convert diesel (1973 ish vintage) to dcc

[Nick362]

is there a video of how to this anywhere on youtube - I have never attempted a conversion to dcc but would like to resurrect one of my old early 1970. hornby diesels so i can run it on my new dcc track

do i just buy an 8 pin saddle, wire it in, then buy a TTS decoder fora class 47 and plug it in??

 

Any help much appreciated!

[Fishmanoz]

Hi Nick, yes you do and no you don't until you've done some research and testing.

 

More info on the specific loco would help us give advice.  But you can start by taking the body off to check the motor type and configuration.  Steps to take:

 

-  first make sure it has been serviced and is running well on DC before attempting a conversion

-  now Google Brian Lambert and go to the DCC conversions part of his DCC pages.  Check what motor configuration you have

-  now do a DC stall current test as he describes.  Stall current must be less than 500mA or you will overload a TTS decoder

- most important to avoid blowing the decoder if you have a Ringfield motor - ensure there is no connection between the LH brush connector and chassis. All covered by Brian

-  make sure you have room for the socket, the decoder and the speaker and that they are insulated from any metal parts when mounted

-  depending on room, you may need to replace the speaker with a sugar cube type with correct impedance and power handling

 

 

I'm not trying to put you off but these points all need to be considered converting an older type loco.  If you do, your conversion should go well. 

[The son of Triangman]

 

Also the loco should be a good runner in sound maintenance before conversion

 

[Chrissaf]

....do I just buy an 8 pin saddle.....

 

I assume you mean an 8 Pin NEM652 Socket. You can buy these pre-wired which makes life a lot easier.

 

As Fishmanoz says above, it is important to perform a DC 'Stall Test' to ensure that your loco current draw is within the 500mA limit of the TTS decoder.

 

If your loco has a 'Ringfield' motor, then click this link and scroll down to the 'Ringfield' section to determine what 'Ringfield' type you have and the optimum conversion method for it.

 

Personally, I would avoid looking for a YouTube 'How To'. YouTube gems are very few and far between and in my opinion are mainly produced by the blind leading the blind. No disrespect intended to any 'visually impaired' forum members.

 

Instead this schematic will help with the wiring.

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TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

 

See also – further TIPs on how to get the best user experience from this forum. TIPs include 'How to post images' and 'How to make links clickable'.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

 

[Going Spare]

If the loco does date from 1973 it will almost certainly be the twin worm drive type because Ringfield drives did not come along in diesels until 1976, and it may even have serrated wheels.  If it is a class 47, it will have the early Fleischmann ringfield motor and smooth treads and directional lighting.

[Wobbley Junction]

I had a go at converting a Hornby Class 37 with the twin worm drive to DCC with a TTS decoder, wiring it was extremely fiddly and it kept cutting out or shorting on points. In the end I gave up and bought a Railroad 37 second hand at an exhibition. It runs perfectly even on speedstep 1/128.

Daryl

[ColinB]

If it is a twin worm drive loco you are going to need a higher current decoder than the current Hornby ones. I did the conversion on my Triang EM2, I even skimmed the wheels so that they would negotiate modern points. The conversion is pretty easy but I had issues with the plastic insulators going brittle and shorting out the decoder. In the end I converted the motor to take a current class 66 motor but used the original Triang bogie. It is worth adding pickups to the dummy boggie.