I have a double deck layout that drops 5" in approximately 18 feet.
I run modern equipment. Trains can be 14 cars long pulled by two powered units. Locomotives are a mix of older Athearn, newer Atheans & Proto 2000. I use Digitrax equipment.
The problem I’m having is that some locomotives “jerk” as they desend to the lower level, usually in the same area, midway down. I have added washers onto the shafts. This has resolved the problem for some locomotives but not all. For the units that still “jerk” I can’t add a second washer. Any suggestions to stop the jerking motion?
Well, my IHC Mike with a Tsunami does it, as do every one of my BLI steamers. I think it is an artifact of the physics of the scale. Real trains have smooth, heavy locos, and smooth, heavy cars. We have plastic cars with huge lash-distance in the couplers, pointed end bearing surfaces running in plastic “races”, plastic bolsters that allow our cars to rock like crazy, and so on.
The effect is something I have learned to live with.
How is your electrical feed in that part of the grade? If you are experiencing a slight voltage drop, that might do it. I’m not exactly sure what happens if a decoder sees lower track voltage.
Coupler slack running in and out would make it even more noticible. Does this problem occur when running up hill?
I have a Bachmann Loco, that I ran w/o a shell and as mine wnt downgrade, i noticed the gears played too much so I added thrust washers to remove the play and it stopped, so maybe try that.
Its in the gears, seems to show-up alot more with Athearn and P2K units. I get the same thing, but put a Atlas or Kato unit on the same train and it doesn’t do it.
Exactly the same thing happens to my P2K’s and Athearn’s. For the time being, if you don’t get into the drive, back off on the throttle slightly before the surging starts.
I found the longer/ heavier the train the worse the surging was. This was w/ SD-7’s, The newer P2K SD-50’s don’t seem to have that problem at all, maybe Proto tightened up the drives on later models. Never a problem w/ Stewarts, Atlas or Katos. Not sure if just shimming the worm will completely solve it, some slop exists in the drive/ universals, especially the Athearn.
Bob K.