Sunday 17 March 2019

Undercarriage Wheels / Brakes

This blog covers the installation of the brakes and wheels on the main undercarriage.

Overview
The kit is supplied with brakes and rims that require assembly as part of the 51% rule. This is well covered in the current manuals so the blog covers specifics and techniques used by this builder.


Installation
MARC brake - mounting plate
Preparation for match drilling

A - 1/4'' OD x 7/32'' ID KS Brass tube used to match mark mounting plate using factory drilled mounting holes in leg [tube protects existing holes]. 
The plate was removed then drilled to a 1/4'' using the drill press
B - Marc brake calliper [supplied with undercarriage kit]
C - Packers were used to set calliper angle for drilling [at hand]


With a calliper mounted with three [3] bolts onto the leg, next the wheel and rim were assembled and tire inflated to mount tyre into the rim. 

The disc was fitted over the axle and into the mouth of the calliper followed by the wheel after lightly greasing the axle. 

The retaining washer was fitted with a 2.5 mm x 15  pin which engaging into the axle for about 3 mm and then Loctited into the retainer washer with an M6 Nord-Lock washer fitted and torqued to 6 Nm.

Note: The pin was installed to create a fix the relationship between the retainer washer and axle allowing the Nord-Lock to work correctly - there are no fixed points available to install a mechanicial retainer relative to the axle, 

Disc Brake

With the disc fixed onto the rims mounting pads welded onto the inside face all four [4] bolts were secured with Nord-Lock washer, finally, the assembly was spun to check for fouling.

Note: Spring washers are supplied to secure the discs with Nord-Lock just a personal choice

The final task was to install the fittings for the brake lines and to secure the brake line to the undercarriage using aluminium P clamps lined with Mylar tape.

Covers
A pair of Matco 6'' MH Series Covers were installed to help reduce the induced drag created by the open face of the wheel. 

The Matco clips were trimmed to a 40 mm overall length to suit the factory supplied rim, to fit the clip into the ring located at the base of the rim, required the inner edge of the clip to be radiused with a washer fitted between the ring and clip. 









Comment
Followed the factory notes and associated diagrams.