Farish No. 8341, Class 33 Diesel - decoder fitting

[fffrank]

Hello all

 

Having a struggle figuring out how to chip my new (second-hand) eBay purchase. Started with some disassembly (and removing years of overzealous oiling). Here's where I got to - but I can't seem to find an idiot's guide to DCC-ing this model. Anyone got any ideas?

 

 

[aleopardstail]

if you find out I'd love to know as I've got a class 25 that looks basically the same

 

only idea to date was a pair of the digihats to isolate the top and bottom bush, each with a small bit of brass sheet for the top with a wire soldered to it, and a thin bit of plastic glued to the top so the existing clip holds it in place - plastic cut slightly larger than the brass bit (which can really be small, its just to get a wire soldered to contact the spring).

 

I think that should isolate both motor contacts to leave them just on the decoder motor output wires

 

then I guess the track wires to where that little capacitor is fitted

[Luke Piewalker]

Digihat (or equivalent) top and bottom. These come with a sturdy (Kynar) heatshrink tube which you slip a bit of over the retaining clip and that insulates the  brush and spring. Solder the decoder wire directly onto the spring.

On my 25 I drilled a small hole in the keeper plate so I could feed the decoder wire for the top brush (before you solder it to the spring) from behind the battery boxes on the underside with it coming out inside the bodywork (when fitted).

Remove the capacitor, solder one track feed to the brass plate in the middle, the other attaches to one of the four bolts that secures the keeper plate.

Kapton tape to make sure everything is insulated, and the decoder can be black tacked/blu tacked or what have you in between the battery boxes.