Bobs dual build

[Bob Jennings 1]

I have found some time today to begin. Thanks to Phil for ploughing ahead. Going great guns.

As I couldn't decide on which scheme to do, I have plumped for building both!

Madness, now I look at the task ahead, but I'm off and running.

 

Edited By Bob Jennings 1 on 09/04/2016 16:05:03

[Bob Jennings 1]

Edited By Bob Jennings 1 on 09/04/2016 16:11:47

[Bob Jennings 1]

With two sets of everything to do, I decided to get the fiddly bits sorted first!

Plus the fluted fin.

 

Edited By Bob Jennings 1 on 09/04/2016 16:12:47

[Bob Jennings 1]

The last pic looks a bit rough, but it was the easiest and quickest way of achieving the form. Hope you get the idea.

Here's one of the pieces sanded to section.

And the other mounted on the fin.

 

I'm going to try two different covering techniques and see which works best. Watch this space.

 

Edited By Bob Jennings 1 on 09/04/2016 16:15:44

[Bob Jennings 1]

I found this FAA scheme in a "what if" scale modelling site.

But I also fancied this as well.

[Phil Cooke]

Nice one Bob, good to see your blog up and running!! It's great that you are building a pair - the two schemes you've settled on look awesome, especially like the RN scheme.

Interesting that you've started with the rudder and the scale detail you've added looks great. Nice touch with the little trim tab too!

Keep up the good work, I'm looking forward to seeing your twin A-4 build develop!

[John H. Rood]

Welcome aboard, Bob! Great fun.

[Bob Jennings 1]

Nipped home at lunch!

I have glue curing while I'm at work. Reeeezult!

Edited By Bob Jennings 1 on 11/04/2016 15:22:19

[Bob Jennings 1]

Right, first boob!

Just because I made sure to cut my fuselage sides as per the plan, that doesn't mean the fuselage formers will fit if you simply glue the angle section along the edges!

I've been left with a bit of a gap. Doh!

So, I suggest you glue the bottom section in place and use the former as a guide to butt the top 3/4 section in place

[Phil Cooke]

...and then do you trim the fuselage side back down to the triangular section Bob?

This is a neat fix to a frustrating problem, resulting in a very slightly slimmer fuselage - which will do no harm.

Its not a boob on your part either! - The gap at the front of the former is because of the pronounced angle of the triangular section combined with tolerances on the strip I think, whilst the former is laser cut with a square edge. I had exactly the same issue - but elected to glue to former up close to the top edge and top strip, then blocked in the former at the bottom, effectively making the former a little longer than as provided.

I think your fix is smarter as it guarantees good joints.

[Bob Jennings 1]

Thanks Phil,
the airframe will be fractionally slimmer all round (lightening the tail too). I'm hoping it won't have any effect on the tail incidence as it's only dropping the tail as a whole downwards in relation to the wing.

[Peter Garsden]

Looking forward to this one Bob. I do love a nice pair, and know yours wont' disappoint. I think if I built 2 I would have some controversy at home.

And big thanks to your help at the weekend with the JW - I have redone and fixed the warped aileron now.

Hoping to start mine soon too.

[Bob Jennings 1]

Thanks Pete, that JW was flying sweetly after some fettling.

Get your Skyhawk started. Not long now!

[Bob Jennings 1]

Here's one of my fins and a diagram of how I worked out all the measurements.

My solution was for an insert as a complete rudder but I think Phil has nailed a much tidier way of achieving the same effect.

[Phil Cooke]

Slightly different methods Bob but the end results will be very comparable - that's one of the things I love most about this hobby! I've just realised I've forgotten to allow for the little trim tab on my 'core' rudder sheeting - I will have to correct that!

[Bob Jennings 1]

Its been a while and a lot has been done since last time.

I covered the fin with heavyweight tissue and Easy Cote from Deluxe Materials.

The trick here was to use a new scalpel blade and run it along the rib edges while holding the tissue in place while the Easy Cote is still wet. This leaves you with a flap attached to the trailing edge which can be pushed down against the shoulder of the rudder.

Fiddly, but it worked for me.

[Bob Jennings 1]

Once dry, I gave it a light sand and a spray of Halfords filler primer and then sanded most of it off.

This will give me a base for the final paint finish which will be the Dark Sea Grey of the FAA scheme.

I did the same to the stab and then set about the wings.

I opted to file the spar slots on an angle exactly centre with the CNC slot, relieving the edges front and back.

There's something really satisfying about setting wing ribs square to a spar... or is that just me?!

[Bob Jennings 1]

I Managed to cajole some Liz Earle tops off Phil's missus, much to her glee, as she just had to purchase some more!

Here's one of them in situ.

You can see that i've marked out the safe areas around the fuz to show where I can go crazy with the razor plane without creating any problems.

Then it was down to creating a load of shavings.

This beast takes a lot of work and I'm currently onto sanding, sanding and sanding.

Here are the fuz and wing components prior to the sand fest. (one wing still on the board)

[Bob Jennings 1]

Anyone who went to the Great Orme last weekend will have seen some of my progress 'live' as we were pretty much becalmed, with no real wind to speak of. I made more work for myself be crashing my JP... Shucks.

One detail I wanted to include is the splitter plate at the air intake. I decided to put a 1/8 slab of balsa between the intake and the side of the fuz prior to sanding so I can sculpt the intricate curves between.

[Bob Jennings 1]

Here's a shot of the area in question.

I'll insert a shaped wedge to keep the splitter plate and intake proud of the fuz and use a round file to achieve the nice curve in the gap at the back.

I'll need to cover the intake and splitter separately at attach to the fuz once that is covered.

The little plate underneath the intake is to stop gun gasses being sucked inside the engine. The cannon is directly under the intake, virtually at the wing root.

[Bob Jennings 1]

Check your references for guns though, not all of 'em 'ad 'em! Particularly the aggressors. I like to think they were removed so no one was shot down through sheer over excitement!

[Phil Cooke]

Great update Bob, good to see you making such good progress on the pair... I need to get my finger out and build my wing! 12.5 weeks to go!

[Bob Jennings 1]

Trying to ignore the sense of panic as the imminent event approaches rapidly, I have cracked on with my two builds.

I have two wings built, this is the Solartexed version. I applied a coat of Balsaloc to help it all go down. Just needs the primer and camo paint.

I am awaiting some Aeropoxy to finish off the other wing as a comparison. The whole of the second wing is covered in lightweight glass and Easycote acrylic resin. Andy Meade mentioned the possibility of adding a hard top coat. So that's what I'm going to do. To avoid trying to fold the glass over the aileron hinge edge, I ran a strip of Solartex along it, then glassed straight over this to produce a nice neat edge.

[Bob Jennings 1]

Here's the port wingtip, the Aeropoxy should fill the weave.

[Bob Jennings 1]

The splitter plates became a bit of a crusade and I re-thunk them a few times, each time sanding a little bit more off the intakes to suit the modification.

I had to 'tex the fus first and attached the intake/splitter combination as a pre-covered sub-assembly.

Not sure what will happen aerodynamically, might whistle a bit at speed, lets see in September.