shay is jerking

[jimw51]

My three-truck shay is running pretty well, but the jerking motion is noticeable on a 6.25% grade.  Any easy fixes?  The problem isn't bad enough to warrant any major disassembly.

[NWsteam]

but the jerking motion is noticeable on a 6.25% grade

6.25% is rough on a real railroad but in the modeling world its even rougher. Your shay might have problems with a grade especially if its curved. My shay handles 4% well but I would question its abilities if it got any steeper. Also try cleaning your track. Locomotives jerk because of irregular power they receive from dirty tracks.

[Paul M.]

6.25 is STEEP.   Also try cleaning the wheels.

[jimw51]

Funny you should mention dirty wheels.  I was reattaching the part that hangs behind the front coupler.  Similar to a bumper on a car.  Anyway I turned the shay over to glue it back on and I noticed a large amount of hair on the running gear.  I cleaned everything with a camel's hair brush.  If that doesn't help, it sure won't hurt.  I keep my shay lubed, but I never thought about keeping it clean.

Jim

[ebtnut]

You didn't mention whether or not the problem was going up, or down, the grade.  Mine has a problem with "surging" when going down grade.  This is normally a result of too much slop in the gear train.  It's not limited to geared engines, either.  The proper fix is to disassemble the mechanisim as much as possible and insert washers where there is any movement discernable.  In the days of open-frame motors, there was often a fair amount of back-and-forth play of the armature.  That's pretty much gone with today's better motors.  In the case of the Shay, one possible partial solution is to use a heavy grease in the gear train to help dampen the slop.

[SteamGene]

You may be lubing it far too much. 
Gene

[billvan]

If you want a relatively easy fix for the down hill jerking from the
Bachmann Shay contact me directly. I have e-mailed  this fix to others in the past.
The address is billvan@connected.bc.ca
Bill