Tumbling Alnico Rods

[Stan H]

I've always had difficulty beveling Alnico rods for a single coil, not to mention the worry of overheating the magnet. Have any of you ever tried tumbling the pieces in say a small rock tumbler to remove the sharp edges?

Thanks,
Stan

[Spence]

Haven't done that.
All you have to do is mount the rod magnet in the chuck of an electric drill and spin the edge against a sanding belt.

[Possum]

I used to do jewelry art and used tumblers alot. Alnico has a hardness of 50 if I remember right which is very very hard stuff. I've seen Korean magnets that look tumbled, they are kind of matte finished all over and rounded edges on the ends. Go to a rock shock for lapidary equipment and they can set you up.....

[Joe Gwinn]

I used to do jewelry art and used tumblers alot. Alnico has a hardness of 50 if I remember right which is very very hard stuff. I've seen Korean magnets that look tumbled, they are kind of matte finished all over and rounded edges on the ends. Go to a rock shock for lapidary equipment and they can set you up.....

I bet it'll work ... so long as the magnets are not magnetized. If they stick together, uniformity could be hard to achieve.

[Stan H]

I bet it'll work ... so long as the magnets are not magnetized. If they stick together, uniformity could be hard to achieve.

I get me magnets uncharged so that won't be a problem. I think I'll try it. Thanks guys.

~Stan

[Spence]

Hang on, surely the rod will be worn all over. You may lose something off the diameter.

[Joe Gwinn]

Hang on, surely the rod will be worn all over. You may lose something off the diameter.

If one uses tumbling media intended for deburring metal parts, the corners will get most of the action.

If memory serves, deburring media are little ceramic pebbles or rods, not fine grit. Granite or Quartz pea gravel might work.

The stones in pea gravel are roughly spherical, while granite chips are jagged.

[Spence]

But why go to all that trouble when the conventional method is so easy and quick?

[Possum]

yeah really its alot easier to sping them in a drill chuck, you can also do this with a hand crank drill chuck and spin it against a grinding wheel, works real fast. Gives you more control over how much bevel you want. Tumbling just rounds the edges a bit. You can request your magnet company to do this, its common practice anyway for them to round the edges a bit..

[Stan H]

Well, I've decided against it anyway...apparently from what I've read it takes a month or so of tumbling to get anywhere. Thanks guys.

~Stan

[Possum]

Won't take a month, there are various grits used in tumbling, you would use a very coarse fast cutting grit to do what you want to do. Also there are tumblers that are vibrating tumblers that work very fast but aren't cheap to buy either. Use a grinding wheel or sander, alot faster...

[Rafael Puyol]

Why do you bevel Alnico rods??
Cheers
Rafa

[Spence]

It makes it easier to drive them through the flatwork. It also has a nice cosmetic appeal too.

[Possum]

Fender did it originally because the rods were shipped with straight cuts and the edges chipped, its also easier to push into the forbon if its beveled. there is a small effect from beveling as it narrows the magnetic sensing window a bit versus a totally flat top. As an experiment make two identical pickups, one with flat tops and one with a pretty radical bevel so the top is more pointy and see if you can hear the difference. Vintage nuts like it, I don't bother unless someone requests it usually....Dave