Warbirds Replicas P51 Mustang

[RICHARD WILLS]

Posted by Phil McCavity on 30/12/2020 11:37:00:

*There was a well known forum member who liked to experiment with designs and materials who was held in high regard by many here, he was using laminating film and promoting it's qualities for years even whilst Solarfilm was still in production. Unfortunately he appears to have disappeared."

 

An experiment that went wrong ?

And Phil, did you mean to say, he appears to have disappeared ? Very clever , I'd take my hat off to you , if I was wearing one

 

Edited By RICHARD WILLS on 30/12/2020 11:58:47

Edited By Martin Harris - Moderator on 19/01/2021 13:54:16

[Phil McCavity]

His experiments with laminate film up to then were successful Richard, he used it on sheet and open structures and pushed it as a better alternative to other film coverings. He did find on open structures that condensation forming inside and between the rib cells was a problem which he overcame with small ventilation holes to allow for drying. I have tried to find his old posts but failed.

[RICHARD WILLS]

Thanks Phil , I can understand you struggling to find him ,

what with his constant appearing and disappearing .

Must be like trying to chat with the Cheshire Cat from Alice in Wonderland .

Nice fella , but very elusive .

[Graham R]

Posted by Phil McCavity on 30/12/2020 12:16:09:

His experiments with laminate film up to then were successful Richard, he used it on sheet and open structures and pushed it as a better alternative to other film coverings. He did find on open structures that condensation forming inside and between the rib cells was a problem which he overcame with small ventilation holes to allow for drying. I have tried to find his old posts but failed.

It probably happened with Solarfilm but being opaque it wasn’t visible.

Its good to see that laminating film is being used. The price of normal model film is now just ridiculous (since Solarfilm have gone). It is worth getting to know this material well before using it for real. Yesterday we used some 36micron to add some strength and protection to a friends very light fpv glider leading edge. What a difference.

Paul, I like ‘The Office’ on your P51. I am trying to do something similar for the Spit. Unfortunately not much can be done with the bf109 du to it’s constructing method.

Did I see a box of celebrations in one of your pictures. Must be a shortage of Haribos due to everybody building during the lockdown.

[Paul Johnson 4]

Posted by Graham R on 30/12/2020 13:43:40

Did I see a box of celebrations in one of your pictures. Must be a shortage of Haribos due to everybody building during the lockdown.

Empty mate your too late...

Did a trial fit of the tail now the wing is finished.

All sanded covered, hinged and glued together now I can use the wing to check alignment.

Still a lot to do to finish the Fuz but see the light at the end of the tunnel... Pilot looks indignant needs painting.... still.

[Paul Johnson 4]

Well here in the undergrowth we find a new P51B taking it's first steps a little unsteady on it's spindly legs.... look out it's being stalked by a predatory reindeer...... yes I have lost the plot.

[Paul Johnson 4]

Tail infill trimmed

[Paul Johnson 4]

Look at the flap droop... just like the real thing.

Did I say flaps? I think they maybe air brakes...

It was sure worth the extra work to have no gapping slit trench on the top of the wing.

[Jonathan S]

Looking amazing Paul, I hope I can do mine as 1/4 as good as yours.

I am still building the left wing. Struggling a bit with some of the basics.

[Paul Johnson 4]

You'll be fine, don't try to rush to 'keep up' the real magic happens when it gets painted.

[Jonathan S]

Ok,

I am making progress with the wing but have some more stupid questions as I make my way through the construction, I am sure its just because I am not got it clear in my head how it all works yet. I will post the questions here and use my thread as a photo journal of the progress maybe.....

Ok so:

1. Is the Arrow shaped flap spar glued to R7 ?
2. When is the best time to attach R1?
3. When do you glue in R2A and should it be at the same level as R2 mine seems to be a bit low when I test fitted it.
4. My R6 does not have the nice flap curve is this correct and if so which side should R6A go ?

[Eric Robson]

Hi Jonathan, 1 the arrow shaped spar is glued to R7 as I explained on your thread.

2 when you are ready to sheet the wing

3 R2a should be the same height as R2 the gap is for the flap actuator which is glued on later, you can use the part as a spacer to make sure it will fit later on Don't get any glue on it

4 if you look at the picture of the flap I sent on your build thread you will see the end ribs are R2 A and R6A and they fit on the inside of the respective ribs.

I brought up the issue about the aileron spars being too short on the previous page Paul and I have resolved this problem in our own ways If you follow what he has said on the subject you will not go wrong.

[Jonathan S]

Eric,

Thanks for that. Just to ensure I fully understood what you guys did. You cut off the end of R6. Then attached the removed part to the aileron spars. Then attached R6a to the flap as per the instructions.

(Any advise on where on R6 it is best to cut?

Also I noticed on Paul's pic he had some triangles on R2a what are they for?

