Blackadder's Scratchbuilt Thunderhawk Redux

[Blackadder]

Thanks for the reply,

The FW model didn't appear to be functional in that the gear would never fit into the well given the actuating cylinder and trunnion placement; the whole design just wasn't workable. Likewise the 3D model showed a ridiculously minuscule gear. Too small!



I managed to achieve a good compromise (IMHO) increasing the size of the landing pad by twice the area and changing where the gear is actually stowed. Unfortunately at the expense of internal storage area but hey it's a military vehicle so a gear cylinder in the living area isn't offensive to yer average crewman.



The main gear pads while a tad small manage to fill the space adequately and there ARE two to share the load and since most of the craft weight is over the nose gear on a fully loaded transport we can be forgiven about the size of the main landing pads.



I've tried all ways to get these to operate and there's only so much crap you can cram into a specific space. I've eliminated the trunnion axis and the shock strut and still no go. I guess that's why the aeronautical engineers get the big bucks. although the L1011 and DC-10 were total fiascoes for the airline industry............



So with a defeat looking squarely in my face I left this portion of the project for a time until I can come up with a viable landing gear retraction mechanism; hey you get good days and bad days.........



Next, the engine cowlings........

 

[zathros]

I can't blame you. Do you do CAD? I thought o f a few ways you could have done that, but CAD would be necessary to get it right, before you cut a part. With the Original gear, there is a few ways you could have gone, but, you said,, what I think is the most pragmatic statement I've heard in a while, and went chose the appropriate course. You're building a ship, not a study of landing gear design.

I'm not a great fan of WarHammer 40K, with turrets on turrets, and the utter nonsense of their tracked vehicles, that would get hung up on the most basic of tank traps. A lot of people do enjoy do though, and that's fine.. Problem for me is being in Aerospace manufacturing for most of my life, my reality factor clicks in, and my eyes glance over. Though the F4 Phantom proved if you put a big enough engine on anything, it will fly, though that smoke trail could be seen for 20 miles on a clear day. I tend to go toward more reality or science fact based fiction. Ultimately, this will still look great, and landing gear up or down, how much difference would it make. It will be a great addition to the 40K world.

 

[Blackadder]

While I have no degree in Engineering I do have a considerable background in Aerospace being an A&P mechanic for 22 years. I got into 40K when my son at twelve took an interest and we built and designed models together and now he is in the computer game design industry. Since the Thunderhawk has no need to roll on wheels having I suppose hover jets although I see no acknowledgement of such in the design and seeing there is no attempt whatsoever at streamlining in the design as well I suppose having retractable gear is superfluous other than preventing the gear burning off at atmospheric re-entry still the FW model does have such gear provisions so making it as true and viable to the original is a fun exercise. The FW designers make no acknowledgement to many of the most basic necessities of aerospace vehicles; aux gearboxes, CSDs generators, fuel controls & etc to name a few. I know they should be there but also all should be covered with cowlings which renders such detail moot plus basing equipment 38,000 years in the future on twentieth century technology is anachronistic to say the least.

Incidentally I think the F4 II Phantom is among the most fantastic AC ever designed. To come up with such an enduring design between 1953-1959, smoke not withstanding, that still holds many speed and altitude records is amazing. The Phantom was in production for twenty years and almost 6000 were built in that time. It was only supplanted because of demand for more politically correct and greener aircraft such as the wimpy looking F16. B 'sides they look so damned cool!

 

[zathros]

Being a pilot, I'd take a F-16 up against a Phantom any day of the week. The Vought F-8 Crusader was the plane they should have built up on, but the production line was closed too soon and they did not order enough. Apples to Oranges, as the Crusaders were Carrier based jets. They flew them in Naval reserve training up till 1987, Introduced in 1957, that's a long time, and at least these had machine guns built in. Too many F-4's were shot down needlessly, talk about political ineptness, only missiles, no guns, till the attached pod, which was really a joke. Fan powered at first!?! France flew the Crusader's till 1999, (does that really count though? )

Same thing Happened with Sikorsky with the Sea Kings. We ended up rebuilding the whole fleet, going to two engines, elastomeric hub, and 5 blades. We tore those helicopters down to the bare frame, and the bonding agent had to be machined off.

