Scratchbuilding a Shay 16. 17.
16: The crankshaft was turned between centers on a wood lathe. 17: After the counterweights had been filed to shape, a hacksaw blade was used to cut a slot in each one. 18: One of the finished crankshafts waits to be installed on the locomotive.
Crankshaft layout Not to scale
Journal rounded (use saw or file)
18.
Counterweights filed to shape
Hacksaw cut
make, but they are easy to lose. I make clevises from a ¹₁₆″ long piece of ¹₃₂″ square brass bar from Special Shapes Co. I hold the bar in a small vise and cut the slot with a razor saw. If the slot isn’t in the center, I cut the “clevis” off the bar and start over again. When I’ve gotten the slot more or less in the mid- dle of the bar, I mark for the clevis pin holes and drill them with a No.78 bit. When either of the holes breaks through the edge of the “clevis,” I throw it away and start all over again. When I get the holes more or less centered in the clevis sides, I mark the ¹₁₆″ length and cut it off with a rail nipper. (I usu- ally get this part of it right the first time.) Then if I haven’t lost the part, I put it back in the vise and drill the hole in the end (Figure 13). See, they aren’t hard to make, but you might want to check out your handy, dandy Precision Scale Company parts catalog. It has a wide variety of clevises.
Stupid mistakes Sure I’ve made mistakes along the
way, most of them due to poor plan- ning, attempting to do things when I was not in the right frame of mind, or because of brain fade. I learned the hard way not to attach the footboards to the end beams before cutting the
76
pockets for the couplers. Those ¹₃₂″× ¹₆₄″ brackets that hold the footboards bend really easily if you bump them
with a Micro-Mark No. 11 size saw blade in a hobby knife. It isn’t a lot of fun trying to unsolder a broken foot- board bracket without also unsoldering a lot of other things like scratchbuilt poling pockets. Oh, and here’s another tip: unless you’re really good with a bu- tane micro torch, resist the urge to sol- der anything on a four-inch-long mod- el. Yes, the flame is pretty small, but it still heats up a lot of things that like to fall off your model without prior warn- ing. Don’t even think about asking my reaction when I tried to close an open joint between the front wall of the cab and the roof with the torch. If you look closely you can see the deep scrapes in the roof caused by the small pliers holding compression on the two parts when the heat of the torch melted mul- tiple solder joints simultaneously.
I
had to make a new front wall, too. Poling pockets really aren’t hard to
make. Lay out what I call rivet plates on a piece of .010″ brass sheet and im- press a rivet in each corner. Don’t be satisfied if the rivet pattern isn’t nice and square (or rectangular as the case might be). The accompanying photo shows the rivet plates that I didn’t use
on another project because the rivets weren’t in good enough alignment to satisfy me. Once you have your rivet plates made, solder one to each corner of the end beams. Then drill a hole in the center of each to a diameter equal to the brass tubing you’re going to use to form the poling pocket itself. As you solder the little brass rings in the holes, allow solder to fill the ring. Then take a small rotary cutter (like the ones made by Dremel) and dish out the pocket. Do this by hand; a rotary tool can eliminate the entire poling pocket in the blink of an eye!
The engine
I had deliberately spent most of my building time on everything except the two-cylinder engine of the Shay.
I
didn’t want to use the Keystone parts. The crankshaft is made of soft metal and turning it into one that will actual- ly operate the connecting rods is out of the question. However, neither did I want to scratchbuild the entire engine. Instead I bought some Precision Scale parts–the cylinders and their sup- ports. I also bought a three-cylinder crankshaft that had to be large enough for the Western Maryland’s No. 6 in hopes that I could cut it down to fit my little Shay. (I couldn’t.) That left me
MARCH 2014
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