As soon as I saw the photos of H0's Trix 22947 VSLF loco, I knew that I had to have one. There is a Marklin version, but only from selected Swiss dealers at a very high price. So before the A$ plummeted any further down the sliding slope of financial doom, I ordered one from a dealer in Germany, Modellbahnshop-Lippe. Very professional service and a sensible 21 Euro delivery.
I am guessing that some of you are wondering why a conversion of a Trix loco to three rail warrants its own thread. For most people, it doesn't and the process is simply to remove a plate, move a wire and install a slider. The problem with this approach on a computer driven layout with contact tracks is that the loco will stop on the contact track because the converted loco, generally, is only getting a ground connection from one side of the loco.
So this slightly more complicated approach is for people, like me, who use lots of contact tracks on their layout and have not done the "diode trick" with their S88 units.
Here is the awesome loco.
Looking underneath we see the front bogie without a slider. It does have a plate that feeds power to the wheels on one side of the bogie. We need to remove this screw and put it somewhere safe. Not on the edge of your work table where it will fall off and be lost forever!
We also need to keep the plate. Remove the front coupler and the front bogie frame to access the stepped screw that holds the front bogie to the loco.
The rear bogie has a contact plate to provide power to one of the wheels on the rear bogie. We are not going to do anything with this now except to note that the wire soldered to the plate is a black colour.
This is the contact plate we removed from the front bogie. Remove the copper plate from its insulating section and enlarge the screw hole in the copper plate to 3.5mm. You also need to remove the four tabs from the copper plate. If you intend to convert this back to two rail operation, then it might be a good idea to order a new plate now.
If the hole is big enough the stepped screw that holds on the front bogie should fit through the hole.
Turn the loco over and cut the black wire that leads to the contact plate on the rear bogie. It is shown with a red arrow in the picture below.
Assemble the front bogie. Install the copper plate on top of the bogie ensuring that the contact is made with the back of the wheels. (same side that the plate came from originally). Then install the stepped screw. (optionally to minimise wear on the copper plate, install a steel washer 3.5mm inside diameter and 0.25mm thick on top of the copper plate). Install the plastic housing and the front coupler. Use the original plate screw, a countersunk M2 - easily lost screw, to hold on the 7164 slider.
Turn the loco over and solder the cut back wire to the two brown wires on the cantery selection plate. At the red arrow in the picture. Make sure that the rear bogie is able to turn fully and there is no tension on the wire.
Before you place the loco on the track, use a multimeter to check that the wheels have a closed circuit left and right side and that there is not direct circuit between the slider and any of the wheels. Place it on the track and let the eCos scan the mFx decoder (or DCC). Success looks like the image below.
The loco runs beautifully and is highly recommended.
Edited by user 23 January 2015 10:28:16(UTC)
| Reason: Typos and shocking grammar.
