Canopy Skirt - Part 3

This blog covers the T1 canopy skirt

Manufacture

With the shroud roughed out in Part 5 , it was refitted to create the final shape but before doing that it had to be in a fixed reference to the frame. With the skirt positioned correctly a series of 3/32'' holes were drilled into the frame to allow cleoces to be used. When doing this a number of thicker sections were noted when the cleco could not close after insertion.

This will required a rethink on how the skirt will be attached.

All edges were dressed to match the line of the canopy frame using a combination of half round bastard files and 80 grit aluminium open cut paper on blocks. Once the straights were completed the corners were developed by cutting cardboard templates until they fitted the frame and then profile transfered to the skirt for filing. The bottom will be done last once the seals are fitted with the catches.

Fitting clecos with the insert showing the template used to transfer the
angle for the band on the other side

Additional templates used to shape the corners

Curved template to join both verticals - template transferred to other side to create a symmetrical profile. A piece of  cardboard the same width as the verticals was used to create the radius on the front side

Skirt after first coat of high build primer was applied then sanded back
Next job is filling with lightweight macro

Elevator Hinges

This blog covers modification to the elevator hinges

Overview
As mention in a previous blog don't drop the aluminum inserts supplied with the kit - I never found the one I dropped but no issue, have one machined.

As small things all take time and a new bush was eventually machined with a 3/16'' bore, however it was discovered that the bore of the factory bushes was 5 mm and checking at the hangar revealed the machinist was correct. At this point the elevator was removed and all the stab hinge points drilled out to 5 mm.

Aircraft Spruce
Part #05-2500

While all the parts were disassembled it was decided to lubricate the spherical bearings with 3 : 1 oil, then pack with grease and to protect them from dirt ingress, aluminium bush's Seal-Its were ordered from Aircraft Spruce.

Each aluminium bush's flange was step machined to create 0.63'' dia x 0.025'' deep lip with the seal fixed over that lip using Loctite Black Max ACC and set aside to cure. 

Spherical bush rotated to allow oil and grease to be added

Parts ready to reinstall

Note: Each seals lip is packed with grease at installation.

Elevator hinges installed ready to remount

Note: Bolt thread will be trimmed to match AN3 bolt

Installation
Starting at the starboard side with the elevator level the hinge with seal was inserted into the stab brackets the a M4 screw slipped through to secure the assembly. The next one was inserted by springing the stab hinge with a soft podgy and inserting the next hinge and seal. 

This was repeated until reaching the port side when the first M5 Unbrako cap head screw was fitted. This proved to be a task as it had to be done using two fingers only in a small opening.

With all the bolts installed they were secured with M5 nylock using a shortened hex key and spanner.

Comment
It would be best to use AN hardware and the factory has been notified of the issue.

If installing seals again the bushes would be machined from mild steel with the step for the seal machined in one operation. It proved to be very difficult to center the very fine step required on the existing bushes.

The lubricated bearings were noticeably smoother and the seals will help keep out grit.

Stab Farings

This blog covers the installation of the intersection fairing for the elevator and rudder.

Installation

Trial fit of the rudder and elevator stab fairings
Note: Components have been trimmed to factory guide lines

Trial fit of fairings

Both factory supplied fairings were trial fitted onto the starboard side but the builder could not work out how the intersection was to be created. 

The factory replied that the fin fairing was installed over the elevator fairing but again an acceptable method of assembly could not be found.

After much thought it was decided that the best way forward would be to make the components fit by placing the rudder fairing under the elevator fairing.

Work started on fixing each component onto the airframe before undertaking any modifications.

Masking tape was applied over the areas to be marked allowing an installation scheme to be developed and with rivets securing the skin to the ribs on the same line care was required not to drill at or near a rib flange. This issue arose at the lower side resulting in two broken drills

It was decided to install the mounting points on the rivet line for the rib starting at the nose rib centering about rivet group [pitched @ 30 mm], then pitching the other holes at 90 mm along the top side. The location off the holes in the fin is a projection of the location of the holes on the elevator. 

Ruler

With all the marking out the most useful tool proved to be a cardboard ruler. This was made from a piece of scrap cardboard with a base at 90 degrees and pitches at 10,15,20,30,40 and 90 mm.

The bottom side was more difficult but in general the same philosophy was followed but with a slightly more uneven distribution based on the restrictions created by the rivet locations on the underside.  

Fixing point currently selected with all parts fixed with 3/32'' clecos
Underside shown at the top of image

Note: Do not attempt to drill in the area of the skin line seen running through
the hole without a cleco - it intersects with the stringer and just breaks drills
This single line defines were the fixings cannot be installed

Marking out the port side using the starboard fairing - rivets on nose
ribs located on rib rivet center line

Note: Approx location of the rivets [circles] - location is
about rivet group center seen in gap between to tape runs.

