turn radius
- Thread starter dagnarble
- Start date
santafewillie
Same Ol' Buzzard
I can't answer directly as I don't model steam, but I would think that you would want as large a radius as comfortably possible just for the effect. My guess is 18" at a minimum.
Willie
Willie
Retired Alex
Member
Documentation for these models says 15 inches but personally I would stick with 18 inches.
Selector
Well-Known Member
From a reliability/fun factor point of view, the closer you get to the engineered minimums in any capacity, the more likely you are to have the probabilities work against you. Said differently, the closer you get to the smallest possible radius for anyone scale model, the more problems you will encounter. Usually that means more snagging, dragging, or even derailments. If it doesn't happen when trailing the rolling stock, it will happen when you shove them because the slack in the draft gear has been bunched during the shoving.
Often it isn't that the trucks and wheels can't deal with the curvature, but the couplers between the cars, or details near the ends of the car frames, abut each other as they turn, and you get derailments.
The cheapest and best use of your time when you are intent upon testing the limits is to actually measure them. Use the real items, including the tight curves you can mock up temporarily on a board, power the rails with some alligator clips and feeder wires, and see for yourself what is possible, and when you get too many problems for your taste. With that firm knowledge, empirically derived, you can confidently duplicate the same thing on your layout. Note, though, that when you add curves, kinks, turnouts, and grades other than what you tested, all bets are off.
Often it isn't that the trucks and wheels can't deal with the curvature, but the couplers between the cars, or details near the ends of the car frames, abut each other as they turn, and you get derailments.
The cheapest and best use of your time when you are intent upon testing the limits is to actually measure them. Use the real items, including the tight curves you can mock up temporarily on a board, power the rails with some alligator clips and feeder wires, and see for yourself what is possible, and when you get too many problems for your taste. With that firm knowledge, empirically derived, you can confidently duplicate the same thing on your layout. Note, though, that when you add curves, kinks, turnouts, and grades other than what you tested, all bets are off.
montanan
Whiskey Merchant
I don't have a climax, but do have a couple of shays. One is an old MDC 2 truck shay and the other is a Bachmann Spectrum three truck shay. Unfortunately my minimum radius curves are 32 inches on the mainline, but I do have number 4's in industrial sidings. They can negotiate the number 4's easily, but as others have said, I probably wouldn't want to go much under 18 inches because of any cars coupled to the locomotive is where problems may occur.
Something to note about manufacturers minimum radius recommendations. They are only talking about the item on it's own, not coupled to other rolling stock and as Crandell said, in reverse and pushing, the couplers we use have no ability to stay straight, they swing generally towards the outside of the curve, bunching up, collapsing the distance between the loco and cars and fouling of one against the other occurs.
