Minimum curve radius

While some of those long cars may negotiate O54, IMO, they really won't run on it. The Lionel Autoracks will drag and bind in O54 curves, and so do the Comet/Horizon cars. Not to mention the overhang on O54 is enough to take out an entire ZIP code inside the curve. Atlas gundersons sort of run on O54, but the wheel flange tends to rub on the inside of the well. I have no MTH gundersons to test.

IMO, all of those cars are O72 cars, you stand absolutely no chance of them running on O36 track. 

The house I'm looking to buy has a basement 14x19. I guess i will wait until then and build a new layout and maybe I can configure o72 curves then. Its not worth doing it on my current layout I just don't have the room. On the other hand it may not be worth buying those cars. I rather have a big layout with 45/36 curves then a small one with 72 curves. 

Work with some easements on your current table to reduce the length of the smaller curves. The outside only has three tracks of 054 in a semi-circle only slight wider. may not work on the entire layout, but if you use 054 as the minimum, but only where needed, it would get you a mainline to run the larger scale stuff.

This is Atlas O track

Would you say keeping my minimum radius curves o54 on the entire layout a good idea?

What I propose is for all of us to start thinking "What is the largest radius curve I can put on my layout?".  Start with the largest and work from there.  I wish I had done this when I started, I still may do it.  I currently have 072 mainline and 054 every where else, but could have gone 090 if I had just looked at what's available.  I think the only issue is trying to choose which switches to use (should have also looked at numbered switches vice radius switches).

You have a 6x8 layout so you could use 064 curves, that would leave 4" on each side for clearance/safety.

Fortunately Bob I did go with my gut and use #5 turnouts for my interlockings. I have RH to RH and LH to LH. I use all Atlas O 3 rail track. However when I start building my new layout hopefully next year sometime I need to figure out what type of switches to use to build a yard area. Im guessing I can try 072 at first and see where it take me... I dont want to kick myself in the rear and downgrade to smaller turnouts even though my current roster works with it.. I need to think of the future and now is a great time to start planning. Moonman, I will save this photo you showed me to my desktop and incorporate it into the new plans.. Thank you

This is the route I'm looking to take with a new layout

That's on a 72" wide table at one end already. If you can go to 80", all 072 would fit.

So, the 054 on the short leg of the mainline could be squeezed to an easement, unless you can make that end 80" wide. That would give you a mainline for scale running.

Makes for a long reach. There's no hatches in the design.

This came up once before regarding the Lionel Autoracks

 check this thread

That's what's I'm realizing now moonman, 14' will be wall to wall width wise and I will not have access unless I cut out a hatch. My other idea I been thinking is building the layout center of the room and doing a 8' x 16' layout. This will give me access to either side with ease. 

If you have the room size for a walkaround, that would be nice. I find that they are more inviting as you can view it from 360º.

It does take a large room. Like two pool tables and such. You don't want skinny areas around it.

Keep thinking of different ideas of how to fit an 8' area for the turnaround ends.

I've yet to meet anyone who has ever regretted going with wider curved sections. 

It's true that they require a bigger footprint, but you can run the large 'stuff" on it AND the "small" stuff looks much better operating on the wide curves. 

I once thought 0-54 was the cat's meow.  Then I up-sized to 0-72 and 0-63.  I'm now in the process of trying to use as much 0-96 and 0-88 as I can.....at which point I will be limited by the size of my basement.

If you can't find a layout with the wider curves to visit in person, please do some searching on YouTube.  Large, scale steam really seems at home on 0-96.

And the two rail guys go even wider.....so go figure.  There's a reason for it.

You won't even like the look of those longer cars on your current 6'x 8' layout even it they would run.  You should wait for more room.  Bigger is better.  Huge is best.

.....

Dennis

O gauge= Diameter

HO= Radius

I have three sets of the Atlas Gundersons and they make for a terrific consist. They do need O-54 curves or the corners of the cars will rub and maybe derail.

I currently have an O-54 and O-63 double mainline and I run my Gundersons on the O-63 mainline.  I have an S-curve on the mainlines and this causes problems in trying to run the cars on my O-54 track.

Like others have mentioned, go with the largest curves you can and you won't regret it.  As part of my extension and rebuild of my layout, I'll be pulling out all the O-54 and O-63 curves and moving to O-72 and O-80 curves.  I actually need the larger curves (at least O-72) to run some of my scale passenger cars.  There is a lot of overhang as my larger diesel engines swing on the curves, so I'm looking forward to a reduced swing on my new larger curves.

Jim