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AD60

5.2 Electric Pickup

Now is the time to mount the pickups. I have done that before with my NS7000 and I was distinctly unhappy with DJH's pickup system. It worked but it was difficult to get it in place and even more so to keep it in place. It works loose when pressure is applied, and that is exactly what wipers are about: applying a bit of pressure on the wheels.

DJH supplies four sets of wipers, each a pair, which must be attached to the loco frame with isolating pins. Getting them in place is a pain and the connection will always be flimsy.

I tried it anyway but it took a lot fussing. The result was mediocre at best. So I abandoned the plastic pins. But that was only the first step.

As a replacement I used two plates of copper clad board and soldered the wipers on them and interconnected both wipers. A first improvement but I still did not like it. There is a simple American saying: "If it don't look right, it ain't gonna work right."

The other side of the loco will get no wipers and DJH is distinctly unclear how to draw current from that side. They suggest allocating the bogies for that. That did not appeal to me at all, it seemed a very unreliable way to collect current. The text about wiring in the manual does not make sense. To my opinion it would result in a short circuit. My brain did anyway so I gave up. Second generation discarded.

I cut myself two narrow and long copper clad boards and soldered two sets of 0.25 mm phosphor bronze wire on them.

The wires were approximately 5 cm long. I gripped them in the middle with a pair of flat pliers and bent them 90 degrees back, creating a U-shape.

 

 

I soldered the short end of the U-shape on the copper clad board and bent the wires back again. I used 240C solder so I can later use 140C solder to attach the connecting wires to the motor and the other unit without the risk of the wipers coming loose again.

 

This is the idea. The little joggle in the wire keeps it well clear of the frame preventing any shorts.

 

To put them in their approximate location it is most convenient to keep the wires straight along the board. This way they pass more easily under the brake rigging. Believe me, they have an annoying tendency to catch anything they can find.

 

The board is laid aside OUTSIDE the frame. Epoxy glue can then be applied...

 

... and the board is clamped into place. Keep the board half a millimetre away from the frame plates (arrow), again to prevent shorts.

 

After setting of the glue, the wipers can be bent to fit and cut to size. This way all drivers get decent current collection.

Later I found that the copper clad board interfered with the gearboxes. By filing I narrowed them down to the appropriate width.
Both drive units will be interconnected so the loco draw current from all sixteen drivers. To uncouple the connection I used small plugs I had laying around. I replaced the thick stranded wire (bottom) with much thinner wire (top).
I also glued the plug to the bottom of the boiler cradle and fed the wire through the firebox to the plug on the other side. Keep left and right apart!