i have two small turntables one i think is a walthers pit turntable and the other is a standard atlas turntable niether of which ar large enough to carry my big boy. has anyone built a cusom turntable to overcome this problem. if you have progress pics please share them. Thank you, Jamie
custom turntable need help
- Thread starter Lab Rat
- Start date
Since the Big Boy is 133 feet long, you'd need two kits like the one at http://www.walthers.com/exec/productinfo/322-804 to combine to make a turntable long enough for your engine. You'd also have design a counterbalance and indexing system that would work, along with getting a much larger motor than the one included with either kit you have now.
The UP only had three turntables that fit the Big Boy, and one of those would only work with the tender uncoupled. The vast majority of times, the engine was turned on a wye. You might take a lesson from the real thing and design a wye track with enough space to turn the engine rather that try to build what will be a very difficult model.
The UP only had three turntables that fit the Big Boy, and one of those would only work with the tender uncoupled. The vast majority of times, the engine was turned on a wye. You might take a lesson from the real thing and design a wye track with enough space to turn the engine rather that try to build what will be a very difficult model.
Jamie, I cannot think of a more difficult, expensive scratchbuild that requires more skills than a turntable bigger than a Big Boy. There's a reason why Walthers charges $330 for a 130' turntable. Even ignoring building one that looks like a real turntable, the problems of establishing the correct pivot point, counterbalancing, and track indexing are extremely difficult mechanincal and electrical engineering problems. It has taken Walthers, which has a large and competent engineering staff, three interations of their turntable to get one that both looks good and works correctly most of the time. Even if you can work out all these issues, building the turntable and pit will require kitbashing, buying a lot of expensive detail parts, and probably casting some of your own details, since many aren't made for very large turntables. This might be a project you want to tackle when you have that roundhouse full of engines and lots of modeling experience under your belt. I can tell you that, after more than 40 years of modeling, including building some pretty complex structures, building something like a 145' long turntable would give me cold sweats just thinking about it. 
i have a machine shop at my mercy and i am educated in electronics and robotics i am also planning so scratch build the round house. the difficulty that you say it include just makes me want to build it even more to prove you wrong. but i do agree it will be a complex project. i am not worried about the look i know i can get that working the only thing i am worried about is indexing but i think i got that covered
flyboy2610
Loveably weird
You could do what they used to do at North Platte to the Challengers before they got a bigger turntable: jack the last 6-8' of the rear of the tender up and let it overhang the edge of the pit. IIRC, the table came from Caliente, Nevada.
did they really do that. thats funny man
Cjcrescent
Master Mechanic
Yes, they really did. It wasn't funny to the crew that had to do it. They didn't use any jacks like they have today, the jacks could weigh 500 to 1000lbs each. Picking up the end of a tender, even with not much water in it was no easy task.
Several articulateds were turned by this method and on some of the Eastern roads, they had to jack up both ends of the loco to turn them.
Build your TT bridge out of balsa wood. It light, holds glue well, and once sealed with paint inside and out, it doesn't warp. Sheath it with styrene. I've built several using this method and still have one that's going to be used on my current layout, when the tracklaying gets to that location. I also used a low RPM motor, and line up the tracks as the prototype did, using the MkI eyeball.
I'll develop a drawing showing you the basic construction, and post it shortly..
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Cjcrescent
Master Mechanic
Jaime;
Here's that drawing of mine. I used 3/8" balsa throughout. That will give you a framework of 1 1/4" wide by whatever length needed. After detailing, with the styrene sheet and shapes on the sides, ties, rail, walkway, etc on top, you'd never know it was balsa.
Here's that drawing of mine. I used 3/8" balsa throughout. That will give you a framework of 1 1/4" wide by whatever length needed. After detailing, with the styrene sheet and shapes on the sides, ties, rail, walkway, etc on top, you'd never know it was balsa.
Cjcrescent
Master Mechanic
Yes. It took one sheet, 4" x36" to build. Like I said, this was a while ago, and I'm not sure that size it still available. 1/4" will work as well, but the center and end blocks would have to be made from 2 1/4" pieces glued together. This will also make the bridge thinner. But again, once sheathed with styrene and detailed, no one will know.
For the Balsa wood check any hobby shop that deals in radio control airplanes.
or try these places
http://www.balsawoodinc.com
http://www.lonestar-balsa.com/index.php
or try these places
http://www.balsawoodinc.com
http://www.lonestar-balsa.com/index.php
