Installing DCC in a Bachmann Spectrum 2-6-0

Yes, Tom T is the guy to ask.  He walked me through this exact install a few months ago.  Worked out great.  I wanted to write a HOWTO about it, but with a new baby, I just haven't had the time.

I used a 583S.  Essentially, the installation involved removing almost all the original circuit boards, and running the wires to the decoder instead.  The hardest part was getting the boiler off to access everything.  The decoder ended up in the boiler where the original Bachmann main circuit board is (which gets removed during the install.)

Now that I look, I still have his original instructions in my e-mail archives.  If he doesn't post here himself, I don't think he would mind me PM'ing them.  I followed Tom's instructions explicitly and all went great.

As far as integrating the sound, I'm sure it's quite simple, but I don't know the exact instructions and I would hate to guess.

I will send you a PM with the first set of instructions, and if you find it helpful, I'll send the rest.


Scott

Done!


The project went pretty smoothly thanks to some advice from TOC. I removed the supressor board from the end of the motor (has a habit of smoking with a bemf decoder) and reversed the journals on the third driver to fix the problem where the drivers drop off the rail. 

I was able to chase a two pairs of wires (one for the chuff sensor and one for the speaker in the tender) thru to the front of the bolier where the decoder was to go. The two pin cable to the tender then became the wire to the remote speaker.After enlarging the DC and DCC diagrams in the Bachmann manual, I was able to figure out all the wiring that needed to be moved. I have it written down somewhere if anyone plans on repeating the exact same install.


To get the Bachmann board and the decoder back into the bolier, I had to remove the feet/spacers that kept the Bachmann board off the plastic shelf that holds the smoke generator and the board. I used some electrical tape at each end of the board to hold it in position. then put a piece of think flexible plastic on top of to insulate it from the decoder. Then a couple more winds of tape around each end of the decoder and I was just able to slide it all back it and get the two screws that hold the shelf in place back in. The function keys are used to switch the smoke on and off. Supringly, it all still worked after gently pushing it in (rather like child brith but in reverse?)


Here's a picture of everything that had to be fitted back in:

Peter, there were some challenges in getting this fitted, but it can be done. I had to pull two pairs of wires from the rear axle where the contacts for the chuff contacts are. One pair to connect the  chuff "switch" to the decoder and the other pair to connect the decoder to the speaker in the tender.The speaker pair I connected to the original two wire plug back to the tender. I soldered the end of the two pairs to a thin brass rod which I threaded from the underside of the engine over the weight and out through the front of the boiler.  I may have been lucky but it worked the first or second time.

I did consider putting the decoder in the tender, but that would have required a radical rewire of the locomotive and additional pairs of wires to the tender if I'd wanted to control the front light and the smoke unit; Bachmann designed these locomotives expecting a simple DCC decoder in the boiler and a sound only unit (Phoenix or Sierra) in the tender. By trimming the spacing tabs off the platform that supports the Bachmann circuit board and using electrical tape to attach it to the plastic shelf and then the Loksound decoder on the top of that, I was able to retain all the functionality (lighting effects etc.) provided by Bachmann.

Let me know if I can be of any more help.

Peter.

Peter, just reread your message. Dave Goodson solved the problem with the center drivers dropping off the track on sharpe curves.

"I've seen it, where the center driver drops off the rails on a curve, and read about it numerous times by others.
So, last night's operating sesion, I decided to drag mine out and run it.
Today, after all the other things I had to do, I decided to tear it down and fix it.
First, I grabbed my big framing square, popped the temp shims out, depressed the lead driver axle down, and checked down all three axles on one side.
Not pretty.
I checked the running board angle, still angled up, even without the shims in place (center of board to benchwork with loco on rails).
Then, I flipped the loco over, pulled the bottom cover on #2 and #3 axles, removed the crankpin bolts on #3 axle, and pulled #3 axle out of the chassis.
Then I inspected it.
First, I noticed the top (top being away from the part that contacts the rails) of the journal has a small pin that sits into a hole in the top of the frame.
Okay, now we're oriented.
Pulled the driver caps, screws, and pulled the wheels off (this is a good time to check your back-to-back for G1MRA 1.575" and install washers between driver stubs and contact drum) and looked at the journal boxes.
Strange.
I pulled the boxes, held them together, with one pin up, one down, and there is about .040" offset in the bearings.
So, I re-assembled the journals and drivers (look at the boxes...there is a "flat" side and a "humped" side...."hump" to driver....keeps the drivers from rubbing on the frame) and dropped the assembly back into the frame with the pins facing out of the chassis.
Put it all back together and on the track, running board is dead level, and center driver......I can just see light between it and rail.

You can tell how yours is put together without taking anything apart.
Rotate the drivers so you can see through the spokes of #3 driver (either side) at the bottom of the journal box.
You will always see a round peg just forward of the centerline, about 1/8" o.d., and a similar square peg just aft of the centerline.
If yours is put together with the pin down (high cab) the pin will just be visible between the square and round pegs."

I was still confused and asked ave for clarification.

"I had to double-check.
Yes, if you have 3 pins in a row, NOT counting the narrow supports at the
very edge of the journal box, you're fine.

iII Ii correct looks like that, with the "i" being the narrow supports at
the edges.
iI Ii is incorrect.

Dave"