Hey guys
I have fitted a Bachmann decoder into Bachmann three truck shay today after moving all locos to DCC. Happy to say a very easy project (if only all was).
Running the model for the first time proved to be very worrying! the loco jumps to a start and is uncontrollable!!! moving the controller forward i regain full control of speed. i suspect the C.V need changing with the shay being powered by a small motor.
Anyone know of the C.V i need to set and the value they need to be?? i'm still new to DCC programming
Chris
The Bachmann motor decoders, at least the most common ones, are of rathe rpoor quality. I don;t think they have a rest option, which is usually the first place to look for odd operation - even new in the package, tehre may be some residual settings from factory testing that a reset would fix. Starting speed is controlled by CV2. Make sure it is set to 0.
A bigger issue with Bachmann locos that affects the perfornace even with the basic decoders, and even more so with better quality decoders, are the capacitors for RF supression that are connected across the motor. These are usually little yellow blobs, sometimes right ont he motor itself, in parallel with the wires goign to the motor. On some Bachmann locos, these are on the lighting circuit board. Clipping these off results in much improved performance even with the Bachmann decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
As you know by now, A Bachmann decoder was a bad selection.
Go to the Bachmann site and download the EX Command document for this decoder. You can also join the forums as many have Bachmann locos and are familiar with these decoders.
Also, turn off the dual mode, DC option for the decoder.
TCS and Digitrax both make good small decoders with the eight pin plug or no plug.
Be advised, the Climax and Shay are known to develop cracked gears which to some seem like a CV issue. If it runs ok on DC, then it should run ok with a good decoder.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Sound like what happens when the capacitors need to be cut.
I usually leave the capacitor in when I install DCC chips in my Bachmann locomotives. The majority of locomotives run fine, however many run erratic, just as you described.
Most owners of Bachmann do not use Bachmann chips when they install DCC, the Bachmann chips are low end quality. I use digitrax, for my Shays I used the Z and N 8 pin plug equiped decoders, both work great.
As to speed control, the Shay is a very slow engine, top speed is about 20 mph going downhill, The motor in the shay is quite adequate.
A lot of Bachman owners cut out the capcitors completely, even if they are not going to install DCC, apparently performance is far better without the capacitors.
Thank you everyone for the advice.
I'll clip capcitors over the weekend and fit another decorder.
Hopefull this will sort the porblem. something so simple cousing so much trouble.
New ddc system to fit before testing. will update in a week or so.
once again thank for the advice.
Busy day, 24 hours of bachmann dynamis was enough and changed it for gauge master pro DCC system.
Given the shay a once over today much to the wife annoyance! The capacitors was removed and showed a massive improvement in loco Smooth running when moving from a start. I also checked the gears, they show no signs of cracking but the rear bogie was sticking once a revolution, tomorrows job finding the fault.
Thank you for the advice and tips.