Tuesday, 9 June 2015

Pickup Winder: Strat Pickups Part 2

After a successful trip to Jaycar in search of rare-earth magnets, I'm ready for the second step in the winding of a set of single coil Stratocaster pickups - magnetising the pole pieces. To do this, two magnets are needed with opposing poles. The magnets are mounted with opposing poles facing each other and the pickup is passed between them.

Using my son's orienteering compass, I determined the polarity of each magnet and stuck them to the jaws of my nut-making vise with just enough room for the pickup bobbin to slide comfortably between them (nothing like wrestling some strong rare-earth magnets!).

Testing the polarity of my rare-earth magnets
Using my nut vice to hold both the opposing magnets
Once the magnets were in place, I took each bobbin in turn and passed them through the gap. It was pretty damn hard keeping the pole pieces from sticking to the magnets! I did 40 passes with each bobbin to (hopefully) fully magnetise each Alnico V pole piece.

Magnetising the neck and bridge pickups as north-facing.
To allow for noise cancelling when the middle pickup is used in parallel with either the neck or bridge pickup, the middle pickup needs to be RWRP - or "reverse wind, reverse polarity". Half of this equation means that the polarity of the pole pieces for the middle pickup need to be the opposite of the others. Therefore, having passed the bridge and neck pickups through the magnets in a "north facing" configuration, for the middle pickup I reversed the direction to create a "south facing" polarity.
 
Magnetising the middle pickup as south-facing.
After more struggling against the pull of the magnets, a quick polarity test of all three pickups showed that I had succeeded in creating a "reverse polarity" middle pickup.

The resulting polarity of all three pickups compared.
With the pole pieces magnetised, it's now time to crank up the winder and see if I can get some 42 AWG wire on these bad boys. Let's hope I don't break the wire first time out! I will be going quite slowly so fingers crossed for no mishaps. I will also be stopping every 500 winds or so to measure the resulting resistance of the coil. That should complicate the process quite nicely ;). Anyway, I need some nail polish before I continue on, so stay tuned for the next installment!