The Snapper's DCC Workshop - NEW Heljan Class 25/3

Discussion in 'Techniques' started by TheSnapper, 19 August 2017.

  1. 3 LINK

    3 LINK Western Thunderer

    Hi Tim,

    Always enjoy reading these topics of yours, food for thought so they say.

    Funnily enough my next loco build will be the jltrt 2251, I notice that you managed to open out the resin firebox, can you tell me how you went about it? I always thought the resin was next to bullet proof, although I have never had any trouble drilling the holes for the hand rails.

    Regards,

    Martyn.
     
  2. TheSnapper

    TheSnapper Western Thunderer

    Hi Martyn

    Thanks!

    Loco was Heather's build though- she may be along soon........

    Tim
     
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  3. Heather Kay

    Heather Kay Western Thunderer

    Hello all. Thanks to Tim for showing his workings. Not being all that electronically minded, it's very useful knowing someone who is!

    Martyn, I have a build thread on the 2251: clickety-click-linky

    The resin JLTRT use is, I believe, impregnated with glass to give it some strength. It does blunt drills eventually. I have had success with a Dremel and grinding disc, or sanding drum, in opening out areas such as fireboxes. It's messy, and potentially nasty, so I try not to do it indoors, or while breathing!
     
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  4. SoundsLoco

    SoundsLoco Member

    Mike,

    There is no 5V option on the MX696S, but it is available on the MX696K and KV. (I know that's not much use in this case, but worth bearing in mind for future, perhaps).

    I normally re-use the Heljan fan PCB. It has a small pot which can be used to get to a modest fan speed, then trim if necessay with CV60.

    Although, when using Swiss Mapping, it is possible to pre-assign specific 'dimming' values for each individual Function Output. This can avoid the use of CV60 and the consequential need for dimming masks in CVs 114 and 152.



    To assign an operating key to FO6 using Swiss Mapping is very straightforward.

    Swiss Mapping requires you to first determine an unused SM group. There are 17 groups, each of 6 CVs following in sequence from CV430.
    (Group 1 is CV430 to Cv435, Group 2 is CV436 to Cv441, and so on. Each CV in each group has a special function; for your simple on/off switching you will need to use only 3 of the 6 in whichever group you use).


    Assuming that SM groups 1 -5 have been used for other functions, the first CV in SM Group 6 will be CV460.

    (read your decoder to check that its value is currently 0 (zero) and if not use a different group which is free).

    Choose the F key you would like to use and put its number as the new value in CV460 (e.g., if you wish to use F15 as that's the same key as the fan sound, say, then make CV460 = 15)

    Then assign the Function Output to that F key:

    CV462 = 6 (for FO6 in forward direction)
    CV468 = 6 (for FO6 in reverse direction)

    That's it.


    All wired or harness fitted ZIMO decoders are equipped with shrink wrap insulation. I think they must have tested this system at some point as I've never had a heat related problem with any of the one's I've fitted. LOL.

    Kind regards,

    Paul
     
  5. 3 LINK

    3 LINK Western Thunderer

    Good Evening Heather,

    Thanks for the heads up, I am already an avid reader of yours when you post further instalments regarding the 2251, especially being that it’s next on my to do list.

    Might sound cheeky but is there a chance of a short video clip, once all the electrickery has been done.

    Regards,

    Martyn.
     
  6. Heather Kay

    Heather Kay Western Thunderer

    Well, I am reliably informed I can run these models on my strictly DC setup, and some of the sound may kick in. On that basis, I doubt a video would help demonstrate much, sadly.
     
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  7. Ressaldar

    Ressaldar Western Thunderer

    Hi Paul,

    many thanks for your reply and explanation. Coincidentally, I had earmarked CV460/462/468 in my mind but it was where the 'power supply' lead should be connected that stopped me from carrying out the installation. Which + terminal should I use?

    I had the loco running on the Club layout last night and was very impressed with the noise from the double sized Zimo sugar cube speaker that my friend had supplied.

    regards

    Mike
     
  8. SoundsLoco

    SoundsLoco Member

    Mike,

    Use whichever of the +ve pads is most convenient, they are duplicates.

    Kind regards,

    Paul
     
  9. Ressaldar

    Ressaldar Western Thunderer

    Hi Paul,

    many thanks for that information, I will retrieve the loco next week as I handed it over last night without the fan wired up. My friend was most impressed with everything else.

    regards

    Mike
     
  10. Threadmark: GW Barnum
    TheSnapper

    TheSnapper Western Thunderer

    Request for Help!

    Has anyone any ideas what this may have sounded like:

    barnum.jpg

    This is a customer commission which was largely scratch-built by David Amias, apart from the cab and firebox.

    Cheers

    Tim
     
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  11. John K

    John K Western Thunderer

    I’d stick a City of Truro sound set in it. Nobody will know any better.
    John
     
  12. simond

    simond Western Thunderer

    Or a Dean Goods.

    Similar firebox, similar smokebox, similar motion, valves & cylinders. Adjust the chuff rate to suit the larger wheels.

    Lovely looking model.
    Best
    Simon
     
  13. Threadmark: GW Saddle Tank 2007
    TheSnapper

    TheSnapper Western Thunderer

    The GW Theme continues......

    P1010713 (Small).JPG

    Although I prefer to install everything on the loco chassis, sometimes it is not possible.

    On this model, there was no room in the frames due to the dummy inside motion etc.

    P1010710 (Small).JPG



    Fortunately, the boiler was hollow enough to accommodate the decoder (Zimo MX645) & stay-alive capacitor (Digitrains “Zimo- SC68 equivalent”).

