Friday, January 13, 2012

Engineering pickups

PickupsThe Super D has a fantastic chassis, amazing motor and so I need to do a decent job with the electric collection. Fortunately, there is enough space down there to do something I've wanted to do for a long while - some engineered rather than bodged pickups.

The idea isn't new, in fact I'm sure it dates from a very early MRJ. What you do is fix a bit of copper-clad inside the frames behind each wheel. Then you make the pickup in a U-shape. One leg is soldered to the paxolin and the other bears lightly on the back of the wheel.

In theory, the wheel can move up and down in its hornblock and stay in contact with the back of the tyre. Adjustment can be carried out one wheel at a time as well without mucking up the others.

Well, it was fiddly but I built it. The copper clad strips are attached to the frames with epoxy. This took longer to dry than expected but overnight it fixed them well. Soldering the wires wasn't too bad once I'd done a couple. The wheels have sideplay but stuffing some tweezers behind them moved the wheel as far out as possible. As long as wheel and pickup touch at this point then everything should be fine.

Anyway, the result was, it worked ! Every single pickup worked. On the track, the chassis runs up and down the length of track. I did this for quite a while as I was so chuffed with it.


Dodgy Geezer said...

"...One leg is soldered to the paxolin.."

I'm impressed! You can solder to paxolin? What flux do you use?

Phil Parker said...

Well I like to use a copper barrier layer...