Project Viper Holiday Special

Seasons Greetings to all, wherever you may be in the world.

Still very much a work in progress, but here are some glamour shots of the current state of the Viper, to help celebrate the holiday season:

Merry Christmas and Happy New Year everyone! May you have a healthy and prosperous year in 2021.

Exhausting Work

Work on the Viper has progressed a little of late, in between work, family, other hobbies and life in general.

One of the tasks at the top of my list was to strengthen the structure of the wings, so that I could replicate the mounting points at the engine housings, without the need for an additional (and unsightly) mounting at the intake. This is based on the original filming model, Revell and Moebius models, and unlike the full size mockup. To do this I added some longitudinal bracing and cut out holes to reduce weight.

I ended up with three longitudinal braces and they all add a great deal of strength to the structure, so much so that it is rigid under it’s own weight and solves my mounting point issue.

I’ve also been keen to get the high engine exhaust nozzle constructed and mounted.  I know this was going to be laborious and time consuming, due to the detail.  I found the best way to do it was to do a little at a time, an hour here and there to break up the monotony.

After much cutting, drilling and riveting I was finally able to position it and see the big picture, ready for the final steps.

Then some further work and mounting.  I paid particular attention to the recessed gap between the rear engine housing and the exhaust nozzle.  I wanted this to look right and it was worth the extra effort – I’m happy with the outcome.

Just a little black to give that burnt exhaust nozzle look.

Still a little more to finish up the nozzle but it’s looking the part.  Then a further two more to build…

I’m planning on putting the wing sheeting back on, as well as the tail fin for a pre-Christmas / build status photo shoot, so stay tuned for that in the next few weeks.

Stay safe out there. 

A Few Greeblies More

I’ve been working on some of the engine greeble details recently, trying out different ideas. I’ve looked at various configurations and materials to arrive at something that looks like the filming prop and has a realistic used look as well. I ended up using some various sizes of copper, aluminium and pvc pipe, plus some very special greeble shapes to arrive at this:

I then did some test weathering and added some of the extra piping:

Further piping was fitted, along with the greeblies at the rear of the intakes. These required careful thought and planning to create the original look of the prop, but I believe I’ve arrived at a suitable solution. There are 6 of these per intake – they’ll take some time to create, but they should look the part.

Just for fun, I also had a play with some red racing stripes:

That’s about it for this episode – until next time.

Structural Integrity

Just a quick update on my recent efforts to strengthen the structure of the rear engine half of the viper.  The landing gear, wings and the rear engine housings are all encompassed in the rear structure, so I’ve included extra support to ensure adequate strength and durability for transport, etc.

I started by correctly aligning the front and rear sections and then used angled bracing to create a space frame:

Then I added the bottom longerons in 50 x 50 mm steel section, as well as the main spar supports for the wing mounting:

Then checked to make sure everything  lines up as expected:

Next I’ll be mounting the port side engine and building the wing.  I look forward to seeing how it all fits together!

I originally started on the viper build partly to give me something to do while I was waiting for another project to be done.  Well that project has come back into my hands now, so I’ll have to share the love around a couple of big projects now.   Project 1968 Dodge Charger has come back home after a number of years away at body and paint:

It looks magnificent in black and the guys have done an incredible job.  Now I just have to remember how to put the jigsaw puzzle back together…

One thing’s for sure, it’ll be a quite a unique garage/hanger with both a Colonial Viper and a 68 Dodge Charger!

Nose Section Panel Sheeting almost done…

The panel sheeting for the nose section is now almost done.  I thought I’d share a few photo’s of how it looks with the panel skinning in place.

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I’m getting close to the stage where I’ll be ready to prepare for painting.  I’m going to fill the rivet dimples with body filler and smooth out all the imperfections, much like a car body.  I’ve done a little bit of this before, but like most things on this project, I’ll be learning as I go.  Then it’ll be primed and painted in traditional Viper colours.

Here’s a link to a short video of the Viper nose section, complete with my own (very poor)arrangement of the Battlestar theme music.  I think it gives some further perspective on the size of the nose section and the beauty of Ralph McQuarrie’s design.

https://plus.google.com/u/0/103838325257783018329/posts/agE2YWLQgXT?pid=6171884820378095138&oid=103838325257783018329

 

Until next time…

Nose Section Sheet Metal Panels/Skin

Nose Section Sheet Metal Panels/Skin

In this month’s entry I detail the fitting of the Viper nose section sheet metal panels or skin.

For me, this is make or break time.  As a proof of concept, the completion of the nose section hinges on how well the sheet metal panelling/skin turns out.  If it is successful and appears as I have envisioned (remembering that my vision is based on the WW2 warbird costruction techniques of the Spitfire, Corsair, Mustang, etc), then in my mind, it green lights the rest of the project.  It will prove to me that the design and construction techniques I have employed for the nosed section can deliver the desired results for the remainder of the airframe.

