Wednesday 26 September 2012

DCC Conversion - How I converted a Ringfield motor

**Disclaimer** I am in no way a professional and accept no responsibility for anyone who chooses to follow this guide or trashes their beloved pride & joy by following the steps below. This isn't published as a guide, it's purely to show how I converted the loco for DCC operation.

The Ringfield motor can be found in later 8F's, Castles, Westcountry class and many Wrenn 2 rail locos, as well as my little diesel shunter here.

You will have to drill out the end cap of the motor to convert a Ringfield motor to DCC. You will also need a decent soldering iron. Mine is 60w - I found that the cheaper soldering irons aren't man enough for some of the dublo soldering jobs.

So this is how I converted my diesel shunter, with Ringfield motor, to DCC:

Diesel Shunter, casing screw removed, ready for dismantling
With the casing removed, it's time to remove the electrics & brush springs, followed by the 4 retaining screws that secure the motor end cap to the chassis - I've also removed the motor bearing to avoid any metal filings ending up inside the bearing when I drill the end casing later...

Motor end ready for removal

Now with the end cap removed from the chassis, the un-insulated brush holder needs to be removed...

End cap removed
I use a brush holder plug from a scrap Dublo loco to carefully push out the brush holder, using a pair of long-nose pliers...

Dublo brush plug inserted into the brush holder from inside, ready to push out the holder

...And it pops out quite easily...


Brush holder removed, undamaged so it can be re-used!

This is the point of no return, so unless you're 100% certain that you want to convert then STOP NOW!



In the vice, ready for drilling

I used a 6mm drill bit to enlarge the hole ready for the new insulator...


New insulator, sourced from the internet

Once drilled, I carefully press the insulator into the end cap...


Insulator fitted

I then need to refit the brush holder, I used the vice to do this bit, slowly & carefully pressing the holder into the insulator...

Pressing the brush holder back into place

Voila!

Perfect!

At this point I test to make sure that both brush holders are electrically isolated before I refit to the chassis & fit the brushes...
There should be no resistance between the brush holders & casing, if there are then remedy this before proceeding any further.

I've now re-assembled the motor, brushes and retaining springs, time to check again for resistance to earth...



Before fitting the DCC decoder, I decided to run the loco on DC to ensure smooth running. A neo magnet has already been installed and as I previously removed the end bearing, I need to ensure that it's correctly adjusted. If the bearing is too tight then not only will the motor not run properly, it will also draw more current, potentially damaging the new decoder...


A rather crude method of testing the loco on DC prior to installing the decoder.

I'm satisfied that all is well so now it's time to install the decoder - This is where a good quality, high temperature soldering iron is a must, the connections to the brush holders need to be done quickly so as not to melt the plastic insulators.

Also worth noting that I've removed all traces of the original electrics. 1 of the 4 end cap retaining screws is also used to earth the brush spring to the chassis via a metal strip (in the below pic it would be the top right screw) which can easily be seen once all 4 screws are removed. This is discarded prior to re-assembly.


The decoder soldered in. I only need 4 wires so the remaining wires are cropped and secured inside heat shrink, just in case I want them in future.

Re-assembled and ready to be programmed. At the moment I haven't set up a proper programming track so for writing the loco address I use the Select controller as there's no need to keep swapping the wires!

When I come to checking the CV's I'll use the Elite controller.


Ready to go!

So after a quick blast round the loop, time for a little slow shunt...



Space is very tight in the diesel shunter, the chip is a very snug fit and has resulted in the case not fitting as flush as it did, I can live with it but purists may not be entirely happy, however a purist would probably have left it on DC!