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Loveably weird
Over at MTF, a member asked a few questions about converting a Bachmann DC Overland Limited trainset 4-8-4 to DCC and sound. I have actually done this, and posted a write-up over there. Unfortunately, when P-bucket launched their extortion scheme all the photos in that write-up lost their links. I've tried to re-do write-ups over there, but the photos will appear for a day or two, then disappear. Not sure what's up with that! So I am going to re-do it here, both for the other fellow's sake and y'alls as well!
I have a Bachmann train set 4-8-4 (#806 from the overland Limited set) which runs quite nicely and is in the greyhound scheme, which is what I want to pull my gray UP passenger coaches. I am going to convert this to DCC with sound. The tender already has a provision for an oval speaker, and I have one on the way to fit it. The decoder go in the locomotive, since there is plenty of room for it, and that means less wires running between loco and tender! (Always a good thing!)
Here is the locomotive and tender:

Here i have the shell off, the motor removed, and the light board and smoke unit removed. The cavity where the board was is where I plan to put the decoder.


I have a question about the motor. There are capacitors and resistors attached to it.

Can I simply remove these? I plan to install a resistor in the wire going to the headlight, and the smoke unit will not be reinstalled. I would much prefer to solder the orange and gray decoder wires straight to the motor terminals.
All in all, this looks like it should be a fairly simple install.
I love a challenge!


Loveably weird
Okay, the speaker is here. It's not a very big speaker, because, as you mentioned, there isn't a great deal of room for one.
This is the speaker I bought:
It is an 8 ohm speaker, and the mounting holes line up perfectly with the holes in the tender's speaker plate.
I used a drill, marked with a piece of tape so as not to drill through the plastic detail piece located under one of the mounting holes on the tenders speaker plate. I drilled both mounting holes on the plate.

The detail piece I am referring to is in the upper right hand corner. This goes towards the rear of the tender.

I used 2 2-56x1/4" screws to secure the speaker to the plate. Here is a pic of the other side of the speaker.

After drilling the holes in the mounting plate, I used a 2-56 tap to thread the holes. Some people don't bother tapping plastic, but I do.
Here is the speaker mounted to the plate.


Here the plate has been inserted into the tender. "Houston, we have a problem." You can see that the speaker extends into the tender past the slot where the two weights slide in.

I think what I will do is cut the weights in thirds and the slide two in the slot, gluing them in place. The remainder will be glued on top of them or glued to the tender in the front half (a combination of both.)
Power for the speaker and rear tender light will be supplied via a 4 pin mini connector plug between loco and tender.
I haven't quite decided how to do the rear light, as this engine didn't come with a function back up light. i may have to some very careful drilling to the casting to be able to get a light back there.


Loveably weird
(I was asked by another member: is that the front or back of the tender you took off? )

It's the front. Just use a small screwdriver on the top front of the tender, between the front panel and the top of the shell, and the front will come loose from the shell. It's just a snug press fit. A small jewelers screwdriver is what I used.




Loveably weird
(At this point, life went bonkers and I kind of forgot about doing updates. I was asked if the project got completed.)

I guess I never updated this.
Yes, I got it done.
I used this connector I got at my LHS:


(Note: this s good connector, but it's a little stiff. If I were doing this again, I think I'd try to find a connector with smaller gauge wires.)
I used an LED for the backup light, as well as the headlight. I mounted the decoder in the boiler, so I just had to use two wires for the LED and two for the speaker to go from tender to engine.
These photos show how I mounted the connector:


Plenty of room for the Tsunami TS-1000 sound decoder. Motor is removed in this pic.

How the motor is mounted:


This ends the original write-up. I just realized I never posted details of how I did the rear light! I'll have to do that.


Loveably weird
This how I did the rear light on this 4-8-4. This locomotive did not come with a functioning rear light, and I wanted to have one, so I added one.
Step 1 was to remove the rear headlight piece from the rear of the tender:

Carefully drill a hole of the proper size through the center of the headlight housing. I used an LED on this model because I didn't want the heat from an incandescent bulb melting the plastic housing.
Test fit the LED into the hole. You can glue it in if you wish, but you really don't need to.

Remove the LED. Glue the headlight housing back into place on the tender, and drill a small hole for the wires just ahead of the housing in the top of the tender.


Install a short length of heat shrink tubing over the wires close to the LED, but do not shrink it down!

Run the wires through the hole in the tender and insert the LED into the headlight housing.

I think it looks pretty good like that. It looks like an electrical cable.


Loveably weird
The tender weights present a bit of an issue. They slide into slots in the body of the tender, but the speaker will stick up into that slot. The easiest thing to do is to cut the weights so they don't hit the speaker, then install them behind and in front of the speaker.


This really was not a hard install to do. It just took some thought as to how to get everything where it needed to go. Installing the decoder in the boiler made the wiring much easier. Only 4 wires go the tender, the 2 speaker wires and the two wires for the rear light. This was actually the first sound install I ever did. I realize that some locomotives can be a nightmare to do, but this one was pretty easy.

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