QUOTE (oitoitoi @ 29 Jan 2009, 00:08)
<{POST_SNAPBACK}>..Does weight put much more strain on the loco motors? Has anyone had any experience of locos becoming 'worn out' through use? ..
In the case of Hornby they use that same 'black can' motor in all their recent releases, including diesel types weighing up to 600g. So you are quite safe up to that weight: provided the loco can still slip its' wheels when held back, the motor will be OK. I wear locos out: it usually takes fifteen years of an hour of operation practically every day, and it is usually something other than the motor that gives up. Motors are discrete easy to replace components in any case.
QUOTE ..Is that a 36" radius or diameter curve? I was planning for minimum 18" radius curves so I'm hoping it's the former! ..
Ah. The drag from an 18" radius curve is about as bad as a 1 in 30, by the time you have vehicles occupying the full 180 degrees. Larger radii impose smaller loads, and are also more reliable if running long trains. A big risk with small radius curves and long trains is a derailment as the vehicles pull across the chord of the curve, often referred to as 'stringlining'.
QUOTE ..I think I can get it to 1:57 or possibly even 1:62 with some precise woodworking, any idea if that could handle 8-10 much better? The locos would be hitting the up inclines at top speed and wouldn't have to stop on them so restarting shouldn't be an issue. ..
Make them as easy as possible. Richard's suggestion of sharing the gradients between rising and falling lines is a good technique. If you can get the gradient to 1 in 100 there are relatively few problems - most 'level' layouts actually have a gradient of this order present.
QUOTE ..Does anyone know the precise height of a hornby A4, A3 or 8F..
The UK loading gauge permits a maximum height just over 13 feet, and all these designs were built to that height. So that's a fraction over 52mm if the model maker gets it right (and it is right on the current Hornby A4, A3 and 8F), allow a minimum of 60mm height clearance over rail top.