Diameter curve question k27

[Expero]

Hi ! Bachmann spectrum K27 2-8-2 really needs 8 foot diameter curves to run well???
Thanks

[Chuck N]

I run mine on 10' diameter curves.  In my opinion anything less would put undue stress on the gears and motor.  They  might go around 8' but they won't look to nice.  There will be a lot of overhang.

Chuck

[mudhen]

I run the K-27s on my outside railway on 20 foot diameter curves, and the look great.
 

[armorsmith]

Expero,

No, the K27 will run on 8' diameter. That does not mean it will run well.  Generally speaking, and from personal experience, they will negotiate an8' diameter curve, but they don't like it.  Mine will sooner or late (mostly sooner) derail the pilot truck and if you are luck you will catch it before it hangs on a switch (turnout).  From experience again, the larger the circle of track you can run, the better the locomotive will perform and look as well.  On an 8' diameter the overhang of the pilot beam (or especially the snow plow) will happily clear all line side structures for you.

My tuppence worth.

Bob C.

[Expero]

impossible to turn 6 feet ?

[Chuck N]

Most of us would say it is impossible, but it is your railroad.  All I can say try it.  It might work for you. Set up a loop with 6' d curves and see what happens.  Or are you just thinking about getting a K?

If you want to run 1:20.3 on 6' diameter curves, go for geared locos, like Shays, Climaxes, or Heislers.   You may have to go to short cars.  I'm not sure if the usual length 1:20.3 rolling stock with body mounted couples would stay on the track going into those curves.

If space is a problem, consider 1:22.5/24.  There are a lot of short wheel base engines and cars in that scale that will easily handle those curves.

Chuck

One other thing to consider is wear on the rail head on the outside rail of the curve.  If the curve is too tight, you will slowly grind away the inside of the rail head.  If you are indoors, this will leave a fine black power that rains down.  It is also possible for the flanges on the wheels to grind down, especially if the wheels are plastic.  This may not effect your engine, but it might be a problem on cars.

A friend of mine has to replace his curves (LGB R1 4'd) every couple of years as the rail head has ground away.  He is using short wheel base engines, (LGB Stanz, 0-4-0).  He runs all day every day when he is home.  A K-27 if it stayed on the track and ran on 6' d curves, would have the same problem.

[armorsmith]

Expero,

Let me clarify my comments above.  The K27 as recommended by the manufacturer requires a MINIMUM of 8' diameter.  That being said, I would say NO, it will not run on 6' diameter.  Comments by Chuck N regarding rail and wheel wear are essentially correct with the caveat that the K has a feature where the axles have a considerable amount of side play allowing this locomotive to run where other similar locos will not.  This will reduce the amount of rail wear but not eliminate it. There are many things that will factor in to wheel / track wear.  Consider that the wheels on the K (and most other locos) are steel.  The track is either brass, aluminum or stainless steel.  The brass and the aluminum are both considerably softer that the steel wheels of the loco, therefore the rail will wear out first.  The stainless steel (depending on the grade) is somewhat equal in hardness so wear will be somewhat even.  Obviously the plastic wheels are the softest material and will be the sacrificial lamb in all cases.

If you have already purchased the K27 I strongly suggest using the recommended minimum of 8' diameter.  If you can afford the space, use the largest diameter your space will accept.  It will run more reliably and look better.  If you have not already purchased the loco, look to a smaller loco that will accommodate the smaller diameter track that your space will allow.  There are times a square peg will fit through a round hole, but the peg might not look the same when it exits the other side of the hole.

My tuppence worth.

Bob C.