Lighting for Slaters 7mm coaches - using split axles?

Discussion in 'Techniques' started by Dog Star, 2 May 2019.

  1. Dog Star

    Dog Star Western Thunderer

    I am trying to understand how to fit LED lighting, controlled from a decoder, into a Slaters 7mm coach. I have some ideas about where to place the decoder, what LEDs to use, how to fit the LEDs in the roof... early days so happy to be influenced by the experiences of others.

    Have you put lights in a 7mm coach?

    What did you do? What materials did you use? How did you arrange the wiring to the lights?

    thank you and regards, Graham
     
    Last edited: 14 May 2019
  2. simond

    simond Western Thunderer

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  3. Dog Star

    Dog Star Western Thunderer

    Thank you Simon (@simond), an interesting couple of relevant posts. How does the power get from the shorted wheels to the interior? (well, at least the first step from wheels to bogie frame).

    Nice that you have a "toilet" in which to hide electronics - neither the Slater's four wheel nor bogie GWR carriages on our shelves are designs with lavatories so everything has to be hidden elsewhere in the bodies!

    regards, Graham
     
  4. simond

    simond Western Thunderer

    Hi Graham,

    Lavatory... :)

    The wheels are shorted (on one side only, of course) so each bogie, (they are brass frames, with fixed bearing ), is live to one rail.

    I tend to have one bogie free to rotate about all three axes, on a domed washer, and the other uses a cross bar so the bogie can see-saw fore-and-aft, but not side-to-side, so I fit a spring on the bogie centre screws to keep everything snug. The connections to the light bar are taken from the bogie pivot screws.

    If you had brass coach bodies, it would be necessary to isolate the bogies (I’d say both bogies otherwise you might have issues coupling up) but it would be relatively simple to arrange a plug-in connection to the bogie.

    I visited the Wirral club a few months back, one of the guys had a rake of MTH coaches, he had removed the pick-ups as they were back-scratchers and they caused far too much drag. Using split axle or American pickup avoids this issue.

    HTH
    Simon
     
  5. Dog Star

    Dog Star Western Thunderer

    Thank you Simon (@simond), I can imagine what you have done when the bogie frame is brass and the floor in non-conducting (as in a Slater's bogie coach). Not so easy with the four wheel coaches where most of the underframe is plastic! I shall need to sit and think about how to build conducting paths into the assembly of the underframes.

    In the meantime, Simon (@simond), can you post a bit about how you made the connection between tyre and axle for your lighting circuits?

    regards, Graham
     
    Last edited: 4 May 2019
  6. simond

    simond Western Thunderer

    Graham,

    Re the shorting links, yes with pleasure, but not for a couple of days.

    For a 4W coach, with plastic body & brass W irons, I’d short one wheel each side, and pick up from the W irons.

    As the meerkat said....

    Best
    Simon
     
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  7. Dog Star

    Dog Star Western Thunderer

    Simon (@simond), any photos of your conversion process?

    Progress has been made with the electrickery.

    Lokpilot V4 FX (pt. no. 54620) has been bought from DCC Concepts (good service, decoder arrived within 15 hours of placing order) along with a score of 1mm SMD warm white (Ebay purchase by Peter). A member of the local MRS has provided a handful of 1K8 resistors and a chunk of veroboard. A trial set up of decoder / resistor / LED (or pair of LEDs) has been made and the decoder programmed for output to an LED through an auxiliary function output (decoder programmed using a LokProgrammer). Now that we understand how to turn the lights on and off the time has arrived to consider where to locate the decoder and how to connect the lighting (in the removable roof) to the decoder (probably under a seat).

    Separately, I am searching for advice on making split axles for the 4-wheel underframe. The first model is a Slater's 7mm kit for a GWR 4-wheel coach so the underframe is plastic with individual brass axleguards (Exactoscale FASS design so sprung axles). Wheels are Slater's Mansell disc so steel tyres and axle with nylon for the wheel disc and I could short one wheel per axle (arranged so that the "short" is on opposite sides of the underframe). A single pick-up on each side seems a poor substitute for pick-up from all wheels.

    Split axle for collection from all wheels seems the way to go for the 4-wheel stock... I have no experience of making split axles although I have read the relevant posts which have been made to WT over the years. Slater's carriage wheels have an axle which is about 1/8" in diameter and that seems too snall to use the method described for driving axles. Current thinking is to make an axle muff into which half-axles are pressed and retained by an appropriate Loctite compound.

    Anyone made a split axle for C&W wheelsets? Suggestions for a material to make axle muffs? Suggestions for a Loctite retainer?

    thank you, Graham
     
  8. Overseer

    Overseer Western Thunderer

    Graham
    I think you are making things too complex if you go with split axles. All you are trying to achieve are low friction pick ups which could be achieved using light phosphor bronze wipers on the back of the tyres, or maybe a more elegant solution would be a link wire from the tyre to a nickel silver ring glued on the front of the boss (not touching the axle) and a sprung collector from the w iron.
     
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  9. simond

    simond Western Thunderer

    Sorry Graham,

    Was away for the weekend and it completely slipped my mind.

    Tomorrow...

    Split axles - why not? Relatively easy if you’re dealing with coach wheels, and if you have a plastic body with brass w irons & bearings.

    Atb
    Simon
     
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  10. simond

    simond Western Thunderer

    image.jpg Herewith photo of one bogie. The wheels are shorted by using a bit of tinned copper wire about 0.4mm. Might be 0.5.
    Soldered to axle with a very hot iron and aggressive flux, let it all cool, ditto repeato on rim.
    Wash and file back so it doesn’t foul on pointwork.

    image.jpg

    You can just about see the lighting strip as I haven’t finished this one with windows (or handles, transfers, etc) yet

    There are some shots of the lighting strip & the capacitor, diode & resistors in the RMWeb thread. Unfortunately, it doesn’t match the compartment spacing. This can be fixed with a bit of faffing.

    HTH
    Simon
     
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  11. paulc

    paulc Member

    Graham , old plastic knitting needles from your local thrift shop or op shop as we call them in Australia will make your muff and very easy to machine , just remember to put a vent hole in so the air and excess goop can escape when you push the axles in. If you have a lathe use it to assemble everything so it all ends up straight .
    I have used them when making split axles for locos with no failures . Now where's that bit of wood that I can touch :D
    Cheers Paul
     
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  12. simond

    simond Western Thunderer

    Knitting needles are an excellent source of plastic rod, but in my experience, do not machine well. I’m not sure what type of plastic it is, but it gets quite hot quite quickly and can get very soft, so go slow with sharp tools!

    You might even find plastruct tube which matches the axle.

    Best
    Simon
     
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  13. paulc

    paulc Member

    Hi Simon , i think there are different materials used as have had ones that wont machine very well but others that are like machining cheese , trouble is you can't tell by looking at them which is which . I usually grab a handful when i go to the shop as they are so cheap and toss the bad ones or use them for something else .
    Cheers Paul
     
  14. simond

    simond Western Thunderer

    Maybe I only ever got the Dairylea ones...
     
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