Friday, January 05, 2007

Brakes - building the shoes


Looks like this is where it starts to get fiddly. The brake shoes are held onto the rigging with pieces of wire. The whole thing hangs on the chassis, with the shoes around the wheels. Fortunately the rigging will be removable.


brake shoes (3 for each side)


brake shoe rigging

I open out the holes in the shoes with a broach then test with 0.3mm brass wire before cutting the shoes from the fret.



I try to cut close to the shoe, but there’s always some trimming to do with etched kits.



There are 3 small holes marked out in front of each axle. The lower 2 need to be drilled through to carry the shoes. Find that my newly-purchased 0.3mm drill bit is too small for my minidrill, so I use the tip of a larger broach till it breaks through, then open the holes out with a small broach till they’ll take the brass wire.



Don’t fancy folding the shoes accurately by hand. Conveniently my 1mm thick steel rule helps keep the angles square.

Suddenly notice that one of the shoes has gone missing, so I’m delighted to find that there are some spares on the fret.


Wires ready to be soldered to the shoe.



I've made both wires long enough to go right through the chassis, but they'll be cut back eventually.



A clamp holds the wires parallel while they’re soldered to the shoe.



Just a blob of solder inside the shoe. I need to keep one wire long to help fix to the rigging. Now to try the shoes in place around the wheels


I find that there's slight contact, so I need to file the back of the shoe just a fraction.


Now the wheels turn freely, I can worry about the rigging.

1 comment:

Chris Higgs said...

Beware, the extra hangers are in fact etched on a thicker material. This probably explains why you found one protruded more than the others later