Graham Farish split chassis - DCC guide

[Number Six]

This thread is a bit out of date now. The latest version of the Farish 170 is MUCH easier to hardwire a chip into. Although it's still split frame, the motor gets its juice through a couple of thin wires that are conveniently accessible. Just snip the wires, bare and tin the ends and solder the chip in (a jeweller's loupe, a fine tip on your iron and a steady hand are rather handy here). There's even a recess in the top of the frame just made for tucking a chip into! I've done this using a spare chip from a Dapol 66 (fitting a Zimo chip transformed this loco, but that's another story).

[mander]

Hi,

 

I´ve tried this on a Class 52 split Chassis. After making the modifications and adding the wiring to the loco I tested it on DC and it ran fine, no shorts.  When I added the DCC chip it, checked there was no short circuits again, tested it, smoke came from the decoder.

 

The question I have, does it have to be right rail and left to the corresponding pins and if so, what happens if you place the loco around the other way on the track by accident?

[Nigelcliffe]

On 11/01/2021 at 14:34, mander said:

Hi,

 

I´ve tried this on a Class 52 split Chassis. After making the modifications and adding the wiring to the loco I tested it on DC and it ran fine, no shorts.  When I added the DCC chip it, checked there was no short circuits again, tested it, smoke came from the decoder.

 

The question I have, does it have to be right rail and left to the corresponding pins and if so, what happens if you place the loco around the other way on the track by accident?

 

No, doesn't matter which way round the pickup wires go (unless you're planning to use ABC braking, then it matters).  Or the motor wires.  

 

What does matter is that there is NO path from the pickups to the motor wires.   What happened to you is consistent with leaving some connection path from pickup to motor brushes somewhere in your work.   It will work perfectly on DC (because you need a path from pickup to motor), and will be a instant smoke with many DCC decoders.   
Need to check, very thoroughly, that there is no electrical path from pickup wires to brush gear, including any possible movement of motor, stray bits of wire, possibility of wires moving, etc..  Checking both pickups for each motor wire (ie. four combinations to check).  A multimeter set to resistance or continuity is used for such checks.     

 

 

[Ken Hewson]

Hi

New to you web site but when trying to view the Fitting a TCS M1 decoder to a Graham Farish 170 thumbs I get access denied.

Can you let me know what is wrong.

Regards

Ken

[AY Mod]

3 minutes ago, Ken Hewson said:

when trying to view the Fitting a TCS M1 decoder to a Graham Farish 170 thumbs I get access denied.

Can you let me know what is wrong.

 

If you mean that you can't see the images in an earlier post that is because we had a server drive failure last year and many images could not be recovered.