Bruce Wood, my future lunch partner, has asked me if I’m nervous about losing my bet with him that the KRM Z20 class kit might come out before I can finish my scratch built Z20….

This is a shot of the 20 just before I pack it to bring down to Sydney on the plane with me to the Aus7 Modellers Group Forum on Saturday.

This is a shot of the 20 just before I pack it to bring down to Sydney on the plane with me to the Aus7 Modellers Group Forum on Saturday. Everything you can see in the photo is compete: the dome and chimney are attached and the tanks are essentially as they should be.

He has to build the loco from the kit against my scratch built efforts. For one of us to claim the prize the resultant model has to be completed, running, painted and ready haul a train.

At the moment I have the cab to build and then I’ll start on the details and working on the rivetted overlays for the sides of the tanks. I’m currently assessing my DCC options: the speaker is going to be housed in the rear water tank/coal bunker with the decoder in the boiler. There will be a headlight front and rear, the marker lights will operate and it will have a flickering firebox. One issue I’ve discovered is that, with all that metal down one end and only urethane up front there’s a fair bit of weight imbalance. I think I’m going to have to weight the front of the loco. This won’t be so much to increase tractive effort, the bloody thing is going to weigh a ton without any added weight, but it does need to be balanced so it doesn’t run with its nose in the air. I’ll put some sheet lead between the frames over the bissel truck at the front and if that isn’t enough I’ll turn down a nice big metal slug to fit in the front of the boiler. This will only be quite short so there will still be room for the decoder, but it can be attached to the smoke box door and it will slide in and out when I need to access the interior of the boiler.

Nervous? Mmmm, I’m not sure 🙂

2 thoughts on “Nervous?

  1. Dear Trevor,
    Make sure you get a Sugar-cube speaker mounted in the smokebox area, so you can get the “Chuff” point-sourced up the front where it should be…
    (a single speaker in the rear bunker makes the loco sound as if the stack is at the back,
    not a good look unless one is modelling a small Garratt or a Baldwin Duplex…)
    Happy Modelling,
    Prof K

  2. One suggestion for the placement of the speaker is to definitely have it up front. A number of small holes drilled in the bottom of the boiler, where it will not be visible should allow the sound to escape from inside the urethane casting. I am skeptical of lead being good for weighting locomotives as I have seen lead oxidise, expand and go horribly wrong. Perhaps you may be able to get a section of round steel bar cut to the right size to put inside the smokebox.

    It is good to see your Z20 class progress so quickly. Last time I looked it was just a running chassis with a boiler plonked down on top!

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