The Home Machinist!

John, I think 2 - 1/2” gauge is a terrific size. Easily moved about, can be displayed in your living room and yet will pull a decent load with ease! I just wish the clubs here in the Northeast United States had 2 - 1/2” gauge rails. Keith Taylor, Maine USA Yes, 2½" has to be my favourate gauge...

A couple more 2½" Gauge videos:

https://youtu.be/dTGVK8lxoB4



https://youtu.be/0Yds7LQFbtQ



5" Gauge Polly rally (for Polly Models Locos) at my local club:

https://youtu.be/BHZ_IbFTQwI



John

Does anyone recognise the gentleman with the hat at 25:37? I'm interested as he has a 2½" Gauge Helen Long

John

Some 2½" Gauge action from the UK:

Black Five and Ayesha:

https://youtu.be/x4DpM-2oZok



Ayesha again:

https://youtu.be/G5D-HAXE32M



John

It's interesting that although LBSC was indeed a big advocate of large ports and steam passages, those on his 2½" Gauge Ayesha are quite small in comparison to those in his later 2½" gauge designs and Ayesha still runs very well. Ayesha Ports 1.jpg I can't remember exactly but the passages...

Reeves have recently sold off all their boiler forming plates and their boiler 'kits' only have the flat sheet and tubes now so I presume they can no longer supply flanged plates.

John

I wouldn't get too hung up on the Keiller ratio for the size of tubes used in our small gauge boilers. Keiller did base his calculations on the tubes in full size locos where the conditions in the tubes are different to those in small diameter ones. In small diameter tubes the gas flow is mostly lam...

Molly has the valves underneath the cylinders whereas this has the valves vertically between them. If you look carefully, what looks like one valve rod in the centre of the valvechest is actually two half round rods side by side, one for each of the valves. It's not a design that I am familiar with....

LVRR2095 wrote: ↑Sat Jun 06, 2020 5:57 pm The Coventry P-7 irrespective of what that article states is 17/32” to the foot.
They called it 1/2” scale as that is what most people called it.

Thanks for clarifying that Keith. It sounds as though they did the same as Bonds then.

John

It's true that 1/2" to 1' was originally used in the UK for 2.5" gauge but it has been 17/32" to 1' since the 1920's. All the early 2.5" gauge designs by Henry Greenly and sold by Bonds of Euston Road, although advertised as 1/2" scale, are actually 17/32" to 1' and cle...

That doesn't sound right to me at all. Even with the 'Johnson Bar' set to neutral you should still have some movement of the valve. With Walschaert's gear you won't get any movement from the radius rod but the combination lever will (should) move the valve a distance equal to twice the lap plus the ...

Out of interest, at home I've got LBSC's original pencil drawings for Virginia as well as a few more. Not sure if there is the full set as I haven't checked them yet.

I really must get around to getting all these originals scanned so that they don't disappear for ever

John