Guitar
I had a visit from Paul Crowther the other day (always a pleasure to see him). He's rather a legend for amongst other things his 'Hotcake' overdrive pedals and the 'Prunes and Custard' (my favorite for theremin).
http://en.wikipedia.org/wiki/Emlyn_Crowther
He wanted to know if my coil winding machine was up and running - he had an interesting pickup for me to wind.
Its an old Hofner pickup which I guess is from the 50's. The guitar has 3 of them and this one has a break in the windings so needs to be re-wound.
This would normally be a straight forward job except for the design of this pickup.
This is the inside of it. The windings (around the outside) are not wrapped around a bobbin. They are just sitting in the pickup and have been wrapped in tape to protect them. In the middle you can see the magnets sitting in a hard putty. There are incidentally only 5 magnets.
So the problem Paul left me with was how to wrap about 5000 turns of extremely thin wire into a coil and therefore make a pickup.
After a long brainstorming session with Sheena we came up with a plan.
We figured that the wire had to be wound around a bobbin and then somehow the bobbin removed.
So I made this bobbin. The sides are plastic from a Strat pickguard (white) and the centre has been carved from candle wax.
The bobbin bolts together and is attached to another plastic plate which in turn fits to the winding machine.
The idea is to wind the pickup on this and then warm the completed coil up and melt the wax. The wax should seep into the coil thus potting it as well. Then the sides can be unbolted and voila a copy of the original coil.
Winding the coil wasn't any different from any other pickup - so now for the tricky bit.
I warm the coil ever so gently with a heat gun. I put my free hand next to the work to judge the temperature - if it gets too hot the plastic will melt and I'll be starting again.
When I see some wax oozing out I ever so gently remove the top plate.
With the wax exposed I can apply more heat and watch it flow into the coil and as it cools becomes solid.
Then I wrap tape around it to hold everything in place. I cannot emphasize enough how fiddly this is. There are a few stray wires and if any of them break I'm starting again.
It may not be much to look at but its taken hours. The slight curve is to match the shape of the pickup casing. I've tested it and I'm pleased with it at 5.5Kohms.
In the background you can see the magnetic lugs - I had to dig them out of the putty.
I put the whole thing back together using 'friendly plastic' instead of putty then fill the casing with wax, solder the back on and its finished.
Its been quite a task but I'm happy with the result.
Glyn
………………………………………………………………………………………….
Feel free to contact me about repair work (if you are in NZ). I only check emails weekly so the workshop phone is always the best 09 307 6501.
- Gibson Lg2 - 1955
This is a beautiful old Gibson guitar from 1955. There's no serial number on some of the less expensive older Gibsons. Instead it has a Factory Order Number. The first letter 'W' tells us the year. This number is not unique to the instrument...
- On Tour - Tales From The Back Line
There are a few different aspects to guitar repairing. All my work happens in my own controlled environment - the workshop. Touring Guitar Techs have to work wherever they find themselves - they need to be quick, have magician like fault finding skills,...
- New Zealand Music Month
. I'm going to do my best to get out and see more live music in May. There are so many of my customers I've never seen play live.Check out http://www.nzmusicmonth.co.nz/ for what's going on.Looks like I'm in for a busy month keeping...
- Reducing Hum - Screening
It is very common for electric guitars with single coil pickups to hum. Humbucking (double coil) pickups get their name from their ability to get rid of hum. A typical 'Strat' pickup will have over 7000 turns of wire on it. I've never worked...
- Even Further Progress
The two-layer neck guitar is progressing further. Now, it's a very nice, compact and well-sounding instrument. There are still improvements to be made, but now that it's playable, I hope to play more and modify less. The neck is very flat...
Guitar
Hofner Pickup re-wind
I had a visit from Paul Crowther the other day (always a pleasure to see him). He's rather a legend for amongst other things his 'Hotcake' overdrive pedals and the 'Prunes and Custard' (my favorite for theremin).
http://en.wikipedia.org/wiki/Emlyn_Crowther
He wanted to know if my coil winding machine was up and running - he had an interesting pickup for me to wind.
