Hi folks. Many people with the new Bachmann Berkshire have reported issues with slow speed running. Mine also had the "hitch" at slow speed that various folks have commented on, but I couldn't see a problem with the mechanism on mine binding in any way. So I decided to try to play with the BEMF CV values for the Tsunami decoder to see if that might help things. And it did. I wouldn't call my Berk "buttery smooth" at very slow speeds, but the "hitch" is largely gone. There is still a tiny bit of hesitation, but perhaps some additional break-in time will help that. Here's what I changed: CV's 213 and 214 set to "1". CV 209 set to 15 CV 210 set to 240 Those of you running this loco on DCC and who are observing "ragged" running at slow speeds might try these CV changes to see if it will smooth out the slow speed running. John C.
I'm pretty certain that the problem (at least with mine) is mechanical. There is a bind in the driver movement that is severe enough to cause the drivers to lock up at slow speeds. Changing directions will get things moving again, but as things stand there's simply no way to run it in forward below about speed step 5 - and I don't think any CV changes are going to solve that problem for me (but again, this is just on mine - YMMV). For now I'm going to try running it around in circles for a few hours to see if breaking it in helps any. But my guess is that I'm eventually going to have to pull off the driver bottom plate and shim one or more of the bearing blocks. Either way, I should know more in a day or two. Cheers, -Mark
Well, that was crazy easy to fix.... First - there is a piece of black foam insulation between the trailing truck and the locomotive chassis. I didn't even notice it was there until I moved the engine to my workbench, but once removed it solved the problem of the drivers occasionally slipping (duh). Second - I don't know what you call it, but there is a short two-way connector on the #3 drivers that hooks to an angled rod. Said connector was bent inwards ever so slightly, causing the stud on the connector to hit the horizontal rod. I bent the connector outwards slightly and now I can run the loco on speed step 1 without any problems. It still runs just a tiny bit uneven at extremely slow speeds, but not enough to worry about (I don't think). In any case, some more break-in time and/or CV changes should smooth things out. Cheers, -Mark
I got my two from two different sources and they worked great with minimal slow speed issues. However, one 765 had a loose screw that takes care of the front coupler and "cow catcher" that would not tighten up so the cow catcher rode on the rails and stopped the loco at any perturbation on the rails at slow speeds. The other , 759, worked great and both handled my oval helix with 1.8% grade with no problem with no run in period. I contacted the supplier for the 765 and it is on its way for replacement. I am quite impressed with a short experience with both pulling 20 cars up the helix. Jack S
My 765 had a front coupler problem, who ever assembled the loco bent the coupler shaft up and installed the cover up side down. The coupler when straightened hangs a little low, I just bent the pin to clear and sanded off the bottom of the cover, the screw tighten and now it works just fine.
Thank you very much John. I reset mine as suggested. It is now creeping smoothly out of the round house area on setting 1. Despite Baltimore and Ohio NOT owning these, my Chesapeake and Ohio now has a repainted tender in engine black. Next step is adding the Baltimore and Ohio decals. I am still experimenting with the whistle on 2760. Seem too high pitched for my ears.
John C. I cut and pasted your suggestions to another n-scale forum where questions about the 2-8-4 were posted. Acknowledged your work. I had already made these changes on my locomotive; ordered a 2nd C&O based on performance of 1st. Thanks again.
