capability 24" Ross turn table with a 8 stall roundhouse

I really can’t answer your question. I believe the Atlas TT is right around 24” and they do offer a 3 stall roundhouse setup for a straight run off the bridge. The roundhouse has been out of production for a while. A search may bring up some info as far as spacing and maybe give you ideas. You would just be substituting the Ross for the Atlas. The Korber site on Mr. Muffins may also offer some ideas.

You didn’t mention what you will be using for a roundhouse. Altoona Modelworks may have some info. and maybe willing to help with the design. They will mill the floor for a straight run from the bridge to the stalls and can probably figure out the real estate you will need.

Dave. The Museum purchased a 24" Ross Turntable and planned a 3 stall Round House because space.  Months later the family of a deceased donor donated his layout which included a 33" turntable and eight stall Roundhouse.  We do not have the room for both.  The problem is only the center track lines up right.  The other 7 are at a angle each need 1 rail to be cut to line up.  But we have a adapter problem.  I don't know if it will index to the RH other 7 stalls. Power to the tracks shouldn't be  a problem.

This is a geometry problem.

This issue is with the distance of half the turntable and the clearance between the end of the turntable and the start of the roundhouse. In order to line-up the turntable with the roundhouse spur tracks you must calculate these distances around the turntable circle. Using the center of the turntable as the start of the arc-segments that define the location of each spur track.

The varying part is the distance from the end of the turntable to the start of the round house, since the dimensions of the turntable and the round house are fixed.

If you extend the track from the two furthermost bays of the roundhouse until the track centerlines cross, you can determine the radius of your roundhouse to calculate how far to place it from the centerline of your turntable and have the tracks line up.

If you have an Atlas Roundhouse this was designed for their 24" turntable, but I am guessing that is not what you have.

Here is a link to an 2017 OGR post Planning for roundhouse and turntable that might help explain how you can figure this out. In that thread @PRR1950 posted this file Korber Models Roundhouse-Millhouse Turntable Planning.pdf

The pdf indicates the radius of the Korber #304 roundhouse is 33.2 inches. So your 24" turntable would need to be placed 21.2 inches from that roundhouse, to line up properly. Reading between the lines of your original post you only have 10", which won't be enough for a #304 Korber roundhouse without rebuilding the roundhouse to a smaller radius.

EAW, I thought about reducing the RH to 3 stalls.  I moved RH to align with the TT and track angle in RH is at a different degree.  This RH was 2 rail.  I add the middle  rl.  I assume this was kit blt building to match the large TT.  It's probably 40 years or more old.

The TT might have to be moved.  That could create more problems with this half blt layout.  I very much appreciate all your help.

@Missabe what radius is the roundhouse? What are the dimensions of the roundhouse? How much space do you have on the layout?

The radius of the roundhouse is irrelevant to this situation.  What is important is the degree of angle on the small pieces of wall between each roundhouse door.  That degree measurement (because you want the track centered and straight within each door) and the available distance between the turntable and the roundhouse determines how the whisker tracks can be laid out.

Just as an aside (because most people will not do this), you can place your roundhouse so that at least one whisker track proceeds STRAIGHT onto the turntable.  Then you lay all other whisker tracks so that they are centered in the roundhouse door and proceed directly to the turntable.  The only "catch" is that some of those tracks may have to be curved (not recommended) or they may have to "cross" another whisker track (just like a junction and maybe requiring hand-laying track) before reaching the turntable pit.

Good luck,

Chuck

The radius is relevant and to me the easiest dimension to measure that will tell you how to place the roundhouse. If you prefer you can use the angle and the distance between the walls to determine the distance. As @AlanRail said this is just a simple geometry problem. You can use a variety of measurements to arrive at the same answer.

20+ years ago. Korber (304 Roundhouse) sections and then Bowser turntables were common.  Most (smaller) layouts did 3, 4, or 5 stalls. You could curve the tracks to line-with the stall opening(s).  I have an interesting Diamond Scale, 20" turntable.