Lionel O60 turnout dimensions

UPDATE

It seems that the problem is in the curved leg - its geometry is not as described by Lionel and it probably needs to be shortened.

Mixy

Milen,  Good question and thank you for trying to resolve this issue.

I've confirmed with actual pieces that the distance between the straight ends of O60 switches is 8 inches, when configured with a 45 degree crossover as shown in your example.

I think one of the main issues may have to do with the actual length of the straight part of the 45 degree crossover.  In the real world, I measure approximately 9 31/32 (9.97) of an inch.  In SCARM when I use the tape measure on the 45, it displays more like 10.00 inches.

This next point may already be accounted for in the underlying SCARM geometry.  It appears so, but I can't tell for certain.

So, just to make sure to cover the geometric oddities of a Lionel O60 FasTrack Switch, the fixed part of the Out path of the switch (the curved part) is not completely curved for it's entire length.  Even with the 1-3/8" Half-Roadbed piece removed, the geometry of the switch is such that the out path is the geometric equivalent to a normal O60 curve with an added 1-3/8" straight.  In the image below, I've overlaid a regular O60 curve with two 1-3/8" straight sections fitted to the divergent end.  The geometry of the curve part of the switch (with 1-3/8" half roadbed pieces fitted) and the actual curve with straights coincide exactly when overlaid in this manner.

I hope this helps.

SteveH

Hi @SteveH,

Thank you for your replies and for the pictures.

0.03 inches difference in the measurement of 45deg crossing is just less than 1 mm, so it is not a factor here.

Same for the real vs theoretical turnout length, measured by the straight leg - 13.094" vs 13.11" - the difference is too small.

But for the curved leg - there is a bigger difference between the turnout spec and the real thing and may be that's the problem.

Mixy

OK, I think that I found the problem - the curved leg is actually not an O60 curve plus extra short straight built-in, but has a different radius and thus different geometry than specified by Lionel.

After matching of the SCARM template against a picture of the real turnout, the curved leg should be shortened with approx 8mm. This may be not looking so big and may be not easy to be catch when that turnout is used alone, but when two of these O60 turnouts were used in a crossover like in the above examples, the discrepancy appears clearly.

I will correct the library and will apply the update for the next release of SCARM.

Sorry, if that bug caused problems with your SCARM track plans.

Mixy

Lionel gave the wrong dimensions for the O60 turnout. They said that the length is 14 1/2 inches, but that is the length with two 1 3/8 inch extensions. The actual length should be reported as 13 1/8 inches with one 1 3/8 inch extension. They show an O60 corner crossing this way with the correct 1 38 inch extensions added in:

When you use SCARM, you get the same results by leaving off the 1 3/8 inch extensions because the software uses the incorrect Lionel catalog dimension: