Hi folks,
While working on the MEG Steam "Wendy" (see
viewtopic.php?f=8&t=88699) it became evident that there isn't a really great 'off the rack' solution for large scale valve handles. Most people working in this scale are either using scale valves that are too small, or regular faucet handles that are more utilitarian than attractive. The solution is to roll your own.
For inspiration, I turned to a set of valve handles that I found on a lovely south African gauge locomotive that I found in New Zealand. You can see that this engine has just about one of every kind of handle you can think of. In my case I mostly need directional handles not round, except for the blower, so I settled on a couple of prototypes.
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The next step is to fire up Solidworks and start modeling! Since I had photos and no measurements, these are eyeballed and made to work well at the size they are being printed at. Special care was taken not to make the handles too long, lest they interfere with other stuff in the cab.
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The handles are all designed to bolt right on to the valves they are mating to, various off the shelf valves from McMaster and the hardware store. So each one has a custom bottom. I measured the valve stem matings carefully and incorporated them into the part.
By using rapid prototyping, I am able to save a lot of time and the cost per handle in stainless is less than having a one-off casting made with pattern, mold etc.
Furthermore, I am given the option when ordering stainless steel from Shapeways to put a patina finish on it. I chose antique bronze, glossy. This will make it fit right in with the copper and brass without having to paint anything.
I finalized the 3D parts, sent them off and a few weeks later I got these beauties in the mail in stainless steel. They are heavy and feel great, and the weathered bronze look is very nice. As you can see they are not perfectly smooth, but that adds to the 'cast' look. And they sure are a whole lot less beat up than the originals! You have to keep in mind just how rough most of this stuff looked in real life (see photos above!) our models have much finer finishes than the original prototype hardware that was subject to much abuse in the field, where a wrench and a hammer substituted for just about every other type of tool.
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If there is any interest I can make these available for purchase and I could also offer them with generic unmachined bases so you can adapt them as you see fit. I can also scale them up or down, within reason.
I'll bring some to LALS and Sacramento so people can check them out in person.
--Mike
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