Working cowl flaps

[Craig Spence]

Hi all,

After researching my next build (Brian Taylor P47 D 76" I come across a few videos of working cowl flaps.

Has anyone done this & would it be feasible on a 76" model?, also I had an idea of creating smoke to come through the cowl flaps to imitate soot escaping but again don't know if & how I could do that.

Thoughts anyone?,

Feedback greatly appreciated.

Cheers

Craig.

[Simon Chaddock]

"to imitate soot escaping"

I am not quite sure what effect you are trying for.

The only soot will come from the engine exhaust although on start up most is oil smake. Only air passes out of the cowl flaps.

Or am I missing something?

[Trevor Crook]

Craig, FMS have put this feature on their 1400mm T28 foamie, so it's clearly feasable. Finding an example to study would be ideal, but there are doubtless pictures and videos on line. Seems like a lot of effort for a feature you will only really see working on the ground, but I guess the same can be said for other intricate scale features. Good luck and show us the results if you go ahead.

[Shane Sunday]

Working cowl flaps is a great idea even if you only see it on the ground. It is however a lot of work getting the geometry correct. There is a fellow Drice on a scale forum who has done it via 2 servos squeezing a wire that has been threaded through tubes glued to the inside of the flap. The flaps must be afixed in such a way that they naturally sit open of coarse.  That in itself would be a chore. But sure it's all a matter of how much you want something. Give it a try.

Edited By Shane Sunday on 08/04/2016 23:12:23

[Craig Spence]

Cheers for the feedback gents,

I saw the same video with the wire, also with wire & tiny push rods. Both worked very well.

I didn't know the big foamie done that, one of the lads at the field have that model so he'll have to demonstrate & I'll have a look at components.

Simon, I know the flaps are for cooling but what I am trying to imitate is start up (oil on start up like you see on the films) also I read that they most commonly used them on high power/ low speed?, not quite sure what that means but I'm assuming take off/ landing?.

Also if they ever had engine problems/ overheating I'm sure they opened the flaps to cool the engine, thinking back on old films im sure black smoke used to plume from the cowl when they had engine bother?.

I'm no expert, just researching & looking for help on ideas.

Cheers gents,

Craig.

[Paul C.]

Initial thoughts that this may be a step too complicated for me 'novice' but a picture of the set up would be great if possible

Paul.

[Craig Spence]

I'll have a look again tomorrow Paul as I'm turning in soon, but it's on u tube I think under P47 D working cowl flaps, something like that anyway.

It's time consuming & requires a lot of patience but not that difficult & looks great in my opinion.

Cheers.

[cymaz]

OO guage engines have systems that reproduce smoke. Now wether that system is viable or the amounts sufficient is anyone's guess

Here

Edited By cymaz on 09/04/2016 06:28:00

[Jez Harris 1]

Matt (Mudders) did a beautiful job of cowl flaps on a YT Zero over on RCMF...

 

Might be worth asking him how he did it.

 

Jez

Edited By Jez Harris 1 on 09/04/2016 09:16:11

Edited By Jez Harris 1 on 09/04/2016 09:17:03

[Bob Cotsford]

ref the 'soot' - a quick sample of some 'P47 startup' google results indicate that all but one YouTube videos show all the smoke being from the exhausts(in front of and below the wing LE just behind the cowl flaps), the exception being a Planes Of Fame machine that did expel some muck from the top of the cowl - backfire?

ps - those engines spin a loooong time before firing up!

Edited By Bob Cotsford on 09/04/2016 09:36:27

[Former Member]

[This posting has been removed]

[cymaz]

I had the wrong idea as well. Oops

[Craig Spence]

Matt did indeed do a good job there, I also love the sliding canopy!.

Plenty of ideas now, just a bit (hours upon hours) of research now.

Cheers fellas.