I just installed a decoder in an HO scale Bachmann 3-truck Shay. It is quiet but it is not as smooth as our MDC 2 trucker ( with lots of NWSL upgrades ).
My main concern with the 3-truck is that the gear bind while decending 6% grades is causing it to be very jerky. Does anyone know if this will break in and smooth out?
Larry
Did you makes sure everything was greased and oiled? Did you give it a break in period before running it on 6% grades? It’s probably not going run as smooth as something with “a lot of NWSL upgrades.” I’m no expert on Bach steam though.
loathar
Thanks for the response. Yes, I let it run on the flat mainline for a few miles in both directions at various speeds. It did loosen up a lot during this time. There appears to be plenty of lube on the gears and shafts.
Larry
I’m really surprised you’re even comparing the Bachmann HO Shay in the same sentence as the MDC one! I’ve had / repaired several of the MDC ones, kits and RTR, both standard an narrow guage, and without exception they run dreadfully [xx(] even with the NWSL replacement gearsets, run in and lubed up; also some of the other “standard” mods required to get these darn things to work.
The Bachmann one runs soooooo much smoother and quieter (I can actually hear to think when its running for example[:P]) right out of the box. The only draw back I have found with them is the tendancy to surge slightly when running constantly at low speeds - I haven’t noticed it on grades particularly - and it occurs whether run in or fresh out of the box. I haven’t really investigated it as its something I believe the prototype did to some extent and its slight enough that I’ll live with it.
I think this surging is more a problem with the decoder than with the Bachmann mechanism. What type of decoder did you put into it? A decoder with BEMF would probably help immensely.
Jim,
Thanks for responding. Of the two shays the Bachman is definately quieter. Its problem seems to be there is enough slack in the gears and drive rods as to alow a significant amount of surge on downgrades. The slower it goes the more it surges, loaded or not.
The MDC shays drivetrain is much tighter. It will creep so slowley you have to stare at it just to detect movement.
Larry
cacole
You might be on to something. I am running an NCE Z14SRP decoder. I dont think it has BEMF, but it has low speed torque compinsation and I have it turned up quite a bit. I"ll turn it off and see what happens. Thanks.
Larry
cacole
Turning off the torque compisation didn’t help. There apears to be close to quarter turn in the drive shaft when changing directions. It is loose at the wheel-gear end of the drive shafts. The motor end looks good.
Larry
I would second the comment about the decoder not being the source of the surge…
… the Bachmann Shays I have experience with run on the club layout I’m involved with which is DC only and therefore they have no decoder installed. Both my Shay, which is about 3 or 4 years old and has plenty of run time, and a brand new one owned by another member of the club exhibit the same tendancy at very low sustained speeds.
Larry may well be right in that the drive line has slightly more play than the MDC one - but at least this is the “proper” drive line not a secondary one driving another set of shafts under the loco.