1/18 Spitfire Mk. XIVe - Race #80

[lunarhighway]

I vote for a deflected rudder, if you do a google search on the spit xix you'll find quite a few recent pictures of airworthy examples,apparently even a small offset of the rudder, can either cause the rudder balance to appear shorter or even longer than the fin.

[airscale]

evening all..

so I got stuck in to the rudder after much banging around trying to make the right one (thanks all )..

..first I transferred the plan onto the brass core, cut it out and used it to score where all the features are.. I also scaled the monforton plan for the pointy rudder so I could nick the cross section profile for the width and shape (I am dangerously assuming it to be roughly the same...)..

..cut out the profiles in brass so I don't sand through them and got some bar stock to make the rounded leading edge..

..assembled these and you can see how the brass cross section will define the shape..

..there is some quite complex structure behind the leading edge so I stuck two bits of bar stock together with a couple of light spots of CA so I could shape both at the same time..

..cemented those in place and built up the counterweight at the top and the thin edge liner too.. I also cut where the trim tab is so I can make it as part of the rudder and break it out at the end (he says hopefully..)

..I pondered how best to do the ribs and decided on coffee stirrers as they are wood and should bond well to the solartex I want to cover the rudder in,, cut them to shape and added both sides..

..and all ready to cover with solartex. This is stuff used for R/C aircraft and is heat activated with an iron to shrink and stick to the structure. I tried cutting out the shapes as seen here but it shrinks too much for that. I also had to add more wood around the trim tabs to close them off and get a good bond all round. It took 6 - 8 attempts as it's not easy when the structure is this small, but after getting the edges stuck and working to the middle I ended up ok in the end...

..and the mainly complete rudder.. I added the tail light but am not very happy it is the right shape...

..the material effect and very slight sag between ribs is good in real life, though difficult to catch in a photo

..need to work out how to detail it with rib tapes and the bumpiness you see where the tape is over the screws fixing the linen to the ribs..

..thats enough for today..

TTFN
Peter

[rob85]

Nice work on getting to the bottom of the tail issue. The fabric covered rudder looks amazing, your doing a great job of this

Rob

[Max Headroom]

Coffee stirrers! That's something else we'll need to squirrel away as 'a useful thing'.

Inspirational stuff.

Trevor

[John Aero]

Peter

Just a point I can't see clearly from the photos, is your fin post hollow? The rounded edge of the rudder is hinged to the fin post which is then shrouded either side to the hinge centre line by the extended fin skin.

The fabric is not held on by screws but stitches of linen cord which is knotted every 3" (I think) with a double knot every 18". The cord is led along the rib on the top of the fabric, sewn/passed right through to the other side around the far rib and back, under the cord tied in a special knot and then the to the next stitch 3 inches further along, ad infinitum. The process is finished by a further strip of fabric 2" wide with serrated edges doped over the string along the rib. Some manufacturers did use screws but with channel ribs and metal over strips but not Supermarine.

John

Edit added this.

[airscale]

Peter

Just a point I can't see clearly from the photos, is your fin post hollow? The rounded edge of the rudder is hinged to the fin post which is then shrouded either side to the hinge centre line by the extended fin skin.

The fabric is not held on by screws but stitches of linen cord which is knotted every 3" (I think) with a double not every 18". The cord is led along the rib on the top of the fabric, sewn/passed right through to the other side around the far rib and back, under the cord tied in a special knot and then the to the next stitch 3 inches further along, ad infinitum. The process is finished by a further strip of fabric 2" wide with serrated edges doped over the string along the rib. Some manufacturers did use screws but with channel ribs and metal over strips but not Supermarine.

John

That is a very timely post John - and a very useful note about how it is done on the real airframe - would be intersted in what you think about the test I have done below. The fin itself is short in width by a few mm so the litho skinning will run out over the edges of the fin post and be the shroud around the rudder leading edge (thats the plan anyway!)

It was a beautiful day today so only fiddled about a bit ..started by sorting the light on the rudder...

..then I found an article by David Glen on rib stitching and thought I would try it..

basically you use a notched template to make a thread weave on double sided tape and cut thin strips along the thread length with lots of tiny sections of the lateral threads..

I didn't have any double sided tape so I used Tamiya tape and washed the lot with diluted contact adhesive which seemed to work well..

after cutting a strip (not as thin as I should have), I taped it down with tamiya tape onto a test bit of solartex and shot some silver dope..

the stitch spacing is too close on the test, but what do you think? convincing, or over scale?