I did A&P work too under the tutelage of an A.I., A&P, who owned the F.B.O., and that allowed me to work on planes, as I was logging hours towards a license. This work allowed me to learn money and subsequently fly for free. Having a state certificate for electronic repair, I also fixed many a Radio. Most of the problems were fixed with a choke on the positive side of the alternator, and a capacitor crossing between positive and negative. Capacitor resonance can be approximated with the following formula: "resonant frequency (in MHz) equals 1/2 pi times the square root of lead length times capacitance.", the leads add capacitance, so keeping them at a 1/4", and right at the alternator works best, Tantalum is great, electrolytic caps don't last worth shit. Usually the caps are in the .5 to 50 picofarad range. We worked on a lot of older classic planes that had crappy wiring. We had to put a copper plate which I made of multiple sheets of thin copper, to prevent Hysteresis, and put one bolt through them to mount all the ground wires to, to prevent voltage drops on the grounding surface, all grounds should to to one point, theoretically.. This was a Piper Cub with a Garmin Stack in it that cost more than the plane!! No much to ground to in a plane made of mostly Ceconite and tubes. The opposite of Warhammer40K!!

 

[mcusanelli]

Wow, this is really a master at work, really beautiful, clean and profesional modeling at it's best!

 

[Blackadder]

Thanks for the reply,

The Nose Cowling

Back (Egad!) so many years ago when my son first started this project I helped him out by shaping the nose cowls out of PVC pipe (Yeah Zathros, I used PVC for the cowls because I needed bulk and styrene tubing wall is too thin).

I had no concept of the scale of a Thunderhawk but I figured on an aircraft of this size that a man could stand upright in the intake duct. It was only afterwards that I found out a FW Thunderhawk was barely as long as a B727-100 series commercial jet but Thunderhawks have humongous engines to push the ungainly brick through the atmosphere so the six foot plus air intake isn't that far out of line.

I used a table top belt sander to obtain a satisfactory rough shape and that is where I left the cowls assuming once the rest of the 'Hawk was well underway I could always polish them to a finished appearance.

Now 4 years later and I having inherited the project my son being away in college and no time for such things I take up the completion of the cowlings still as yet unpolished.

Below you see an assembled cowl and the three components that make it up

 

[zathros]

You shaped that with a table top sander? Sir, you are a true Artist!! I would have made a form cutter and mounted on my lathe, but I am inherently lazy (and severely disabled) so i always go the easier route. This model is so awesome. Have you considered using slightly larger tubes so that you could slide on that beautiful landing gear you made, for a static ground display? Who cares if it doesn't work, it looks great! Of course, you could make some kind of crazy jet bike and use them on that. It seems like such a loss of fine workmanship.

As far as materials, Dude, you're on a progressive model forum that is predominantly paper sharing your master craft with us. Using whatever works has always been my mantra always. I am not a purist when it comes to making things like this.

On a side note, I have been messing around with conductive glue and laid down two very fine beads of said glue (from Radio Shack), and successfully lit an LED from 5 inches away. The substrate was paper!

 

[Blackadder]

How Many Blades?

After viewing a number of intake fan assemblies of Thunderhawks I have decided on 16 blades; the reason being expediency.

Were I to go more and readily divide the fan by 4 the next logical number of blades would not be 20 but 24. 20 is out because of the necessity of dividing each quarter of the disk into five blades. Since the disk is only 25 mm in diameter the chances increase having different width blades regardless how sharp your pencil/ scribe may be. 24 blades though easier to calculate also increases the margin for error.

If memory serves an L1011 Rolls Royce engine has around 32 blades but those blades are close to a meter long (From the center of the hub) and that is a much larger aircraft than the Thunderhawk is purported to be.

Fan Manufacture an Easier Way for Larger Fans

16 blades seems the best for while easy to fit accurately on a disk it is busy enough to simulate an intake fan especially if the cuts are made on an angle to augment the illusion of a fan.

For that reason I have selected styrene 1,0 MM thick and drew appropriate sized circles on some scrap styrene.



and then into 16 segments the ends of the blades coincidentally worked out to 5,0 mm wide.

I then glued a small hub to the center of the disc to act as a guide for the inner end of the cut (To prevent the blades from being cut off completely.):



Employing my chisel blade I cut into each segment at approximately a 45° angle so the edges of the blades appear to overlap.



After all the cuts were made I glued a small disc to the back of the fan to reinforce the axis point and with needle nose pliers twisted the blades to give a fan like appearance.



I used the curved nail file to adjust the blades for a close tolerance fit in the intake duct. It is a handy little tool that can be found in many stores that sell women's nail polish.

 

[Blackadder]

.............Have you considered using slightly larger tubes so that you could slide on that beautiful landing gear you made, for a static ground display?

I actually did use larger tubing for the sleeve ultimately but we're getting ahead of ourselves regarding the landing gear and I'll be returning to that later in the thread.....

As far as materials, Dude, you're on a progressive model forum that is predominantly paper sharing your master craft with us. Using whatever works has always been my mantra always. I am not a purist when it comes to making things like this.

