Rudder Stab - Part 3

This aircraft is to be fitted with a red beacon located at the top of the rudder stab and a Aviolight beacon was selected based on its low weight of 40 grams and compact dimension's.

Red Beacon

An ABS plastic former was machined and glued into the factory supplied fiberglass tip. It was hoped that all it would require is a small amount of filler to be finish it off - this was not to be the case.

With the ABS former in place, automotive filler was added, then sanded with 60 grit painter's paper wrapped around a dowel. Additional filler was added and the sanding repeated then repeated again. The images of this process are to ugly for public publication so I restricted images to the final product which was the goal.

Fitting to Stab
As all the other faring fitted with little effort it was anticipated that this one would be no different - WRONG!

The fairing was fitted and when viewed from a firewall looked like a caricature of the Cat in the Hat. Examination of the stab skins showed that they did not line up so this had to be corrected. This should have been picked up at assembly were the leading edge skin could have been corrected easily.

Refitted the faring and it now looked like the Cat's had a hard night at the local bar, re-examination showed the base was now not square to the fairing vertical, to fix this the base was sanded to square.

At this point the next issue became apparent - the ABS former was square to the old base and with the fairing square now square to the new base but it now looked like the Cat had put the hat back on after a full week binge.

Misalignment of leading edge

At this point the builder responded by applying a series of incantations based on dubious parenthood and upbringing and after a cooling off more bog was added in anticipation of a round of fresh sanding at the next work secession. This capped three of the most unproductive weeks I have had on the project - ugh!!

Electrical Panel - Part 1

The aircraft cockpit that I most admire was installed in the FW190 designed by Kurt Tank. In a era when components were bolted to the first free bulkhead, Tank managed to provide a pilot with a console and ergonomics before it was a word. 

In any project you need a reference for a styling and to some degree this is mine and most cockpit since the 60's.

Hardware

With  the switch panel located at the top, connection to the circuit breakers only require a short loop of wire to provide power.

The circuit breakers used are Klixon for their small size with the only real disadvantage over the Potter & Bloomfield is that you appear to be unable to pull a breaker. 

The switches are a toggle's from Aircraft Spruce.





Panel Construction
Panel frame was manufactured from 0.030'' 2024-T3 aluminium sheet cut with the Ofla knife, dressed and folded. When all openings were finished the panel was primed and painted to match fuselage.

Preparing panel for mounting

The bulkheads were match drilled from the panel and three [3] x M3 mm riv-nuts fitted into both bulkheads, then the panel fixed with cheese head screws with spring washers.

Trail assembly

The openings are covered 0.030'' 2024-T3 plates fixed with 3 mm riv-nuts and cheese head screws with spring washers.

The panel for the circuit breaker was drilled using a 7/16'' [11.1 mm] drill. A breaker was installed at each end and the inbuilt anti-rotation tang used to mark it location at each end then a line drawn between the marks. Next a breaker was then reinstalled at each hole with the tang location marked and drilled using a 2 mm drill.

Trail fit to fuselage

Panel Finish

The big issues is how to paint the panel's, grey was a big change after the use of traditional black but everyone is grey so "black back again".

The only question left is how to finish it quickly but with a little style. It could be painted and decaled but not only is that slow and hard to do these days as the advent of large scale printers has changed the graphics industry so why not print the panels..!

The CAD system was fired up the labels drawn full size - exported at 1 : 1 to a PDF to see if they can be used by the graphics shop. If this works the main panel will be done the same but like all projects I have to wait and see..!

Jazz tracks wound UP and taking a few moments to dream

Rudder Cables - Part 2

Normally in these blogs reference to any additional information is at the end. With the task of preparing the cables and lock wiring the following article's were read and viewed before beginning.

The Big Squeeze

Video on Lock wiring Turnbuckle

Cutting Cable

Swagging Cables

My Big Squeeze

The goal

The manufacturer of the Swage-It tool recommends two [2] ferrules be used at each termination. A length of 1/8'' cable 4500 mm long was prepared at both ends applying one wrap of masking tap to allow it to fit through the ferrules.

The Swage-It tool will only work correctly with copper Nico Press ferrules, installed in accordance with instructions supplied with the tool using either plated or natural depending on cable type.

NO EXCEPTIONS......!



Rudder End
The initial assembly is covered in the article from kit planes and EAA video. 

After placing the ferrule against the thimble the Swage-It was fitted about the center of the ferrule and nipped up until it grips the cable lightly - once final adjustments were made, tension was maintained by pulling the cables and then using a series of 1/4 turns both bolts were tightened until they bottom out evenly

The Swage-It tool was re-positioned so the crimping jaw aligned with the outer edge of the ferrule, crimped then repeated at the rear. Positioned the second ferrule then crimped it using the same procedure.

Test crimp with Swage-It
Refer sample photo above

The waste was trimmed back using a cold chisel with a block of steel, I chose to leave about 15 mm for fear on nicking a cable. The standards state that the minimum tail is one diameter. 

The exposed tail was wrapped with self bonding buytal rubber tape to prevent unwanted installer blood loss and associated pain.

The crimps were visually inspected and checked using a go-no gauge on both sides at each crimp, next the cable was threaded through the fuselage, pulleys and nylon guides. 

Then at the rear secured using temporary AN3 bolt's to the rudder horn. 

Note: Due to the larger profile of the copper ferrules the opening through the tail had to be enlarged as they caught on the factory opening which was designed to accommodate the smaller steel ferrules.

