Train Turntable for inspiration purposes

Hi Deem,

For a "most basic" turntable have a look at the " Train Turntable" on my Corrimal Colliery Incline thread. 

Don't get too bogged down with the specifics - look at the basic concepts

• turntable deck is only electrically connected when aligned with incoming or storage tracks
• the turntable deck is un-powered during the turning process
• track on the turntable deck always matches incoming track wrt DCC or DC "polarity"
• storage tracks are powered from the deck = No chance of short circuit regardless of the angle the table has been rotated.
• simple construction - no electrical slip rings etc required. 
• if space between tracks is limited, the shot bolt connections can be replaced by fly-wires and alligator clips wired to the far end of your incoming track. These wires can connect to two screwheads, each wired to one of the rails on the incoming track. Provided that you pick the correct screwhead there is no chance of a short circuit - Hint use colour-coded boots on the alligator clips to matching colour-coded screw heads.

With this approach you can use the piece of rail you already have in place as your turntable.

If necessary we can discuss in more detail, but this is about as simple as it can get, 

Combine the two...

If you have the Atlas turntable just attach your longer length of track on top, add electrical jumpers between the "Atlas rails" and yours and adjust the height accordingly. Mind you, as I type this, I remember that the Atlas turntable has a Geneva mechanism in it that only aligns the rails to the tracks around the perimeter of it's ring. That might be defeated though, I've never taken one apart.

You could also build up a gallows style contraption and have the electrical connection at the top.

Personally, all of my turntables are built up using phono plugs underneath for both the mechanical pivot and electrical contacts. Works very well!

Good luck.

Dee. how long is the space

Dee. how long is the space for staging?

Maybe consider a "train turntable" to turn and stage trains?

Photos from the net attached. It could be shorter and single track on a board with simple wiring than what's shown.

Barry

Dee here's another idea

Dee here's another idea ...this time CN, in S scale, by well known author/modeler Trevor Marshall.

Enjoy,

Barry 

@John, I'll check it out.

@John,

I'll check it out. Thanks.

@Rick, Good idea and thinking

@Rick,

Good idea and thinking outside of the box or shall we say pit so to speak ; )

@Barry, Way too short not to

@Barry,

Way too short not to mention snug up against a window.

This should work for the next

This should work for the next session I have with a friend to turn around the doodlebug and locos.

Live clips that are wire to the track to this TT will live here when not in use.

The nails help keep the alligator clips from slipping off and moving the "bridge".

Storage tracks

Hi Deem,

If you lay your storage tracks and then line your turntable track up with the storage track (using alligator clips or similar):

• this sets where your next set of nails have to go at the far end of your turntable track, just as you've done in the previous post
• install your storage tracks and (alignment?) nails one storage track at a time. 
• connect the each alignment nail at the other end of the turntable track to the corresponding rail on the storage track directly across the turntable. When the alligator clips are attached to the alignment nails, then the alligator clips now power only the turntable and the storage track that the turntable is aligned with. All other tracks apart from the approach road are electrically dead. Electrically the approach road should now "see" the turntable track and the aligned storage track as a stretch of parallel track. No fancy reverse circuits are required.    
• remember storage tracks don't necessarily have to be straight 
• I'd suggest that you get some colour to identify left and right alligator clips - Left clip ALWAYS goes on the left nail to the left rail. Put the wrong clip on the wrong nail and you could get a short circuit. 

The nails are a simpler idea that the shot-bolt approach  

I like simple,

Turntables

I have something similar to yours on my staging yard, I just went crazy and mounted wipers underneath the pivot so it auto reverses the polarity.  A friend has much the same thing only using a peice of Homasote in a hole cut in the Homasote with alligator clips.

Hey John,I don't quite

Hey John,

I don't quite understand what is going on here:

"connect the each alignment nail at the other end of the turntable track to the corresponding rail on the storage track directly across the turntable. When the alligator clips are attached to the alignment nails, then the alligator clips now power only the turntable and the storage track that the turntable is aligned with."

I'm trying to visualize it, bear with me : )

Dave, So may options to

Dave,

So many options to consider, which surprisingly are economical.

