Gibson "Ripper" repair

[Yves]

Hi,

I thought this might be of interest to some of you.

This was kind of tricky repair due to epoxy like encasing, but it ended up to be doable.

So, I took of few pictures FWIW:
Gibson Ripper rewind


Yves.

[David Schwab]

Nice work!

It's amazing how much the Ripper bobbins look like the Bi-Centential Thunderbird pickups, only wider. Classic Bill Lawrence design.

You're a glutton for punishment leaving the coil wires hanging out like that though! You should solder them to insulated hookup wires before you start winding. It's too easy to break them that way.

[Yves]

Nice work!

Thanks!

You're a glutton for punishment leaving the coil wires hanging out like that though! You should solder them to insulated hookup wires before you start winding. It's too easy to break them that way.

Well unless it's a HB bobbin with center hole - in which case I have the inner wire coming out through that hole - I like to have some length of spare winding wire to make a few turns onto the bobbin before soldering to the hookup wires.
This way, even the start end wire leave some place for repair work should this have to happen.
I never had some problems really doing things that way.
Note that the picture you reffer to is only a step of the process, then after I "double tape" the hookup wires, once soldered, on the bobbin: once the soldered ends with thin isolating tape (tape under and on the solder end), and then the whole bobbin with paper tape which makes the whole thing pretty much sturdy.

[David Schwab]

I drill a small hole in the bobbin. Then I wrap the start of the magnet wire on a hookup wire, and then solder it, and tape it to the inside of the bobbin with the wire coming through the hole. When I'm done winding, I connect the finish to a lead and then tape it down on the coil.

I used to do it your way and would end up breaking the start wire more times than I care to admit!

But what ever works for you is the best way to do it.

[RedHouse]

Are the magnet(s) placed on the outside edges. or inside th coil forms?

In this pic it looks like they are outboard of the coil forms, but then that could be wax or potting.



Is it built it like a P90 but with the coils around the magnets instead of the poles?

[Yves]

Are the magnet(s) placed on the outside edges. or inside th coil forms?

In this pic it looks like they are outboard of the coil forms, but then that could be wax or potting.

Yes the magnetS barS are placed on the outside edges, and potted with the black stuff you can see on both the magnets and bobbins (epoxy I believe, as hard as epoxy in any case)

Is it built it like a P90 but with the coils around the magnets instead of the poles?

Well yes , so no ;-) :yes the pole pieces are going through a metal plate with two magets at each ends. But "similarity" stops here: the plate is much wider than a spacer in a P90, and travel through TWO bobbins.
If you look at the other pictures in the FB link on my first post, you may have a better understanding (magnets don't appear on the pictures of the empty / rewound bobbins)

[RedHouse]

On the P90 question, I meant to ask if the magnets were arranged like on a P90, with like poles forced together (S+S or N+N)

[Yves]

On the P90 question, I meant to ask if the magnets were arranged like on a P90, with like poles forced together (S+S or N+N)

Yes, I think I got it that's what I meant by similarity with magnets and plate and yes they are opposite, similar to this design actually:
Patent US3916751 - ELECTRICAL PICKUP FOR A STRINGED - Google Patents

[David Schwab]

On the P90 question, I meant to ask if the magnets were arranged like on a P90, with like poles forced together (S+S or N+N)

Yes, both poles face each other. This is what is known as a sidewinder.

[RedHouse]

You guys are crack'in me up, "they're opposite" and "they face each other".

[David Schwab]

You guys are crack'in me up, "they're opposite" and "they face each other".

They are not opposite. Same poles face in. You can see it in the patent drawing.

[Yves]

They are not opposite. Same poles face in. You can see it in the patent drawing.

Yes sorry for that, that's language messing, I meant "opposing" as seen in the patent (I guess at least it translates corectly that way to mean pole against same pole)

[RedHouse]

Ah, ok I got it, thanks gent's

[big_teee]

Does anyone know what the gauss would be at the top of the pole screws?
with the magnets at the end of the bobbins, you have to charge the bobbin bar and the small screws.
Would the gauss at the end of the screw be more than 200, or less?
Thanks,
T

[David Schwab]

Does anyone know what the gauss would be at the top of the pole screws?
with the magnets at the end of the bobbins, you have to charge the bobbin bar and the small screws.
Would the gauss at the end of the screw be more than 200, or less?
Thanks,
T

That depends on how strong the magnets are. But you don't lose much. It's a lot like a P-90.

[David Schwab]

Does anyone know what the gauss would be at the top of the pole screws?
with the magnets at the end of the bobbins, you have to charge the bobbin bar and the small screws.
Would the gauss at the end of the screw be more than 200, or less?

I found my notes. 600-700G.

[big_teee]

I found my notes. 600-700G.

That is at the top of the steel adjustment screws, not at the magnets, right?

[David Schwab]

That is at the top of the steel adjustment screws, not at the magnets, right?

Yes, at the pole screws.

[RedHouse]

I found my notes. 600-700G.

Is that 600-700G on your pickup or a Gibson?

[David Schwab]

Is that 600-700G on your pickup or a Gibson?

Ripper pickup.