Stab clecoed to turtle deck at a pitch of 90 mm
starting at the nose

Intersection of elevator faring was cut to allow it to be brought into contact
with the fin faring, this area is glassed with 100 mm tape x 5 layers

Note: Two [2] 1/8'' clecos installed to hold the loose components
onto the fin faring

Comment

All the trimming used a Dremel motor tool with a extension shaft with a quick change plastic disc. It was found that discs marked for plastic set at about 15000 rpm gave the cleanest cut.

Sanding was all done using 80 grit aluminum open cut paper and a flat hard sanding board.

Seat Upgrade

This blog covers the upgrade to the factory seats

Seats
A concession to the military theme of the cockpit is the leather covering of the seats with a upgrade to the comfort levels.

Both seats have been covered all over with leather, this was done based on the advice of the motor trimmer as it avoids the issues of the securing the edges to the rear of the seat as done with the factory covering, so the shell is covered all over in black leather with a felt liner fitted to the interior seating face.

The seating face consists of three [3] separate parts - headrest / back - seat cushion - front leg support and are held in position with Velcro strips fitted to the back and inserts as required. In addition an adjustable lumber support is incorporated into the back cushion secured by the Velcro strips fitted to the seat back.

The lower seat cushion has a high density heat forming foam sourced from Aircraft Spruce that provides better butt support.

Seat cushion

Comment
Passed the floor mounted comfort test and the smell off leather cannot be beaten.

Rudder Stab - Part 4

This blog cover a small modification to the stab attachment

Stab Install
With the elevator stab installed the rudder stab was next. Once mounted on the back of the fuselage the builder was confronted with the re-installation of the front mount and it bolts - put simply there was not practical way to install the nut.

It was removed and a AN4 floating nut installed then fixed with 3/32'' counter sunk pop rivets.

Rudder Cable
The rear openings for the rudder cable were enlarged in the rear of the fuselage - the stab post was modified to match.

Modification to provide additional clearance for the Nico Press crimps

Comment
Rudder stab is now functional complete

Panel Drilling - Part 7

This blog covers the final drilling for the front mounted instruments and trail assembly with the panel now ready for painting - black.

Overview

Tucano Panel

As part of the styling it has been decided to front mount a number of the instruments. The airspeed was flat backed and just screwed on but the altimeter and ROC required a larger hole at the 7 o'clock position. 

This was achieved using a step drill plus a block of wood to hold the drill in alignment after it cleared away all the aluminium. A small amount of dressing was still required to achieve a neat fit.

Drilling to fit the altimeter

Fixing an error - Two pieces of aluminum sheet were covered with packing tape.
With one held to the rear with the spring clamp, Loctite aluminium epoxy is spooned 
into the cavity, top strip fitted, then all the excess extrudes out
the opening with little dressing required once cured

Trail assembly of all instruments with the AVMap GPS at the panels center.
The unfilled holes are for Flybox prop controller [lower LH corner]
Fuel Data system [upper RH corner]
Other opening blank - maybe indicatior lights
Rubber U channel is for apperance

fit

Propellor - Part 1

A Four [4] Blade propeller is a feature of the Shorts Tucano

4 Blade Blade Ray from Alisport
Dia 68'' weight 10 kg
www.alisport.com

Option C - Electro Hydraulic Power Pack
used in conjunction with a Flybox controller 

Flybox Electronic Propeller
Model EFC57-P
Controller is used by factory

This package is now in transit - it is untried on the Tucano and was chosen based on a lot of email traffic with it's weight in the lower range for a constant speed considering the extra blade. It uses a rotary joint to connect to the power pack to the propeller and while I am not a lover of these it is the only practical solution.

The FlyBox comes recommended by the factory and it's specification is impressive.

This is why they are called experimental - time will tell, will it not.

Fuel Valve - Part 1

Note: Not suitable for use with a fuel-injected engine as the factory has found issues with it leaking at the higher pressures.

This blog covers the installation of the fuel selector. 

Fuel Selector
A Newton Consulting fuel selector was chosen because of its style of selection, which will allow operation from the seat without adjustment to belts.

Model: SPRL V1-3P-C way fuel valve with conforming selector was selected

The lift and turn selector is secure and should be easier to operate as installed with the optional locking detente to avoid accidental operation.

This model allows the left or right tank selection while opening a return to the tank as required by the Rotax. All fittings are 3/8'' lines with AN nipples.

Valve & extension kit
[right angle optional]

Face Plate
The selector was disassembled, and the parts were placed in a safe place. This is part of installing an extension kit and the extension drive. 

The plate matched the mark on the front panel and the firewall for later drilling. 

