RMweb Gold Mikkel Posted March 4, 2021 RMweb Gold Share Posted March 4, 2021 I’m converting a Rapido/Model Rail 16xx loco to another class (2021 ST), and was wondering if it’s possible to do away with the PCB. Here is the subject: A sketch of the wiring: The PCB is not an easy fit in the saddle tank that I will be fitting. As I am DC and no-sound, I was wondering if the PCB could simply be removed and the pick-up wires connected directly to the motor instead? And if so, whether that might reduce running quality? (according to Rapido it’s a conventional skew wound 5-pole can motor). Lastly, I was wondering what the purpose of the small PCB might be, which would also have to go if I remove the main PCB. Any help would be greatly appreciated. I’m used to converting locos, but usually leave the electronics alone as it is not my strong side. Link to post Share on other sites More sharing options...
Simond Posted March 4, 2021 Share Posted March 4, 2021 Mikkel, I'm not sure what the “small PCB” is, but my view is that you can do as you suggest, wire the pickups directly to the motor. of course, it will go the wrong way. Life’s like that. the rule is “right rail positive is forwards”, but of course, the rule may not be universal atb Simon 1 Link to post Share on other sites More sharing options...
Grovenor Posted March 4, 2021 Share Posted March 4, 2021 The small PCB is just a dummy plug that you remove to plug in a decoder. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted March 4, 2021 RMweb Premium Share Posted March 4, 2021 Know nothing about this particular loco but would the small pcb (not quite sure where it's located) be firebox glow/flicker by any chance? I see some recent locos now have this 'feature'. Can't really see any reason why you can't do as you wish whatever. 1 1 1 Link to post Share on other sites More sharing options...
RMweb Gold BMS Posted March 4, 2021 RMweb Gold Share Posted March 4, 2021 If you leave the plug in place you will connect the dcc decoder output directly to the input; which is likely to blow the decoder. Link to post Share on other sites More sharing options...
WIMorrison Posted March 4, 2021 Share Posted March 4, 2021 1 hour ago, Grovenor said: The small PCB is just a dummy plug that you remove to plug in a decoder. That wiring does not describe a DCC Dummy plug in any guise that I have ever seen, plus it has 10 wires which is not a DCC standard. Also the wiring colours are all wrong - and this isn't a DCC loco anyway. It would appear to be a simple way to connect the various wires in the loco. Should be OK to remove and simply reconnect wherever you want. 1 Link to post Share on other sites More sharing options...
John ks Posted March 4, 2021 Share Posted March 4, 2021 If you like working with images then following pic should be self explanatory John 2 1 Link to post Share on other sites More sharing options...
RMweb Gold Mikkel Posted March 5, 2021 Author RMweb Gold Share Posted March 5, 2021 (edited) Many thanks everyone for the useful and informative replies, not least John for even illustrating it. I'll be snipping wires by evening (edit: or rather unsoldering them in proper fashion!). And yes the 16xx does come with firebox flicker, I had forgotten all about that. Edited March 5, 2021 by Mikkel Link to post Share on other sites More sharing options...
Simond Posted March 5, 2021 Share Posted March 5, 2021 If you like the firebox flicker, you can probably connect the two wires to the pickups too - in parallel with the motor. or don’t, and install it under a brazier (note spelling) to keep the workmen warm in the yard. 1 Link to post Share on other sites More sharing options...
RMweb Gold Mikkel Posted March 5, 2021 Author RMweb Gold Share Posted March 5, 2021 Thanks for that Simon. I'm not really a fan of firebox flicker. But I might keep that tiny LED and install it with a battery somewhere in my brother's flat. Just to confound him when he discovers it. He lives in a country where the authorities like to keep an eye on their citizens... Link to post Share on other sites More sharing options...
Simond Posted March 5, 2021 Share Posted March 5, 2021 Laugh? he’ll probably find some choice descriptive adjectives for you... 1 Link to post Share on other sites More sharing options...
Pete the Elaner Posted March 5, 2021 Share Posted March 5, 2021 19 hours ago, Simond said: Mikkel, I'm not sure what the “small PCB” is, but my view is that you can do as you suggest, wire the pickups directly to the motor. of course, it will go the wrong way. Life’s like that. the rule is “right rail positive is forwards”, but of course, the rule may not be universal atb Simon There is no need to guess: there is a convention. When wiring DCC, there is a mnemonic "red & black to the track, orange & grey go the other way"...the other way means the motor, but that doesn't rhyme. Remove the board but leave enough of these 4 wires to identify them, or if required, connect them together. Connect red to orange & black to grey. If the manufacturer wired the loco correctly, it will now run in the correct direction. 1 Link to post Share on other sites More sharing options...
WIMorrison Posted March 5, 2021 Share Posted March 5, 2021 10 minutes ago, Pete the Elaner said: There is no need to guess: there is a convention. When wiring DCC, there is a mnemonic "red & black to the track, orange & grey go the other way"...the other way means the motor, but that doesn't rhyme. Remove the board but leave enough of these 4 wires to identify them, or if required, connect them together. Connect red to orange & black to grey. If the manufacturer wired the loco correctly, it will now run in the correct direction. If you look at the pictures then you will see the colours ... 1 Link to post Share on other sites More sharing options...
RMweb Premium ELTEL Posted March 5, 2021 RMweb Premium Share Posted March 5, 2021 18 hours ago, BMS said: If you leave the plug in place you will connect the dcc decoder output directly to the input; which is likely to blow the decoder. But as I understand Mikkel he is removing the PCB board so there won’t be a socket, and Mikkel operating analog (DC) 2 Link to post Share on other sites More sharing options...
Simond Posted March 5, 2021 Share Posted March 5, 2021 Which is why I quoted the “rule” regarding the “right rail positive = forwards” if he’d asked about DCC, I’d have answered that question... Link to post Share on other sites More sharing options...
RMweb Premium ELTEL Posted March 5, 2021 RMweb Premium Share Posted March 5, 2021 7 hours ago, ELTEL said: But as I understand Mikkel he is removing the PCB board so there won’t be a socket, and Mikkel operating analog (DC) I was answering BMS ...... Link to post Share on other sites More sharing options...
Theakerr Posted March 6, 2021 Share Posted March 6, 2021 (edited) The PCB board with the decoder sockets definitely does something because there have been several reports on this forum including one from myself of DC locos running badly, often after running well. Once the PCB board is removed they revert to normal running. So by default it does seem safe to remove the PCB board and wire directly. I know I do as a default on the new Bachmann B1s because it gives significantly more room for additional weight. Edited March 7, 2021 by Theakerr to correct my terrible english so I made sense 1 Link to post Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now