I wasn't aware this was a paper model site but there is no reason my work couldn't be duplicated in paper and cardboard I suppose. I like working in styrene because of the durability.

a side note, I have been messing around with conductive glue and laid down two very fine beads of said glue (from Radio Shack), and successfully lit an LED from 5 inches away. The substrate was paper!

That intrigued me but it seems Radio Shack no longer produces the conductive glue

 

[zathros]

I purchased the glue 3 weeks ago. It's called "Conductive Wire Glue", crap, I better go buy what they have left!!

This stuff is basically the same thing, probably better, actually, looks more controllable, as the Radio Shack is kind of watery, and dries to a brittle state.

Link =http://www.amazon.com/0-2ML-Silver-...id=1459021216&sr=8-5&keywords=Conductive+glue

 

[Blackadder]

Thanks for the info I placed my order for two tube of the Hong Kong stuff on your recommend (No Pressure)

Did you see the post above the reply to your quotes?

 

[Blackadder]

A Mélange of Ideas

There are so many different styles of nose cowls for this model most of them wrong but some good points to most as well.

I am picking and choosing that which takes my fancy from each.

The image below shows some interesting features and an out right wrong namely the fan too close to the front of the cowl.



What purpose the flaps serve on the outer circumference of the cowl is unknown but they are an interesting feature and therefore included.

 

[zathros]

Yes! I read you posts thoroughly. Your technique intrigues me. I love seeing fine craftsmanship. (sent P.M. on private matter).

 

[Blackadder]

The Model I Love to Hate

It's no secret I am not enamoured with the Thunderhawk but when I see this engine 10 inches /250 MM long I have to admit it's growing on me. The nose cowl is roughed in and mounted and the overall look is pure sex. I can't wait to start detailing these engines...............




The rails sticking out the rear of the cowl are a close tolerance fit so the engines are three component modules which facilitates painting and modification.




This image shows the camber of the wing but also brings into question "What actually supports the wing outboard of the engine because most wings I know have a wing spar but here the spar must run through the spinning compressor section of the engine; what's up with that?????


Finally the rear of the engine with the exhaust in place.....



Next, building the tail section.......

 

[zathros]

As far as modeling pornography, this is the best I've seen it years. I don't have to even hide my mental wanking. Yes, I'm a model wanker.

 

[Rhaven Blaack]

This work that you are putting into this, is AMAZING!!!
This thread is an inspiration to those who are interested in doing the same thing.
KEEP UP THE GREAT WORK!!!

 

[Blackadder]

Sorry for the interruption but spent the last few weeks posing my Chaos Warhound. This thing has been basically pained in the box for a couple of years whilst I was working on a unique pose and working up the courage to glue it together. Now that I've accomplished that I'll start on a log of that build but now to the T'hawk where we left off and a belated thanks for the replies.

The Vertical Stabilizer Build:

A bit of departure from my usual building technique; I could conceive of no reason to make the tail as a separate modular assembly I probably won't be removing it for any reason and it is a simple assembly.

I'm starting from a light weight but sturdy framework slightly modifying where it attaches to the engine exhaust due to my taking what I consider the best ideas of the two 3D versions I am working from.

Although I intend to add a movable rudder (not present in the background wallpaper) and taper the control surface to the trailing edge. but the first order is to get the proportion correct.



Vertical Stabilizer Interior

This seems like a good way to build a rudder system. At any rate its rather strong and with the exo-armour should withstand regular usage.

The extra long rod is the rudder hinge axis and the cut out forward of the rod will house the counterweight hinge extensions.




The rear angle looks good but the front needed to be less extreme .....



Vertical Stabilizer Sheeted:

I sheeted the vertical stabilizer with 0.030 inch styrene because I want to add an airfoil to the surface. The notches are cut out and framed and the rudder axis threaded through the bushings.



Next I cut out the superfluous material



The final step of the sheathing and dressing the slots for homogeneity and I was ready to build the rudder core

 

[Blackadder]

So as you can see the rudder is very thin at this point and once the armour sheathing is installed there will be the core sandwiched between layers of external skin elimating weak glue joints in critical axle areas........ (I hope)


Once dried the rudder is mounted for fit and the tolerances are very tight through the extreme movement of the rudder travel.

 

[zathros]

This is pretty informative stuff here, one of the best threads on the forum.

 

[Blackadder]

Thanks,

Armour Detail on Tail:

about half done on the vertical stabilizer detail. Things are starting to shape up. The rudder has about fifteen to twenty degrees of arc left stop to right stop so that should be adequate. I hope to be installing the rear vents and panels tomorrow.



Vertical Stabilizer Assembly is pretty much done. Rivets are outsized yeah I know it but they go with the clunky motif of the model.

In the foreground of the image below is the rudder assembly that shows the multiple layers of construction:




Next, the rear louvers............