's Avatar
Angry Monk,
That is a great model. I thought Matt Keenon's bipe was small and this is almost half the size!
Is there any chance of a video?
Crossup is right as Billy has not posted since November. I to hope he is alright.

When will the atomic workshop 8mah lipo be for sale? I cant wait, just imagine the models that we will be able to build. sub gram scale models????


May 18, 2007, 03:20 PM
Your ruler, in part...
Angry_Monk's Avatar

i will try for a video over the weekend. it will be hard considering the size of the model and the speed at which it flies... there is a chance the video will show nothing and you'll have to take my word that the model is in picture
May 18, 2007, 04:14 PM
The ceiling is the limit!
micromad's Avatar
Yes I know what you mean about filming these tiny machines. I will add this plane to the sub gram thread.


May 20, 2007, 02:26 PM
Your ruler, in part...
Angry_Monk's Avatar
just posted a video of the plane: https://www.rcgroups.com/forums/showthread.php?t=688363

luckily you can actually see the plane flying around. i was convinced that most you would be able to see would be a small dot in frame
Sep 16, 2007, 07:43 PM
is it supposed to smoke??
3dFlyer88's Avatar
holy crap man your planes always amaze me...
Sep 18, 2007, 07:43 AM
Registered User
Angry Monk

I always struggle with little DD props, is that balsa blades ? And what size/pitch ?

The planes beautiful.



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