O-42 Curves 2 rail

Since you are talking about a jig I'm assuming you will use flex track.

To be sure, I would get the radius of the center rail on the track made by the maker of the engine. Then you will know if they go by inside rail, outside rail or center rail.

 

To be safe you could go by 21" radius to the inside rails as I don't think anyone goes beyond the rails for measuring.

 

You can also search track radius here on the forum, this has come up before.

Why not go with a larger radius if you have the space?  There's a lot of room inside an 072 circle/36"radius for radii larger than 21".

I'm running 2 rail GarGraves stainless steel flex track. I built a jig for the 072 cause I was informed on here that would be best for my size engine. I just wanted to make sure I could go smaller. I was just using 21" radius cause that's what the spec's say. I like the idea of a larger radius inside the 36" radius. Just wasn't sure if I could and didn't want to lay all that track and find out it wouldn't work.

 

Mike

I have a couple of MTH ES44AC's that are rated for O-42 curves and they run just fine on O-54 curves and switches. O-54 is the smallest diameter I have, never tried it on O-42 (or in my case O-45 with Atlas track). You could go even larger than O-54 inside your O-72 loop.

Reply By rtr12: O-42 CurvesI’m going to be bending the track so I’m sure I can do a 54 jig and fit them in with plenty of room. thanks!
Mike From Seattle

I'm 3 rail so that may make a difference if you have a 2 rail engine? I have been thinking 3 rail and noticed you said 2 rail in a later post above. 2 rail scale engines usually require a larger diameter/radius curve than my 3 rail stuff. Bigger is better with curves either way, so go as large as you can.

 

If your engine is 2 rail you might want to ask over in the 2 rail scale forum, they will know more about it there for sure. I would ask over there in 2 rail anyway, just to be sure before you go to a lot of trouble to lay the track.

Thanks for the information. Is there any way I can just move this thread over to 2 rail?

I would agree, go with the biggest diameter you can for the inside track.  Just make sure that there aren't any clearance issues as your trains enter/exit the curves.

 

I currently have a double main of O-63/O-54.  After my layout rebuild, I will have O-80/O-72.

 

You will have overhang around a curve, no matter what diameter you use.  The bigger the diameter, however, the less the overhang.

 

Besides, no telling when you might decide to buy a bigger engine/passenger car/freight car!

 

Jim

Only way I know of (other than ask the webmaster or moderators) is cut and paste your original question? I think it would be worth a new post though, the 2 rail folks may not see it here.