How are spring straps done? What is rock mechanism here?

[johnpenn74]

Fellow live steamers,

I am working through the spring suspension on my tenwheeler and trying to put the "tilt" back into the leaf / saddle combination. Seems that it was designed out of it somehow and doesn't rock adequitely. In looking at some other prototypes and several live steam locomotives I am left with he following questions.

1. How did the prototype put a bundle strap around the springs? Forged? Casting?

2. In the picture how does this spring group rock on a forged saddle? Granted I have seen a few other modern mecahnisms on other engines but looking for some insight on this turnoff the century model. Is this the same treatment on anyones k-27?

JP

[Marty_Knox]

There is a piece missing. There is a pin with a head on both ends, that sits in a groove in the band and in the saddle.

[NP317]

My Ten Wheeler leaf spring assemblies use a bolt through the top center of the spring leaves, threaded into a "nut" on the bottom.
That nut is made from a section of brass half-round (length = the width of the leaves) that forms a "rocker" on the bottom surface.
This rocker fits into a shallow matching-radius grove on top of the inverted U-shaped saddle bracket that rides on top of the axle box.
Sorry: no pictures available.
~RN

[RET]

Hi,

In some models, the spring assembly is fastened (usually bolted) to the inverted "U" in the picture and the bottom of the "U" is radiused to rock on the top of the axlebox. This could have been what happened in full size as well.

As you have surmised, the spring "suspension" has to be flexible to evenly distribute the load as the wheels move up and down to follow the track. I've found that if this happens freely, the locomotive will stay on the track no matter how much the track flexes. If the suspension can't move freely, the wheels won't stay on. With a free suspension, it s amazing how much even the full size ones will weave and bounce around while staying on.

Hope this helps.

Richard Trounce.