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WHEEL DESIGN AND FABRICATION |
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The wheels we fabricate fall into one of three categories: First, we can provide exactly the right wheel for the scratch builder. In many cases, the real locomotive that a scratch builder desires to model no longer exists. Often, only photographs are all that is left. However, reference sources permit us to produce a drawing if we know the diameter of the wheel, the spoke pattern, and counterweight shape. Other dimensions can be extrapolated from a photograph. |
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Second, we can provide replacement wheels for those worn out, or broken in accidents. In those cases, we request the customer send us an surviving wheel to copy. Details of flange design will be worked out with the customer. Third, we can provide conversion wheels. The most common case is an “O” gauge wheel replacement from three rail to two rail configuration. |
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| After an acceptable drawing is produced,
a master pattern for the wheel is produced. The master pattern is made slightly oversized.
An impression is taken of the master pattern. When the impression material has set, the
pattern is removed and liquid wax is injected into the impression. When the wax is cooled
and is solid, that wax reproduction of the master pattern is removed. It is then invested
in a high-temperature plaster mold, placed in an oven and the wax is burned out of the
mold. Brass is melted and cast into the mold. |
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| When the casting is removed from the
investment, the wheel is machined to the desired dimension, and bored for the axle and
crank pin. In larger wheels, keyways are ground into the axle, and broached into the wheel
to assure proper quartering of opposing wheels. The bearings and drive gear is assembled on the axles, and the wheels pressed to place. COSTS Costs will vary depending on the complexity and number of wheels in the order. If we have never made that particular wheel before, there will be a charge for making the master pattern. If an additional order for that particular wheel is made, you will be refunded half of the master pattern fee. |
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