Turntable opinions

Carter, The Fleismann and Marklin while probably fine operationally my not look quite right on a North American layout and also may be expensive. Who know what code rail they use....most likely code 100. Since you already have the Walthers you have a bridge that will look very good with out any further detail. You could use your bridge with an Atlas TT to power it. The Atlas TT is very reliable ( a little noisy) and very inexpensive. These Atlas units have been turning locomotives for model railroaders the first and every time for a decades. They are not very pretty but if you used one only to turn the bridge you would not see it. Because it is so dependable and cheap there have been a number of ideas and projects presented over the years converting the old Atlas into a something more realistic. I took a few ideas gleaned from the past along with some of my own and built my HO Neanderthal Turntable. It was made with some scrap wood, some leftover drywall mud, a piece of flex track, and of course a good old Atlas unit bought second hand over twenty years ago. If you think you might want to consider making your own TT using that nice Walthers bridge check this link for some pictures, ideas and building guidelines.

Even if you have to buy a new Atlas you should still probably have spent far less than $100 even including your Walthers Kit. It may seem like a pain building up a TT but when using the Atlas to drive it you will only build it once and should never have to fool with it again. There are few TTs of any manufacture or at any price that will do any better. Bruce

"Carter Braxton" wrote in message news:nnc3g.63617$F snipped-for-privacy@newssvr29.news.prodigy.net...

Bruce:

Good work, chief. I like the use of freight car trucks as self-aligning carrier wheels, and the film canister spacer. Maybe I'll try building one.

Cordially yours: Gerard P.

Wow, thank you for the detailed resonse. I wish I had seen your work before I installed the Walther.

The problem I'm having now is with the bridge binding at certain points around the circle. A friend of mine thinks I can warp the pit to eliminate the binding but I have my doubts. Seems to be a poor meshing of the motor gear and the gear wheel.

I resolved the problem of poor electrical pickup for the bridge track but this mechanical problem is really frustrating me. That's why I've been asking about the better grade turntables.

Thanks for the other option though.

Carter

in article WPy3g.69687$ snipped-for-privacy@newssvr13.news.prodigy.com, Carter Braxton at snipped-for-privacy@sbcglobal.net wrote on 4/25/06 5:06 PM:

The Walther's turntable does indeed bind. For mine, the well was not round. With some subtle pressure here and there, it could be made round. But its gear and motor just are not up to the job. Use an Atlas to turn the bridge, and you get 7.5 degree indexing. The challenge to to mount the atlas under the Walther's and lash the Walther's bridge to the Atlas table. You can pick either one to do the power to the rails job; If you use DCC, there are a couple of auto-reverse solutions, I suggest looking at the MRC auto-reversing module which works well with turntable bridges

Herer is a description and a place to buy one:

Yes, the Fleishmann at least, uses Code 100 rail for lead in and bridge track. It is not too tough to shim code 80 (or 70) to the same height at the Code 100 lead in tracks.

I have run into the binding problem with my Walthers TT also. A rather inelegant solution is to wood add screws into the baseboard around the periphery of the TT. Especially add screws where the bridge binds up - screw them a little tighter and, perhaps, loosen some of the others. Once you can have the bridge moving freely, then's the time to work on the mechanism.

HTH,

Ha!

We're currently using a Marklin 7286 turntable (I think the Fleischmann ones are the same unit) bought used on ebay. No instructions or indexing unit was included, so I hacked one up from a couple switches and a power supply. It doesn't automatically go to a specific position, but it 'latches' precisely to the next index spot when an intermittent button is released.

It really works well. The only thing I haven't been able to figure out is how to get it to move in both directions - it only latches when the polarity is set so it moves counterclockwise. But that's a small complaint - these are really nice quality turntables. *

Paul Vader wrote: ...> It really works well. The only thing I haven't been able to figure out is

That's something I've been wondering about lately... I assume the prototype could move in either direction, but I've never heard it discussed, and I could see where it might be possible that they could have been designed to only go one direction. Do the prototypes go either way? Were there any made that only went one direction?

Most (at least) prototype turntables could revolve in either direction. Some often moved better in one direction than the other, due to weight distribution and traction problems. Unlike model turntables, almost all were powered by one or two traction wheel(s) beneath one, or both, ends of the bridge. These drove against the ring-rail via friction. Despite various ways to mount the driving wheel (often sprung), sometimes the wheel got better traction turning in one direction than the other (torquing of the bridge structure?).

The position of the loco on the bridge also affected the turning mechanism (see below). Ideally, the loco should be balanced on the bridge, but sometimes you want it just a little off center, to load the driving end of the table for more traction. I've seen a table TRY to rotate the bridge, with little success (wheel slipping), and then the crew would have to reposition the loco and try again, until the thing would work.

Propulsion for the table was usually by electricity (via overhead wires going out to the 'arch' over the center pivot of the bridge), but was occasionally powered by an air motor or small steam engine driven from the loco's supply. Smaller and older tables were often just pushed around by hand (an "Armstrong" turntable). Such hand powered tables usually had a long pole sticking out from one or both ends of the bridge so a few guys could push on it. surprisingly, if weell maintained and balanced, they turn quite freely, though it takes a LONG push to get all that weight moving.

Radial centering of the table was established by a large (usually ball) bearing at the center of the pit. A large roller thrust bearing also at the center carried much of the bridge and loco weight. The trucks at each end of the bridge, riding on the ring-rail, were mainly to support the weight of the loco as it went on and off the bridge. Except on very long tables thay often caried little of the overall weight. Usually the bridge could tip slightly (end to end), and it was common for one end or the other end to lift a tiny bit off the ring-rail as a loco moved across the bridge. That's why an off center loco often had an affect on the traction of the rotation driving-wheel.

