fabric control surfaces

[Hacker]

 

Here is my Typhoon rudder that was fabric covered. Not to repeat myself from my posting in GB but l laid tape in between the ribs and used Mr Surfacer to make the ribs. This is what l ended up with. l would like you guys input on this as frankly l am not satisfied with the results. it was not quite what l was hoping to acheive here. l think it can be done better but how??

 

hacker

[bdthoresen]

Hack- Love the work so far- Here is what I have done in the past-

 

I have scribed lines where the ribs are supposed to be. I use an Olfa P scriber, and scribe pretty deeply- I then superglue thin copper wire into the grooves, leaving about half of it exposed. I then use some Dope for covering Balsa models, and cover the control surface with Tissue paper (Not Kleenex, of course- the gift kind!)- I brush a liberal coat on the surface, then lay the tissue over it while still wet- it will shrink a bit, tightening the tissue. Once dry, I trim the excess and do the other side. You can also use the tissue cut into thin strips to replicate rib tapes. Prime as normal- You can also give it a VERY light sanding when dry to eliminate the fuzz if present. But do not use too much dope- it WILL eat styrene- Hope this helps....

 

 

THOR

[Edgar Brooks]

There's a popular misconception that fabric sags between the ribs; it doesn't, unless the worker makes a mess of it. If you've, ever, built a flying model, you'll notice that the paper, or silk, pulls tight, and flat, across the parallel (top) edges of the wingribs, only "sagging" where there are different pulls, (at the leading edge of the ribs, for instance.) The tapes aren't very prominent, even in full size, and certainly not in scale models. They are, simply, strips of fabric, often cut in dead straight strips, only a few thou' thick, which are doped over the stitches. The stitches resemble little bumps, under the tape. During the war, after the tapes were doped into place, the whole thing was given two coats, of half-strength, then three coats, of full-strength, dope. Probably because it's known as "shrinking dope," this myth has grown. I've sent you a couple of photos, of a Typhoon rudder, and I have more photos, of a Spitfire rudder, and the full process, of sewing, and doping, in progress, on a Swordfish. On all of them, only the stitches are (faintly) visible, with, occasionally the tape, faintly, as well. 5thou plasticard is too thick, to be in scale; in 1/32nd it equates to .16" which is a bit thick for fabric. Ordinary paper would probably do, but it is possible to find sheets of very thin plastic; 5 coats, of dope, tends to blur the edges, of the tapes, anyway, so (gently) running a cogwheel (some call it a "pounce" wheel, I believe) on the back should be sufficient to produce the "stitches." Sorry this is a bit long-winded, but it's a shame to see modellers doing unnecessary, fairly longwinded, procedures.

Edgar

[Hacker]

Thanks Edgar. l am just trying to get the "effect" to speak of. What they had orginally on the rudder was equilant to rope so l sanded it off, but this left the rudder rather blank looking.

 

hacker

[LSP_Matt]

Some good info going in here guys. Am looking forward to trying the copper wire trick.

 

Very interesting Edgar...nice to know how it was done IOT better emulate the effect on a model and interesting in general.

 

I guess the only issue when modelling is whether you're inclined to create a representation of the effect ( hence you may exaggerate the appearance deliberately) or you are looking to create a faithful scale repsentation. Then its becomes an issue of taste I reckon.

 

e.g drybrusing. Overly drybushed MG breeches, cooling jackets, switches, cockpit levers etc really make a model 'pop' to me. Its not accruate or a faithful scale representation at all really but it looks interesting and I quite like it. To others it might be overdone.

 

Cheers Matty

[Guest Paul Budzik]

While I will agree that a newly done fabric control surface can be done up flat it does depend on the amount of underlying support and the age of the surface when modeled on an "in sevice" a/c. I will admit that I am the first to avoid modeling something if you can't see it (whether it is hidden or just too small to see without a magnifying glass), but there isn't anyway of getting around this issue unless you want to tell everybody that your model depicts an aircraft that just came off the assembly line (I've never gotten away with that explanation yet and with the current trend of heavier aging, I don't think it would work now) Here are a couple of photos, one of which is pretty grainy, yet you can see the definite scalloping of the fabric between the ribs.

