Rudder Pedals - Part 4

Pilot and Co-pilot rudder pedals are connected using the stainless steel connecting rod's supplied with the kit fitted with M6 threaded rod ends at both ends.

This assembly was used to position the rear pedals - on this aircraft 10 - 12 mm of thread was left projecting from the end of the connecting rod. Both rods were adjusted to the same length and installed to set the position of the rear pedals. 

The pedals have to be fitted before the rod can be be installed finally.

Connecting Rod Installation

With both pedals installed the final center distance can be determined. The factory supplied M6 nylock nuts to lock the rods end but this builder favored a traditional method of a lock [half] nut. 

One issue that had to be considered is maintenance with access to the front attachment only through removable hatch's in the panel cover.  Examination showed that with the limited clearances use of Loctite would create great difficulty in the future. Even hex headed bolts would be a tough job and using cap head screws would prove impossible.

The method described required silver brazing the factory area washer onto the underside of the bolt head with the bolt locked using wire secured to a suitable tab. 

Four [4]  tab's were fabricated from 0.015'' annealed 304 S/S sheet from the firewall fabrication. 

Rod End Mounting Components

To ensure that that both assembly's are at the same centers a simple jig was manufactured by drilling 1/4'' holes into the edge of the work bench at the finished centers. To keep the rod ends on the same plane while tightening the nuts the rod ends are locked using two over size washers, M6 bolt and a clamp. The washers and clamp will lock both rod ends parallel to the table allowing the locking nut to be fully torqued while holding the tab in its correct location for ease of assembly.

Torquing lock-nut against tab and spring washer
Tang of file stops the tab from rotating

Fanged Bolt
Bolt are plain shank in rod end

The tab and lock-nut are secured against a M6 spring  washer at assembly. 

Assembly required the pilot pedals to be bolted first then the the co-pilots using the flanged bolts. Before installation four [4] 1/16'' holes are drilled in the flange of the bolt washer for the lock wire attachment. 

The bolts were inserted and tightened and operation checked.

Comment

The components are painted red for inspection and to allow passengers to be told "If its red do not impede it operation" as it a little tougher to monitor people in a tandem.

Fuselage Floor Plate - Part 3

Note: Location of the rivets securing the plate to the longeron should be considered with the location of the seat bolts - our location was adjusted to line about the center of each rivet group.

This post should be read in conjunction with Part 1 on the floor plates. In particular the installation of the angle support for the co-pilots plate at Station 3.

Port Floor Plate
Drilling mounting holes using factory jig

Both plates installed square to the longeron and drilled to accept 1/8'' pop rivets using factory jig at 30 mm pitch. At this time the mounting holes into the angle mounted on station 3 are not drilled as the lower skins have to be installed for this task. The reinforcing plates are to be installed once the location of the rudder pedals are determined.

Fixed the plate with 1/8'' countersunk pop rivets using the holes drilled previously.

Finishing the Floor Plates
Once the pilot rudder pedals and connecting rods the location of the doubler was determined and fixed as per the front floor plates.

Floor Plate Attachments
Rivets for attachment at Station 3 are not fitted
allowing station to be aligned with pre-drilled skins

Joystick Assembly - Part 2

The Infinity stock grips were selected for this project as they fitted into the theme. A pair of right hand set were located on the local RAA market and purchased. It was decided that not all of the switches were required for the pilot with even less for the co-pilot, so the switches not required were removed. The unused openings were plugged with plastic buttons.

While the hand piece were open the cable was split and the unnecessary core's removed and the remaining cores fitted into loom tube and installed in the joysticks, threaded through the air frame.

Fixing Mounting Grip's
The hole the base of the grip was the correct size as the stick grips 1.0'' [25 mm] so the installation requires no adapters and are secured using the mounting provided.

As this aircraft is from a styling view point RAF meets RS Warbirds, a collar was machined and painted yellow to place under the stick as per the image opposite.

Joystick installation

The collar is machined from ABS Plastic and painted yellow and fixed with one [1] 3/32'' pop rivet to column.

