Jump to content

Tamiya 1/32 F-4J 'Silverkite 211'... with working features


Biscuit Tin

Recommended Posts

Hello all,
I'm new here and wanted to share a recent project, one that is nine tenths finshed - but may benefit from being shown from the beginning.
 
I've loved Phantoms since I was a child - their taut, 'business-like' appearance and reputation for power and speed always appealed. Later, as a young(er) adult I was also fortunate enough to see, courtesy of Her Majesty, an RAF version engage ground targets with its vulcan gun. Not something to forget in a hurry.
 
Anyhow, my build is a US Navy version, namely the VF-92 aircraft flown by Curt Dose and Jim McDevitt in their successful raid on Kep airfield in 1972. It is a fascinating story - engagingly told by the pilot himself here  . I also like the white noses of that squadron and the 'I-don't-give-a-damn-whether-you-can-see-me-or-not' attitude of the overall schemes of that period.
 
My version is a bit different from most models of this or similar subjects, however. I set out to build-in the following features: working flight controls, retractable undercart, wheel suspension, working lights, illuminated cockpit and gunsight, openable canopy, deployable flaps and arrester hook and spinning compressor blades. It is, as you can imagine, quite a lot to pack into a model, even of this size. And how well it works, well, you'll be able to judge for yourselves.
 
Why? Well I had some success doing some of this with a 1:24 Trumpeter Hurricane a couple of years back and fancied the challenge of mimicking the very different operation of a jet's controls - more on that later. But generally, I like the idea of a model being able to show some of the life of the real thing, so the model can sort of explain itself in other words. Some other boat and vehicle projects I've done in the same vein can be seen here if anyone is interested.
 
Where to begin? I started with the wheels, imagining - wrongly - that these would be straightforward, especially after the nightmare complexity of the Hurricane. But, in reality F4s have, like a lot of naval aircraft, quite complex wheel geometry - not apparent when you look at them - to say nothing of the linkages between the landing leg itself and the secondary doors. So I had to make each of the main struts in brass, and adjustable in all axes, so I could firm up on the motion when I had worked out what it should be.

20170115_141130%280%29-S.jpg

 

 

You can just about make out the screw that will tighten the landing gear when the correct angle was worked out.

 

Next discovery was that the gear struts themselves are almost certainly not quite in the right place on the model. No matter how I tried to work it, the wheels and doors could not function properly, this close to the fuselage. And indeed if you compare the wheel doors to available drawings, the secondary door (the little outboard gear door on each main wheel) is larger in real life than on the model. I concluded the wheels must be about 2 or 3mm too far inboard.

 

I also wanted the wheels to turn freely so fitted bearings. You can more or less see that the strut itself looks like real chrome... and that is because it is. I found this remarkable - as in easy to use - kit from the US that allows you to chrome up (well polished) brass tube and I made a lot of use of it on this project.

 

The oleo struts are supported by small springs in the cylinder.

 

20170122_133433-XL.jpg

 

The slot in the oleo is to keep the wheel pointing in one direction as it slides up and down past a locating pin.

 

The nose gear works the same way. You can see I had to replace the plastic 'scissors' as the orignals would break quickly when the gear moves up and down.

 

20170205_182921-S.jpg

 

Here you can see one of the main gear struts in the retracted position. The scissors are from the Eduard set and are useful for this kind of project, as long as the pieces are soldered rather than glued.

 

You can just about make out what turned out to be the solution to the geometry issue. The main hinge is angled downward in the forward direction and slightly outward from the fuselage in the horizontal axis. This general arrangement was found by experiment - and confirmed by photographs.

 

20170924_180740-M.jpg

It is also worth mentioning that either the model wing section is too shallow or the gear too deep but, as supplied, they cannot possibly retract and I had to narrow the tires and wheels by about 1.5mm. Also, there is a sort of connecting piece across the well that is severely in error and prevents retraction, whatever the shape or thickness of the gear. That had to go. But because no one will see in the wheel well I have not replaced it with a corrected part.

 

 

Hope this is of interest.

 

Next up, engines and fans...

Edited by Biscuit Tin
Link to comment
Share on other sites

Yes, am having a bit of a problem with the pics - I tried to paste jpg images into the text, with a limit of 600 pixels horizontally, but they don't appear andI can't find an 'add image' icon that you find on some other sites. Hints most welcome!

Link to comment
Share on other sites

Yes, am having a bit of a problem with the pics - I tried to paste jpg images into the text, with a limit of 600 pixels horizontally, but they don't appear andI can't find an 'add image' icon that you find on some other sites. Hints most welcome!

 

In the new posting area, the link and photo options, are directly beneath the smiley.

Link to comment
Share on other sites

Yes, am having a bit of a problem with the pics - I tried to paste jpg images into the text, with a limit of 600 pixels horizontally, but they don't appear andI can't find an 'add image' icon that you find on some other sites. Hints most welcome!

 

 

In the new posting area, the link and photo options, are directly beneath the smiley.

 

Also, be aware that you can't upload or add images directly to your posts. You need to upload them to a 3rd-party host site (Flickr, ImageShack, Imgur, etc), and then use the 'image' icon in the post editor to link the images to your post.

 

Kev

Link to comment
Share on other sites

Many thanks but still can't seem to get this to work.

 

Now have flikr acount - and pictures visible in my 'photostream'. Have copied links and tried tp paste them in the dialogue box caused by the image icon on your site and just get one of those little 'broken image' symbols in my text. Anyone with any ideas what I'm doing wrong?

 

I know most people can get the hang of this... but wouldn't it be slightly easier to have a browse feature than can download images straight from a laptop or phone or whatever? Many thanks in advance.

