I plan on putting in a turntable on my layout–I plan on a 6 X 12 foot modified from plan # 39 in Wescott’s 101 track plan book (similar exc. with broad curves).
This is probably a newbie question, but here it is: how thick should the foam base really be.? Yea, I know , thick enough to accomidate the pit–but just how deep does that need to be? I ‘m not sure yet which turntable I’m going to do–probably the 135’ Walthers or one of the CMR’s. On the Walther’s specs, it states to allow for a depth of 2 1/4 inches, whereas the CMR’s are just over an inch (1.0625" as I recall?)
Anyway, that would imply that 2 inches is not deep enough foam for the Walther’s and 1 inch is not deep enough foam for the CMR’s. I plan on using extruded foam–at Lowe’s, doesn’t come any thicker than 2 inches.
I have 1" foam glued to 5/8" plywood. I cut a hole through both with a jigsaw until it was large enough that the 90’er TT sank down to sit flush with the lip of the foam edge. That way, the rail heads also matched up.
Basically, if your TT has a lip, and can rest securely on that, you need do nothing more than cut out the aperture that will permit that position. In fact, any adjustments and wiring will be easier if there is nothing under the TT. If you are unsure of the lip’s ability to support the TT and a loco, place strapping under it.
What I would do! I would go a head buy the turntable of your choice and go from there. Thats what I did. I bought a Diamond Scale 135 ft turntable. It is a 100% highly detailed kit. It take a little tweeck’in to get it working smoothly. But I have had very good luck so far with it.
I bought the Diamond scale about 5 year ago. I would have known Walthers was going to release a new highly detailed turntable kit . and all you would have is drop it into the layout. I might have went that route.
I have built my layout bench work around my turntable, with homasote roadbed at 1/2" thick my plywood sub roadbed 1/2".
Buy your turntable first go from there. I think it would be less frustartions in the future.
I plan on buying the Walther’s 130’ drop-in TT and was going to do as selector did, use jigsaw to cut hole thru foam and plywood. I never thought wiring would be easier that way but it makes sense. Anyone know if the Walther’s 130’ TT has a lip to hang on?
Surfstud–you can look at the template/installation instructions on the Walther’s web site–but I can’t tell from the description whether there’s a lip or not.
Followup newbie question #2: I plan on using an L-girder/joist benchwork frame. My question is: what do you do with the joists that run under the TT area? Seems as if the two choices would be: (1) Move the joists off center–but if they would happen to run through the middle of the turntable, that would involve moving the joists around 9 inches(for a 130’ table–pit dia. approx. 18 inches) or (2) sawing out a groove in the joist itself–that could be pretty deep if you just used plywood and with the Walther’s 130’ TT (2 1/4 " depth clearance required). I do have Wescott’s benchwork book, but I was hoping to avoid the separate frame for the TT he recommends.
A couple pieces of advice from someone who learned the hard way. If you are using Atlas track for the leads to the TT, You need to bevel 3-4 inches of ties so the the tie nearest the TT is flush with the lip. Otherwise your locos will hit a bump when they move from the bridge to the leads and might even derail. I found a belt sander does quick work of this.
Whatever you do, keep loose ballast out of the TT pit. The ring and the cog teeth must be kept extremely clean. Even a small piece of ballast can stop the bridge from rotating. One modeler posted that he used masking tape to form a dam when ballasting near the TT and I think that is an excellent suggestion. I would also go with WS medium grade ballast instead of fine ballast anywhere near the TT. If any does stray into the pit, it likely won’t wedge into the teeth and will be easier to clean out. The fine ballast is small enough to get between the teeth and is a royal pain to get out.
These points are mentioned in the instructions but I am passing it along here for emphasis. They are not kidding. I had a time lag between the time I read the insturctions and when I did the finishing work on the TT and forgot these points and paid the price for it.
Good advice je. I’ll keep it in mind. Glad you mentioned the fine ballast vs. medium ballast near the TT. I hope to have a wealth of information when I am done building my layout. I’m doing my best to avoid pitfalls but sometimes that is the best way to learn.
I have included a picture of my installation. You can sort of see the lip of the pit. It is very light coloured on the far side because I had been grinding it down to get it round. I have found that the bridge does not rotate freely through all quadrants.
Pay attention to how the roundhouse/backshop tracks will align with the loco leaving the bridge and entering a bay. Rails will have to align closely for angle at the lip of the bridge or a kink could cause binding in the wheels of longer steamers. Also, file down rail heads, or shim if you prefer, to ensure that smaller truck wheels don’t jam and cause stalling.
Finally, and this was something I decided I wanted…you may shudder…, I cheated and extended the bridge rails for about 3/4" past the ends of the bridge. Also, I extended the House bay rails about 1.5" beyond the concrete apron. The latter is not a problem prototypically, but the former sure as heck is. However, it allowed me to get a better meeting angle, for one, but the big advantage was permitting me to turn my biggest loco at the time, a Hudson, and get it into a bay.
Thanks, Surfstud31. They can be a real pain to get right during installation, particularly the non-indexed, non-pre-fabbed ones. However, once you beat them into submission, they add so much in the way of relief and variety to your layout. Additionally, the roundhouse, as you must have guessed, can hold locos without them cluttering up the layout trackage if space is at a premium.
I hope yours goes well…no reason for it not to. Please post a pic when it is all done up nicely and you are happy with it. Also, feel free to ask for help if you need it…I’ll do my best.