Thanks

[Eric Robson]

Hi Jonathan;

The triangles on Pauls' flap are gussets to give support to the rib R2a, you will notice the gap where the actuator arm fits, without the gussets the only attachment point is a small notch on R2a . If you use the gussets (made from scrap 1/8" balsa) don't glue the front of the rib to the forward gusset as this is only a stop for the up position of the flap and also a support for the static flap spar.

the aileron ribs are all marked with cut points, when cut out they form an inverted V to allow the aileron downward movement . Cut R6 flush with the fixed wing spar then make the other cut flush with the aileron spar taking care not to damage the soft balsa spars ,it is best to use a fine razor saw for this.

[Paul Johnson 4]

Well guys it just had to be done... added a radiator cowl door.

used some scrap 1/8" ply from the kit to form the sides and the piece of balsa removed from the cut out.

Two reasons I added it, one it looks the part and two the incoming cooling air from the chin inlet will create a through draft to help keep all the electronics cooler.

[Paul Johnson 4]

A small 'GOTCHA' to be aware of is where I passed the snakes through the rear of the fuz I took the elevator snake to the top of the balsa but not through the ply inner.

Now this is fine for the rudder as all aligns well but for the elevator it's a little too low.

When you come to do this you might want to go a little higher through the ply or as in my case made a little offset rod to connect it up. It needs to go on the very end of the horn. This still gives lots of elevator movement so no worries of not enough throw.

Most of my warbirds usually have no more than about 5mm to 8mm of throw for normal flying. That's plenty for most scale warbird flight.

[Paul Johnson 4]

In case anyone is interested I obtained a set of these cheapy taps and dies to make all my threaded rods where needed.

[Graham R]

Morning Paul and all WR builders,Happy New Year to one and all.

Your P51 is coming along nicely,I thought that you may have put the elevator torsion bar inside the fuz or is there not enough room.

Is the radiator cowl door able to open and close via servo. that would be cool!!!

I have not looked at the building instructions yet, the photos on here makes the flap assembly look a bit complicated along with adjustment for the spar that is too short.From what I can see in the pictures - the laminate covering looks good. Did you manage to get it down without wrinkles?

[Paul Johnson 4]

Hi Graham,

Happy new year to you too.

Yes on the wings using 100C first then 130-150c to remove any stubborn ones. Yet to try it on a complex curve e.g. Fuz. If you go straight in with the hot settings it seems more likely to wrinkle.

"Is the radiator cowl door able to open and close via servo. that would be cool!!!" .

[Ron Gray]

Personally I think it largely depends on how you apply the lam film to the surface you’re covering. I tend to use the ‘normal covering film’ method of sticking down to one edge, then stretch film across surface to remove any wrinkles then stick to opposite edge. Once sealed all round then lightly apply iron (150 degrees) to film surface to shrink it then go back over it again with iron and smooth down with cloth or iron. The other method I use on smaller surfaces such as tail feathers is to seal to one edge then gradually move from that edge to opposite edge smoothing down as I go, I use a lower heat setting doing it this way but do go over it again with a hot iron pressing it lightly to the surface increasing the pressure once I’m happy it’s stuck. Obviously I’m referring to balsa surfaces rather than foam which is a different ball game!

The other thing I find good is to use a ‘woodpecker’ which forms little indents (pricks, if I’m allowed to use that word) in the balsa. This tends to prevent air getting trapped forming bubbles.

Edited By Ron Gray on 03/01/2021 14:32:09

Edited By Ron Gray on 03/01/2021 14:34:55

[Paul Johnson 4]

Ron,

Many thanks for your advice, how did you find using the laminate on a concave surface? (wing root fillet). I am yet to try that, all tips appreciated.

[Ron Gray]

I’ve got various tools to help me in those problem areas. For concave surfaces, wing roots, I use a piece of copper tubing which I heat up then stick down the middle of the curve then work my way out to the edges agin using the tube tool. The heating of it is a bit hit and miss to start with and I’ve used a variety of heat generators, sealing iron (turned up full), hot air gun, blow torch (too hot!) but in the end I use my mini heat gun (HobbyKing special) as I can concentrate the hot air flow so that it warms the tube up quite quickly.

The tools I use for these hard to get at areas are, copper pipe (plumbing) off cuts, 12mm, 15mm, alloy tube 6mm, 10mm, sheet metal (1.5mm) bent to form a nice smooth angle for getting into the corners of tailplane fuse/fin joints.

Looking at the Dec BMFA news, Tony Nijhuis uses similar tools and methods, I must be doing something right!

[leccyflyer]

The laminating film looks great on Paul#s Mustang - very impressive and a technique I haven't used before. Purely as a result of this thread I've ordered up a trial pack and will try that out before committing to it on a WR build. Thanks guys.

[Paul Johnson 4]

Ron, your an inspiration... just though of using this tool.

Got it off ebay for £20.

As i use it for wire heat shrink a lot the curved shroud gets hot enough to do the job, just tried it on some scrap laminating film i have at work...

[Trevor]

I use this iron:

**LINK**

Its curved sides are ideal for wing fillets, and you still have full temperature control.

Trevor