Visualisation help is at hand

Hi Deem 

have a look at this image - Yes its a "quick and dirty" Powerpoint image  This is the set up for a loco or vehicle arriving onto the turntable from the approach track.

For a loco to get onto the table, the alligator clips power the track while the alignment nails hold the track aligned. 

Now if you turn the turntable, first you have to disconnect the alligator clips. This renders the turntable track totally un-powered. It doesn't matter it you spin the turntable 360 or 180 degrees, the only way to get a loco off the table and back onto the approach track is to reconnect the alligator clips. Provided you reconnect them as shown, the deck "polarity" (either DC or DCC speak) will always match the "polarity" of the Approach Track. Change the locomotive direction on your DCC controller and drive your loco back onto the Approach Track. 

To turn a passenger/mail car - shove the passenger car onto the turntable track while aligned with the Approach Track. Uncouple, leaving your passenger/mail car on the turntable track, and retreat your locomotive back onto the Approach Track, Disconnect your alligator clips. Rotate the turntable track 180 degrees and reconnect your alligator clips as shown above. Drive your locomotive back onto the turntable track and couple up to your now reversed passenger/mail car, Change the loco direction and drive back onto the Approach track and go take your reversed passenger/mail car to where it is needed for its next train.  

Now to park a loco on a Storage Track - Getting the loco onto the turntable track has already been explained above - Have a look at the next diagram, where the turntable track is aligned for a storage road.

 Note the connections from the alignment nails that line up with the storage track. The only way a locomotive gets power on the deck is via the alligator clips attached to both the track and the alignment nails that align with the selected Storage Track The only way the Storage Toad gets power is from the connection to the alignment nails for that specific track. Again while the turntable track is being rotated between the Approach Track and any of the Storage Tracks, the alligator clips are disconnected from the turntable, and the turntable track and all storage tracks are totally un-powered.  Nothing can move under power or short out.

Clear as mud??  

Awesome!

Awesome!

John. So kind of you. Much appreciated. This is so helpful for this makeshift TT and also for a better one in the future.

I put the nails in today and colour coded them. Also laid the storage tracks.

Note my longest motive power just fits.

Track 1 (with the current tester on it) will be for the small road switcher;

#2 (with the ramps) for the Mikado, which rarely visits Stonehammer;

#3 for the 4-6-2; that brings in the passenger cars

#4 for the 2-8-0; that brings freight;

and #5 for the RS3 Road switcher; that brings passenger cars and freight or both at the same time.

Now I have to do the aspect of the hobby I dislike the most - wiring nevertheless this certainly so far has been an educational exercise.

I'll have to drill holes to go next to the nails so I can feed them under then and back up through holes to the storage tracks. I tested the nails to be sure they conduct electricity. I hope I will be able to solder wire to them.

If only the locos' wheels rolled freely without the power on, I could do the 0-5-0.

I can feel my neck start to ache already : )

Saving an aching neck

Hi Deem,

who said wires always have to be routed underground?? Bundle your wires, route them around your turntable perimeter and disguise the wire bundle as a solid fence. The only excavation required is removing some ties under straight track so you can slide your feeder wires through. 

A whole lot easier than getting down and under,  

Is Stone Hammer a war game? 

Is Stone Hammer a war game?  Seems I've seen that somewhere before.

Roco/Atlas Bridge Parts

Not sure if this has any possibilities for you, but this was some early experiments I did utilizing the base pieces from the Roco/Atlas curved cord bridges parts,...
http://ttps://model-railroad-hobbyist.com/node/4122?page=2#comment-85674

Sounds good, John. I need to

Sounds good, John.

I need to get some stranded wire that is quite flexible. What gauge do you recommend?

Brian, Now that is something

Brian,

Now that is something I overlooked. I wonder if they come in 12 inch lengths.

Re - wire size??

Hi Deem, 

Having NO experience with DCC, I can only make suggestions. Ignore or adopt them as you work things through yourself.

