Just a quick q on Ringfield 'Type 2' conversions to DCC

[RobinofLoxley]

In case of any doubt Type 2 is the Nomenclature used by Brian Lambert to categorise the conversion procedures - type 2 is the one where there is no cable from the tender wheels, the motor block and chassis are used to carry the power to the motor brushes. In my specific case its a King Class, tender drive obviously.

 

The nylon screws are on order from Peters spares.

 

I was just wondering the best way to connect the 'Red' wire to the block and chassis. I cant see anything wrong with simply soldering the wire to the chassis weights, as these are connected via a screw; I could equally put a ring connector around the screw body and just tighten them in place. I would connect one wire to each weight, but Im 99% sure that its all a common framework anyway so only one wire is needed. Have I erred? Thanks.

[Amand]

Easiest way is to remove the brass coloured gear retaining clip. After removing any surface oxidisation it takes solder well, and when removed it doesn’t use the metal block as a heat sink. I take it you’d be soldering onto the brush retaining arms, do all three in one go.

[RobinofLoxley]

2 hours ago, Amand said:

Easiest way is to remove the brass coloured gear retaining clip. After removing any surface oxidisation it takes solder well, and when removed it doesn’t use the metal block as a heat sink. I take it you’d be soldering onto the brush retaining arms, do all three in one go.

Thanks for the reply. (I had looked at one or two videos on youtub and quite frankly theyre not up to much, as my tender drive stock has design variations seemingly unknown to these posters).

 

I hadn't considered the possibility of using the retaining clip. Im not keen on it because to me, there is too much risk of poor contact, as the clip is not a forced fitting on the gear drive pinions but a loose one.

 

I was intending to use the brush retaining arms because the first tender drive I am converting, which was the best runner on DC, has screws into the motor housing that Im fairly sure carry current. I was going to replace them with the PS13 screws which I understood were to eliminate this contact, being nylon. However the screws I have dont fit, they are the wrong diameter and screw pitch. So I will have to isolate the retaining arms by using plastic washers that I will have to make, not what i wanted on the first conversion but there you are.

 

Sorry, i dont understand the reference to using the metal block as a heat sink.

[Amand]

The retaining clip should be a tight fit where it locks into the chassis block. I’ve soldered all my ringfield models to this clip and never had a bad contact. If you leave the clip in place when soldering the block will act as a heat sink, drawing the heat away from the area being soldered, so it’s best to remove it. With regard to the nylon screws I’ve used them too on models that have a live connection. Trim the last few mm from the end first.  Screw half a turn, wind it back 1/4 then forwards 1/2 turn so the block cuts the screw thread to fit. With practice you will get a screw that drives fully home and locks the arm in place. It the screw is too slack then use one winding of PTFE tape.

 

A better solution is to fit one of the CD type motors and use diodes to reduce the voltage if running on DC. For DCC my standard fit Zimo decoders are used with the output voltage CV changed to limit the top speed.

[RobinofLoxley]

5 minutes ago, Amand said:

The retaining clip should be a tight fit where it locks into the chassis block. I’ve soldered all my ringfield models to this clip and never had a bad contact. If you leave the clip in place when soldering the block will act as a heat sink, drawing the heat away from the area being soldered, so it’s best to remove it. With regard to the nylon screws I’ve used them too on models that have a live connection. Trim the last few mm from the end first.  Screw half a turn, wind it back 1/4 then forwards 1/2 turn so the block cuts the screw thread to fit. With practice you will get a screw that drives fully home and locks the arm in place. It the screw is too slack then use one winding of PTFE tape.

 

A better solution is to fit one of the CD type motors and use diodes to reduce the voltage if running on DC. For DCC my standard fit Zimo decoders are used with the output voltage CV changed to limit the top speed.

Didn't think about the other connection!!

 

I'll try that approach with the screws, but the insulation method is always available as an alternative. One side, there is no way on the first conversion that the screw shaft will go in.

 

I'm using 100% Zimo on a z21 and I can adjust the top speed through the app. A CD motor conversion is planned for an old A4 which lacks power and has to pull my old pullman stock as a heritage train 1960 style