This installation is for a HO Scale Bachmann RS-3 using a TCS WOW121 Diesel Decoder, AK-MB1 Motherboard with built in Keep Alive®, motor mount and UNIV-SH1-C WOWSpeaker kit.
HO-Scale Bachmann RS-3 shown prior to installation.
To start off this install, we must first remove the front coupler screw highlighted above and below and it's housing.
Next, remove the rear coupler screw highlighted above and below and it's housing.
On the locomotive bottom, remove the single screw highlighted above in red from the bottom of the tank.
Next remove the two highlighted screws from under the tank on the bottom of the chassis. With these screws removed, while gently pulling outwards at each end and along each side of the frame, lift the shell off of the frame. Take care to release the handrails as you lift off the shell so they don't break.
The Bachmann RS-3 shown with the shell off. Remove the two screws highlighted above along with the wires from the original lighting board and remove it from the chassis.
Trim, tin or lengthen the wire leads as needed and using small lengths of TCS 3/32" and 3/64" shrink tubing, insulate these solder leads. Clip off the two caps shown in blue and trim off the three tabs highlighted in red flush with the chassis to prepare a platform for the new motherboard and speaker. The speaker shown in the front of the locomotive shown here was also removed and discarded.
The installation area shown prepped for the motherboard. Using foam double sided tape, with the motor mount trimmed to a flat bottom width wise, mount it to the platform. Make sure to 'test fit it' with the AK-MB1 in place to be sure it is mounted correctly front to back.
Using the same foam double sided tape, mount the AK-MB1 to the frame and solder the track and motor wire leads to it as shown. You can place the lighting into it's original positions to prepare for the next step. Solder the lighting wire leads to the motherboard according to the included wiring diagram. TCS motherboards include on board current limit resistors for LED use. There is no need to apply external resistors for LED use.
With the 35mm X 16mm WOWSound speaker inserted into the UNI-SH1-C enclosure, mount this assembly to the frame as shown using foam double sided tape. In this installation, we pre-routed the front lighting wire leads in a tape 'channel' under the speaker enclosure to keep the installation neat and prevent wire shorts. Solder the speaker wire leads to the motherboard according to the included wiring diagram.
If your speaker enclosure installation covers the portholes on the enclosure, we recommend adding new port hole(s) similar to the original porting. Be sure that the new portholes are the same size and amount of the original and are vented freely into the locomotive We have found introducing a port of the correct size greatly increases the volume and sound quality of the installation. Too much or too little porting decreases the sound quality.
To allow for space for the speaker enclosure, it is necessary to trim the interior of the shell top. First, remove the upper cab section and then using a sharp blade, carefully trim the shell as shown above. This will create maximum space for the enclosure to fit.
You can now plug in your WOW121 decoder.
Lastly, in order to keep the wires neat and prevent possible shorts, lace the wires into a bundle using lacing cord, which is a wax impregnated string
used for wire bundling and making harnesses. There are many choices of lacing cord available from Digikey www.digikey.com. We use part number 802534B BK032-ND
As the speaker assembly will partially be seen in the cab, before assembly, we darkened it along with a small portion of the wire leads with a black marker to minimize it's appearance. Close up the locomotive and reinstall the coupler assemblies. Be sure to be mindful of wire routing and reassembly of the shell as to not damage or foul the installation. Your Bachmann RS-3 is now WOWSound equipped and ready to roll!
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.
TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.
You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775
Other solder tips
When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire