Peabody Packet

[Glidiator]

Hi,
Anyone construct and fly this model by Walt Mooney. Got the plans from Aerofred mailer.
Seems a pretty straight forward construction. And since the motor sticks are just soils sticks and not hollow nacelles it is easier to build.
Would be happy if a flight video is available.
And any other suggestions regarding this model.
Have been doing indoor duration models but such models relieve the monotony of standard construction and add to the variety of one’s collection. Also made Bill Browns Yvette. Flies pretty well. And such offbeat designs are good examples to show during workshops to demonstrate the design possibilities.

[Glidiator]

Peabody Packet plan

[Glidiator]

Here is the associated article

Anant

[lincoln]

Looks like a fun project.

Around here, it wouldn't be legal for Bostonian contests, but maybe not everyone uses the same rules. Of course, the air doesn't care about that, so it ought to be a fine sport flyer anyway.

[Indoorflyer]

All the interesting designs by the guys who pretty much "invented" the category are not "legal" any more.  I'm comfortable with "Bostonian-like" models

[Glidiator]

Not aiming for competition. But models such as these give some relief from the serious construction of indoor competition duration models.
I also use such off beat designs as examples of the design possibilities when doing workshops with students. Made Bill Browns Yvette- flies great and looks unique. Made it Rubber Powered - will make a capacitor powered version also.
Always tell the students— you don’t need wings to fly— the design only needs to follow the aerodynamic principles to do so.
I make them fold the origami flying ring from a simple A4 sheet or make it from a used disposable mineral water bottle.
Anant

[Glidiator]

Some pics of the Packet
Covered with very thin plastic bag material. Will not warp components especially in the high humidity here. Did some modifications— the wing attached to fuselage with Rubber bands. Booms attached to wing with rubber bands. Inverted v tail attached at vertex with thin strong string knotted on very small tabs.
So can dismantle all parts for transportation.
Undercarriage yet to be attached.
Will be a challenge to trim it for decent flights.
A method of winding twin props and locking them till launch
release
https://youtu.be/VSz3xoAwkDg

Had a query.
Would I need to make props rotate in opposite directions. Plan or article does talk of this. If so would reversing the port side prop and winding in opposite direction do the needful.
Anant

[Glidiator]

Another attempt to upload pics

[dputt7]

Anant
          Very neat work, I wouldn't mind building one myself.
  Reversing the propeller and winding the other way would make the model spin in a circle. I've built a few twins for Indoor ,all Scale models, and used props that rotate the same way. I normally put in 50 or more turns in the outside motor and that ensures it continues to turn as the power runs down. Good luck.

[Glidiator]

Covered with very thin plastic bag material. Will not warp components especially in the high humidity here. Did some modifications— the wing attached to fuselage with Rubber bands. Booms attached to wing with rubber bands. Inverted v tail attached at vertex with thin strong string knitted on very small tabs.
So can dismantle all parts for transportation.
Undercarriage yet to be attached.
Incidentally have used the Paulownia wood for wing leading and trailing edge spars. It is much harder than balsa though a bit heavier.
For this twin prop it would be better to have counter rotating props. The plan and article does not say so.
If I reverse the port prop and give rubber anti-clockwise wind it should meet the requirement.
Your comments.
A method of winding twin props and locking them till launch
release
https://youtu.be/VSz3xoAwkDg

Will be a challenge to trim it for decent flights.

[Glidiator]

Anant
          Very neat work, I wouldn't mind building one myself.
  Reversing the propeller and winding the other way would make the model spin in a circle. I've built a few twins for Indoor ,all Scale models, and used props that rotate the same way. I normally put in 50 or more turns in the outside motor and that ensures it continues to turn as the power runs down. Good luck.

Thanks for the inputs. Will test fly soon and see how it performs
Or will small tab on the tail give rudder effect. Have done that for my capacitor model though that is single prop. Works well and can adjust radius of circle.

[dputt7]

  yes the trim tab will turn it OK but if there is a slight difference in power as they run down and this favors the inside motor then it will overcome the trim tab and usually crashes into a wall. The extra turns are just for safety and you will have to experiment to find the approximate number. Another trick with twins is to use a bit less downthrust on the inboard motor as this helps to hold up the inside wing.

[Glidiator]

Thanks dputt7 — useful tips.
Even on the capacitor model the circle radius keeps getting bigger as thrust and forward speed reduces.
As per plan there is no downthrust mentioned.
The prop hub is snug fitted straight into the boom. You recommend a bit of downthrust?
Lots of test flying required to arrive at best combinations.
Construction is the easier part of the story.
The trimming struggle is yet to come!
Anant

[THB]

I've never seen this model before - very interesting.

[Glidiator]

Finally got down to test flying this model in the restricted space of my cluttered drawing room after almost a year of building it.
Initial glide tests were quite promising. A couple of paper clips added to the starboard boom balanced the model laterally. Initial flights showed a bit of stall - so added some nose weight that corrected this problem. Added card tabs on each arm of V tail to provide for additional lift.
Initial powered flights showed a tendency to turn sharply to port.
Gave 50 additional turns on port motor to correct sharp turn as I wanted it to fly straight along the length of the room. Card tabs were up full 90 degs - the air flow in flight would bend them backwards reducing the elevator angle.
Test flight done with 3/32 rubber - loop hook to hook length - starboard prop 250 turns - port motor 300 turns.

Finally got a good straight flight across the room and recorded it in slow motion that gave a good idea of its flight performance. Could see it climb gradually after the halfway distance - would have picked up enough speed for the elevator tabs to take effect.
No damage done in the crash into the opposite side - Paulowina wood seems pretty strong.
Keen to do full power test flights with longer loops in large indoor space once they open up after the lockdown restrictions are relaxed. Will also try outdoor flight in calm air.

The Slo Mo video
https://www.youtube.com/watch?v=0BTm6zshuF8

Was taken at night- the light is a bit dim and the flicker is due to the LED bulbs that is seen only in slow motion recording and is okay in normal recording speed.