This installation of TCS M1 Decoder is for HO Scale Northwest Shortline ALCO 2-8-2T Minarets and was performed by Richard Todd.
After 40+ years in its box I decided it was time for the #37 of The Pacific Lumber Co. to take to the rails! The locomotive was built for Northwest Shortline by Toby in the 60’s to represent an Alco Minarets logging engine. The engine was constructed using standard techniques of that period. Sheet brass and bar stock were used to construct the super structure and frame. The frame, cylinders and pilots were chemically blackened. After a thorough cleaning, the superstructure was painted semi gloss black. The running gear was thoroughly cleaned and lubricated. The drive gear box was removed to ensure that the mechanism would roll freely. It is essential that the mechanism be free of “binds” before fitting the motor and decoder. I firmly believe that this engine was haunted, as every time I thought I had identified and fixed a bind, a new one appeared. One must have patience!
The original Pittman motor was replaced with a Sagami “can” motor. The motor was mounted to the frame using DAP Alex Plus, a latex acrylic caulk. This is a paintable, flexible caulk adhesive. Simply apply the caulk to the mounting plate, position the motor in the correct position and press it into the caulk. Smooth the edges of the caulk to conform to the frame and the motor. Let it dry over night. It can be painted at any time after it dries.Once the motor installation was complete, I tested the frame on a test track using DC power. Once I was sure it ran smoothly, I proceeded with installation of the decoder.
The M-1 decoder fits perfectly in the slot under the motor. The red wire was passed forward under the motor mount and through the gear slot, then back to the frame bottom plate retaining screw. The end of the wire was tinned with solder and bent to fit under the screw. The black wire was passed forward under the motor mount and soldered to the wiper assembly on the left side of the locomotive. The orange and grey wires were soldered to the contact pins on the motor. The frame was test run on the railroad to ensure proper operation.
The headlights were drilled out using a 5/64 drill to receive Miniatronics 1.5 volt clear incandescent bulbs. The bulbs were cemented in using a very small amount of Goo. The insulated leads were snaked back to the area of the motor. The white wire from the decoder was soldered to the remaining lead from the front headlight, and the yellow wire was soldered to the remaining wire from the rear headlight. A final piece of black tape was applied to ensure no unwanted contact.
The blue, yellow and white leads from the decoder were brought up the back of the motor, then over the top of the motor and secured with a piece of top grade black tape. A 330 ohm resister was bent into an “s” shape and taped to the top of the motor with the leads of the resister exposed. The blue wire from the decoder was soldered to the lead of the resister facing aft and one lead of each headlight bulb was soldered to the resister lead facing forward. Another piece of black tape then covered the assembled resister leads.
The engine was placed on the rails and test run with the superstructure off the frame. Once proper operation was confirmed, the superstructure was attached to the frame. The M-1 with back EMF provides incredibly smooth operation, smoothing out the small irregularities that these older engines frequently exhibit.
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