Wrenn Duchess Class LMS

Scale:
HO Scale


This installation uses the following decoder:

T1



This installation of TCS T1 Decoder is for HO Scale Wrenn Duchess Class LMS and was performed by Robert Lewis of Tilehust, Reading, United Kingdom.

To remove the body, un-screw the retaining screw located above the front pony truck.
Important, Both motor brush sleeves must be isolated from the metal chassis. The brush holder (2) is factory fitted within an insulating sleeve. This arrangement has to be replicated with the other brush sleeve (3). This can be achieved by purchasing an insulating sleeve from one of the many Wrenn spare suppliers in the UK. The component parts can be seen in picture 3, the insulating sleeve being the darker one.
To begin, remove the rear pony truck, the permanent magnet and the metal poles. Release the brass locknut and unscrew the top motor bearing, the commutator can now be removed. The existing brush sleeve has to be removed, this can be done by passing a fine square ended punch through the insulated brush sleeve, and locating it on the edge of the un insulated sleeve, a few gentle taps with a hammer will push it through. the hole in the chassis has to be opened out to the match the outer diameter of the new insulating sleeve, this can be done with a drill or reamer. Care must be taken to ensure the hole remains in line with the opposite brush sleeve. The new insulating sleeve can now be inserted, I placed a small drop of super glue (Cyanoacrylate) on the sleeve to ensure it remained in place. The original metal sleeve can then be inserted, ensuring there will be clearance between it and the commutator. Just to ensure insulation I used some transformer tape (yellow) on the exposed end of the metal sleeve. ensure to clean all swarf (filings) from the metal chassis, then reassemble the commutator and bearing, magnet and pony truck. Connect the red decoder wire to the solder tag (1) and the black to the wheel pick up wire (2). connect the grey wire to the front brush cap and the orange to the rear. Test the installation before replacing the body. If all is ok the wires can be held in place with hot glue, I mounted the decoder vertically on its long side using hot glue in the area in front of the solder tag. Replace the body and securing screw. While the locomotive was apart I also replaced the magnet with one of the Super Neo Magnets now available, it was a big improvement compared to the original steel magnet, which had lost most of its magnetism due to its age.

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 than a 1/32 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire than 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