Build Log - Simple Twin-Boom Pusher - Page 3 - RC Groups
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Apr 22, 2011, 06:54 PM
Trapped in California
foamflyer's Avatar
Quote:
I'd think you could also taper the tail ends of the booms. And I had another thought... how about trying an inverted V-tail? -- seems like it would be easy to mate those up to the already angled booms. I bet this would really scoot as a delta wing as well. Might have to try my own.
Very cool idea!
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Apr 26, 2011, 05:39 PM
Registered User
runCMD's Avatar
I just bought a stack of the blue fanfold from Lowe's. I am looking at building a twin boom pusher to play around with for FPV. I will likely be trying to get started on this tonight. Eventually the plan is for a larger, modular plane that can carry more payload.
Apr 26, 2011, 06:59 PM
Registered User

Motor and prop question


Nice plan and video. What prop did you use?
Last edited by nvmike; Apr 26, 2011 at 07:52 PM. Reason: I found the motor specs in post 1
Apr 28, 2011, 10:12 PM
Trapped in California
foamflyer's Avatar
Quote:
Nice plan and video. What prop did you use?
It's a TowerPro 8x3.8.
Apr 28, 2011, 11:53 PM
Registered User
Wow, nice! Gotta build one. Thx for the build info.
(squints at foamflyer's avatar)....... what is that?
May 01, 2011, 07:28 AM
Fly to live. Live to fly.
rrcc's Avatar

What side is best for aileron & servo?


What side is best for aileron & servo?

I'm fuzzy on my high school physics, so I'm asking that question. The prop spins clockwise, which would bring about a reaction (Newton's action and reaction?) spin (torque?) in the plane in a counterclockwise direction. That would make the plane tend to bank to the left. In the video I noticed that upon launch it does bank to the left. So this makes me think that the aileron & servo are better on the right side wing to compensate for the counterclockwise torque spin.

Can anyone comment on the physics of this?
May 02, 2011, 11:49 AM
Trapped in California
foamflyer's Avatar
Quote:
Wow, nice! Gotta build one. Thx for the build info.
(squints at foamflyer's avatar)....... what is that?
That is my RPG (Red Powered Glider). More info at http://www.foamflyer.info
May 02, 2011, 11:51 AM
Trapped in California
foamflyer's Avatar
Quote:
I'm fuzzy on my high school physics, so I'm asking that question. The prop spins clockwise, which would bring about a reaction (Newton's action and reaction?) spin (torque?) in the plane in a counterclockwise direction. That would make the plane tend to bank to the left. In the video I noticed that upon launch it does bank to the left. So this makes me think that the aileron & servo are better on the right side wing to compensate for the counterclockwise torque spin.
Interesting comment, and you're probably right, but it doesn't matter (to me) what side the aileron is on. In the video I can't really explain the bank to the left, other than it was the maiden flight and needed a little trim. It doesn't do that anymore.
May 17, 2011, 03:59 PM
low tech high tech
vtdiy's Avatar
Wow, Foamflyer, a sheet foam version of the So series! Excellent.
May 27, 2011, 05:41 PM
Bacon makes everything better
UberSpeck's Avatar
I love this plane! Would you consider it stable enough for a beginner?

Quote:
Originally Posted by foamflyer
I decided to apply some British markings to this plane, so I printed some with a color laser printer and attached them with yellow wood glue. Using a laser printer is better than inkjet, the color will not fade as quickly and is more immune to moisture. Notice how the large roundels on the top of the wing were cut to accomodate the steps in the KFm3 airfoil.
Jun 08, 2011, 02:57 AM
Bone Breaker
Lammergier's Avatar
Wow I wiped out one of foamflyer's twin boom Kf3 wings out of all blue cor. I'm really impressed with how if flys. The stall traits of the Kf3 are amazing. I can stand it up on it's wing tip in a tight slow turn and no tip stall. Foward stalls are mushy and predictable. I love the look. I made my booms square. Using all knock off gear I had on hand. I would not recomend it for a newbie. With no dihedril in the wing you have to stay on the stick all the time but it would be a good aileron trainer.
Last edited by Lammergier; Jun 08, 2011 at 03:01 PM.
Jun 08, 2011, 03:29 PM
low tech high tech
vtdiy's Avatar
Nice job Lammergier! Looks great.

I think you mean "whipped out" one of them instead of "wiped out" -- unless you crashed!
Jun 08, 2011, 03:44 PM
low tech high tech
vtdiy's Avatar
BTW, the So series do make great first trainers if the builder adds about 6" to each wing tip angled up to give polyhedral and more wing area.

Then eliminate the single aileron and cut a single big rudder into one of the vertical fins.

When ready to transition to intermediate training, cut off the wing tips, and add the aileron.

Important with these planes to check lateral balance as well as usual CG location. The lateral balance can be off either because of a single aileron, or equipment weight on one side of the plane.

A coin inserted in a wingtip can balance it laterally., if it's off.
Jun 08, 2011, 03:57 PM
Bacon makes everything better
UberSpeck's Avatar
Quote:
Originally Posted by vtdiy
BTW, the So series do make great first trainers if the builder adds about 6" to each wing tip angled up to give polyhedral and more wing area.

Then eliminate the single aileron and cut a single big rudder into one of the vertical fins.

When ready to transition to intermediate training, cut off the wing tips, and add the aileron.

Important with these planes to check lateral balance as well as usual CG location. The lateral balance can be off either because of a single aileron, or equipment weight on one side of the plane.

A coin inserted in a wingtip can balance it laterally., if it's off.
Thanks for the advice! I'll give it a try
Jun 08, 2011, 04:16 PM
low tech high tech
vtdiy's Avatar
Uberspeck, here's my old primary trainer set up that way -- solid wired foam instead of the new built up construction, but you get the idea.

Note the elevator cut away at the corner to clear the new rudder.

https://www.rcgroups.com/forums/show...=5#post7423538


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