If the panels/skin doesn’t work as planned, then it’s pretty much back to the drawing board for the entire project.  Given the time I’ve already invested in the project (estimated at 150 to 200 hours), then I’m not sure I’d be prepared to start all over again.

So here we go, here’s what I’ve done.

I firstly etch primed and painted the nosed section frames/bulkheads and stringers.  I’m not sure this is absolutely necessary on an aluminium airframe construction, but I figured better to provide as much anti-corrosion protection as possible.

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I then begain the fitting of the panel/skin to the top, relatively flat section of the nose.  Better to start simple and work my way up to some of the more complicated curved sections.  I used 1.0mm aluminium sheet for this part of the skin.  Cleco’s were used to hold the panel in place while all holes were drilled.  The holes in the sheet panel were dimpled and all stringer\bulkhead frame holes countersunk.  The panel skin was then attached with countersunk aluminium pop rivets.

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My aim is to replicate the panel lines of the original design as best I can.  I’ve elected to use the panel lines on the Moebius 1/32 Classic Viper model as my guide.  It’s a very good replica by all accounts and it is relatively easy to measure and scale up the individual panels on the model.

I then started on the bottom panel, using the same method for alignment and attachment, but using 0.6mm sheet aluminium.  For this panel, however, I left the outermost seam unattached, to allow overlap of the other panels.

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With top and bottom attached, I then started on the right hand side panels.  The pictured panel appeared to be the least complex in terms of curved profile and it also forms the central panel from which all the other side panels can be designed and positioned.

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Then the inter connecting panels to for the skin between the side panel and the bottom panel were sized, cut out and fitted, all from 0.6mm sheet.

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I then begain to design and fabricate the upper panels/skins.  I decided I wanted to make one of the panels a compartment door, complete with hinge.  This is to give it a practical look and feel, similar to the old warbirds, but also to provide me with internal access to the fuselage.

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Well there you have it – that’s the story so far.  I’m very pleased with the results.  Looks like a classic  Colonial Viper nose section to me and it looks like it was built using the classic WW2 warbird construction techniques.  I’ve yet to finish off the compartment door and then complete the side panelling on the left hand side of the nose.  Then it will need filler applied to the countersunk rivets and some unnecessary panel lines, before priming and painting.

From my point of view I’m inspired to continue with the rest of the project.  It has validated the design and construction techniques I have used and I know they will work effectively for the rest of the airframe.

I welcome any feedback on the project to date and would like to hear any suggestions people might have.

Until next time…

ColonialViper

Fuselage Nose construction

In this post I describe how I went about building the fuselage nose section.

Firstly I built a rotating jig and mounted the bulkheads/frames.  These were carefully aligned to ensure the correct profile was maintained.

 

Bulkheads/formers aligned on the build jig

Bulkheads/formers aligned on the build jig

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Stringer locations were then refined to ensure correct alignment.

Stringer alignment

Stringer alignment

I was then able to begin attachment of the stringers.  I used aluminium angle in a range of sizes – some flexibility was required for some portions of the nose, so smaller size angles were used in these areas.

Attaching stringers

Attaching stringers

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Attachment of the stringers required numerous hand built custom aluminium angle components.  This was a time consuming and laborious task – measuring, cutting, bending and drilling each angle to suit.  I then began to rivet everything into place, once again ensuring the alignment remained accurate.

Bulkhead/formers and stringer attachment detail

Bulkhead/formers and stringer attachment detail

After many hours and many hundreds of rivets, the stringers are all attached.  Starting to look like the genuine article!

Forward nose construction

Forward nose construction

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Next time I’ll be detailing the development and construction of the inner intake nozzle.

Intake Nozzle Build and Forming Bulkheads

This month I’d like to share how I went about constructing the Viper nose intake nozzle and how I formed the nose section bulkeads or frames.

Using the fueselage profiles described in last month’s post, I traced the shapes on 12mm plywood sheet and cut them out using a jigsaw.

Intake nozzle plywood bulkhead frames

Intake nozzle plywood bulkhead frames

I then traced the profile onto 1.0mm sheet aluminium for the rear bulkead and allowed extra for the flange formation.

 

First aluminium bulkhead frame - rear intake nozzle

First aluminium bulkhead frame – rear intake nozzle

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The front an rear intake nozzle bulkheads were then correctly aligned and joined.

Intake nozzle bulkheads

Intake nozzle bulkheads

 

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The inner and outer skin required for the nozzle has a number of curved sections and I felt the best way to do these was to develop cardboard templates, so that I could accurately mark out the sheet aluminium.

