Bits & Pieces - No 7

This blog covers detail tasks associated with main gear accessories

Brake Hydraulic Connections

Connection to brake caliper

The hose used is 3/16'' NSR tubing and SAE brass fittings designed to be used with this hose. In the exposed area near the wheel, the hose is covered with 10 mm loom tube for increased protection and appearance. 

The bare nylon tube was run along the face of the main spar secured with aluminium P clamp and pop rivets located in available factory holes in the spar web.

Electrical
The six wires from the two [2] limit switched combine at a 6-way plug located in the wheel well. Selected plugs are Seal All connectors having an integrated mounting slot in the back to accept a fixed mount. 

The mounting was fabricated from 2024-T3 x 0.040'' sheet, alodined, fixed to the wheel well using three [3] 3.2 mm pop rivets. The wires were prepared to the plug manufacturers specification, installed in the plug and fitted. The opposite side plug had six [6] length of wire run for later termination installed into 10 mm od wire loom and fixed to the spar using nylon clamps with pop rivets using available factory holes located in the spar web.

All exposed wire of the limit switches was installed into a nylon braided cover for appearance and protection in service with ends sealed with silicone or heat shrink as required.

All limit switches were fitted at the factory supplied mounting points using two [2] M3 x 30 cap head screws with M3 flanged rivet nuts installed in the lower mount to make removal of that switch more practical in service.

Main Pivot Bolt
The main pivot bolt was a threaded screw and this not personalty acceptable but hunt as hard as Google lets one, no alternative was available. At this point, the exotics were examined and a Titanium bolt  Grade 5, 6AL/4V was located and looked like it meet specification, after a lot of research a single M10 x 1.0 pitch x  40 mm was ordered just to suck and see.

At arrival, a trial fit proved it was correct and careful external examination showed it was manufactured to a high standard with the plain shank just a little short of requirement.

At this point the excess thread was removed with a hacksaw and a 2 mm thick washer machined. The bolt was inserted into the rod end and retained using thread locker applied at installation

Note: The head has an integrated washer but its was a tad small and the factory washer consumed too much of the plain shank. WD40 was sprayed to keep the bolt cool when cutting with the blade feeling blunt but it did cut cleanly


Comment
The connection bolt will be monitored for its performance in service but Titanium appears to have a suitable specification for this task but if a high tensile bolt is found it would be used.

Note: Titanium bolts are no substitute for bolts above 8.8 strength - recognizable through stampings of 10.9 or 12.9 on the screw head. If in doubt you have to assume that titanium bolts are NOT suited for the application to ensure your own safety.