DO NOT PANIC!
REPEAT! DO NOT PANIC!
I am not changing scale/gauge again. The Augusta Railway will be built in HO as planned. But...big but...what if later I'm tired of it or continue to have eye problems and want to change to On30? Well, there is no harm in maybe planning that out a little...just in case. Especially before I cut the roadbed this weekend.
There are a few things you need to consider when rescaling a layout from HO to On30:
1. Track separations - now need to be 3" from centerline to centerline on On30. For this layout we have three problem areas: the lower Augusta passing siding, the upper Augusta passing siding, and the two loops. All of these are fairly easy fixes, and the South end of lower Augusta can use a good curved turnout that I found. Oh, the hidden trackage will need to be widened.
2. Grades - the grades remain at 3% maximum, so there is no problem there.
3. Overpass clearance - the overpass needs to be 4.5" for On30 clearance, so we may lower the inner loop to keep from increasing the grade on the outer loop.
Actually, it won't be much of a problem. I'll draw it out one night this week.