Dan Mitchell ============

So I would venture to say that it's an excellent piece of crap ?

( rim shot )

Carter, While I don't have a Walthers TT you may be able to bring it into round with a one of those fasteners used for duct work. Basically its big a metal band with slots with a screw to tighten it. Kind of like the fasteners used to connect radiator hoses in a car only much bigger. If the plastic is not to stiff the even pressure of the fastner all the way around might take out the warp causing the bind. If not you could try to warm the plastic pit with fastener around it with a hair dryer or put the assembly in the oven at a very low temperature. That might help the plastic pit soften then stay round enough after it cools. Don't know if this will work but it might be worth a try. Of course if the drive mechanism is the real problem another TT or drive is the only option. I've heard that thedrive is not so hot. You would think that someone would have come out with an aftermarket drive for theWalthers TT by now as it seems like so many people have them. At least you have a really nice bridge and pit (provided it can be made truly round ), so you are part way home. Bruce

Bruce,

That's a great idea; I'll pick up a clamp or two tomorrow and give it a try. Your suggestion is certain to provide a rounder pit than any other I can think of. Thank you!

Keep in mind that if you can't find _one_ big enough for the job, you can link two or more together...

Many years ago, at the Sacramento Railroad Museum, I watched a gas-electric car get moved onto the turntable by a small diesel switcher. The motor end of the gas-electric was on the same end of the table as the switcher, putting the table way out of balance. When the operator tried to make the table rotate, the motor could not move it. Eventually they had to hook a backhoe to one end of the table and drag it around. Had they just coupled the switcher to the other end of the gas-electric it would have worked.

Or try a cloth strap clamp, or even string like in the old days of furniture repair.

In the Transportation Museum in Otaru, Japan, there is a small powered turntable which is rotated in an unusual way. At one end of the bridge is a small horizontal air cylinder, the piston of which drives a mechanism which on the outward stroke grips the carrying rail and so pushes the bridge a short distance, on the return stroke the mechanism does not grip the rail. So the bridge moves round in a series of jerks. Quite amusing to watch the little 2-6-0 going around in this manner. The compressed air to drive the turntable is provided from the loco. compressor. I think that the final lining up is done by man power. Regards, Bill.

"Daniel A. Mitchell" wrote in message news:H184g.26$ snipped-for-privacy@news.itd.umich.edu...

William Pearce spake thus:

And of course there are the two cablecar turnarounds in San Francisco on the Powell St. line, both person-powered. Up until a few years ago, you'd regularly see tourists helping push the cars around on the upper (Fisherman's Wharf) end; the Muni gripmen always got a kick out of that ("make them tourists *work*!").

I'm amazed! Nobody suggested yet that you build your own. If you want a smooth operating TT mechanism, go down to your local bicycle shop and get a front wheel hub. It has a beautiful ball bearing setup to rotate the axle. Mount it in the center of your pit. Next, take a stick and some plaster. Drill a hole through the stick and use it on the axle to create your pit wall and floor. Make a step for the pit track. I would say that you should make your own bridge, but since you already bought one, use it.

As for indexing, Bowser made a neat set. It used a fiber optic under the approach tracks and a LED or small light shining through a pin hole in a mask on the ends of the bridge to trip the power interupt.

Doesn't anybody build anything for themselves anymore?

Old Fart

On the surface it does not appear they do. I very rarely go to hobby shops other than our local train store. They have tons of RTR these days but still have a good supply of building materials and some kits. But the other day I went to a rather large general hobby shop because it was convenient. I was getting low on .80 drill bits and thought I'd pick up a dozen. Well....they had no drill bits and while they had some kits of various types and some building materials the store was dominated by ready to fly airplanes, ready to run trains, ready to race slot cars, ready to run RC cars, ready to do whatever action figures, along with ready to display diecast things of all sorts. Get this........ they even had a big section of built up weathered and distressed military models that actually looked pretty good and were less expensive than the plastic kits of same things. I saw a 1/16 Radio Controlled RTR Tiger Tank that was just as neat as could be. It had sound and shoots plastic BB's and shoots them very well. I was impressed with the model but not so impressed that I'd part with $160 for a non train item. When I got home I found one on the Internet for $77 including shipping and ordered it. I think I'll enjoy plinking tin cans with it and stirring up the IL2 dive bombing mocking birds that live in my yard. When not in use it will look fine on the book shelf. So I can understand why RTR is popular as I did not have an interest in building a Tiger Tank but wanted one anyway if the price was acceptable to my personal dollar amount thresholds. Those thresholds can be much greater for trains but I build or bash most every thing except locomotives and I often put the tools to them as well. Probably many people feel the same in regards to trains as I did to the RC Tank They want to have some fun if the price is tolerable and that fun does not include hours of construction, painting and fiddling. When I look back to the old days the greatest selection in trains was mostly kits of one type or another and many things had to be scratch built if you wanted them. Yet when I think about it most people who had trains ( it seems that many more did back then ) had mostly RTR stuff and fairly plain layouts. They had RTR but just didn't have as much to choose from. The RTR railroader has always been a big part of the hobby but he's served better now. Yetb there is such a huge selection of kits and supplies to build with these days I'm sure there are still some hobbyists that build things. Bruce

Doesn't Bowser make some nice turntables as well?