Pilots Seat - Part 2

The front bar was drilled and tapped to allow future installation of the crutch strap. A set of four [4] holes were drilled to suit M6 grade 8.8 screws to allow mounting of the seat using four [4] M6 medium length rivet nuts inserted into the longeron, these were chosen as they provide a larger head on the underside at installation when installed.

The original slotted holes for the bracket mounting were filled and dressed.

At this time upgraded drawings for this area were received from the factory and builders are advised to refer to the latest drawings. The work described had been completed before the drawings arrived for the affected area.

Latest Drawings from Flying Legend

Inserting Rivet Nut
Block required to initiate closing of rivet nut

Rivet nut's installed
Two new ones added at the location shown on factory drawing.
Middle nuts from original install at factory bracket locations

Seat Bracket installation
Bolt at center of bar for crutch strap

All parts were painted satin black using Wattyl Super Etch Black and Machinery Grey for final installation of rudder pedals, foot supports and the seat. The seat required many, many reinstalls to check position before drilling holes and in all took a full weekend for that task and bracket preparation.

Pilots Seat - Part 1

A trial assembly of the seat showed that the seat would not just be a bolt in exercise. A quick call to the factory confirmed that the manufacturer was having problems with accurately inserting the attachment point's in the seat shell. While the seat can be installed it was not square enough for this builder, even with the brackets adjustment maxed out. 

This required a rethink.

As the problem was attachment position in relation to the brackets it was decided to break that connection. A piece of 2'' x 1/4''  2024-T351 aluminium was selected to allow the necessary countersunk screws and tapped holes to be installed. The first task was to define the relationship of the mounting holes to the seat body. Tape was located across the base of the seat using the molded crease line and a center-line was established and the bars located off these center lines.

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Locating the mounting bar

Mounting Bars

The bars were removed, drilled, countersunk and fitted to the seat shell using M8 X 10 countersunk Unbrako screws.

The next task was now to locate the seat in relation to the air-frame. This took a number of fitting with the brackets clamped to the longeron and resting the seat in the fuselage.

Seat Location

Stick Location

Seat aligned about stick center-line

A length of M6 threaded rod was inserted into the pilots stick using the front stop mount with the center of the cushion marked with tape as shown. The rod was centered by measuring its location to the frame. 

The back of the seat was positioned 185 to 190 mm from the side of the fuselage placing the side of the seat cushion at approximately 200 mm from the outside edge of the frame using the bulkhead as the reference between both sides. A final series of visual tweaks using the rod and center line on the front of the cushion finally located the seat. The first set of holes was transferred using a felt tip pen from the brackets to face off the front bar. With the seat removed both holes were tapped M8 through.

The bracket were mounted using M8 x 10 Unbrako cap head screws - reinstalled as per the above and the final holes marked on the rear bar. With the seat fully bolted to the frame the final check confirmed that the seat and bracket were in line and square to this builder satisfaction.

Brackets Mounted
The seat brackets inside face aligns with the inside
face of the fuselage longeron

Engine Mount - Nose Wheel

A trail fitting of the factory engine mount confirmed that all the mounting holes aligned correctly between the mount and fuselage. The mount was then removed and the necessary fitting work to allow installation of the front undercarriage leg commenced.

Engine Mount Preparation

Both rear pivot faces were dressed on both sides to remove the paint and to ensure that the brass pivot tube projects 0.75 mm [0.030''] nominal beyond the end of the pivot mount ensuring the link will pivot freely with the bolt tightened.

Upper Pivot Mount Dressed

Fitted the limit switch trip to the arm with M4 x 12 pan head screws and spring washers.

Installed the upper pivot arm onto the engine mount after applying grease to the all working faces with the shaft of the bolt coated with Loctite "No Seize" before installation. After the bolt was inserted the exposed thread were wiped with wax & grease remover to remove all lubricant transferred to the thread during assembly, torqued the bolt and rotated the link to confirm free movement. 

