Joining 054 Curve to 031 Curve. A recipe for de-railiment?

If your equipment runs on O31, then it should not have a problem at 042 O54 etc.  Transition should be OK.  I have done this.

Not only is this NOT a bad idea, it's actually a good idea.  But, rather than going 54-54-54-54-31-31 (assuming 16 54s per circle and 8 31s per circle), I'd suggest going 54-54-31-31-54-54 for a half circle. That way, the train eases into an out of the tight 31" curves.

Your end points will vary depending where you place the O31 pieces in the curve.  R4D's easing into the curve is a good plan, where you start the curve and where you want to end up will dictate placement.

Thanks for the info guys.

My choice of where I place the 054 sections is extremely limited.  The center of my layout has a 90 degree crossing as the center of the figure 8, but it is situated in a diagonal position in relation to the outside loops.   Consequently, the figure 8  circle on one side is slanted diagonally towards and pretty darned close to one of the outside tracks.  So, I can't widen that half of the loop with 054 curve, or it would actually go way overtop of that track.

The only part of the figure 8 loop that I can expand outward is the opposite side of that loop, because there is alot more room there between the 8 curve and the outside loop.  So, that is the only place I can put the wider 054 curved section.

You have given me great answers, and some encouragement that hooking the 031 and 054 together doesn't necessarily mean trouble.   I'll try it out and let you know.

Thanks again,

Mannyrock