TTFN

Peter

[lunarhighway]

To me it looks about as good as it will get! one thing i noticed is that you also covered the trim tab. I assume you will still separate this somehow? as this is a sepparate hinged item and the seems are fairly noticable up close you can even see trough as can be seen in the XIX picture... also i'm not sure about the XIV, but the XVIII trim tab was metal covered i believe, so give it's size i think the xiv's might be too

Given your exceptional attention to detail i'm sure you have a plan for this, but i though i'd mention it before you would perhaps have to destroy some hard work and details you're putting into this rudder.

Edited June 5, 2016 by lunarhighway

[airscale]

To me it looks about as good as it will get! one thing i noticed is that you also covered the trim tab. I assume you will still separate this somehow? as this is a sepparate hinged item and the seems are fairly noticable up close you can even see trough as can be seen in the XIX picture... also i'm not sure about the XIV, but the XVIII trim tab was metal covered i believe, so give it's size i think the xiv's might be too

Given your exceptional attention to detail i'm sure you have a plan for this, but i though i'd mention it before you would perhaps have to destroy some hard work and details you're putting into this rudder.

thanks for keeping me straight! - yes the trim tab has been built to (theoretically) be cut out later when all the stitches & taping is done. It is only really the solartex skin to cut through and then it should bend and break free as I cut the brass and seriously weakened what was left..

we will see

[John Aero]

Yes it was a rare beautiful day, so it was hood down and we went off to meet my granddaughter in town for a long lunch

I don't really like commenting on such exquisite workmanship but the jigged thread web is similar to making climbing rigging for model ships. I feel that the test piece is over scale. In 1/18th scale the rib tape would be approx 2.5 mm wide. I've only done this in 1/48th scale and I cheated by using strips of decal on the master as rib tapes and then on the female mould scoring fine lines on the indented moulded rib tapes and then ran a roweled wheel (old sharpened watch cog) along the tapes so the little points looked like the knots.

Perhaps a modification of this might work in your case. Lay very thin, glued on brass etch thread with knots along the rib positions and then use decal strips over the threads with Microsol to suck the tapes down. The Etch artwork could then become a standard part of your armoury.

John

[gingerbob]

and remember, knots only on one side, but thread and tape on both. I agree with John- my first impression was that it looked a bit "bulky" for scale. Do you have a friendly neighborhood Spitfire you can go examine?

bob

[xffw45343tg]

A question that will reveal the cosmological scale of the gap in our skills:

How do you even manage to cut brass sheet so accurately? I see in the pictures some evidence of laser-like marking out, but the piece for, say, the rudder or wing trailing edge look perfect - like they've been die cut. Something tells me that the junior hacksaw and blunt files in my toolbox would be of little use...

Kirk

(Watching in awe)

[John Aero]

Just had a silly thought! Doesn't someone do 1/35 scale etch Barbed wire in straight lengths? ------x-------x-----

John

[airscale]

evening folks

thanks for dropping in and for your encouragement

and remember, knots only on one side, but thread and tape on both. I agree with John- my first impression was that it looked a bit "bulky" for scale. Do you have a friendly neighborhood Spitfire you can go examine?

bob

thanks Bob - I wish I did have access - I might ask Boultbee Aviation at Goodwood actually as that is pretty local. I did check the close-ups I have of a XVI at an airshow (one below) and could definately see knots (or at least bumps) both sides - am I missing something should the bumps only be on one side on an original unrestored rudder?

A question that will reveal the cosmological scale of the gap in our skills:
How do you even manage to cut brass sheet so accurately? I see in the pictures some evidence of laser-like marking out, but the piece for, say, the rudder or wing trailing edge look perfect - like they've been die cut. Something tells me that the junior hacksaw and blunt files in my toolbox would be of little use...

Kirk
(Watching in awe)

many thanks for your kind words Kirk - with the brass sheet I mark it out with a scalpel & steel rule, hold it in a folding tool and cut it with a circular cutting disc or slitting disc in my dremel - you can get nice and close with the cut and if there is any waste you can just grind it away as you go

Just had a silly thought! Doesn't someone do 1/35 scale etch Barbed wire in straight lengths? ------x-------x-----

John

thats a good one John! I will have to look into that as I haven't settled on an answer yet

..so, I am still working on the rudder and trying to make it look like this..



..there seems to be some variation in the size and appearance of the rib stitching so I have been trying different things and to be honest I am not sure I have hit on the right combination yet..

..before that though there is a lot of rib tape all over the rudder anyway, so I have been trying to unpick the order these are laid down and start setting them out as the actual rib stiching & tapes appear to be the last to be added,,

..I used tamiya tape and while I would love to have been able to get the 'pinked' edges its just not possible so I stuck with just straight cuts,, here I am also starting to break out the trim tab..



