A keeper plate fits across the bottom of the bearing retained by two 12BA screws tapped into the bottom web of the guide. The bearing is drilled and tapped 12BA for the rod. The 12BA threaded rod is screwed into the bearing. Ensure it does not foul the axle. It must be a free fit in the keeper plate. The keeper was made from scrap nickel-silver from a fret; drilled for the two retaining screws and a hole for the spring screw. Assemble the bearing into the guide and pilot the hole for the spring guide from the hole in the keeper plate. Drill and tap the bearing 12BA. Fit a long 12BA screw; reassemble into the guide and fit the spring. Retain with a nut and washer.

Suitable springs can be purchased from Eileen’s Emporium or a specialised spring maker. If a fully threaded screw is used under the spring ensure it runs freely in the keeper plate. The thread will ‘buzz’ if it fails to clear the keeper plate. Alternatively thread each end of a rod so that the plain portion goes through the keeper plate.

Mark out the chassis sides in a similar manner to that for the Slater’s guide. In this case the slot for these guides has to be a little larger than the square dimension of the bearing.

Again check for the location of frame spacers. And modify to suit.

Assemble the guides to the frames taking the centres from a set of rods. Illustrated are jury axles, but again a chassis jig could be used.

Solder the hornguide in position keeping the sides vertical. Arrange the bearing to side midway in the slot. Note in the illustration the rods have been removed to make the picture clear.

Assemble the rods and wheels to the chassis. It is likely that the springing may be too stiff and the chassis rides high. Either change the spring for a lighter rate or trim a number of coils from the spring. This can be a process of trial and error. The spring retaining nut should just compress the spring when all is set up. Lock the nut when you are happy with the position.