Overview
The canopy on this aircraft has been modified in a number of ways some planed and others forced by the execution. Yes, it added a bomb in extra time so be warned.
Installation Shroud
The shroud is the most distinctive feature of Shorts T1 Tucano so this was the first extra item fabricated. While simple on the outside, the execution was a protracted task due to a lack of experience and the risk of damaging a very expensive piece of perspex. After weeks on/off of filling and sanding, the time to fit it onto the perspex and frame had arrived.
The scheme developed seemed /simple enough, the external edge was to be fitted using 18 x 1 mm double-sided automotive trim tape with the rest affixed with beads of SikaFlex Eurthane adhesive sealant. The first issue was that when dry fitted all look great but now all those little issues raised and in the end it was decided to cut the single piece shroud into four [4] pieces and then re-fit them.
This worked well except for the last one on the starboard side and this turned into a custom fit - why? - who knows but once it was 80% done it had to be finished.
The shroud was a big job and once painted it will now have to have the edges filled as they are not as flush to the perspex as the builder would have hoped. This was caused by the mounding tape as it packed up the edge up by a1 mm and exaggerated any fabrication errors.
Once done the band across the top had to be dressed, while the initial thoughts were for a painted black band at this point something more substantial was required.
The answer came in a roll of concrete gap foam that was glued together to form a 20 mm thick light flexible strip with the top having a series of lighting holes drilled to create a sense of importance.
It as glued onto the canopy with a pair of 3D printed ABS covers blending it into the frame.
Handle
The kit did not include an external handle and it was decided to modify a commercial flip out but he the builder saw prices in the $250 plus range back to the CAD system. A flip-out handled was printed and installed. This required the cutting of a suitable hole through the side so this was done with a combination of fear and care. In the end, it was secured as planned with two [2] x M4 aluminium screws from the inside of the frame into the handle body.
The handle will lock using a piece of fridge magnet strip fixed to the inside of the body with a screw located into the handle
Will be made available on the web site once ready for sale.
Latch Cover
One of the last issues was the latch cover through the side cover on the frame. A number of attempts to install the factory slotted stainless steel covers were tried but with deteriorating results. It was decided to print an ABS cover and install it covering up the gaping hole in the side cover, after a couple of tries a successful model was developed and a Marwen cover printed with instructions.
Will be made available on the web site once ready for sale.
Canopy Handles
They were printed, painted and fixed using M4 grub screws onto the existing handles.
Will be made available on the web site once ready for sale.
Seals
There are no details on seals but it was decided to add a D seal along both of the fuselage sides of the aircraft, Using any sealing material can cause an inability to close the cockpit due to the forces required, do not be filled by how soft it feels as the forces added up quickly making a closure on the latch side impossible.
Explosive Cord
One of the key features of a Shorts T1 is the white lines created by the explosive cord used as part of there aircraft ejection systems. While these were to be painted, the builder was not 100% on board and resulted in a better product being discovered. This was in the form of 9 x 6 mm D foam self-adhesive door seal material by Raven in Australia.
Using photos of the Shorts T1 canopy a suitable generic scheme was developed and applied.
The overall result idea produced a good result on the inside, this builder will have to wait for the unveiling until the painting has been completed.
Canopy Installation General
My canopy was an early model and the new aircraft have larger hinges and a ring [frame] that locates the frame to the fuselage but my issues I will outline for reference.
The first issue was the hinges these required packers to locate the frame into alignment with the frame. Once this was done the shroud was fabricated and this is covered under the category "Canopy" in this blog.
After fabricating the necessary structure some real issues surfaced with the worst being that the canopy now was 6 mm out of alignment at the front this was traced to the 15 kg of thrust from the gas strut when closed and the clearance in the hinge pivots.
The original canopy was located on pins on the port side, these did not now line up and after numerous attempts at modification and redesign, they were abandoned as a lost cause, at this point, I could remove the strut or burn more time.Not being very smart it was decided to press on.
In the end, a roller was fitted to the frame that countered the strut and rollers added to the canopy frame at the from and rear. Bakelite button aligned the canopy as it closed at the from countering the tracking forced generated by the roller with buttons at the rear bulkhead being the last locator. Did it work? - yes - Did it burn time - Yessssss.
Final Clean Up
When applying the adhesive to secure the canopy the dread of all builders occurred - some got onto the exposed area and the time had arrived to fix it. A Novis kit consisting of Part 1,2,3 was purchased along with a sheet of 600/1200 grit wet and dry.
The affected area was sanded with the 600 and then 1200 grit in straight lines crossing at 90 degrees. Next the area was polished using the Novis #3 the #2 revealing a smooth canopy and no mess.
Finally, the whole canopy was polished using Novis #2 and cleaned and polished with #1.
When the painting is complete the exterior will be treated in the same manner to reveille hopefully a shiny clear canopy.
Comment
Based on the drama this builder has created assembling the canopy I would have the factory fit the perspex if you can afford it. If not fix the canopy using an automotive urethane adhesive sealant and do this with it installed and locked on the airframe and allow it to cure. The assembled unit is very flexible so it is the builders opinion that it would be best to not build in any distortion if possible.
The shroud was a lot of work but in the end, it makes this a Shorts T1 not just a Tucano.
Why are these things not as simple as our dreams -eh?
