Sunday, 22 March 2020

Sound Job (fitting sound into a Farish 31)

Having invited others to post on here I ought to lead the way; so here goes with my second sound fit, of a 2FS locomotive, a Farish class 31. Of course the conversion is straightforward for getting the model to run on 2FS track. It is a case of either turning the wheels yourself or sending off to the Association wheel turning service. This particular locomotive has the A1A A1A wheel arrangement with the two centre axles on the bogies having different size wheels to the remaining four. This is, of course just as it is on the prototype. Because of this I made the decision to machine these wheels myself. I won't bore you with the conversion, since for most folk it's a case of post the wheels off.

I have now satisfied myself that the best way to sound fit these 'N' locos is to discard the circuit board that allows directional lighting when running in analogue mode, well that's the way I see it and in my case these locos are never going to be re-analogue'd again. It is true that some form of simple 'circuit board' may be necessary in a lot of cases and the 31 is such a case because the head-code panel lights are illuminated by an upward facing LED and that needs to be re-fixed in place on a home made board (as seen) after the old board is discarded. The great advantage in getting rid of the board is, as you can see in the pictures, to save space to easily accommodate the decoder.


Above - regrettably I did not take pictures as I went along so all you have is the finished item seen here. This picture shows the chassis and, yes I know it looks a bit of a mess, but for me there are a couple of firsts. The rear lights are the blue, yellow and white wires which go/return via the pads at each end of the loco chassis. I'm now going to guide you left to right along the chassis pointing out certain things.

Just to the right of my thumb is the transversely mounted YouChoos MicroCube5 speaker (there are other sizes available) which is really quite a capable bit of kit. Loud enough for me - in fact when I last had Callaton out I had to turn the volume down a touch to avoid irritating other exhibitors. Next to that is the home made circuit board, necessary to enable me to fix the LED in place to illuminate the headcode box. The LED is the white square with a yellow circle which has to be soldered (carefully) to the PCB, across the gaps, otherwise it won't work or worse still cause a damaging short circuit. Apart from cobbling up the circuit board being a first for me, if you look very carefully at the board and you will spot my second 'first', the ultra miniature panel mount resistors on the board itself. These are minute and you will need a steady hand to solder them in. There are two reasons for using these

1) space saving convenience.
2) getting the lights dimmed to an acceptable intensity.

The purple speaker wires can easily be seen.

Next is the Zimo decoder itself which still has the manufacturers sleeve around it - easily accommodated because there is no Farish circuit board. A small part of the chassis has to be filed way here to enable the speaker to sit sufficiently behind the cosmetic cab detail. I did try to create a space for the speaker just to the left of the broad band of yellow masking tape but couldn't get the speaker I was using at the time to fit. The effort wasn't wasted though because it created a little extra space for the decoder which otherwise would have had to move to the right a little. The collection of wires to the right of the decoder are just a tidy up job but in there can be seen the older larger resistor which I had already installed before I got the panel mounts. I didn't see the point in replacing that since the extra work of swapping over just to save a little space didn't seem to me to be worthwhile. If I was doing this all the time I might be able to become quite proficient at it. As it is every time I start a new project I have to scratch my head a bit before starting and, up to now, at some stage during my construction I have had to seek advice. I'm grateful to Nigel Cliffe for checking my work, advising where I've gone wrong and pointing me in the right direction.



The photograph above is duplication so far as the chassis is concerned but does show I have got a driver in the cab and for good measure there's a bloke in the other end too..! There are now a couple of jobs still to do. Number change (can't have a Stratford loco at Callaton - might have to be one from Thornaby or Immingham) and a spot of weathering. 

Mick S.

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