Does anyone have an idea of how to index a scratchbuilt turntable, or where I can get complete plans? [ 03 February 2002, 10:01: Message edited by: Graphite ]
Somewhere recently I've seen an article about using an Atlas turntable mech under a scratch -built turntable, which gives full indexing - I can't find it at the moment - might be in Feb 2002 Railway Modeller, but I need to go on a hunt. If I find it I'll let you know
Atlas uses a Geneva mechanism, set for eight equal spaces around a circle. By its design it will advance and stop at each location as it seeks the one you desire. It is the mose accurate of the mechanical types that I have seen. I am using a Diamond Scale 134 foot turntable and pit with 33 stall tracks. I use a computer controlled indexing system from New York Railroad Supply that stops each track withing .0040" every time and has 33 stall tracks. Everything is mounted on ball bearings, and has to be precision machined to operate correctly. Contact: Doug Diest at: sales,service@nyrs.com get his catalog. If you build your own turntable and pit, set the pit rail with an indicator for flatness and perfect circle, to use a computer control. Bit of advice: Set your turntable, where you can reach it easily, because you will (or someone will) run an engine into the pit! Be sure it sets level in all directions, or you will have a 200 ton crane coast off into the pit too! Yep! I sure did! [ 05 February 2002, 10:22: Message edited by: watash ]
Graphite, I am moving this topic to the inspection pit where you may find more modelers with turntable building experience. jjbcnc - welcome to trainboard! [ 04 February 2002, 03:24: Message edited by: yankinoz ]
I believe that Diamond Scale makes an indexing kit. It's a mechanical, rather than electronic indexer, but it works pretty well. Just take your time installing it. Pat
jjbcnc, I can highly recommend the 134 foot Diamond Scale pit and turntable kit. You can get it with a hand crank, or motor kit and an indexing setup that can fit any number of stall tracks. Contact Neal Wolf at newolf@compuserve.com and ask for his catalog. He has all kinds of accessories for around the engine shops. The detail is very well done, and his prices are the best I found. Tell him I recommended him to you. (It wont cost you any more) He just likes to get feedback from satisfied customers. And, he really stands behind his products too. Here is a shot of the pit: You can see the plug I cut loose with a router to obtain a perfect circle with slip fit, just behind the micro-sized drill press. The painted partially completed table is up side down on the right.(black). Here is during the assembly of the turntable, showing how well the instructions are laid out to fit all the ties in the propper order. (came out right on the money!) You can see the line of ties stuck to 3/4" masking tape, with sticky side up, that are placed over the fullsized instruction sheet. On the other side of the vernier caliper is the girders mounted to the support end blocks where the wheel dollies go. In the back ground is two #12 turnouts, and a #10 that will allow access to the engine house from the mainline tracks coming down from the mountains. Here is BigBoy #4005 sitting on the table. It hangs over the table about three feet both ends just like the real ones do. (I left the hand rails off until I'm finished with the fitting and detailing.) The table will lift off to clean for dust, bugs and stray engines in the pit. I'm doing some machining on some other parts, but will get back on this turntable project soon as warm weather get here. My old bones are not fitted with central heating. [ 05 February 2002, 12:37: Message edited by: watash ]
Thanks, Watash..and all. The article was in Model Railroader last month-about putting an Atlas works under a scratchbuilt turntable. I guess I'll do something like that. Just need a little one. But I wondered if there was a way to index it yourself for manual operation-like gearing or something. I think I have an idea..if it works, I'll share it.
Graphite, you can rotate the table in a number of ways, but the INDEXING must be very accurate. It has to align at both ends of the table too. Strangely, if the table does not lock in place someway, it quite often will rotate a little while an engine is rolling on or off, and the engine drops into the pit! When that happens, you have to build a sleeper out beside the fallen engine, call the big hook, shore up under the out riggers, and lift the engine up and swing the table back under the engine. It takes quite a few photos to document all this, so buy several rolls of film!
Watash, I forgot to tell you I am in N-scale. I found a 135ft turntable at Custom Model Railroads. Thanks for the suggestion.
