w1nd6urfa

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Finally i got round to starting my Spitfire build.

First task: I found the radiators to be very thin fiberglass, since I want to scale them up opening the front and rear, and hating the idea of them breaking during transport I decided to make molds and pull better copies.

w1nd6urfa

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On to the wing control surfaces. As I mentioned a few pages back, i don't like control linkages sticking out on such an iconic plane.

The following photo is from page 3 (another member's build )

w1nd6urfa

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So I studied how Brian Taylor did the control linkages on his plans
The flap actuator is very scale: when extended it pops up over the wing as per full scale

w1nd6urfa

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Some CAD work to bring Taylor's plan onto the TopRC geometry:

w1nd6urfa

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My kit was an early 2015 delivery, did not include the servo "L" brackets, had to make some from 2mm alum angle

w1nd6urfa

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I shaped the horns according to CAD plan to be placed internally

w1nd6urfa

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Dry fitting

w1nd6urfa

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w1nd6urfa

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3mm airply beams epoxied between ribs to mount servo on:

zrooster

Outstanding! A build by someone with some actual building skills (as opposed to me ). I'll continue to post my progress on the theory that someone at my "level" might find it useful...out of the mouths of babes and all that.

Look forward to seeing your progress!

G

w1nd6urfa

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You're making me blush!

Actually I was going to build a Taylor Spit, got as far as dry fitting the wing ribs together and then this beautiful kit appeared
What I mean to say is that I had done a lot of homework prior to this

zrooster

I wish I had the time and skill to kit or scratch build, but the fact is it's taken me over 6 months to put this ARF together due to time constraints alone... I'm really not far from the maiden now (here it sits next to my ESM Dora):


but we're talking no frills, just the ARF as it's described in the instructions... I do plan to do some weathering and paint a few details eventually. I'm also tempted to change the insignia from Johnny Johnson, to another spitfire icon: Douglas Bader, Don Gentle, Bob Hoover (shot down in a spit), or John McGee (author of high flight)... Leaning towards Bader... That'll be post maiden, though.

Are you you planning on doing anything to the cockpit?

w1nd6urfa

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As you wisely suggest, all detailing, panel lines, rivets, painting, cockpit etc will be done post-maiden

I'm curious how yours will fly with the 55cc and 4-blade.
I plan to use a Moki 30cc and 2-blade 18x10

zrooster

Sorry, I misspoke. I've got a 35cc in the spit (53cc twin in the FW next to it). I'll maiden it on a 2 blade prop as insurance, but I ran the 35 with the 4 blade on my test stand and there was only a loss of about two pounds of thrust. I measured ~16 pounds (this is a low number due to the inefficiencies inherent in my test stand) with a 2 blade 19/10, and ~14 pounds with the 4 blade 17/8. The plane should weigh ~19 lb all up, so that should be sufficient thrust for everything except sustained vertical climbs.

As a note chris923 posted here that he's running a DLE 55 with a biela 19/8 4 blade...in fact, we're running the same spinner/prop combo, except he's running a bigger prop to harness the bigger motor... I was hoping to minimize the size of the hole in my cowling...

w1nd6urfa

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Oops! the 4-blade prop caused my confusion

Chris923, have you flown yours yet?

w1nd6urfa

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Finished the flaps setup

If you do this mod (and unless you have tiny fingers!) you need the special tool shown in the photo. I cut the 2mm bolts to 8mm length and swapped the ny-lock nut with a standard (thinner) nut

w1nd6urfa

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That's good enough for now, I will cover the hole with Solartex covering for the time being, the swinging indicator door will be done post-maiden.

chris923

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No, much to cold and wet here. Maybe late April. Several months ago asked this forum if anyone had a set of suggested throw for the flight surfaces ( Manuel has none) I haven't heard back from anyone flying yet.

I run the same 4 blade on a DLE55 in a TF P51 No issues, that is a heavy plane then this spit.

ForcesR

Chris923; I have the H9 30cc Spitfire which is the same size as your Top RC Spitfire. The recommended throws on the H9 is what I started with and I adjusted the throws after flying to my liking.

Ailerons: Low-16mm up, 14mm down, 20% expo; High-25mm up, 22mm down, 20% expo.

Elevator: Low-10mm up, 8mm down, 20% expo; High-17mm up, 14mm down, 20% expo.

Rudder: Low- 32mm right/left, 20% expo; High-51mm right/left, 20% expo.

Flaps: Mid-22mm down, Full-67mm down.

Roger

chris923

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You the Man! Thanks a bunch Roger!

zrooster

Thanks for the help, Roger!

w1nd6urfa

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These are the throws of the real Spitfire IX (from the well-known engineering book):

w1nd6urfa

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I started the CAD plan for the ailerons. I browsed the Brian Taylor plan and remembered that it uses a very sophisticated triangular horn mechanism to simulate the real Spitfire linkage and have it fully hidden in the wing.
Some people have built it this way:

w1nd6urfa

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I decided it couldn't be done without serious surgery to both wing and aileron, so my plan is simpler and the pushrod partly exposed

w1nd6urfa

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To get the scale throws (26 deg up, 19 down) I need to figure out a mechanical offset.
Anyone remember the trig formulas, sine cosine?