8th May 2016
At this stage of assembly it’s all a bit freestyle as there are lots of areas to take care of. I find this part of the build quite enjoyable as I get to flit from one bit to the next. While one part is drying, another can be worked on. So in this update I’m going to post the pictures in the order they were taken which will involve a bit of flitting from one job to the next.
First up is the rear section or “Beaver Tail” as it’s know.
Not a lot of drama here, just a case of cleaning up the parts and gluing them together. Again, there are no locating pins for these parts, but they fit together nicely enough so just a matter of getting the parts held in place with some pegs and running some Tamiya Extra Thin glue around the joins.
The beaver tail fits between the engines at the rear of the fuselage.
As you can see below the beaver tail is a little too wide and forces the fuselage to bend a bit, which creates some gaps.
This was easily sorted by sanding a little off the sides of the beaver tail with some sanding sticks.
Just sand a little at a time and dry fit the part often until you’re happy with the fit.
Here’s the improved fit – the gaps are much smaller now.
Because the fuselage either side of the beaver tail is quite flexible it doesn’t sit perfectly. So to get the seams to line up I lined up one part of the join and glued it. When the glue has dried it’s a simple matter to move on to the next section, manoeuvre it into place and glue it. Rinse and repeat until all of the joins have been aligned and glued.
Due to the fact that the shape is quite complex here, it’s not possible to clamp the beaver tail in place while the glue sets, so for some areas it was a case of holding the part for a few minutes until the glue set enough to hold.
Moving for’ard time to assemble the cockpit halves…
Again I worked along the seams, aligning a section, gluing it, letting it dry and then moving onto the next section.
The main thing here is to take time to get the seam level without a step, and to get the panel lines lined up.
To get the rear of the cockpit to line up, I applied a dab of CA glue, manoeuvred the part into position and hit the CA glue with a blast of activator spray. This immediately cures the CA glue, fixing the part in place.
CA glue can for a brittle join that can crack if flexed, so when using this technique you always need to apply plenty of thin glue (Tamiya Extra Thin for example) to weld the parts together. The CA glue can be thought of like tack welding just to hold the parts in position as they are glued for real.
Here I have fitted the rear shelf. You can also see the damage to the cockpit floor where I had to remove the glued in kit seats when I decided to swap them for resin seats. No worries, the damage will be hidden by the replacement seats.
This part won’t be very visible when the canopy is down.
Moving back to the intakes…
Here I have fitted the long insert on the left, the right hand side one is yet to be fitted.
These parts took a bit of working out as to where they were supposed to fit, the instructions not being very clear.
What you’re aiming for here is for the right had edge of the insert (highlighted in yellow) to line up with the ridge in the fuselage marked in red. The part will fit sitting on top of the ridge marked in red but this is incorrect.
With the inserts fitted it is time to consider the geometry of the variable position intake ramps.
Here you can see the position of the ramps as standard. This is the configuration for supersonic flight where the ramps are lowered to reduce the amount of air being forced into the engines. I also believe this would be a suitable position for engines off and on the deck judging from the reference photos I have seen.
Here’s a front view showing how far the ramps project into the intake.
The configuration I want is for subsonic flight for which the ramps are retracted to allow more air into the engines.
To achieve this I am going to leave out the hydraulic actuator from the long front ramp, and will remove the actuator mounting bracket circled in red using a 2mm Trumpeter chisel.
To retract the inner (shorter) ramp the hydraulic actuator was reduced in length as shown below.
Here’s how the intake ramps look in the subsonic position.
For a change of scenery I decided to next work on the engines.
Pretty basic assembly here, the engine body was assembled from two halves glued together. The end piece was then attached taking care to get it concentric with the engine body.
The kit offers two choices of afterburner petals, one where the petals are restricted as shown below, and one where the petals are dilated (fully open).
The fully open position is for when the engines are run at or above 100% when the afterburners kick in. Since I’m building this one in a “hit the brakes” configuration I’ll use the restricted petals.
This also allows me to use thinner acrylic rod up the engines to mount the aircraft on.
The engines have a plastic tab to help locate them, but this just gets in the way. I will be cutting the tab off before I attach the engines.
Here you can see a dry fit of the port engine with the tab still on. The panel lines don’t quite line up like this.
The engines will be glued in place later after I have modified them to accept a suitable length of acrylic rod.
Ok, back to the intakes…
With the front intake ramps fitted, I sanded them to be flush with the upper front section of the intake and re-scribed the panel line (circled in red). The panel line on the left in the red circle didn’t exist so I added this one separately.
This was my first test drive of the Holly 0.15 panel line scribing tool. It certainly creates fine lines but you have to go gently with it as it can distort and go off track quite easily. It’s great for getting into tight corners though so will definitely get a lot of use in the future. I might have to get a 0.2 one as well, definitely wouldn’t want to go down to the 0.1 scriber, I think this would be too flimsy.
Looking at the inner intake ramps, I noticed that their leading edge is very thick. This will need to be thinned down with some sanding sticks.
Here’s the inner ramp with it’s leading edge having been thinned somewhat.
Next up I glued the inner ramp actuators in place. These actually fit quite snugly onto the rail they attach to which makes getting them in the right place quite easy.
And before I go any further on the intakes it’s time to give them a coat of flat white.
For this I used Tamiya Flat White XF-2 which was sprayed neat. The reason I sprayed it neat was so that it covers nicely – if it was thinned it would take a lot of coats to cover the grey. Also by spraying it neat you need to lay it on wetter than usual which allows the paint to cover over minor blemishes in the intake seams. Kind of like a very fine primer filler.
While I was in painting mode I also gave the pilots a coat of black primer prior to brush painting, and the engine compressor blades also got a coat of flat black.
Note here that (as usual) I CA glued the pilots heads onto cocktail sticks to provide a solid handle to use when painting. It’s easy to crack the CA glue joint with a blade once they’re done.
Next update: More work on the fuselage and finishing the intakes (at last 😉 ).