 

 

I think this represents this pretty well

 

 

Paul

[Hacker]

Mr Budzik How did you do your rudder on the Tempest?? The Tempest and Typhoon rudders are the same so this pic of the model one is good reference for mine thanks

 

hacker

[Edgar Brooks]

It's extremely unsafe to use photos of aircraft, in flight, when looking at fabric finishes. The cold, and airflow, will cause anomalies (witness the upward "quilting" effect, on Wellingtons' wings.) If you look at photos, on grounded aircraft, the tapes/stitches, though still visible, are far less pronounced. In fact, that model's rudder is nicely done, and should look much more realistic than most kit producers' efforts. I hope that everyone realises that I'm not trying to criticise (my own efforts wouldn't bear close scrutiny,) simply to clarify.

I saw a recent comment, on another site, that the tapes are impossible to see, and the author produced a photo, of a completely smooth elevator, to prove it. Unfortunately, he didn't realise that many aircraft, due to the expense of Irish linen, are being covered with synthetic materials, which don't need dope, but are heatshrunk, (after being glued, instead of stitched, to the ribs.) The heat, from an ordinary domestic iron, held a short distance above the surface, is sufficient to do the job, but needs total concentration, since the shrinking process continues, for a short while, after removal of the iron. One man, local to here, is ruing this, since his newly-covered fin ended as a mangled heap of wood & plastic, because he started daydreaming.

Tony Woollett's method, on his 1930s models, which, to us, always looked most realistic, was to make the rudder (or whatever) slightly undersized, but smooth, then skin it with 10thou plasticard; first, though, he would draw the ribs, on the inside of the plasticard, using an ordinary ballpoint pen. This gave raised "ribs" on the outside, which varied, in height, depending on the amount of pressure exerted. The card would then be attached, with fairly heavy-duty double-sided tape. It's a one-chance method, but he was good enough to make it work, in his favourite 1/35th scale. I've tried it, and, after a few (!) goes, got it right. The trick, since the pen stretches the plastic slightly, is to draw the pen across the whole item, then sand off the bulges, from the outside, where they're not needed.

Edgar

[Derek B]

Hi Dave,

 

Both Edgar's and Paul's methods are valid, as are their arguments for and against flush proud ribs - on the ground, they are generally as Edgar advocates, in the air, more in line with Paul's views (it mainly depends on the shape and function of the epennage - tailplanes are symmetrical, so even - high - pressure airflow, causing the fabric to push in slightly. Wing upper surfaces on the other hand create low pressure - suction - ares, which tend to cause the fabric to billow slightly).

 

All of the above approaches to creating ribbed tapes are valid and useful. Another easy methohd of reporducing these tapes is to have a perfectly smooth primed rudder. Using good quality masking tape, mark out the rib tapes, but in negative (i.e. only apply the tape to the areas in between the actual rib tapes). Using an aerosol primer, spray a few coats over the rudder. Remove the masking tape to reveal very finely raised 'rib tapes'. A final light sanding over these newly created rib tapes will help blend the edges into the rest of the rudder surface (I used this technique to very good effect on my Hurricane fabric wing masters for the aileron fabric tapes).

 

HTH

 

Derek

[Guest UMIRESIN]

Staggers in after carving into the wee-wee hours on a master , <--MAKING NOTE : WHEN OUT OF COFFEE FILTERS -DO NOT!!! USE BATHROOM TISSUE,ESPECIALLY THE SCENTED STUFF MAKES YOUR COFFEE TASTE FUNNY. ACK ! !

O.K. seriously I just want to throw in my 2 cents worth here also . Both Paul , and Edgars comments have creedence . In studying my all time favorite " civvie " aircraft of all , the Beechcraft D17-S " Staggerwing " of which i have more books on than is probably legal I noticed this aircraft shows both sides of this string on a single aircraft . On the fuselage in particular the wooden former / stringer structure is seen quite clearly in flight , or on the ground . yet on the wings which are fabric over airfoil former/stringer the fabric is so taught you can see very little sag .

