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UK owners must treat the insides of all the rotor blades and open tubes against possible corrosion. A soft rag is soaked in warm ‘Waxoyl’ and dragged through the cavity on a wire, leaving a thin film on the surface.
Here’s my vice - mounted balancing fixture. To find out if you have the two thin steel plates absolutely horizontal, see which blade is heaviest then rotate the assembly 180 degrees and see if the same blade falls by the same amount.
I’m not sure about the vertical balancing method shown in the manual. You are told to balance washers (up to four) on the end of a pitch horn. - which I held in place with a tiny piece of tape. The manual later tells you to add the washers to the outside of the rod end - past the rotating axis, effectively adding weight to the other blade. Hmmm. I’m still thinking about this one.
Update: Southern Helicopters told me to ignore the vertical balancing procedure. They will fine tune the balancing on the final setup.
The build instructions tell you to mount the TR frame tight to the 4th bulkhead. Two things prevent you from doing this. There is some cast-in lettering on the bulkhead where the top right TR frame runner sits. I ground this away with my Dremel. And there is a significant radius around the inside corner of the casting that would prevent the frame runners sitting both flush on the outer rim and tight to the vertical face. I filed the ends of the runners with a matching radius.
Here you can see the two lengths of studding holding the bearing plates the correct distance apart. The recommended block of wood (with its aluminium handle) is in place at the far end of the runners. I also cut two 3 mm thick aluminium plates to wedge between the ends of the runners top and bottom to help keep them tight to the bulkhead. You can just see one of them above the wooden block
The Rotorway drawing shows the length of the aluminium angles at the rear frame as 4 1/2 inches. I felt this left the hole a little close to each end. I extended the length to 4 5/8 and filed a slight radius so the angle sits neatly in the crease formed by the two riveted stringers plates.
Here’s the frame in position. I’ve bolted and Clekoed the parts at this stage so I can strip everything, de-burr the holes and paint it before final riveting.
I was a little concerned that the holes in the pulley plates aren’t drilled very accurately. I tried putting all three bolts through a pair of plates and found a slight misalignment. I selected best matched pairs and drilled through, keeping them aligned with at least two bolts at a time. Thankfully the pre-drilled holes seem to be undersize anyhow.
I’m fortunate to have a universal milling machine which I used to shape the plates. I held them in the vice with the templates attached then levelled them by eyeing the template lines against a spirit level.
I left the pairs bolted together to shape and dress them then stamped the pairs A and B to identify correct orientation later.
I have another builder to thank for this one. I made four 4 mm thick steel square plugs for the TR floating bearing carrier plates. Holes are drilled centrally in the plugs which are a nice sliding fit in the carrier’s square holes. This keeps both bearings and thus the TR shaft perfectly aligned.
I like the idea of Black and White striped TR blades so I made a simple holding jig from a 2 ft x 1 ft piece of 1/8 in steel with a welded bush in the centre to accept the TR shaft
I first painted both blades with a couple of light coats of grey etch primer then marked out the stripes, 3 Black and 4 White on each blade, keeping the joins between the trailing edge rivets. I used narrow PVC Automotive stripe masking tape to define the edges and masked the gaps between with regular masking tape. I painted the white first and let it cure for a day or so.
Next stage was to remove all the masking and remask on the edges of the white stripes and paint the black. If the same number of coats are applied in each colour the white and black stripes will all be at the same level. A light rub down and polish will make the joins disappear to the touch.
UK CAA requires these little P clips be made to secure and guide the TR cable along the inside of the Tail Boom. Four rivets are drilled out at specific positions and replaced with new rivets, also fixing these clips. The clips are covered with Heat Shrink and are a good loose fit around the cable allowing it to slide without chafing.
The tail rotor assembly is fitted. Now I’m playing with the GRP shrouds. I’ve masked the tail boom to protect the paintwork while I work.
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