Cockpit Assembly
The rudder was locked using two lengths of 75 x 25 mm DAR pine clamped to the fuselage sides then chocked using two piece's of packing foam fitted between the timber and the rudder skins. A length of aluminium angle was placed along the side of the fuselage using the top row of rivets as a datum. The distance to the edge of the rudder checked at both sides with the foam blocks moved in and out to adjust the position until both measurements are equal.

The front pedals were located using the firewall as the datum so it is critical that the connecting rods are the same length to proceed.


Basic Guidelines
"Safety all turnbuckles with safety wire using either the double or single wrap method, or any appropriately approved special safetying device complying with the requirements of FAA Technical Standard Order TSO-C21. The swagged and un-swagged turnbuckle assemblies are covered by AN Standard Drawings. Do not ever reuse safety wire. Adjust the turnbuckle to the correct cable tension so that no more than three threads are exposed on either side of the turnbuckle barrel. Do not lubricate turnbuckles."

Refer video for details

A&P Rigging Chart 
Ambient of 85 deg F [29 deg C]

Rudder Pedals
Assembled the cable loosely with a loop formed at the end with both ferrules installed onto the cable, fitted the thimble and the loose end of the wire through the first ferrule. 

Adjusted the length until the face of the thimble was in line with center of the mounting hole in the turnbuckle while applying as much tension as practical by hand, wrapped masking tape at the rear of the ferrule. 

Fitted the Swage-It as described previously and slid the ferrule up against the thimble and lightly clamped the ferrule. This operation was repeated a number of time to ensure NO slack was in the cable and to adjust the position of the thimble and when happy crimped the ferrule.

The second ferrule was placed about 50 mm [2''] from the first, crimped with the tail finished as described previously.

Cockpit Rudder Connection

Comment
The cables will be tensioned and lock-wired in a later blog once the fuselage has been displayed at AUSFly in September and will be written up at that time.

Rudder Pedals - Part 5

The technique for fixing the bolts originally outlined in Part 4 depended on the lock wire to hold the bolts into the pedal spigots but a little voice kept saying "not a good idea you are breaking the rules."

Connecting Rod Bolts
The treads of the bolts and nut in the pedals were cleaned with wax and grease remover to remove all trace of the no seize.

The bolts were all inserted and tightened using the flange of the nut and a pair of multi grips. Not personally a preferred method but the use of the cap head screws combined with access precluded any other method.

Each bolts was then lock wired using s/s lock-wire wrapped around the head on the washer side to ensure it did not lodge between the bearing and the inside face of the washer.

Each bearing checked for freedom of movement after lock-wiring before doing the next.

Comment: Fixed...!

Outrigger Bearing

The rudder pedals are connected to the nose gear to allow the manufacture of the rudder cables that is the last component in the rudder controls. A search reveled that item 16 the outrigger bearing was misplaced or missing from the kit. Additionally the aluminium cover for the slot in the wheel well had to be replaced with a stainless steel copy and with this aircraft fuselage having to be ready to display at Aus-Fly in 2015 the die was cast - manufacture with what was on hand rather than wait for the parts to arrive [a more practical option]

Some of the techniques outline would be applicable to the installation of the factory bearing but this blog is written to document the work so the builder can claim credit under AC29.21

Lever assembly

Manufacture of parts
A set of covers were manufactured from 0.020'' 304 stainless steel sheet left over from the wheel well fabrication. Cut a 22 mm diameter hole using a hole saw on the center of the sheet located at the top for the shaft to run through.

Using a piece off 0.25'' Bakelite a pair off bearings blocks were cut using 57 mm and 20 mm hole saws. The bore was polished to finished diameter using a suitable socket wrapped with 120 grit aluminium open cut paper until the arm [item 37] would rotate smoothly. 

Centered the bearing on the opening in the s/s cover and then drilled four [4] holes at 90 degrees with a #30 drill.

Cut the arm to it correct length and dressed end [see image below].

Lever cut to size

Alignment
The scrap from the lever arm was dressed and used as a spigot to align the assembly. With the bearing clecoed to the cover and the side of the wheel well was matched drilled. 

Match drilling using spigot

The assembly was removed and four [4] M3 rivet nuts installed and the bearing retained using four [4] using M3 x 16 mm counter sunk screws. The assembly was reinstalled with the spigot and the cover fixed with 3.2 mm s/s rivets. The mating face of the cover was coated with high temperature silicon to seal the mating faces. Once riveted the bearing was removed for final drilling. 

Counter sunk screws are fitted to prevent
silicon entering rivet nuts during fixing

The bearing was drilled and tapped M3 to suit the Seal-It installed on the face of the bearing to prevent the ingress of dirt into the bearing. The bearings seals were purchased blank for this project. The opening was created using the other scrap piece of 20 mm tube to create a wad punch. The outside edge of the tube was ground to a sharp edge at a angle of about 20 - 30 degrees creating a punch slightly undersized hole when fitted onto the lever shaft.

The bearing was reinstalled with M3 x 16 counter sunk screws and the seal fixed with M3 x 6 mm screws. The mating face of the bearing was treated with high temperature silicon before assembly.

Bearing and seal

Finished Assembly

Comment

Doing it again it would be better
locating the bolt closer to the pedals

When installing the bearing the use of the lever scrap as an alignment spigot ensured a perfect alignment with the rudder pedal stub shaft for all components.


Overall all components aligned well with no fouling in operation.

Rudder Shims

Drill pilot hole #30 through
Do not trim long tab it is need to hold the
shim during drilling

Enlarge hole to 6.0 mm

Trim using stainless steel scissors
A 2 - 3 mm tap is left on the un-drilled
side and placed against the bearing block
as an anti-rotation tab

Installed ready for caps