    P1010716 (Small).JPG



    The capacitor was clear-shrink-wrapped and then wrapped together with the decoder with an oversize piece of black sheathing to form a double insulated package. The idea is to avoid any chance of shorting, as it would be loosely located in the boiler.
    Decoder.jpg


    For the same reason, I wrapped some Kapton tape around the top of the motor


    P1010717 (Small).JPG



    The only place for the Zimo cube speaker was behind the motor. I had to move the pinion gear temporarily to one side to fit it in. I used Araldite to fix it and it works well.


    P1010723 (Small).JPG


    Final testing could be done with the decoder package resting on the dummy inside motion!

    P1010721 (Small).JPG
     
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  14. TheSnapper

    TheSnapper Western Thunderer

    Thanks John & Simon for your suggestions

    John - I know you favour Zimo - Digitrains don't seem to have a project -have you used the YouChoos one? If so, is it OK?

    Tim
     
  15. John K

    John K Western Thunderer

    Hi Tim
    I’m afraid I haven’t used the YouChoos sounds. You are correct that I use Zimo wherever possible. I have no Western engines, but a young friend has used the Truro from Olivia’s which comes on an ESU V4. BTW, Olivia’s also have a Dukedog listed which might be a better option Olivia's Steam Sound Functions. | Olivias Trains
    Best
    John
     
  16. TheSnapper

    TheSnapper Western Thunderer

    Like @Richard Carr here 7mm - Heljan Class 25/3 I have been working on a Green Heljan Class25/3 for “a customer”. I liked it so much that I bought one myself, but plumped for the factory weathered blue version, out of curiosity really…


    Fitting the decoder
    As Richard says the original PCB is fixed to a black plastic mounting plate.
    There are holes located in the correct position for attaching an XL-size decoder, either ESU Loksound or Zimo. (There is also another set of holes which are perhaps for an L-size decoder, but I didn’t have one to hand, so I couldn’t validate this).

    Mouting_Plate_1(Smal).jpg

    Again, as Richards points out, using an XL-size decoder, you cannot get the body back on properly if you retain the mounting plate it in this position. It fouls the roof, or the things attached to the roof, such as the fan assembly and the fan PCB.


    My initial idea was to get the decoder to sit lower by removing about 2mm from the metal pots that support the mounting plate, using a piercing saw.
    I then inverted the plate & removed the moulded-on collars for the screws from one face of the plate. I then created 6BA threads in the outer 4 holes and attached the decoder to the board using nylon screws.

    Mouting_Plate_2 (Small).jpg

    However……….


    This procedure turned out to be insufficient to allow the body to sit correctly with the decoder in situ. So with thinking cap on, I came up with the solution of moving the mounting plate off-centre, so that the decoder would sit between all obstructions in the roof-space.


    New holes need to be drilled in the mounting plate for fastening to the chassis supports, and care had to taken to avoid blocking the holes for the body-mounting screws.

    Mouting_Plate_3 (Small).jpg


    Off-centre (Small).jpg
    With hindsight, it may be that the first procedure to lower the decoder mounting plate may not be necessary, and that moving the decoder off-centre might provide sufficient clearance. I will try this first when I do my blue one, and report back….


    Wiring

    Lo & behold Heljan have at last used different coloured wires which makes things a bit easier to follow.


    To tidy-up the wiring from the body to the chassis, I connected the common feed wires for the lights & fan together (3 into 1), soldered everything to a small piece of Veroboard, secured it to the roof with Black-Tak, and used a miniature 4-way connector betwixt body & chassis.

    Four-way(Small).jpg

    I didn’t do anything fancy with the lights, retaining the built-in switch for operating the red lights, as my “customer” uses some Lenz controllers with limited F-buttons.

    However using my Lokprogrammer , I did a swap to activate the fan (wired to Aux3) whenever the Fan sound was switched on. I adjusted the fan rotation speed using the 5v output on the decoder and the potentiometer on the fan PCB


    I blocked out the cab-illumination which is part of the headcode lighting; I can’t imagine this is prototypical:

    Cab-Lights(Small).jpg



    Speakers
    I considered fitting a speaker in the fuel tank, but couldn’t find a way to remove the cover. I also thought about fitting a speaker on the gearbox, as Richard did, but decided instead to go for 2 Zimo “Double-Dumbo” speakers in series to give 8 Ohms , which the XL decoders seem happier with.

    Here's the completed installation:

    Complete.jpg

    The decoder used was an ESU Loksound XL with Class25 project from Lergomanbiffo (available from DC Kits - DC Kits - DE Videos)


    Runs well, and sounds great - just like a 25!
     
    Last edited: 31 December 2018
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  17. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    Having seen the 25/3 photos above is there space between the flywheel and bulkhead in which to locate and lower the decoder in the model releasing the space above the motor for a larger speaker?

    Also make you wonder why they didn't combine the fan, it's motor and PCB into one unit to save space.

    Is it programmed to run randomly with sound after the loco has been idling for a period then switch off (similar to a car radiator fan) without the use of a function button?
     
  18. simond

    simond Western Thunderer

    Given they put the mountings in for an XL, you’d wonder why they didn’t make sure there was space for it...

    All the best for 2019
    Simon
     
  19. TheSnapper

    TheSnapper Western Thunderer


    Hi Dave

    ............is there space between the flywheel and bulkhead in which to locate and lower the decoder in the model releasing the space above the motor for a larger speaker?[/QUOTE]

    No there isn't:
    Side-View.jpg

    Also make you wonder why they didn't combine the fan, it's motor and PCB into one unit to save space.
    Er, yes....!

    Is it programmed to run randomly with sound after the loco has been idling for a period then switch off (similar to a car radiator fan) without the use of a function button?
    I haven't set this up, but I suppose it could be done. Not sure if the fan sound is a designated Random sound, but I might investigate this with my own model, when I get around to it.

    Cheers

    Tim
     
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