Graham Farish N gauge Class 25 25326 DCC install?

[aleopardstail]

Hi, I've recently picked up a GF Class 25, 5 pole motor, #25326, and very nice she is, runs smoothly. I would like to convert to DCC but have never converted an N gauge model (I did some OO stuff well over a decade ago)

 

I've had a go on google but the chassis for this model seems unlike the images I've found, its not the classic split chassis along the length of the model - the motor contacts appear to be on the top and bottom of the motor. I have yet to buy a decoder, ponder a Zimo MX617F, the model doesn't have lights and no burning desire to try and fit them (though there is space at the ends so who knows later)

 

are there any guides for this type of chassis?

 

shes a beautiful little loco and I really don't want to break anything

 

any help or suggestions very welcome

[woodenhead]

White gears, that looks old.

 

Digi-hat is your friend for these - not used one myself but I did read all about them in the past.

 

https://www.dccsupplies.com/item-p-100525/digi-hat--the-easy-way-to-convert-graham-fari

[aleopardstail]

I think the gears are new, apparently changed at some point. I can sort of see how the digihat works, guessing used to isolate the top brush from the chassis - not entirely sure how to secure it though, likely needs that metal strip on top of it replacing with something insulated but with a small brass contact that can have a wire soldered to it.

 

wondering if it may need similar on the bottom

 

I think shes one of the older British made models given "Britain" is on the bottom, have a class 47 with brass gears of a similar vintage but slightly different internal layout as well.

 

both appear to have space for a small decoder without too much butchery (the cl25 has space both above the motor chassis block, at the ends and likely on the underframe, the cl47 above the chassis block)

[Luke Piewalker]

Copied from my post in the 33 thread

 

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.

 

The screws on the end allow you to remove the end sections of the chassis block which do indeed secure the bogies.

[aleopardstail]

excellent, will give this a go