Its an old Hofner pickup which I guess is from the 50's. The guitar has 3 of them and this one has a break in the windings so needs to be re-wound.
This would normally be a straight forward job except for the design of this pickup.
This is the inside of it. The windings (around the outside) are not wrapped around a bobbin. They are just sitting in the pickup and have been wrapped in tape to protect them. In the middle you can see the magnets sitting in a hard putty. There are incidentally only 5 magnets.
So the problem Paul left me with was how to wrap about 5000 turns of extremely thin wire into a coil and therefore make a pickup.
After a long brainstorming session with Sheena we came up with a plan.
We figured that the wire had to be wound around a bobbin and then somehow the bobbin removed.
So I made this bobbin. The sides are plastic from a Strat pickguard (white) and the centre has been carved from candle wax.
The bobbin bolts together and is attached to another plastic plate which in turn fits to the winding machine.
The idea is to wind the pickup on this and then warm the completed coil up and melt the wax. The wax should seep into the coil thus potting it as well. Then the sides can be unbolted and voila a copy of the original coil.
Winding the coil wasn't any different from any other pickup - so now for the tricky bit.
I warm the coil ever so gently with a heat gun. I put my free hand next to the work to judge the temperature - if it gets too hot the plastic will melt and I'll be starting again.
When I see some wax oozing out I ever so gently remove the top plate.
With the wax exposed I can apply more heat and watch it flow into the coil and as it cools becomes solid.
Then I wrap tape around it to hold everything in place. I cannot emphasize enough how fiddly this is. There are a few stray wires and if any of them break I'm starting again.
It may not be much to look at but its taken hours. The slight curve is to match the shape of the pickup casing. I've tested it and I'm pleased with it at 5.5Kohms.
In the background you can see the magnetic lugs - I had to dig them out of the putty.
I put the whole thing back together using 'friendly plastic' instead of putty then fill the casing with wax, solder the back on and its finished.
Its been quite a task but I'm happy with the result.
Glyn
………………………………………………………………………………………….
Feel free to contact me about repair work (if you are in NZ). I only check emails weekly so the workshop phone is always the best 09 307 6501.
Workshop Hours
Mon……. 8-6
Tues……. 8-6
Wed…….. Closed
Thurs …..8-6
Fri ……….8-6
Sat/Sun ..Closed
Tues……. 8-6
Wed…….. Closed
Thurs …..8-6
Fri ……….8-6
Sat/Sun ..Closed
Mr Glyn’s Guitars
21a Khyber Pass Road
Auckland
New Zealand
http://www.mrglyn.co.nz/
www.facebook.com/MrGlynGuitars
www.mrglyn.blogspot.com
09 307 6501, 021 912678
- Gibson Lg2 - 1955
This is a beautiful old Gibson guitar from 1955. There's no serial number on some of the less expensive older Gibsons. Instead it has a Factory Order Number. The first letter 'W' tells us the year. This number is not unique to the instrument...
- On Tour - Tales From The Back Line
There are a few different aspects to guitar repairing. All my work happens in my own controlled environment - the workshop. Touring Guitar Techs have to work wherever they find themselves - they need to be quick, have magician like fault finding skills,...
- New Zealand Music Month
. I'm going to do my best to get out and see more live music in May. There are so many of my customers I've never seen play live.Check out http://www.nzmusicmonth.co.nz/ for what's going on.Looks like I'm in for a busy month keeping...
- Reducing Hum - Screening
It is very common for electric guitars with single coil pickups to hum. Humbucking (double coil) pickups get their name from their ability to get rid of hum. A typical 'Strat' pickup will have over 7000 turns of wire on it. I've never worked...
- Even Further Progress
The two-layer neck guitar is progressing further. Now, it's a very nice, compact and well-sounding instrument. There are still improvements to be made, but now that it's playable, I hope to play more and modify less. The neck is very flat...