The last week and a half have seen most of the major components come together. The windscreen brow was cut out of its vacuum pull and fitted. It’s great the way it has made the whole of the windscreen structure quite rigid.
Marking the windscreen brow for cutting
Fitting of the brow
The rear glass was also cut and fitted. This completes all the glass component installation. The final fit-ups for the wing fillets were also done and the fillets painted.
All the aluminium 2mm Bend Diagrams were completed and bending done. This resulted in a flurry of spray painting 🙂
Work could then begin in earnest on the centre pedestal including the finalisation of the control column, rudder pedals and elevator centring mechanism, with these all having being in place today.
Thought I should share how we have progressed over the last week. The seat and support frame have been completed and it looks every bit the part. With it installed the cockpit shell has suddenly been transformed. Sitting in it, albeit without any of the controls mounted, one gets a sensation of what it must feel like sitting in the real aircraft. Soon, it will be almost indistinguishable from really being there.
Seat with support frame
Rear of support frame with height adjustment handle
View from the top
Assembly of the seat support frame
Painted the structure looks like something from a WWII tank!
The seat height lever operates as per the original. It is interesting to feel the different working heights of the cockpit and how it affects the view out to the front. I fitted two 350N gas struts (the original had spring cylinders), but the forces they introduced to the frame were a little unsettling so I decided to take them out again. I am not sure what the spring force on the original is but I think I will tune them down to 100N each and see if that is manageable. As it is, the seat moves easily without them if you press your back against the rear and move the handle. Only a minimum of leg input is required.
The door has been completed and installed. Again, the latching mechanism is as per the original, and operates very smoothly.
The column too is starting to take shape nicely.
I have received the double mould for the windscreen brow section and had 4 clear acrylic pieces pulled from that. Next I will be cutting that out for fitment.
Some things just require more work and attention than others. The assembly and installation of the windscreen and canopy being a case in point. First, having assembled the windscreen, you need to ensure that the canopy edge matches absolutely when it is closed. So you need to assemble and install the canopy before you can fit the windscreen. You can then line the whole lot up, mark off, offer a prayer that all is good, remeasure, check again and finally commit to drilling the coaming holes.
This week has been somewhat nerve wracking in that way…
Happy to say that all seems to have come out well though.
Here are some pics and descriptions of the build this week:
Trail fitting canopy liner strips
Assembly and riveting of canopy liner strips
Lining up the canopy
The drilling and trimming of the Plexiglass canopy is potentially a hazardous exercise, the plexi being very brittle and prone to cracking. Using a Dremel tool at 25000rpm+ however ensures that the material melts before any stresses are induced and makes the task a lot easier. I started off using screws for the assembly however this does not clear the rear of the cockpit, so had to revert to rivets. Great care needs to be taken here to apply only the lightest pressure as the canopy will crack if you don’t.
I used a system as per the original Spitfire which incorporated bronze slippers running in the canopy rail. As I could not find bronze I substituted this with brass. Regrettably the sliding action is not sufficiently smooth, so I will redesign the mechanism with nylon rollers as used in the popular Vans RV sliding canopies.
I could then line up the windscreen with the canopy in full forward position before doing the final drilling and fixing of the coamings. The windscreen is now firmly mounted. I am still missing the top eyebrow section of the windscreen. For this I have designed a mould and have assigned a plastics vacuum forming company to manufacture it and vacuum pull a few samples. Along with the canopy, coamings and some machined parts, this will be something that I will make available at reasonable cost to prospective builders.
Finishing off the windscreen rear
Canopy and windscreen in place
The instrument panel has been fitted to allow the final positioning of the internal coamings, gunsight carrier and gunsight dimmer bars. Again a painstaking process to ensure everything lined up correctly. I am very happy with the way this is coming together.
Work has now started on the door. The design needed some modification to ensure that the canopy rail remains unobstructed. The machined parts for the door latches are looking great.
Another busy week and the covering has been completed. New skills learnt were to scarf the covering plywood. I marked the scarf lines at 8 times the thickness of the flexi-plywood, being 3mm and lined them up before sanding them down.
Went rather easily and once the fuselage had been covered, the overlapping areas sanded down nicely to a smooth finish.
The balance of the 2mm aluminium parts has arrived, some of which had been bent by the supplier. All looking good.
2mm Al Parts
Seat frame sides
and the rest
The seat is back from the upholsterers and looking good.
Next up is the Malcolm Hood so that the windscreen can be fitted. Eight weeks to go to Aero SA and much to do!