I built a CMR 135’ turntable kit and customized it to my wants. I also built my own indexing controller using IR detection with super high accuracy. When I installed it I made it dual mode automatic with indexing and manual control.
The only time I use the indexing is for visitors or when I’m just lazy so I do both. After you get the hang of manual operation its almost as easy as using indexing.
Not all turntables had a control shack on the bridge, I don’t have any idea how they controlled the bridge. As a kid in the early 50s I hung out at the El Paso SP yard almost all summer for three years and I always got a blast from riding in the control shack when they moved the 4-8-4/GS4s and the huge AC-9s in and out of the roundhouse.
I have experience with both kinds, DC motorized and DC indexed. I enjoyed both, but as a manual operator of all my turnouts, I had the most fun making the bridge rails line up manually. I got good at it very quickly, so it’s no big deal. Still, my early indexed one from Walthers did a good job. Haven’t had it operational in four years, but I hope to use it soon.
If you are a lone wolf operating a frenetic schedule, trying to make smooth stops at the high platforms with two trains simultaneously, it’s nice to ‘fire and forget’ the loco being turned to replace the juice motor on a future train. Go for automatic indexing.
If you are the designated hostler, turning the loco to line up with a stall or the proper outbound track is part of the job. Manual alignment is easier, and probably faster.
If you are operating the end of the railroad station, where everything arrives from or departs to hidden staging, the turntable alignment adds to the fun. Go manual.
As for me, my top of the mountain colliery has a manual turntable that never turns a locomotive. (The TTT operates its steam smokebox uphill, to keep water over the crown sheet.) There’s an indexing turntable in Tomikawa’s future, for the reason mentioned above.
A lot of people use the Atlas TT. No matter what you do to or with it, the Geneva motion is utterly unlike anything the prototype would do, and the fixed 15 degree index points are too limiting for me.
Chuck (Modeling Central Japan in September, 1964 - 146 trains a ‘day’)
I wish somebody had explained that to me 10 years ago when I bought one! Not only are they completely unprototypical, but if you made the mistake of buying one of Atlas’s drive systems you can hardly hear yourself think when it is operating. They are about 20 times louder than a dentist’s drill and 10 times more annoying!! “Grind, whirr, squeak, rattle, crunch…”, and that happens at each 15 degree interval.
I thought that by building mine into a pit style TT I could quiet it down. Wrong!
It is by far the worst model railroading purchase that I have ever made!
Our club has the Walthers 130’ indexing TT. We didn’t choose indexing, it came that way. Due to some operator issues with the indexing some members have indicated they would prefer manual indexing. This would be fine with the way our TT is installed but we don’t have that option.
I have a mix. I have an Atlas that hides under snowshed and only has to do a 180 on each loco. The Geneva motion works well for it. Dave, Atlass changed to a belt-drive TT motor a few years back. Haven’t tried one out yet, but expect it to quiet things considerably.
The TT in the Durango terminal is a Diamond Scale with a high accuracy NYRS drive. It can be reached, but is in the middle of a loop, so I rely on the indexing it provides.
My other two TTs are scratchbuilt manual turn and index, one at each end of my helper grade, built on 1/4" phono plugs. You can line them manually very easily, but both are near the layout edge and are easy to reach.
My scratchbuilt turntable at Lowbanks is finger-operated, with indexing provided by the Mark II eyeball method:
It’s within easy reach, as it’s right near the aisle edge of the layout:
At Mount Forest, on the upper level, I also have a Walthers 90’ turntable, which I’ve motorised using the can motor and gear train from an old VCR.
It’s hooked-up temporarily so it can be controlled using a walk-around throttle, but the wheels on the bridge are out-of-round and very noisy and rough-riding as the bridge rotates. If I can’t fix it, I’ll put a scratchbuilt one in its place, and likely leave it as a manual one. Indexing is by-eye, although the accuracy is iffy due to the slop between the bridge assembly and the pit.
I also note that, barring those reasons, most/all of you went with manual alignment.
I “inherited” a big Diamond Scale turntable. It’s been tucked away for quite awhile. But sometimes I daydream of actually using it. Which is why I asked my question. And now I have a reasoned answer.
ALL turntables are indexed. It is just the method of doing so that is different. Almost all are manually “indexed” by the operator probably about 99+% however, many, did I say many years ago I saw 2 different turn tables in the SW part of the country that where at least semi automatically indexed, one was on a private industrial sight and only had 3 positions, they used a sliding shoe that was extended by hydraulics to essentially chock the bogies when they reached a certain position, the other one was on a shortline RR, if memory serves and they used a 3 color light signal on the ends of the bridge to help the operator position the rails after the proper rail was selected by an electrical circuit. I wish I had taken pictures of both of these and could remember where they were, but as has been related before on this forum, there IS a prototype for everything.
I don’t mind manual indexing, but have to accept a couple of things that may not be obvious if you’re younger. If you’re aligning solely by sight, you need the TT close by…until the eyes no longer suffice. Even with the close-in manual ones, I tend to use my finger on the TT-to-rail transition to confirm alignment. Not exactly prototypical, but points out that part of the lack of indexing on the 1:1 is because things are big enough to see unaided. That’s often not the case on the layout.
And, while there are other ways to deal with the reversing needed when swinging the bridge 180 or more, I like how this is done automatically as part of indexing, as is alignment at opposite ends of the TT bridge.
If (when) I get to the point where I can’t see well enough for proper alignment then indexing will be a must. It would be smart to install the system now and just wire in an over ride so I can play with it with just a toggle switch. Something to think about.
I am thinking of using a train set power pack as a controller instead of a plain toggle switch so I can speed up or slow down the speed of rotation. What think ye?
