Replacement 21pin PCB for 8pin Locos

[Roy Langridge]

I am getting quite fed up with trying to cram lighting boards etc. into old 8pin locos where I want to benefit from multiple functions, the sort of things that are standard on the more modern 21pin locos. I find it made all the harder by the fact that these locos often were not designed with sound in mind and space is very limited.

 

So, harking back to my previous existence as an electronics engineer, I am now giving thought to designing and having manufactured a replacement PCB to upgrade some of my locos to 21pin decoders, providing solder connections for the functions available on the chip with resistors included to support head / marker / tail and cab lighting. The intention would be that in the PCB would fit in the existing mounts and be produced as a professional board with solder resist and screen printing. I am currently looking at the 8pin Bachmann Class 44 / 45 / 46.

 

So, my question is, would anybody else be interested in such a scheme? I have had a brief look at costings and I believe that the cost could be around £10 per board based on what I consider a relatively achievable number of boards. Given that LEDs are fairly cheap this would mean that a replacement board and LEDs would probably not be significantly different to the cost of a typical lighting kit. (I don't intend to be providing the lighting).

 

What do you think?

 

Roy

[richard brown]

Very interesting idea but if you are replacing the board why not look at the new Next 18 connection then you should be able to use it on locos with less room.

 

Richard

[newbryford]

Have you looked at using the ESU 21 pin adapter board?

http://www.esu.eu/en/products/accessories/adapterplatinen/21mtc-adapter-board/

 

I've hard wired an 8-pin socket to one a few times.

 

They also do one that enables Aux 3 and 4 to be used.

http://www.esu.eu/en/products/accessories/adapterplatinen/21mtc-adapter-board-2/

 

Cheers,

Mick

[Roy Langridge]

Have you looked at using the ESU 21 pin adapter board?

http://www.esu.eu/en/products/accessories/adapterplatinen/21mtc-adapter-board/

 

I've hard wired an 8-pin socket to one a few times.

 

They also do one that enables Aux 3 and 4 to be used.

http://www.esu.eu/en/products/accessories/adapterplatinen/21mtc-adapter-board-2/

 

Cheers,

Mick

 

Thanks Mick,

 

Following on from your post I ordered one of the adaptor boards and it does just what I wanted to achieve.

 

Roy

[Huw Griffiths]

I am getting quite fed up with trying to cram lighting boards etc. into old 8pin locos where I want to benefit from multiple functions, the sort of things that are standard on the more modern 21pin locos. I find it made all the harder by the fact that these locos often were not designed with sound in mind and space is very limited.

 

So, harking back to my previous existence as an electronics engineer, I am now giving thought to designing and having manufactured a replacement PCB to upgrade some of my locos to 21pin decoders, providing solder connections for the functions available on the chip with resistors included to support head / marker / tail and cab lighting

Very interesting idea but if you are replacing the board why not look at the new Next 18 connection then you should be able to use it on locos with less room.

Have you looked at using the ESU 21 pin adapter board?

http://www.esu.eu/en/products/accessories/adapterplatinen/21mtc-adapter-board/

 

I've hard wired an 8-pin socket to one a few times.

 

They also do one that enables Aux 3 and 4 to be used.

http://www.esu.eu/en/products/accessories/adapterplatinen/21mtc-adapter-board-2/

Without wishing to sound cynical, it could be suggested that: "The really great thing about standards is that there are so many of them."

 

Not to worry, I'm sure that somebody will be along shortly with a new "universal standard", which everyone's supposed to use … .

 

 

Huw.

[bigal10]

Roy, you may also want to consider the Plux 22 option.

 

I have around 30 sound equipped locos, mostly which are run on Zimo sound Decoders, and a few by ESU.

I have recently been diverted towards the Zimo MX644P 22 and the use of Zimo's excellent ADAPLU adapter board, for exactly the same reasons as yourself, that I wanted to make full use of as many functions as possible, for lighting and roof fan etc., whilst also using stay-alive systems, and big speakers.

 

The Zimo adapter board has quite large solder pads, and allows for up to 9 functions, my first conversion was a Heljan 26, by removing the original motherboard, a whole raft of space is then available for capacitors, speakers, and all the wiring for LEDs and resistors.

I'm not bragging, but thanks to a lot of help and advice from Paul Chetter, Digitrains, and DCC Train Automation, I now have a loco that does exactly what I want, with front and rear markers switchable, cab lights that auto extinguish, and fabulous sound thanks to Charlie Petty's speaker enclosures!

 

The Zimo 22 pin adapter board is quite slim, 24mm if memory serves, and sits down well inside the Heljan chassis, above the motor and drive chain, and has solder pads for track power at both ends, so reduces stray wiring.

 

Like you, my next project is going to be a Bachmann 46, there must be masses of free space under the existing motherboard for all that tackle, plus a motor-driven fan, methinks!

 

Regards,

 

Alan.