On the rudder fin however of said beechcrafts i can clearly make out the inner structure shapes under the fabric . even light hides this at times . In the case of a " loaded " fabric surface as Edgar points out in flight I agree temperature changes plus airflow at times do pronounce that scalloped look . In this link this is once again showing both to be correct note in the pic that seems placed on the site rotated incorrectly of the rudder shows this best , and another pic shows a rather strangely located clear navigation light . ( rear root of the horizontal stabilizer ? ? )

http://www.hawkertempest.se/hendon.htm

Either way I agree with both sides of this string . one technique I have used myself other than the wire metod paul uses ( which i did on my Beech ) was i took a good grade masking tape , and pressed this to a scrap sheet of clean styrene . I then cut very very narrow " tapes " from this , and placed these on my piece . Then i sealed these down with a few coats of primer . After final painting , and the application of "dull coat " it looks pretty convincing .

[Guest Paul Budzik]

In the past I have used some of the other methods mentioned above, 1) building up a thickness of primer to simulate tape 2) thin strips of styrene that were sanded down etc. I think all the methods are valid depending on what seems to be most common for the prototype that you are building. In the particular case of the Tempest, as much as I tried to avoid it, any clear shot of the rudder evidenced some sagging between the ribs to a greater or lesser degree, in flight or not, and I knew I would get jumped about the lack of detail (and yes that's a consideration, like it or not, when you put yourself out there)

 

 

So looking at this photo, what do you do. The bottom of the rudder exhibits definite scalloping while through the bulk of the rudder you can plainly make out the ribbing and surface irregularity. You could make yourself crazy just simulating the rudder. I submit that you chose your poison and go with it. For me, I think I made the right choice in this case.

 

Derek, The rudder was done by scibbing lines in the rudder to hold .010 copper wire. The wire was affixed with cyanoacrylate cement. Additional gap-filling cyanoacrylate was added alongside the wire.

 

 

All was blended in and primed.

 

By the way, have you done the main undercarriage for the Tempest yet? If so, any pics?

 

Paul

[Guest UMIRESIN]

Your Tempest inspires me Paul . old school is the way i work too . I just cannot get the gist of working with photo-etch frets myself some use today . basically ? I can't see em good then , there is the cutting where a teeny tiny part flies off into the unknown just as my # 11 blade went through the fret ARG!

by the way , has anyone ever seen the Doering brothers model making websight ? These guys were almost scarey ! ! http://www.doxaerie.com/doering_brotherstwo.htm

 

These guys used wood , but mostly formed tin plate sheets WOW ! ! Is it me ? , or does that one Vultee design resemble a Ki-61 " Tony " ?

Maybe off the topic , but I wanted to share this site . check out all links & pictures on the home site especially doering bros 1 -2 - and 3 it's unbelievable ! !

[Guest Paul Budzik]

I don't know, I'm blown away by a lot of the cockpit stuff and radial engine detail of these new aftermarket products. I think as long as I can see it on the finished model without magnification its wonderful and a timesaver. But if the detail is hidden or I have to hand someone a magnifying glass and a penlight and direct them to a specific detail, I have to admit that I've lost some of my interest. To many nice models I want to build. I think after this Tempest, I'm going to do some of those 1/32 Trumpeter kits and if there is some good aftermarket, then I'll give it a wirl.

 

Paul

[DMurph]

I agree with you Paul, for me when I build a kit I like to add as much detail as I can. One it is really only for me I enjoy the challenge of the build and I like the detail even when it is hard to see. That is why I take the in progress shots. so as to show others.

 

I also believe a great exterior paint job and weathering is most important. Maybe itis like an old asian meditation thing if I take my time and pay as much attention to detail on the inside then the outside will follow.

 

Besides with the cost of kits I want to get the most out of them!

 

Cheers Murph...

[Hacker]

 

Derek, The rudder was done by scibbing lines in the rudder to hold .010 copper wire. The wire was affixed with cyanoacrylate cement. Additional gap-filling cyanoacrylate was added alongside the wire.

All was blended in and primed.

 

 

Paul

 

Hmmmm. Sounds better then what l did. besides now that l seen your tempest rudder l can still modify my typhoon tale to look a bit better then it does now

 

hacker