first look at the CKH semi kit

The model prototype is finally here, and it’s a good feeling to finally hold the physical model after months of work. And it really affirm that the model is really happening!

Let’s take a look!

At 1:20, the model will be about 13″ long when finished. This size will be able to accomodate a lot of details to the engine.

The model is made by 3D printing. This gives it more detail than a model made from CNC manufacturing. Check out the staybolt details on the firebox! There’s even spring hangar bearing surfaces on the frames, and hook points for the tender chains on the drawbar!

The round raised area left and right are boiler washout plugs. The middle is the blowdown plumbing attachment point.

They are a couple of things that should be observed about this model:

1. This was made from the first prototype model, the one without boiler jacket and saddle finishing. Final version of course will have those.

2. The surfaces are a bit rough as a result of manufacturing, with some white powder residue. Ruling on curved surfaces are obvious because of the same, but these can be sanded away easily.

The engine’s 2 frames. The upward bend on the forward legs (right) is a result of manufacturing process, and can be bend back to correct easily (but it still supposed to have a 1-degree incline)

The kit will have tiny details such as the bearing surfaces for the equalizing spring hangars.

Really tiny details: the tender safety chain hooks on the drawbar.

3. Some parts, especially the frame, is a bit flexible. It may require the user to add metal supports to the forward leg to actually hold the weight of the engine. The upward bend is also the result of manufacturing, but I was able to bend it back down in place.

And 4. Some parts are “warped” very slightly due to manufacturing tolerances. This, I think, won’t be noticeable when the engine is finished, but I thought you should know.

Saddle (this prototype is without cover)

Under the saddle is the circular mount for the pilot truck

I really like that the details like how the staybolt heads on the firebox came out. The spokes on the driver tapers like it should, and even the tender hook on the drawbar came out great.

Extremely accurate driver

Spokes are tapered outward as they should

The final kit will have over 60 parts (maybe 70). This preview is only showing 5! I’ll show you know what they are later, but they will make a very accurate CK Holliday. Or, the kit can be a basis for many other 4-4-0, such as the EP Ripley, since there are very few Holliday-centric parts (I think less than 4).

Reverse of the driver shows some manufacturing process leftovers

Dry fitting the parts

I ordered the rest of the parts so I’ll show them here when they’re ready. Now, I’m off to the hobby shop to get some supplies to put this thing together!

4 thoughts on “first look at the CKH semi kit

  1. Wow…..I’m so excited. Can’t wait to see the final result. By the way I have parts from Hartland Locomotive Works for the tender (not sure if your familiar with them) that I think can complement the Holliday. By the way…..upon completion of this one is it possible to get parts done for a Ripley model? All that would be required are domes, extended fire box, headlamp, cowcatcher, smokestack, and of course the cab. Also what price would the Holliday kit cost?

    Luv your work…….keep going and don’t stop.


  2. As far as the flexible frames, I think things will “stiffen up” considerably when you start attaching cross members, like the pilot beam, air tank, reverse gear, wheel axles and cylinder saddle.

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