Reasonable warranty period for hand-wound pickups?

[David King]

What's your statute of limitations on your work going bad? I'm just curious if there's any consensus on this.
Is it possible to blame the materials or the end user or is the winder always the cause of future problems?

[Jazz P Bass]

Now you have me curious.
A pickup is a coil of wire.
How can it fail?
In other words, what are the main reasons for returning a pickup.

[David King]

Open coil or shorted coil to magnet/s. I'd include shorted turns but that would be tough to prove other than the pickup would measure low for DCR.
I have a sinking suspicion that many pickup winders wouldn't see a problem with coils shorted to magnets and wouldn't consider that a warranty issue at all. I see it all too often.

[big_teee]

I'll fix it, if it hasn't been tampered with.
If you decide to change the magnet and break a wire, the winder shouldn't be responsible.
If you decide to remove a chrome or nickel cover and get the pickup too hot and melt a bobbin, the winder shouldn't be responsible.
If your playing the guitar and it just quits, in a normal warranty period it should be repaired.
That's my .02
Terry

[Jazz P Bass]

Being a know nothing as far as pickups, I have to ask.
Isn't the PU wire insulated?
If so, how can it short?
How would it short to a magnet?
Are these issues related to sloppy winding practices?

[FunkyKikuchiyo]

I haven't developed a real policy (yet), but most folks are limited lifetime. Depending on the pickup style there is a change that any will go bad at some point - small if they are well made - and for the sake of good customer service it is worth just eating it when one goes bad.

Customers can (and will) mess with pickups and destroy them, but I haven't really had to deal with this beyond cutting leads too short. My feeling is that if someone goes bad because of customer tampering, it should be pretty obvious when you actually see it.

The only customer driven pickup killing that seemed borderline to me is when I have a client who is very sweaty. Typically their guitars will have corroded hardware and other issues, but with uncovered humbuckers, sometimes they end up opening coils, especially at the bridge pickup. I even had one client that did this chronically. It wasn't his fault per se - I'd call it a design flaw, albeit a common one, and I encouraged him to try to get a new one under warranty (he uses DiMarzios), but he didn't feel it was worth his effort.

I think of Martin that will pay for a neck reset on a 50 year old D-28 as long as an original sales receipt can be provided. It is their fault because they were very late to the whole truss rod thing, and they valiantly pay their field techs decent money to do this all the time.

[Magnut]

I feel like I have a fairly liberal policy. I have a 60 day period to return or swap, and a lifetime guarantee on workmanship.

I think it's pretty easy to see when a pickup has been abused and it would be rare for one to fail. I hope to see the one that fails if it helps to create a more robust better functioning pickup. The ratio for failure against successes should be so low that it makes it very practical to have such a policy. I created this policy for many reasons, it turns out the best side effect is it makes me be very careful to good work. Problem solved and everyone happy!

[SonnyW]

Here's how the wire can short to the magnets. There is tremendous compression on the bobbin due to winding tension. If you have 30 grams of winding tension, which isn't unusual at all and 5000 turns of wire, you generate 30 grams x 10,000 compression force along the axis of the bobbin. That comes out to 300KG or 660 pounds. If you have 7500 turns in a strat bobbin it is 1.5 x that or 990 pounds. I studied this when trying to figure out why I was warping butyrate humbucker bobbins sometimes when potting. I measured the tension on my CNC winding machine with a tension gauge. 30 grams isn't much. It is easy to get more than that when handwinding. There is around half a ton of pressure pushing the closest wires into the magnet in a typical strat pickup. So if the insulation on the wire is at all subject to plastic creep, the closest wires can short. The copper just swims through the plastic over time. I lacquer dip and then tape my single coils to ward off this shorting. Sweat doesn't help it roughens the magnets. And heat doesn't help at all. I have warped butyrate humbucker bobbins by potting at 150 degrees for 20 minutes. I am of the opinion that not taping, too long of potting at too high of a temperature, or handwinding too tight can lead to magnet shorting and is a workmanship issue. On the other hand, if a customer drops a pickup or tries to push a magnet down that is just asking for a failure. So to me it it shorts at the magnets it is either a workmanship issue, or they tried to push the magnet down. I see more failures at the eyelets or opens of the outer layers of the coils due to rough handling though. - just my .02 worth

[-Elepro-]

There is around half a ton of pressure.....

.... you say i can use a pickup bobbin as a jack stand for my car ....

i'm not sure and i thought many times when i read this values...but i think it is not the correct method for measure pressure. Maybe we have to multiply tension by layers (and not by turns)

[ken]

I warranty mine for life to the original purchaser for materials and workmanship. If the buyer does something goofy like slicing up the coil with a razor blade or rolling the pickup in iron filings, however, rewinds are $34.95 each. I actually can't remember the last time one of my pickups ever came back dead, but usually I just send the customer a brand new one to replace it because that way I can do an autopsy on the bad pickup.

ken

[SonnyW]

.... you say i can use a pickup bobbin as a jack stand for my car ....

i'm not sure and i thought many times when i read this values...but i think it is not the correct method for measure pressure. Maybe we have to multiply tension by layers (and not by turns)

I just calculated it in the same way as if it were a block and tackle system, which it resembles accurately if all friction is neglected. I am sure friction is an important factor, but I'm not sure how to take it into account. I didn't put too much thought into it. I wasn't trying to get too accurate of a number, just convey the idea that there is a lot of pressure. Maybe we have some mechanical or physics type folks on here that can elaborate better on the theory of this than I can. I would be happy to stnd corrected if someone has done more work on it. -sw

[David Schwab]

I just calculated it in the same way as if it were a block and tackle system, which it resembles accurately if all friction is neglected. I am sure friction is an important factor, but I'm not sure how to take it into account. I didn't put too much thought into it. I wasn't trying to get too accurate of a number, just convey the idea that there is a lot of pressure. Maybe we have some mechanical or physics type folks on here that can elaborate better on the theory of this than I can. I would be happy to stnd corrected if someone has done more work on it. -sw

I would think that the tension is distributed amongst the windings and not cumulative.

[Joe Gwinn]

I would think that the tension is distributed amongst the windings and not cumulative.

As wound, the tension is constant, set by the winder. Then things relax.

[David Schwab]

As wound, the tension is constant, set by the winder. Then things relax.

Right. I meant each turn doesn't make the tension on the bobbin higher since you aren't pulling the early wraps tighter.

[Mark Hammer]

Looking through all the responses, I would think that the length of warranty period would vary according to:

a) what sorts of "protections" you have built into the pickup itself to prevent known sources of malfunction from occurring
b) how much you charge

If the selling price warrants it, go lifetime. If the product is not designed to be immune to all known sources of normal abuse, and you haven't factored repair into the selling price, then you'll want to make the period much shorter and identify potential repair costs for tyical sorts of issues up front.