[Roy Langridge]

A few points, if I may;

 

• the form, shape and purpose of the PCB may be copyright protected property of Bachmann and offering a replacement might land you in an un-winnable legal battle
• the 21 pin MTC form is obsolete, even though it's still used by some Continental manufacturers.
• the Next18 interfacer is probably not obtainable for small numbers and/or individuals. As a matter of fact, I have looked into this and the connectors are a proprietary form supplied by a single (German) manufacturer.
• for future-proofing of your design, consider the PluX22 interface.
• if you sell these, the boards need to comply with CE and/or equivalent marks, which is a very, very costly and lengthy process
• sound attracts only a minority of DCC users, so designing it with all bells and whistles (pun intended 0 will probably render it too expensive for a fair number of potential customers
• if you want this a success, you need to sell these at every shop that sells Bachmann. Bachmann might not be so accommodating and banning their outlets from selling your product. There's nothing you can do against it as it's part of the supply contract these outlets will have with Bachmann.
• think very carefully about commercial viability of the product. A good Engineer doesn't make a decent marketeer

HTH!

 

Thanks for your reply, however, I think you may have misunderstood (probably by my bad explanation) what I was intending.

 

I was not looking to copy the Bachmann PCBs, simply provide a means of connecting a 21pin decoder to the various wires in the loco and to lights / speaker. In effect providing a PCB with a socket and sufficient solder pads - nothing that I consider Bachmann could claim copyright on, especially as such a board is seeking NMRA compliance, nothing more. The only "loco" specific difference would be to make sure it fit within the available space - not necessary matching the dimensions of the original PCB.

 

This was a project that solved a need of mine and I was simply seeing if anybody else was interested, as such, there was no need to sell through all loco vendors. Interestingly, if I were to sell through model shops, a ban on their sale by Bachmann would probably be illegal under European law.

 

As for CE marking - this is a grey area as I would (in theory) be selling a component, not a product. I say grey area as obviously it can be argued that a PCB is a product in its own right - however, it is near impossible to prove compliance of a PCB with some of the regulations without it being in use, and what a user connects to it is down to them. CE marking need not be expensive for a simply component as the vendor self declares and, for a PCB, the relevant regulations and directives are limited. The use of Notified Bodies can be expensive, but is not mandatory.

 

You are right that PLuX22 would be better and I am not in favour of Next18 myself.

 

All of this is, however, irrelevant as the board mentioned by newbryford was perfect for what I intended to achieve and my investigation to make a PCB ends!

 

Thanks again,

 

Roy

[tractor_37260]

I am getting quite fed up with trying to cram lighting boards etc. into old 8pin locos where I want to benefit from multiple functions, the sort of things that are standard on the more modern 21pin locos. I find it made all the harder by the fact that these locos often were not designed with sound in mind and space is very limited.

 

So, harking back to my previous existence as an electronics engineer, I am now giving thought to designing and having manufactured a replacement PCB to upgrade some of my locos to 21pin decoders, providing solder connections for the functions available on the chip with resistors included to support head / marker / tail and cab lighting. The intention would be that in the PCB would fit in the existing mounts and be produced as a professional board with solder resist and screen printing. I am currently looking at the 8pin Bachmann Class 44 / 45 / 46.

 

So, my question is, would anybody else be interested in such a scheme? I have had a brief look at costings and I believe that the cost could be around £10 per board based on what I consider a relatively achievable number of boards. Given that LEDs are fairly cheap this would mean that a replacement board and LEDs would probably not be significantly different to the cost of a typical lighting kit. (I don't intend to be providing the lighting).

 

What do you think?

 

Roy

 

Roy

 

An interesting idea, but as already mentioned you could end up getting hassle with copywrite issues etc.

 

I've spend a lot of time in the last few years trying to make the most of what DCC can do for loco multi function lighting options, hardwiring, adapter boards, adding a 2nd function only decoder etc and then trying to find/make space to get it all to fit in, occasionally finding that the body just would not fit back on properly afterwards.

 

On recent projects, I found it was much easier to fit a hard wired Zimo MX645 decoder, with all the functions you need on the one decoder, thus leaving more room for a decent speaker/s and a stay alive cap if required, this is also more cost effective.  Especially relevant in smaller locos ie Class 20/26/27 etc where free space is at a premium.

 

The SWL 24 shows just what can be achieved nowadays, when a little bit more thought was given at the design stage of the electrical circuits etc 

 

Regards

Ken

[blueeighties]

Why are people moaning on about copyright and such rubbish? The op was just looking for a simple solution, and possibly to help fellow modellers out. So much seriousness on here these days.

I prefer to dispose of the loco pcb and hard wire the new chip in. Makes life so much easier. For 21 pin chips I make my own 21 pin wired flyleads.

[Suzie]

The Zimo ADAPLU range of PCBs are excellent and options such as the ADAPLU50 even include 5V power so you can have constant brightness lighting or servos.

 

Usung a PluX board will give you more flexibility to install the appropriate decoder for the task (Plu-8 motor and two functions only all the way up to Plu-22 nine functions with sound) rather than using a MTC-21 or Next-18 board which will limit you to a small range of decoders.