DCC 6 pin tags

[the fuzzler]

I'm putting a toe into N gauge DCC. It seems that I'll have to buy some non-socket fitted locos, and get the 57/66 with the 6 tag dcc pcb.

 

How easy are these to do ? I'm okay with a soldering iron on OO stuff, but the small size scares me. Anyone got any photos/advice on such installations ?

 

Thank you

[Edwin_m]

There's a pic on the Farish website. You should get one of these datasheets with the model but sometimes they are missing so work remembering the link. This is the 66 but as far as I'm aware all the other PCB-DCC locos use the same arrangement.

 

The soldering itself I didn't find too bad if you are OK with soldering wires to N gauge rails for example. I've done four and not managed to wreck one yet! You need to run the wires in between the components on the PCB so that the roof goes back on (it probably wouldn't on that photo!) and make very sure that the decoder can't touch the metal chassis. Good idea to start from the pad nearest the decoder and work away from this so you don't have to solder near the wires you have already finished.

 

Also best to slip a couple of bits of heat shrink onto the motor contacts where they go down into the chassis if they don't have this already, and also a Plastikard spacer in the gap between the chassis and the PCB. Decoder-frying shorts can happen here, for example if the replacing the bodyshell pushes the PCB down a little bit. Check the wiring on your programming track after you've finished and again after you put the body back on!

 

If you make a total hash it is possible to get spare PCBs at a price, or even to hardwire the loco with no PCB, though to do this you'll need resistors on the lights. It's also very easy to get independent control of the tail lights with a four-function decoder.

[Nigelcliffe]

Its a matter of practise, confidence, right tools, right materials.

 

Practise - get some scrap PCB and arrange some solder pads (use a file or saw to cut small pads). Get some wire of the same type as that used on decoders (eg. the off-cuts !). Practise soldering wires to the solder pads until Confident you can do it with a good clean joint with a very small solder blob, and quick enough to not melt all the insulation on the wire.

 

Right tools - soldering iron with clean tip. Decent lighting. Method to hold everything in place (tweezers, clips, cradle for loco, etc.). I use a scratch brush to clean any oxide from solder pads before starting. I usually use a temperature controlled iron, but have made very small solder joints with an 18W mains iron.

 

Right materials - solder is now complicated by the "lead free" rules for all commercial products. So, if re-making a commercially made joint you have to use lead-free solder (higher temperature, harder to make a joint). If making a new joint, stick with lead-based solder. You need two soldering iron tips, one for each type of solder.

 

 

I have made new PCBs for Farish diesels, using a fine saw and file to cut tracks. End result with a six-output decoder is independent lights, and a cab light, and my trademark working couplers.

[Etched Pixels]

I find the tag ones are actually harder to convert than the non DCC ready Bachmann Farish to be honest - although in part because you've got lighting to solder up.

 

The tas are very small, the holes are small and if the wires stick more than a tiny amount below they'll touch the chassis block and short. If you use just insulation tape expect them to wear through it in time. You also need to fit shrink wrap around the motor contacts to make sure they never short against the chassis block. The later designs with the circuit board have the motor wire insulation problem fixed.

 

For the 66 you can simply get a later Dapol one which has a socket, for the 57 there isn't an easy alternative other than patience and practice.

[Edwin_m]

To be honest I just ignored the holes, tinned the end of the wire, put a blob of solder on each tag and dunked the wire into it. A solder sucker is useful if it all goes wrong...