Upper Pivot Installed
This pivot must be installed before fitting engine mount

The main pivot point for the leg consists of a brass top hat bearing and washer fixed with an M10 Grade 8.8 bolt. The area where the brass bearing are installed has a coat of factory paint that was removed. The edge of the area to be not to be cleaned was marked using 20 mm masking tape with the paint removed using a combination of flat files, 240 grit paper and scraping. With the paint removed from both sides the bare steel faces were lightly dressed with a flat file. 

The top hat bush was dressed with a file while avoiding damaging the face of the boss, next the washer was polished on a flat surface on 240 grit wet & dry paper. When both were finished the assembly was trial fitted to the pivot point on the undercarriage leg which indicated that the assembly would not rotate freely. 

The bolts securing the main pivot were manufactured using a 10 mm grade 8.8 hand threaded to provide the correct bearing area - threads were de-burred and lightly primed, twice with Wattyl single pack etch primer to provide corrosion protection in the thread root.

Main Gear Pivot - typical both sides

A suitable 1/4'' drive socket was wrapped in a piece of fresh 240 grit wet & dry paper until it was tight fit in the undercarriage pivot point and rotated squarely through by hand. Once the bush would rotated freely in the hole the pivot point was then de-burred and the assembly re-checked.

The lower pivot point for the lower link was dressed and the bushes inserted to confirm they projected beyond both faces for 0.030'' [0.75 mm] nominal.

Nose Gear Lower Link Attach Point

Engine Mount Installation
The mount was fitted onto the firewall with the upper link installed as it cannot be fitted after. All mounting bolts were fitted with the aid of a 6 mm drift and 8 ounce hammer. The Nylock nuts were fitted at the inside face with flat washers and torqued to 100 inch pounds.

AN5-26A bolt's were substituted for the factory bolts grade 8.8 bolts requiring two full AN960 washers. A grade 8.8 bolt has a maximum allowable stress of 870 N/mm2 where as a AN bolt has 880 N/mm2 [125000 psi] so they are structurally equivalent but with the AN5 bolt begin 0.002'' smaller in diameter, this was considered by the builder acceptable as the AN bolts allowed a plain shank at each of the load bearing point's between the mount and air-frame. 

Nose Gear Mounting
The brass bushes were greased with the pivot points, assembled with the mounting bolts pointing out to create the maximum clearance for the push rods connecting the undercarriage to the rudder for steering. The freedom of the leg was confirmed with it freely oscillating when disturbed. At this point the final link was greased and installed and the operation rechecked - no binds were detected and all bolts torqued to their recommended values.   

Hydraulic Cylinder
The cylinder supplied with the kit required each end to be sealed - the top side was treated with Loctite 601 for a permanent assembly and the lower with Loctite 232 [Teflon tape is used by the factory]. The position of the two inlets was aligned to allow the hydraulic hose's to be connected at the front or the cylinder.

To mount the cylinder brass top hat bushes were inserted into the mounting holes with the factory bolts fitted and torqued top and bottom. The ports for the cylinder were covered with masking tape with a small hole pricked allowing the cylinder to breath during assembly and hand cycling.

All bolts are marked with yellow paint to confirm that all bolts are now torqued.

All in all no real issues encountered - a good few days.

Rudder Stab - Part 2

It was pointed out to me by Franco from Flying Legend that the first third of the rudder and elevator stabs are to be flush riveted. This had been missed at the assembly of the rudder stab and it was intended to leave it that way, however the inclusion of a beacon on the top of the fin lead to a rethink.

Rudder Stab
To provide a route for the beacon wiring the stab the leading edge was the most suitable route with the option to flush rivet only requiring de-riveting it would be possible to kill two birds with one stone.

Once removed the fin and ribs were dimpled using the same tool & technique used on the elevator stab. Dimpling was added to each hole up to the but not including the front spar. 

Two [2] 20 gauge wires were run up the face of the stab using a series of 1/2'' flared holes added using a hole saw and flaring tool as used on the side covers. The cable's were inserted in a nylon web cover located using nylon saddles and riveted to aluminium angles folded from 0.020'' aluminium.

The front nose was reinstalled, clecoed after a final check re fixed using countersunk rivets.