Do you have the roundhouse already?

If you have the roundhouse, the distance will be determined by the roundhouse and turntable track angles.  Set your turntable pit in position and draw straight line on the bench work centered on the turntable track outlets like spokes on a wheel.  Then if you set the roundhouse in place, you can move it back and forth until all of the lines you drew line up perfectly with the centers of the doors.

turntable

Ok great, but what if the roundhouse is already installed on the layout and can't be moved due to surrounding landscapes? Would it be safe to say doing the reverse by drawing lines from the center of the stalls out to where they intersect that would show me the center of the pit?

                                                                                     Thank you in advance

                                                                                                              Ed.

Yep that would work

You can do that, it will work as well. Little bit of reverse engineeringI  would call it.

Rob

turntable

A great big thanks to all for their help and advice.

                                                                            Ed

Eassy way to locate your turntable.

Measure the center points of each stall at the front and back of the stall.  Then use a straight edge to draw a line from the back of each stall extending out 2-3 feet.  If you locate the lines correctly they will all intersect at one point which is the hub of your "wheel."  The intersection point will probably be somewhere around 1-2 feet out from the back of the roundhouse.  That intersection point will be the center of your turntable pit and the center of your turntable bridge.

Yes..as long as you come

Yes..as long as you come straight out of the round house. Theoretically all tracks should intersect at the very center of the turntable..the pivot point. If not fudge it. But there may be a price to pay if too far out of alignment.

In your case mark the opening of each door to the roundhouse. Remove roundhouse and mark dead center of each door opening. Lay out a straight edge of wood or metal the width of the track. ((I use window screen frame, White Lineal Screen Frame - 5/16" Lowes/Home Depot), they are metal and almost the exact inside width of HO tracks). where they intersect is the pivot point. Also, I use these for straight runs when laying track.

Carter

turntable

All that sounds like great advice,now for the tough one.Whats the best way to attach the track to the inside of the roundhouse?

Track inside roundhouse

Did you say you cant remove roundhouse? If you cant the easiest way would be to cut your flex, assuming you use flex to the desired length. Run a bead of caulk along the center line, you don't need a lot, smooth it out with a putty knife too make a thin coating on your roadbed, on the bottom of the flextrack, on the end inside the building,  spread some caulk on the ties, turn the track over and lay it on you centerlines. press the track down firmly, maybe use a ruler or long screwdriver to press the track down inside the RH, if you cant get your fingers in there. That should do the trick. Remember, you don't need a lot of caulk here, you don't want it oozing up between the ties. If you plan on ballasting later, the ballast will hide the caulk, and glue/water mix will hold the ballast as well as the track.

Remember this is worth exactly what you paid for it, but it should get your track down.

Rob