..more and more tape added and the trim tab recess being lined..



..now pretty much finished the foundation tape..





..and finally to the tapes... still debating - I was on number 3, but now I see the close-ups I am not so sure..maybe number 5 is more subtle..



any thoughts? ..I will try a few more things - I might try CA blobs on a wire as well actually..

TTFN
Peter

[Pastor Rich]

Hi Peter,

Yes, I agree that #3 looks good but #5 is more subtle. #4 seems a good in-between but both #4 and #5 lack the spacing between knots that #3 has. Overall I think that #1 looks the best for shape; but is too large for scale. (Hopefully my TLAR tool is properly calibrated -- That Looks About Right)

For what it's worth!

Awesome being privy to modeling on a new level!!!

PR

[xffw45343tg]

many thanks for your kind words Kirk - with the brass sheet I mark it out with a scalpel & steel rule, hold it in a folding tool and cut it with a circular cutting disc or slitting disc in my dremel - you can get nice and close with the cut and if there is any waste you can just grind it away as you go

Thanks for the info Peter; A good excuse to put a folding tool on my Christmas list.

Incidentally, have there been any developments on your 1:24 photo-etched Harrier instrument panels?

Cheers,

Kirk

[Doctorgaz]

I think what stit to try to make something average between the 4 and 5 option....

Cheers,

Gleb

[John Aero]

5, I think. I can't remember when 'pinked' tape edging came in but the norm in the 30's was to fray the tape edges to assist doping adhesion. On the modern rudder illustrated, I find it odd that they have done the extra diagonal tapes as to me they serve no purpose as the lines they follow are the structural members which are not on the surface and not stitched.

John

[TonyTiger66]

Hi Peter,
I'm no modeller, just a kit-basher, but I feel I can contribute a little here as it's just perceptions of what 'looks right'
They're quite pronounced on the aircraft rudder picture aren't they? It makes me think that number 4 could be good, but a close up of it would be good. I have to say John Aero's idea about 1/35 scale barbed wire is good.

In essence, number 1 looks good and very close, but as Pastor Rich said, it looks over scale for the rudder.
Superb work and the Trim Tab cutout has worked beautifully.
This thread is an absolute joy to follow

Best regards
Tony

[airscale]

thanks folks

Thanks for the info Peter; A good excuse to put a folding tool on my Christmas list.

Incidentally, have there been any developments on your 1:24 photo-etched Harrier instrument panels?

Cheers,

Kirk

Hi Kirk, well I have the masters complete for the PE and I pretty much have the decals finished too, but they just didn't make it into the last production run. I am still in two minds as to whether to release them or not. I expect I will, but not sure when as the lead time will be on the decal printing..

5, I think. I can't remember when 'pinked' tape edging came in but the norm in the 30's was to fray the tape edges to assist doping adhesion. On the modern rudder illustrated, I find it odd that they have done the extra diagonal tapes as to me they serve no purpose as the lines they follow are the structural members which are not on the surface and not stitched.

John

Thanks John - I wondered that too as the only diagonal features in those positions I can see on plans & pics of the rudder skeleton are internal rods - perhaps it just helps with stiffness at speed?

... have also decided to go for number 5..

that was a very thin strip of tape put down first, followed by running an adapted rivet wheel (to get 3mm pitch) hard along the sticky side of another strip to get the wire like raised bit, and the bumps for the knots..

..like this..

..I have done one side and am reasonably happy it is subtle enough..

once I feather in the edges and paint it silver it should look ok... (I hope)

..in other news I made the trim tab fairing...

hard to see whats going on here, but this is a card jig with a slot in it (nearest camera) which I inserted folded annealed litho. I then bent it back flat with the jig and you can see it 'unfolded' at the top..

..the finished fairing...

..now to finish the rudder - hope to be back later with it painted..

Thanks for all your consultation

TTFN

Peter

[hendie]

stunning work.

If you are still looking to try pinked edges - could you run a riveting wheel along a length of tape a few times to perforate the tape, then cut along the perforation ? Accuracy would be needed to get the cut along the centers of the perforation, but going by what you've done so far, that shouldn't be an issue

[F4u]

More good work Peter should look good with paint on.

Guy

Edited June 13, 2016 by F4u

[airscale]

..done...

tailwheel bay next I think..

TTFN
Peter

[Pastor Rich]

BRILLIANT!!!

Question: What did you form the tail light cover from?

I'll bet you even made a working bulb inside!

Thanks again for sharing your creative inspiration!!

PR

[CedB]

Very nice Peter, excellent result.

[Tomoshenko]

Sublime