Templates for intake nozzle outer skin

Templates for intake nozzle outer skin

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I then used the templates to mark and cut out the outer skin from 0.5 mm sheet aluminium.  These were then drilled and fitted with cleco fasteners.  Clecos have been extensively used in metal aircraft construction for decades and I’ve found them excellent to work with.

Aluminium outer skin for intake nozzle

Aluminium outer skin for intake nozzle

 

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I then repeated the process for the inner skin, first developing a template and then cutting and fitting the sheet aluminium.

Templates for inner intake skin

Templates for inner intake skin

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The inner skin was then fixed in place with cleco’s.

Intake nozzle with inner and outer sheet aluminium in place

Intake nozzle with inner and outer sheet aluminium in place

 

I countersunk the rivet holes and used flathead, countersunk 3.2mm rivets to fasten the sheeting.  I intend to fill these with body filler prior to paint, as the Viper has no visible rivets on the airframe except for the canopy frames.  Filling countersunk rivets is common on airframes where speed and minimisation of drag are critical.  P51 Mustangs, Spitfires and Me262 warbirds all had countersunk and filled panels.

I then proceeded to mark and cut out the remaining nose section bulkheads from plywood sheet.  I then spent a bit of time ensuring the alignment of the bulkheads appeared accurate.

 

Refining the bulkead alignment.  Intake nozzle too low at this point

Refining the bulkead alignment. Intake nozzle too low at this point

 

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After I was satisfied with the bulkhead profile alignment, I marked out 1.0mm sheet aluminium and cut out with a jigsaw.  I learned a few tricks along the way with the nozzle construction which made the remaining bulkheads much easier to form.  I also cut out lightening holes with bi-metal hole saws and flanged for greater strength.  And they look very cool – a must have for any airframe!

Formed aluminium bullkhead frames for the nose section

Formed aluminium bullkhead frames for the nose section

 

Next time I’ll detail the fitting of the bulkeads to a jig and construction of the nose section frame using stringers.

Engineering the Colonial Viper

Where do you start with the engineering design of the Viper?

My inspirations are firmly based on the fighter warbirds of WW2 – the Spitfire, Corsair, Mustang, etc.  I’m aiming to engineer the Viper in a similar manner to these World War 2 fighters, using aluminium airframe construction techniques.

Spitfire cutaway drawing

Spitfire cutaway drawing

 

Spitfire fuselage bulkeads/frames

Spitfire fuselage bulkeads/frames

Spitfire fuselage construction

Spitfire fuselage construction

Spitfire rear fuselage construction detail

Spitfire rear fuselage construction detail

Spitfire fuselage with skin

Spitfire fuselage with skin

Many years ago I completed a mechanical engineering diploma, which covered subjects like engineering drawing,
materials, processes and workshop training.  I thought I’d purged most of that knowledge, but it’s amazing
how much of it I had retained.  It was to prove invaluable during the initial design stages of the project.
I initially sketched a schematic cutaway, detailing the internal bulkheads/formers.

Colonial Viper cutaway view sketch

Colonial Viper cutaway view sketch

Design started with a search for any available plans on the internet, particularly, the fuselage profile
(formers/frames/bulkheads).  The original prop designs were available, although I couldn’t find any of
suitable quality – at least not enough for me to loft (expand in size) into full scale plans.

Original Colonial Viper blueprints

Original Colonial Viper blueprints

Viper fuselage bulkhead profiles from the original blueprints

Viper fuselage bulkhead profiles from the original blueprints

The most difficult sections to engineer would be the front section of the fuselage with it’s many curved profiles
and the three engine intakes.  The other components, like the circular engines, wings, fin and rear of
the fuselage are relatively simple, geometrically speaking.

The original Monogram/Revell plastic model kit is not a bad reference but is known to have a few inaccuracies.
The more recent Moebius kit is a lot closer in accuracy to the original filming models and full size prop.  At
1/32 scale, I decided the Moebius model would be a great guide for the overall dimensions.  Armed with a pair of
digital vernier calipers, I measured the dimensions of the model and scaled them up to full size 1:1.

I would use a combination of the accurized plastic model kits and the original prop designs to develop
my own fuselage profile designs.  These were initially drawn onto graph paper and lofted to full scale
drawings.  These drawings were then plotted onto signboard and cut out for use as templates, to verify the
fuselage alignment and to allow plywood form blocks to be made.

Viper profile sketches

Viper profile sketches

 

Plotted Viper profiles for lofting to 1:1 scale

Plotted Viper profiles for lofting to 1:1 scale

I decided to concentrate on the nose intake and first 1/3 of the fuselage.  I developed a full scale half fuselage mockup to check the accuracy of the formers, the stringer locations and the appearance of the overall profile.

Viper fuselage nose section profile

Viper fuselage nose section profile

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Next time I’ll be detailing the construction of the nose and intake using sheet aluminium formed using plywood form blocks.  Stay tuned…