Recommendations:

1. For a small layout with only one or two locomotives in motion simultaneously, you are unlikely to push your maximum current limits.
2. Whatever you used for your hook-up wire between your track and DCC bus should be fine if it is stranded wire.
3. If your hook-up wire is solid core, the curves needed are not really that sharp, so you should be able to use what you already have
4. Once installed, there is no repeated bending of the connections between the alignment nails and storage tracks, so stranded wire probably is not required for this wiring if you have solid core wire available. 
5. The only place more flexible multi-strand wire might be required is on the fly-leads leading to the alligator clips. These 2 wires will be subject to movement and hence bending of the wire. But the degree of bending is probably unlikely to cause internal failure of the wire. So this shouldn't be a problem. Solid core wires probably will outlast the life of this "temporary" turntable. 
6. If the wire plus insulation diameter of your existing hook-up wire is such that it is less than the tie height, then it should be relatively easy to remove some of the plastic spacing and may be a tie or two under the rails, and then slide the wires through this gap. If not you may have to go down a wire size or two.
7. If you have to reduce your wire size slightly, again this shouldn't be a problem, because only one locomotive is being fed via the alligator clips and that locomotive is only in motion for relatively short periods getting on or off the turntable track. You are most unlikely to heat the wires between the alignment nails and storage tracks enough to cause problems. 
8. Do the excavation and feed your wires in under the tracks. I'd recommend using 2 different colours so you can track which goes where easier. Connect your wires at the track. Any slack in the wire can be feed back under the track and the track and the wire length can be adjusted when you set up your connection to the respective alignment nail.
9. Run and connect one wire at a time       

That'll probably be more than enough from me,

9" lengths

To the best of my knowledge those base pieces are all 9" long. Of course you might glue them together then cut your 12" length. If I were looking for a 12" length, I would cut off sections at either end, while leaving the joint between the two ends at the center (rotation point). At one time I thought that rotation center might just rest on a very thin sheet of Teflon material. The outer ends might be able to just rest on plain old metal balls held in recesses in the plastic frame.

BTW, I was experiment with use baking pans/pizza pans as the turntable pit.,...but I used upside down plate girder bridge pieces to make a more robust/std turntable bridge.
 
oops, wrong pic
 

 
(didn't use the baking pan as I wanted a deeper pit)

Structural depth in question

I see Brian's final build has a girder underneath which would be a prototypical structural depth. A prototype curved-truss deck is shallow and is designed to only span between curved-truss struts (about 5 or 6 feet at most). To span a turntable pit (30 to 50 feet) from center to perimeter requires more structural depth than that. I see from photos that turntables achieve this structural depth in several ways: through girders, deck girders (as Brian's), or another way such as suspension cables over a gallows. The desired pit depth is one determinant in choosing whether the structure is above or below the deck.
I thoroughly enjoy all of the posts, and seeing what you are doing, Deem.  I think your quick-build turntable is brilliant, and the 'down-under' connections are topnotch. There are always good ideas here.  I would have never thought to use an RCA plug for a pivot!  I enjoy this community very much, and hope to eventually have some model railroading to post! I'm gathering ideas every day!

Remember the aim of the game here...

Hi all,

Remember the aim of the game here was to build a quick/cheap/easy non-prototype-based turntable for a bare staging staging area without scenery. 

Turntable deck timbers, deck trusses, handrails etc are simply "gilding the lily" when it comes to this specific turntable design situation. And they could overly complicate what is a very simple and probably the most basic turntable design to have been mentioned on this forum so far. 

Deem's specification was:

We've figured out how to wire it - So this makeshift turntable's replacement may be some time away in the future. Deem already has done a detailed turntable at Stonehammer. I'm pretty sure he could have opted for a more detailed turntable design if he had chosen to go that way. 

But Deem's request actually was how to make his "makeshift turntable" work. Sometimes a design doesn't have to be "pretty", but it just has to work (without too many hassles). 

Concerning the Atlas

Concerning the Atlas turntable. 

In order to extend the rails to accommodate longer equipment maybe using a saw/Dremel tool he could remove enough of the molded on plastic "stops" so he could easily extend the rails out over the end of the pit sides? This would do away with all the extra,temp. wiring/turning /reverse challenges and be a very simple, low cost way to turn equipment. He would only need to remove enough of the stops to allow a 180 degree turn not a full 360. 

Many prototype roads did extend the turntable/bridge rails through the years to handle longer locomotives with out replacing a small one.

Maybe too many, choices for dear friend, Dee? Maybe we should leave him alone to make his own choice?

Barry