Re: One More LO&S

John Stutz

My recollection matches Dave's.  And his comments are the primary reason why I sold my Hassenger, since the problems are worse with the four truck engine. 

The powered truck needs to pivot to follow curves, but also needs to resist the vertical torque.  Short of duplicating Nakamura's complete rearrangement of drive, one solution is to move the upper right angle gearbox, the one on the locomotive frame, onto the truck.  This puts the input torque on the longitudinal axis where it can be restrained by the bolsters.  Another would be to substitute a NWSL worm drive gearbox on the truck axle, with a torque arm to the truck's bolster.  Space would again be a problem, and the upstream drive's speed reduction would need to be reworked.  Probably the the best would be to follow Nakamurra's lead: rotate the axle drive to horizontal and add a transfer gear case or belt drive in the firebox, so lowering the drive.  A Nigel Lawton / Hollywood Foundry style square belt drive would be quietest, but requires multiple belts in this high torque application.  

Note that I haven't tried any of these, which are just possibilities coming up as I write.  I will be very interested to see what the Shay Fixer came up with.

Dave's earlier comment about the differences between PFM's Shay drives and Westside's are quite relevant.  PFM's approach, a worm driving a small gear on the line shaft, requires a bit of a-prototypical concealment, but ensures that all of the line-shaft/axle gear pairs are loaded to about the same degree.  Westside's approach eliminates the concealment problem.  But the 3/4 to 7/8 of the power that goes to the line-shaft, now goes through the driven axle's gears, with consequent wear and potential for early failure.  So watch the lubrication here, on Westside's or any similar Shay drive.

John Stutz

On December 8, 2020 7:35 AM climax@... wrote:

I think it involved soldering a wire on the truck that went into a soldered on loop on the locomotive bottom.  This prevented the truck from twisting when power was applied due to torque.  The only problem was that the truck would not turn much either thus limiting the amount of turn the loco could negotiate.
-----Original Message-----
From: John Cytron
Sent: Dec 8, 2020 10:26 AM
To: ""
Subject: Re: [HOn3] One More LO&S

    OK, thanks John Stutz and Dale Buxton on the engineering/torque aspects of the West Side Shay drives. It was very informative. I have both a Westside #8 narrow gauge and a West Side Shay two truck standard gauge (I cannot remember if it was a 37 or 42 ton Shay).
    I recall in some old messages that there was a way to fix the drive truck to keep the Shay on the rails by soldering in some braces. I have been having some computer problems and c annot find those messages.
    Could someone repeat the fix?  Thanks in advance.


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