I have two shay locos, 2 truck hon3. Is fourten inches an acceptable minmum radius?
Yeah, I'd think so. When I'm running my Keystone HO 2-truck class A, even a standard trainset 18" radius looks huge.
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The specs on my HO MDC Shay is minimum 15” radius (four 1965/70 MDC Kits). My tightest radius on my layout is 24” so I would have to go with the MDC specs. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
johnbalichI have two shay locos, 2 truck hon3. Is fourten inches an acceptable minmum radius?
I can't answer, but I suggest you make a test track and find out.
I run all my locomotives through a test-track/obstacle-course to be sure they are capable.
-Kevin
Living the dream.
The acceptable minimum radius for an electric-model Shay can be appreciably tighter than if the outside driveshafts needed to propel the locomotive as in the prototype. The limit will be where the external driveshafts start binding or separating, and that will in part be a function of truck swing relative to the line of the chassis. Not immediately obvious, perhaps, is that swing one way may be better tolerated, or allow a tighter effective radius, than swing the other way...
This is real easy to 'primary test' -- rotate the trucks on the model in opposite directions as far as they will go, with straightedges along the flanges. Mark the point where the straightedges cross, and the two lengths where they make flange contact. This is the center, and two tangents, to the minimum radius.
In practice the driveline might bind a bit before that point, so actual 'curve testing' (e.g. on a few continuous ess-curves laid in flextrack) would be a logical next step. DO caulk the flex down; DO use a track fixation method that is easily 'reversible', too...
johnbalich I have two shay locos, 2 truck hon3. Is fourten inches an acceptable minmum radius?
Tolerable might be the better term when discussing min R. Use it where you have to, but try to depend on something more generous.You'll be much happier than if you're trying to squeeze in as much track as possible with all 14" R curves.
Don't forget that while your loco may go around 14" R just fine, what about when it's coupled to your rolling stock? Small min R tends to demand short cars also and coupling on such curves can be problematic.
I have a small PFM 2-truck Shay and suspect it will do a 14" R curve. It goes around 17" OK and seems to be OK with shorter based on clearances/driveshaft lengths.
Mike Lehman
Urbana, IL
Testing is a good idea. We don't know if we are dealing with a small 18 tonner or a large MDC.
Simon
snjroyTesting is a good idea.
Amen to that. When pushing the boundaries, empirical facts are more reliable than best guesstimates.