"MDC" F-14 pusher build

[mjcp]

Hi all,

I'm mid build of an F-14 profile pusher, following the plans from RC Groups for the MDC F-14 from c. 2005->

Thought I'd pop a few pics up as i go

I'm building from foam board (the original plans are for 6mm depron)

the wings are a flat section, no airfoils! They have a carbon spar and pivot around the large circle in the last pic. The servo is a 9g metal gear one that I had on the shelf. alas its now stripped itself after I got some glue outside of the hinge when attaching the top deck.

Motor and power will be 2200kv running off a 1500 mAh 3s (50-70C). Control is via elavons on the tail only (with throttle and wing sweep channels)

mjcp

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[mjcp]

Here's the swing wings in action:

https://youtu.be/h2yWAIpARv0

mjcp

 

[ClearSkiesCalmWinds]

Very interesting.

 

[mjcp]

Made some more progress this evening...

Motor mounted and prop fitted. Its a *very* tight fit... it needed a little bit of foam board trimming to stop it fouling!

Got the upper deck fitted without glueing the deck to the wings this time and remembered to change the servo before fitting too... Its good to leave a note for yourself sometimes

I've run out of foam board now, but managed to squeeze a single tail out of the largest remaining bit.

mjcp

 

[mjcp]

Got the tails and elavons fitted last night...

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[wilmracer]

Nice! It should fly great.

 

[jpot1]

Very interesting work. I'm curious what the "circles" are around which the wing pivots? As well anything special that you had to do when converting from the depron based plans?

Looks great!

 

[mjcp]

Very interesting work. I'm curious what the "circles" are around which the wing pivots? As well anything special that you had to do when converting from the depron based plans?

Looks great!

The pivots are just foam board, I cut out the circle and re-used the centre of the hole as the pivot. The outer edge of the hole is lined with tape to neaten up the edge.

Then there's a 1mm thick layer on top of the circles to give a slight clearance between the wing and then upper deck:



_________________________ Upper deck
......... ======== ....... 1mm Spacer
-------|V|-----------------|V|------ Wing VtapeV Pivot VtapeV Wing
_________________________ Lower deck


mjcp

 

[mjcp]

Time for a little colour... Air defences grey and white underside. Graphics came from a guy on RC Groups and are designed for another F-14 on there, they are kinda large but trim down fine for my purposes.


mjcp

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[mjcp]

Had some more time today to work on the F-14, I have re-printed the graphics at 80% this time and they look a bit more scale.

I also had a bit of time to work on the canopy too. I've opted for a simple all natural/white paper for the glass parts and black pen/paper for the Jolly Roger's black canopy outline.

mjcp

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[Crash and Burn RC]

That is awesome!
I was thinking of building this plane, but decided not to.
I might have to try after see yours.
make sure you post a flight video!
Colin

 

[mjcp]

Maiden was a handful immediately after launch... *WAY* too much pitch input... It looked like I was some sort of 3D wiz 3-10 feet off the ground EEK!

However, I managed to get it level and pointed in the one direction to climb out and get some altitude... Then it flew great (with smaller elevator inputs from my dumb thumbs)


Next up were some high speed/low speed fly-bys and rolls then decided to sweep the wings. They worked sweeping back and roll rate was fast but controllable.

Then I tried to sweep forward but nothing happened.... Err... Uh-oh!

Managed to land it in one piece and discovered the sweep servo was stripped.

I was able to sweep it forward by hand and it was able to stay swept forward for the second flight. I dropped my rates from 80 to 60 on the elevator and all was good for flight 2!

Big grins

mjcp

 

[mjcp]

F-14 early flight video

Managed to get someone at the flying site to video a flight today...

F-14 in flight:

Youtube Video

mjcp

 

[Crash and Burn RC]

Managed to get someone at the flying site to video a flight today...

F-14 in flight:

Youtube Video

mjcp

That flight looked awesome, and so does the plane!
Seeing this build makes me really want to build one.
Can you give your opinion on the build and flight characteristics?
I love the paint scheme too.
Colin

 

[mjcp]

(sorry for the delay, new job!)

It flies great...

High alpha/low speed it can do some pretty interesting things, but NEEDS airflow over the tail to do them... With wings fwd and airflow, you have control!

Acceleration is great! launch with 3/5 or so throttle, move your thumbs and firewall it, you can go vertical in a blink.

Roll rate is fast, like a drill when wings swept, it rolls pretty true to centre with little yaw as there's no ailerons.

Pitch changes are brutal, at speed, with prop wash over the elavons, its able to do a 180 through the vertical in almost its own length! I'm a bit worried I'm going to eject the battery its that quick. (my battery is a snug fit and there's a mag hatch and hinge holding it in)

I've stripped the wing sweep servo, so I'd suggest a 15g/all metal gear mini servo for that, you may need to alter the designs slightly to fit this.

I fly it with a 1500 3s, my battery beeper goes off after 30 seconds of full power... so could do with an 1800 or 2200 ? If I ignore the beeper and reduce the full power back to cruise/play, I get a good 5 mins before the beeper comes in.

mjcp

 

[CrossedUpChris]

I'm gonna build one of these when I get back from my holiday. I want to make it really fast so was going to buses a 28/36 2200 kv motor. Do you think this would fit?