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starting my own pickups!

wilser

wilser

May 4, 2004
4,789
53
Northern Virginia
www.ramirezbass.com
#1
Hello,
This is my second self would pickup. The first one really sucked, but this one is a lot better. I'll be using this on my ash/bubinga bass. Show below is one of the coils, there are two of these to form a humbucker. Covers will be made to match the body (bubinga). For those of you with keen eyes, yes, the bobbin is made from lollypop sticks. They were dipped in minwax wood hardener to make them a little more 'stable'. Magnets are alnico 5 and as you can see from the picture, still needs leveling.

Invalid Link Removed
 
#3
Invalid Link Removed
tjclem said:
What did you use to wind them? How long did it take? More details. :hyper:
Click to expand...

I have spent the best of the last week building a winder with a sewing machine motor and some parts bought from mcmaster-carr, plus some scrap wood and mdf. It's still too fast, I made a mistake while calculating the pulley diameter. The motor has a pedal driven variable speed thingy, but it's too hard to control.

Each coil takes about 15-20 mins depending on how fast you make the motor go. They are both about 7-8 kohms.

here's a pick of the (very ugly!) winder.
 
#8
Phil Mastro said:
Where'd you get your magnets? I've been thinking of making my own pickups, but couldn't find decent sized-shaped magnets for pickups anywhere.

Oh, and I think your winder looks cool.
Click to expand...

magnets are alnico5 rods from mcmaster carr. 1/8" diameter and come in 5" length. I cut them to size using a dremel and an abrasive wheel. they have many different diameters, also.
 
#12
andvari7 said:
How and where are you going to add the wiring? Additionally, is the north or south pole facing outwards?
Click to expand...

you can't see it in the pic, but there are two small holes in one of the lower corners. The start and end are tied out there and I used a small piece of sandpaper to remove the coating. I then inserted the leads and soldered it to the copper.

North is out on one of the pickups and on the other south is out (up). One was wound on one side of the winder and the other on the other side, thus making them reverse wound. To make it humbucker you need current flow in opposite directions and also reverse polarity. So All I have to do now is wire the end of one to the start of the other. Should work out pretty good. I'll post sound clips when the bass is finished.
 
#14
andvari7 said:
Wow. How does that pickup winder work?
Click to expand...

The shaft is mounted on a couple of flange ball bearings. Also each end has the bobbin mount in a couple of flange bearings which are epoxied to the bobbin mount. In the shaft's center (sort of) there's a pulley which is driven by v-belt by the motor mounted on the rear. You mount the bobbin in one end (using double stick tape) and turn on the motor (activated by foot control). Since I chose a pulley based on my calculations on how many RPMs I wanted the bobbin mounts to turn, I just have to keep it on for RPM*minutes, depending on how many turns I want (for example, for 5000 turns, it's 5000/650 ~ 8 minutes). It's very simple really. I'm working on a C++ Unix program to use as a counter. I've done that in the past on a previous winder I built, but it all got stripped and lost when I moved. I will glue a small magnet to one of the bobbin mount ends and wire a reed switch on the base directly below the magnet. As the mount turns it activates the reed switch which is wired to the laptop via paralell port. I had problems with debouncing the reed switch before, so according to my calculations and the current RPMs, by including a ~86ms delay it should work just fine. The shaft in the front is for guiding the wire and controlling tension. I use a dirty sock to hold the wire :) (bare fingers can break it).

On my previous winder I had built a circuit that was wired to the computer and I could control start/stop of the DC motor. So you could set up a count threshold in the PC and hit the start button, it would activate a pin on the parallel port, which in turn activated a solid state relay, which in then started the motor. When the threshold was reached, the motor was automatically stopped. Too bad at the time I could never get magnet wire wind anything.

hope that helps.
 
#17
wilser said:
magnets are alnico5 rods from mcmaster carr. 1/8" diameter and come in 5" length. I cut them to size using a dremel and an abrasive wheel. they have many different diameters, also.
Click to expand...

Good to see you're still at it. I've read of bobbins being made out of some interesting materials but I think this is first for popsicle sticks. Whatever works to get the job done in the beginning is good enough.

Anyway, this post made me think about some reading I ran across the other day that cautioned about using alnico 5 mags on a grinding wheel. If you heat them up to like 1500 degrees (or whatever it was) there can loose their strength - and a grinding wheel may do that. I think it was the Bill Lawrence site and he specifically mentioned it in reference to guys grinding down pup poles on strings where volume was excessive.

I still haven't read through all that Lollar stuff so don't know if it was mentioned in there or not.
 
#18
luknfur said:
Anyway, this post made me think about some reading I ran across the other day that cautioned about using alnico 5 mags on a grinding wheel. If you heat them up to like 1500 degrees (or whatever it was) there can loose their strength - and a grinding wheel may do that.
Click to expand...

It's just like grinding tool steel, too much heat and the steel loses it's temper. If you take 'er easy and dip the steel (or magnet) in a can of water every few seconds it shouldn't be a problem at all.

I don't quite recall my blackbody radiation, but from what I know about my mini-foundry 1500° F is glowing pretty cherry already. Personally, I use the old school "if it burns my fingers it's too hot" method when I grind tool steel. I hold the bit with my hands and any time it starts to feel warm I dip it in water. Not the most health concious, but it works just fine.

-Nate
 
#19
All magnets loose their magnetic capabilities beyond their Curie-point.
IIRC, some manufacturer's sites list the Curie-points among the other specs of their magnets.

Wilser: Good luck with the pickups! I was thinking of making my own, as well, but after much reading I still couldn't find any formulas for impedance/tone, and it was too much of a hit or miss matter for me... besides, I'll need that bass as a gigging bass, so it better be good from the start...
But anyway, hope yours turn out well!
 
#20
FWIW:

Here's the excerpt (without Bill's permission of course):

===
However, heat can be a severe problem when an Alnico 5 magnet is exposed to temperatures above 1000 F, approaching its Curie temperature of 1634 F. At these temperatures, Alnico 5 undergoes structural changes and cannot be re-magnetized. Why do I mention this? Because it happens quite often, when someone doesn't like the unbalance in output of a pickup with staggered magnets and goes to a bench grinder or a belt sander to grind a magnet down. You take a chance that a magnet gets too hot and becomes damaged.
===

My impression from this was that the heat generated at the point of contact could be excessive.

Anyway, just thrown out to create some awareness.
 

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