Black Sheep’s back!
I read the ‘Model railroader’s guide to DCC’ and in the book I figured out how to convert the ‘OLD SCHOOL’ Athearn units, but I have a few Bachmann Spectrum engines that I am wanting to convert to DCC and the book does not even mention how to do that, or even if it can be done to those engines.
Is it possible to convert an open spoke BACHMANN SPECTRUM engine to DCC, and if you can, how would you do it,
Thank, Black Sheep 25
What particular Bachmann Spectrum engine are you referring to when you say “open spoke?” Nearly all Spectrum steam engines are DCC ready with an NMRA decoder socket in the tender. All you will need to do is open up the tender by removing a small, phillips head screw that should be located near the front tender truck and lifting the tender shell off of the frame.
You can install DCC in any DC locomotive. Although the particulars for a Bachmann are different from an Athearn, the underlying principles are always the same in every case. The generic how-to steps below will apply to ANY loco, but you’ll have to figure out how to perform them on your particular engine.
First, test the stall current on your motor. Read http://www.tonystrainexchange.com/download/DCC-for-Beginners-tte8x11.pdf, page 8 in the middle for a description on how to do this. The stall current will tell you the theoretical maximum current that your motor would ever draw, in a worst-case scenario, so you can choose a decoder with an appropriate current rating and reduce the risk of burning it out.
Electrically isolate the motor from the frame. In DC, there are two electrical connections that run the motor - one that is connected to the right side rail, and one that is connected to the left side rail. (At this point, disconnect any wires that go to lights, etc. from the motor.) Bachmann used to (still does?) use a “split frame” electrical pickup to feed the motor. The loco frame itself was split in half, with each half insulated from the other down the center. The current traveled from the metal wheels, through the frame itself, and to the motor electrical leads by physical connection to the frame halves. In other cases, there may be wires running from the frame or wheel wipers directly to the electrical leads on the motor. For DCC, the only electrical connection the motor must make are two wires going to the decoder. The electricity from the rails must NOT reach the motor directly - it has to go through the decoder first. That means you have to electrically insulate the motor from the frame to ensure there is no unintentional electrical connection between them. This is usually done with electrical tape or similar material. Depending on how tight a fit it is inside your loco, this may pro
Black Sheep 25, this is all spot on advice given above. Here is some info specifically for the Bachmann Spectrum
I have not had a Spectrum with a stall current above 1 amp and a bit.
TERMINOLOGY: I assume by open spoke you are referring to a steam locomotive. Or did you mean open frame motor…which I don’t believe are in any Bachmann Spectrums. I think I have only seen can motors in them. However older ones are not isolated from the frame so you will have to take the steps mentioned in the posts above.
THE GOOD NEWS: When all the steps are written down, the process can seem intimidating to read. Be heartened. After a few conversions, I find a diesel with a split frame can be hardwired as described above in less than an hour. A steam locomotive with an NMRA plug would be faster, unless you are planning to change the bulbs to LEDs (although some newer Spectrums have one and sometimes both front and rear lights as LEDs. They can vary like this. I had a decapod with an incandescent headlight and an LED in the tender and no NMRA plug.)
Changing the headlight to LED in a Spectrum Steamer can be very, very difficult, particularly getting the shell open and off the loco without breaking something. Bachmann Support doesn’t recommend trying to get the shell of some steamer models at all.
If you have an older Spectrum steam loco that needs to be hardwired one can still get enough access to the motor…it is just getting to the headlight that can be very hard. So I have just connected the existing incandescent headlight to the decoder in several. As mentioned check with the decoder instructions.
Most newer Spectrum locos have an 8 pin plug in the tender. But beware of eratic throttle responce if you do not cut the cap from the spectrum board. Check out the TCS website for more info. WWW.tcsdcc.com. Click on instalation pictures.
Hey guys,
I thought I better clarify what I was asking, I screwed up with an explanition of the engine I am wanting to convert. The engine in question is a ‘Bachmann Spectrum F7 diesel that has a CAN Motor inside.’
If someone knows how to convert this engine, please let me know and what system you would recommend.
Black Sheep 25
A thousand Apologies for any confusion.