Link to comment
Share on other sites

Hello again, and sincere apologies to all for my inability to put pics up yet - but the live links below will have to do until I can sort this out.

 

One part of the project was to be able to see the compressor blades turn. To do this I cut away the plastic molded blades and replaced these with fans (windmills really) made of brass disc soldered on to small brass collets and then sprayed with the excellent Simoniz auto chrome paint, of which more later. The blade number may not be correct but it would have been hard indeed to make them any narrower.

 

20170416_153643-S.jpg

 

To turn the blades I fitted two one inch edf fans which I hoped might also be able to make the model taxi. My 1/24 Hurricane is quite powerful enough to taxi on its own and I hoped that the two fans might produce about equal power. They do... but the model has unfortunately become much heavier so won't budge unless on a slight slope. The brass device you can see was intended to convert the joy stick lateral movement into movement of thread linkages - an approach I abandoned later.

 

20170429_181245-S.jpghttps://www.flickr.com/photos/138640112@N03/38576745686/in/dateposted-public/

 

The flight controls were acheived with a simple brass bellcrank mechanism for the rudder - and a slightly less simple slider mechanism to seperate fore-and-aft and lateral movement in the control column. From port to starboard the rods connect stabilator, flaperons and rudder.20170429_181133-S.jpg

 

20170429_181108-M.jpg

 

Here you can see the stabilator mechanism at the other end, with small balancing weight. Without this the stabilator will flop one way or other without control input. It would have been better to give the stabilator more freedom of movement by using a heavier balance closer to the point of pivot - but I was trying to save weight at that point so accepted a narrower range of movement. Alternatively, I could have abraded internal plastic away until the part had natural balance of its own but apart from being tedious, this approach can risk considerable damage to the part.

 

20170527_165630-S.jpg

 

The rudder connects to a very small bellcrank and a locating lug.
20170429_181414-M.jpg

 

Here is the v stab cut out - and drilled for an optical fibre stern light. I suspect the v stab to be slightly too thick on the model but can't prove this.

20170429_181615-S.jpg

 

And here are the small bearings for the stabilitor. I needn't have bothered because the main problems were caused by parts friction that was very, very hard to isolate and remove. The slightest friction on things like this and the force becomes too much for the very delicate control column.

 

20170429_181326-M.jpg

 

Next up, flight control surfaces and cockpit stuff.

Edited by Biscuit Tin
Link to comment
Share on other sites

Hi all, I have added live links to images in Flikr until I can work out how to make actual images appear.

 

While I don't use it myself, several of our members do use Flickr to post their images, so hopefully one of them will be along soon to let us know how they do it.

 

In the meantime, I clicked on the last image in your most recent post, to view it in Flickr. In the bottom right of the image viewing area, there's a set of icons for performing actions with the image. The second one from the left (a curved, right-pointing arrow) triggers the 'share' window, with several options in it: 'Share', 'Embed', and 'BBCode'. Click on the last one (BBCode), copy the highlighted text, and then paste it into your post edit window here. This should give you something like this below:

 

38576745686_d0da79f5cd_z.jpgRe: phanto1 by Biscuit Tin, on Flickr

 

Give it a go and see if it works for you.

 

Kev

Link to comment
Share on other sites

Flight control surfaces were quite a challenge. A cursory glance at the F4 (and indeed many other aircraft of the period) shows it to be covered in very tiny 'piano hinges' which are used for pretty much every moveable surface. It is possible to make other discrete hinge types as a subsititute, but they simply don't look right and most are very weak.

 

So, in the end, I designed photoetched hinge strip and assembled them myself. They were fiddly to make but resulted in a surprisingly strong and realistic looking hinges. They need to be sort of bent at 90 degrees to fit into the slots cut where the plastic molding of them was.  Here you can also see the L.E flaps, hinges - and actuators which were made using a sort of bell crank type mechanism.

20170713_091328-XL.jpg

 

Here are the trailing edge flaps and the flaperon hinge. All the flaps, leading and trailing, are mechanically linked to the arrester hook and deploy when the hook is lowered.

 

20170713_091420-X2.jpg

 

The funny crutch shaped thing in the wheel well is not found on the real thing and is intedned to push the weel back into full detente on the suspension spring. Without the wheel being fully retracted like this it will not fit in the well and the inner door cannot close - it's the same on the real thing. On the real thing, however, there is a lever on the wheel mount that is pulled up mechnically, as the wheel comes up, to ensure it is fully in before being retracted. Given the size of the componants involved this would be almost impossible to model at this scale - unless working in steel.

 

The flaperons are actuated by a sort of semi-realistic rendition of the hydraulic jack that powers them. On the real thing, this jack can itself can be moved for and aft hydraulicly, hence allowing the flaperons to function as flaps and aileron simultaneously.

 

20170924_180801-M.jpg

The flaperons were spring loaded to somthing close to the horizontal - but only just as the control forces are not strong.

 

The flat straplike thing at the outboard end of the main gear was intended to work as a gear down lock with the hole locating to a small pin in the head of the landing gear piston case. This did not work well as it was to close to the centre of pivot and so the gear still wobbled. In the end I have used a sort of removable piston restraint to lock them - like the real thing, when left for any time.

20170924_180801-M.jpg

 

In the pic above you can see that the wing was getting pretty busy before being closed up and it was a fiddle to keep optic fibres, springs and actuators from interfering with each other.

 

All this cutting away of the wing left it really weak and liable to almost Spitfire-like dihedral under load, so I added a first then second wing spar in brass. Here's the second, afterward of the two. It attaches to the aft wall of the wheel wells.

20170915_161223-S.jpg

 

That's it for now.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...