Many of us 1-scalers have older models with the AC motor that aren't very conducive to upgrading to digital. That has changed thanks to ESU's production of the 51965 magnet, a permanent magnet to replace the field winding on the older Marklin motors. What it does, in fact, is turn the AC motor into a DC motor, which then allows us to add a decoder and have a modern digital locomotive with all the bells and whistles (pun intended) of their contemporary counterparts. I have two such locos, a BR80 steam loco and a DHG 400. The BR80 will be getting synchronized smoke along with sound, and since that's a more involved process I'm going to start with the DHG diesel, which is getting a digital upgrade with sound only (okay, and maybe some fancy lighting upgrades, too). Here is a picture of our candidate:
Below is a picture of the inside of the locomotive after the three screws holding the body on are removed. There is some wiring that have done but no worries. Everything is coming out- the reversing mechanism, the motor, etc. Now is a good time to lubricate the gears, too...
The first step of the upgrade is to replace the field winding with the new permanent magnet by removing the four screws and taking the motor apart. You'll need a nut driver to hold the 5mm nut while you turn the slotted screw (the four screws are visible in the image below with my screwdriver on one of them). Frankly, for me that was the toughest part of the job, as I was using a 7/32 nut driver, which is juuust about the right size, and Marklin has made sure those nuts are on TIGHT...
Below is a picture of the three pieces of the motor (and the brushes) once the four screws are removed. In the background you can see the packaging for the ESU 51965 permanent magnet. It's really a simple swap from here- take the old center section out, replace with the new magnet, and you are ready to reinstall your new (DC) motor.
Here is how everything looks when the motor is reinstalled with the permanent magnet. Note the lack of coil and wires. Don't forget to snip off the noise suppression diode between the motor poles, which is still partly visible in the picture below. Compare this picture to the image of the motor two pictures above- what a difference, eh? There are now only TWO wires connected to the motor and the whole reversing solenoid mechanism is gone. Plenty of room for a decoder, speaker, and even some additional modifications...
Last picture for today: I hooked up leads from the chassis and wheel pickups to the two sides of the motor and test-ran the locomotive using DC power. It ran flawlessly. Next I will install the decoder with sound, and maybe add a few other special upgrades...
