I have discovered that there is a lot you need to know about locomotives to be able to pull off making a reasonable model of one. I am learning, albeit slowly.
The first important thing I have learned is that you definitely need a really good set of scale drawings to work from. I built “The Jupiter” from exactly 1, count ‘em, ONE side view (that I could scale from) and a couple of “¾ shots” for info about painting details. I could not find a front view anywhere. As a result, its wheel spacing, and hence the track spacing, ended up being about 25% wider than it should have been. Fortunately, anyone looking at the model sees it from the side and the boo-boo is not terribly obvious. But it does bother me.
I was able to locate a few more pictures of “Old No. 119” and some pictures of similar locos, so I did a much better job of getting it right. But I still had to do quite a bit of fudging because I still had no straight-on front or rear views.
This time I am starting with a very good set of plans, thanks to the “Cyclopedia – Volume 1, Steam Locomotives”, by Linn Westcott. If you are interested in steam trains – for modeling or just for reading -- this is a great book (available online for about $10 off the sticker price). It is just amazing to me how different they all are.
The second important thing I have learned is that even though these were a tiny models that could be easily picked up with one hand, to be successful you still have to build them from the ground up. I know this because I did it wrong both times.
In building a locomotive model it is nearly impossible to get the wheels aligned properly. Invariably, the wheels never seem to quite all hit the ground together. I had to continuously “fudge” the rail height and/or the space between the rails to make everything work out right. The trick was to do this without making it too obvious. This time I built the roadbed, rails and ties FIRST. When the wheels are finally attached to the rest of the loco, the whole thing will be sitting on the rails so everything has to line up.
Carving the Drive Wheels
I purposely chose all three locomotives because of their huge drive wheels. They provide a lot of character for the loco and I really like that historic look. But an equally important reason is that the larger wheels are much easier to detail.
 |
| Complete wheel on left. Partially completed wheel on right |
I first turned a basswood wheel of the proper scale diameter and cross-section on the lathe. I have a bunch of wheels to make this time -- I’m planning to build the tender, too -- so made myself a template to compare with each production piece to keep them all the same. I left the hub and the edge of the wheel "raised" with the spoke region “dished in”. I then sketched in the spokes and cut out the area between them. The actual wheels have 20 spokes. I settled for just 16 because the additional 4 don’t add much -- unless you are a real perfectionist – and 16 spokes are a whole lot easier to layout than 20.
Since the wheels are relatively thin (~ 1/8”) basswood, I never attempt to carve the whole way through. The cross-grain and the amount of removed material would make the wheels far too weak. Instead, I carefully make a stop cut around the edge of each opening (between the spokes) and remove about 1/16” of the wood there. When the wheels are painted and mounted on the locomotive, the effect is pretty good. I won’t even attempt to put spokes in the 12 smaller “Idler” wheels. That would be just insane!
I do try to get most of the other details right, however. You can see the “counterweight” between the spokes along the one side of the wheel (opposite the hole for the drive pivot). In the real thing, this weight is there to balance the weight of the drive rods to keep everything from flying apart at high speeds. The Empire State Express was the very first train to exceed 100 mph (it actually did 112.5 mph on May 10, 1893). When you multiply the enormous 84” diameter wheels (that’s 7 feet!) by Mr. Pi you get a circumference of almost 22 feet! At 112.5 mph wheels were going around 7.5 times every second! Later, the 84” wheels were replaced with ones that were about 75”.
The Boiler
 |
| Boiler and Wheels on tracks |
As before, I turned the boiler out of one piece of basswood, but since I had actual drawings this time I knew from the front view that the Empire State Express had a “Wagon-Top” boiler. You can see from the picture that the rear portion of the boiler is larger in diameter than the front. What is not obvious is that, while it is circular, it’s center is not in line with the rest of the boiler. Its centerline is slightly higher placing the bottoms of the two circular cross-sections approximately in line. (I’m guessing that this had something to do with improved steam generation because it greatly increased the complexity of the boiler shape.) However, getting the shape right was quite a task. For a better lathe operator there is no doubt a method for turning with 2 different centers of rotation. But discretion being the better part of valor, I turned it to be symmetrical and carved and sanded it to the proper shape. The hard part was getting the conical transition between the two offset centerlines to look right.
I then glued on the bottom (rectangular) section of the boiler. I can’t tell from the drawings or photos where the boiler stops and the wheel-mounts start. But all of that detail is behind the wheels so just between you and me, I’m going to let that part go:--) The block with the "X" is just a spacer to keep everything lined up for the picture.
One from the Bench
The difference between ordinary and extraordinary is that little extra. - Jimmy Johnson
'Til next time...keep makin' Chips!
1 comment:
Very impressive Tom!... cant wait for the finished locomotive!
Post a Comment