triang dmu motor bother

Obviously there is no connection between the rail and the brush. At this point you need a means of checking electrical continuity to find the break. Before I owned a multimeter, I used a Faller house interior light unit (2 wires, a holder and a 16v bulb) Before that I used a 6"* length of wire and watched for sparks. (* pre NZ going metric) One wire on the rail and the other to each point where the current is carried by a new component. That way you can find where the current flow stops.

The DMU bogie I have has a Paxolin plate on the underside with a rivet which holds a wire wiper which springs against the back of the flanges. From there, a wire is soldered inside the rivet and goes up through the frame to the insulated brush. The brush sits in a slot in the insulated holder rivetted to the motor frame and the hairpin spring has a piece of insulated tubing over the wire. The pickup wire end (either a metal tube or a kinked brass rectangle) slips between the top of the brush bar and the insulated tube over the hairpin spring. Possible faults:

- the wire wiper is missing.

- the solder joint between wire and rivet has failed.

- you have the wire connector placed in such a way that there is no electrical connection.

Some Tri-ang motor bogies used bent phosphor bronze wipers (flat strips) riveted to the back of the paxolin plate rather than the rivet and wire. These wore away with use, but it's not immediately obvious without dismantling that the wiper, where it touched the wheel isn't actually there.

Regards, Greg.P.

I am ressurecting a couple of old Triang dmus. One of them, after motor

to. Now, I have reversed the polarity, making sure to reverse the wheels etc - (the models ran the opposite way to evrything else on the layout) and the first motor is very happy with the arrangement. However, the second motor will not pick up current from the track. I have checked all the connections from wheels, pickups etc right thru to the brushes and it is all connected. When I place it on the track, nothing happens, but if I tickle the brush on the insulated side with a wire touching the appropriate track, it moves immediately.

G'day, To reverse the direction of travel you do not turn the wheels. You just reverse the wiring and change the Brush Insulation to the other side. If you reverse the wheels you would also have to reverse the Pick Up Plate. Graeme Hearn

to reverse the direction of travel, would it not be quicker to turn the magnet around? David

No. On the motors used in these old locos, you change the insulation by moving a plastic sleeve from one wire to another.

Also, removing the magnet weakens it, which increases current draw.

Only works with some Tri-ang locos as the whole chassis is live.

Is this still true of modern magnets (post 1960)? Also a magnet can still be turned by using a steel spacer while turning it.

Kevin Martin

True, and I forgot to mention that you also have to move the isolated pickup wire along with the plastic sleeve. The plastic sleeve isolates the V-shaped brush spring, which is connected to the chassis via the motor mounting bolt.

Don't know, but others have claimed that the new supermagnets aren't seriously affected by removing them from the motor. Yer takes yer chances... Use of steel spacer is a nice trick. May try it some time. ;-)