Scale Sterling single

[Aerolight]

I was playing around with wheel sizes for my new loco and after settling on a size I wondered what a scale sterling driver would be.

62 mm traction size is the scale size by my reckon. For reference Lego drivers are 30mm and by the old naming scheme they would be XXXXXXXXL (LOL)

The wheel would theoretically (5 hour print maybe my next project) run smooth on Lego radius curves with a 2 driver setup, but only with a bogie both in front and behind it. 

This could be done by springing the non drive wheels to centre but will require some nuance to work.

Sry for yet another theory post but thought someone might find it interesting.   

[Hod Carrier]

I'm certainly interested in this idea, particularly from a dynamic perspective. Have you worked out the axle spacing yet? I think that this is ripe for a bit of prototyping.

The Stirling Singles were 4-2-2s, and as such the issue of centreing the wheels might solve itself without having to resort to springing. Rather than looking at the wheel arrangement as a fixed axle with a leading bogie and a trailing pony truck you could view it instead as a two axle chassis with two trailing pony trucks, it's just that the first of these is rather large and has the body attached to it. My thinking is that rather than using the more conventional double pivot for the leading bogie you could probably get away with just a single pivot which should cause the following axles to centre normally.

I'll admit that my thoughts are untried, but I'd be interested to see what happens.

[Black Knight]

As far as my research went, the sterling silvers driver was 2.464 cm in diameter. In my world that would be a 13 (XXL): My scale (mostly German steamers) goes like:

• 5 (S) for ~950 mm
• 7 (M) up to 1250 mm
• 9 (L) up to 1500 mm
• 10 (LL) up to 1750 mm
• 11 (XL) up to 2000 mm
• 13 (XXL) for 2300 mm

As my range only goes up to 2300 mm and my stuff is mostly 6-wide so ymmv. I find the size 13 wheels already tough on R40 curves, so if you want your design to actually move, I assume >13 to be a no-go on anything R40 (including switches). Not sure if this was helpful as you're clearly bound to print larger wheels. ;)

Please show some pictures of your behemoth wheels when you have some!

Edited May 3, 2021 by Black Knight
typo

[zephyr1934]

7 hours ago, Black Knight said:

As my range only goes up to 2300 mm and my stuff is mostly 6-wide so ymmv. I find the size 13 wheels already tough on R40 curves, so if you want your design to actually move, I assume >13 to be a no-go on anything R40 (including switches).

If I went larger than XXL I'd go blind... as in blind drivers, but I try to make everything I build R40 compatible. To do flanged for wider radii curves would require some experimenting. I'm sure it could be done after some trial and error though.