The face plate is mated to the extension drive, the 1/8'' hole for the brass drive indent pin is matched drilled and the indent pin is driven in.  All screws had a small drop of Loctite added at assembly.
  
Reassembled the selector after greasing the extension drive shaft - checked operation.

Installation

After locating the mounting position, the mounting holes were marked from the face plate when disassembled. 

The brass drive rivet provides the indent and must be re-installed after match drilling into the adapter.

Note: Mounting screws were not supplied with the kit and had to be sourced.

Drilling Mounting
Holes 3.5 mm with 38 mm hole saw for the cutout
Better done in the flat but selector type was up in the air 
while drawing the layout

Adapter mounting on the firewall
Holes 5 mm on the valve PCD & a 16 mm hole drilled with a step drill
Mounted located at the centre height of the selector in the lower panel

Safety Issue
With the adapter installed onto the firewall using cap head screws, an issue was noted. The shaft connecting the valve and extension is designed to float captive between the two devices and could slide between the screw heads and lock the assembly. 

After examining a series of options, a custom 3 mm thick washer was manufactured and fitted with counter-sunk screws. This was the safest option while maintaining the original design intent. 

Note: See comments re: this issue

The drive shafts supplied were trimmed to the correct their correct overall length, and a coupling created from a piece of 1/2'' x 0.035'' 2024-T3 was inserted into the shaft and then fixed at both ends with 1/8'' x 6.5 mm pop rivet [2 off].

Assembled extension shaft

The 3 mm washer was fixed to the firewall adapter using 3 [three] 10-32 counter-sunk screws treated with Loctite Thread Lock. 

Valve firewall

The shaft was slipped on at the firewall end with the selector reassembled to the instructions supplied. With the tube fitted to the adapter, the selector was inserted and secured using M3 x 12 stainless steel counter-sunk screws. 

Checking revealed a bind, and this required a 90 deg. The chamfer is to be incorporated on the washer at the firewall side. This traps the torque tube between the valve adaptor and the washer.

The completed assembly operated as intended.

Note: The valve and selector have to be phased - this was done by placing the valve and selector in the left-hand position and riveting the shaft to the coupling.

Comment
The operation of the valve allows easy clear selection of the required tank in flight. The valve lacks instructions and drilling templates with a range of accessories that are poorly configured, letting down an excellent product.

Doing it again, I would move the valve to the port as it may be tight for fittings between the hydraulic cylinder and the valve.

Issues
At the time of ordering, Zen-like skill was needed to navigate the Spruce site for the parts and an additional extension shaft was not ordered. Currently, there has been months of back-and-forth emails in an attempt to purchase an extension shaft from Aircraft Spruce.  

If you try to order it after an original order, it's just not possible. To do this, you have to order a complete assembly, but there are no instructions to calculate the length and not having the correct information = impossible = Catch 22.

Dilbert truly understands

Big surprise, I opened my last Spruce shipment to find a complete extension kit that I did not order - I think - cost $US 118, whereas the extension and single universal is $ US 13!

I decided to use the shaft and universal, creating two unused adapters. Also supplied with the new adapter kit are a spacer washer and screws that were not supplied with either of the two extension kits, so I can only assume that was missed previously by Spruce.

Can I explain? No chance, but as I have been waiting over a month for a reply to be supplied the extension only, I decided to just finish the drive and fight on for common sense to prevail. 

Hand Brake - Part 1

This blog cover the installation of a handbrake.

Construction

The valve selected was one on the shelf that close's both ports. To activate the valve a remote cable is fitted onto the lower panel. 

Grove Brake Valve
Part # 06-01261

T-Handle dash control is manufactured from aluminium and brass. Locks positively, will not vibrate loose. One-fourth turn locks it in any position and will hold up to 100 lbs. All part numbers are from Aircraft Spruce Catalog Installation A hole was drilled in the lower panel as detailed on the layout drawing then the handle was installed with the hardware supplied. A mounting bracket was folded from 0.040'' 2024-T3 aluminium, treated and then match drilled to suit the valve. The valve is secured to the bracket using M5 screws and rivet nuts installed into the bracket. Note: Valve mounting holes drilled from 3/16'' [4.8 mm] to 5.5 mm. Valve and mounting brackets Bolts to be trimmed and cable bracket to be riveted The bracket was fitted to the firewall using three [3] 4 x 8 mm and cable attachment was fitted with two [2] 3.2 x 8 mm pop rivets from the firewall side. Next the valve was fitted and the cable offered up to the valve and trimmed to suit. A bracket was then manufactured and fitted with an aluminium clamp fitted to the cable outer and the wire inner terminated into a wire swivel from the parts box. Hand Brake System T handle lock nut replaced with nylock half nut Finishing A suitable label will be printed to suit the operation and fitted under the T handle on a 0.020'' aluminum plate at a later date.