Lucas K2F magneto coil rewind

[N_Cook]

A pensioner has asked me about possiblity of rewinding some of these magneto
coils.
http://home.graffiti.net/diverse:graffiti.net/K2F.jpg
laying on cm/mm graph paper.
Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, not a
trick of the light.
A is aluminium housing for the contact breaker
First comment is he has 5 of these , all not working at all or properly, so
probably not good design anyway, as none were abused in use.
He has one good magneto , he moves around 3 bikes. He can get some or all
nonworkers commercially reconditioned , at a price each. But of course he
would like all 5 rewound and he knows, like me , that having researched and
set-up for one then the following 4 rewinds are much easier. I use a
coil-winder machine but little experience of these sorts of coils.
No electrical data found on the net for these.
As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
He has some sort of technical data for these , when he can find it, but
first thing is how to (after desolding) slide the laquered-in coil out of
the central section between the 2 steel pole pieces marked S, and because of
the boss marked P that holds the HT wire lead out, coil would have to be
removed from the other open section, underneath in pic. Anyone know the
number of turns, wire gauge to save having to count off ? and details of
interlayer insulation (if any). How is the HT coil output removed from the
boss P or whereabouts is the join to a feedthrough under the output laquer?

 

[Dr Ivan D. Reid]

A pensioner has asked me about possiblity of rewinding some of these magneto
coils.
http://home.graffiti.net/diverse:graffiti.net/K2F.jpg
laying on cm/mm graph paper.

You don't say what make it is, nor which bike(s) it fits.

Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, not a
trick of the light.
A is aluminium housing for the contact breaker
First comment is he has 5 of these , all not working at all or properly, so
probably not good design anyway, as none were abused in use.
He has one good magneto , he moves around 3 bikes. He can get some or all
nonworkers commercially reconditioned , at a price each. But of course he
would like all 5 rewound and he knows, like me , that having researched and
set-up for one then the following 4 rewinds are much easier. I use a
coil-winder machine but little experience of these sorts of coils.
No electrical data found on the net for these.

A quick educated guess, and I found a very similar device here:
http://www.srm-engineering.com/electrical1 -- Lucas K2F. The company
claims to have a complete reconditioning service.

As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
He has some sort of technical data for these , when he can find it, but
first thing is how to (after desolding) slide the laquered-in coil out of
the central section between the 2 steel pole pieces marked S, and because of
the boss marked P that holds the HT wire lead out, coil would have to be
removed from the other open section, underneath in pic. Anyone know the
number of turns, wire gauge to save having to count off ? and details of
interlayer insulation (if any). How is the HT coil output removed from the
boss P or whereabouts is the join to a feedthrough under the output laquer?

There's an exploded view here:
http://members.aol.com/Pinman1/blowup.htm
http://members.aol.com/pinman1/magnetos.htm -- sounds like disassembling
the armature is best left to someone experienced.

Workshop manual here:
http://www.bolsover.com/lucas/sectionL5partA.pdf

One particular item was: primary 20 g 4x45T; secondary 40 g ~30x250T
by the looks of it:
http://www.britbike.com/ubb/noncgi/ultimatebb.php?/ubb/get_topic/f/11/t/002638/p/1.html

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

[Dr Ivan D. Reid]

A pensioner has asked me about possiblity of rewinding some of these magneto
coils.
http://home.graffiti.net/diverse:graffiti.net/K2F.jpg
laying on cm/mm graph paper.

[Idiot; Read the Subject line]

Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, not a
trick of the light.
A is aluminium housing for the contact breaker
First comment is he has 5 of these , all not working at all or properly, so
probably not good design anyway, as none were abused in use.
He has one good magneto , he moves around 3 bikes. He can get some or all
nonworkers commercially reconditioned , at a price each. But of course he
would like all 5 rewound and he knows, like me , that having researched and
set-up for one then the following 4 rewinds are much easier. I use a
coil-winder machine but little experience of these sorts of coils.
No electrical data found on the net for these.

http://www.srm-engineering.com/electrical1. The company claims to have a
complete reconditioning service.

As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
He has some sort of technical data for these , when he can find it, but
first thing is how to (after desolding) slide the laquered-in coil out of
the central section between the 2 steel pole pieces marked S, and because of
the boss marked P that holds the HT wire lead out, coil would have to be
removed from the other open section, underneath in pic. Anyone know the
number of turns, wire gauge to save having to count off ? and details of
interlayer insulation (if any). How is the HT coil output removed from the
boss P or whereabouts is the join to a feedthrough under the output laquer?

There's an exploded view here:
http://members.aol.com/Pinman1/blowup.htm
http://members.aol.com/pinman1/magnetos.htm -- sounds like disassembling
the armature is best left to someone experienced.

Workshop manual here:
http://www.bolsover.com/lucas/sectionL5partA.pdf

One particular item was: primary 20 g 4x45T; secondary 40 g ~30x250T
by the looks of it:
http://www.britbike.com/ubb/noncgi/ultimatebb.php?/ubb/get_topic/f/11/t/002638/p/1.html

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

[N_Cook]

A pensioner has asked me about possiblity of rewinding some of these magneto
coils.
http://home.graffiti.net/diverse:graffiti.net/K2F.jpg
laying on cm/mm graph paper.

You don't say what make it is, nor which bike(s) it fits.

Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, not a
trick of the light.
A is aluminium housing for the contact breaker
First comment is he has 5 of these , all not working at all or properly, so
probably not good design anyway, as none were abused in use.
He has one good magneto , he moves around 3 bikes. He can get some or all
nonworkers commercially reconditioned , at a price each. But of course he
would like all 5 rewound and he knows, like me , that having researched and
set-up for one then the following 4 rewinds are much easier. I use a
coil-winder machine but little experience of these sorts of coils.
No electrical data found on the net for these.

A quick educated guess, and I found a very similar device here:
http://www.srm-engineering.com/electrical1 -- Lucas K2F. The company
claims to have a complete reconditioning service.

As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
He has some sort of technical data for these , when he can find it, but
first thing is how to (after desolding) slide the laquered-in coil out of
the central section between the 2 steel pole pieces marked S, and because of
the boss marked P that holds the HT wire lead out, coil would have to be
removed from the other open section, underneath in pic. Anyone know the
number of turns, wire gauge to save having to count off ? and details of
interlayer insulation (if any). How is the HT coil output removed from the
boss P or whereabouts is the join to a feedthrough under the output

laquer?

There's an exploded view here:
http://members.aol.com/Pinman1/blowup.htm
http://members.aol.com/pinman1/magnetos.htm -- sounds like disassembling
the armature is best left to someone experienced.

Workshop manual here:
http://www.bolsover.com/lucas/sectionL5partA.pdf

One particular item was: primary 20 g 4x45T; secondary 40 g ~30x250T
by the looks of it:
http://www.britbike.com/ubb/noncgi/ultimatebb.php?/ubb/get_topic/f/11/t/0026
38/p/1.html

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

Ta for that, i'd not found that pdf
I suspect the owner has a paper version of that pdf

Perhaps 40 awg in that thread , I would expect from previously winding
outboard engine magnetos that it was more like 45 swg gauge.
Every time I touch this armature the secondary ohms varies, 45K and 27K on
the last 2 occasions, so at least cannot make matters worse.
I wonder if you have to remove the pulley-like paxolin drum numbered 27 on
that pinman pic, before releasing the internal HT leadout, to then remove
the coil.
I can now see how to remove the coil assembly but not how that leadout is
connected into the paxolin drum. I can see me using glass tape being used
instead of cloth for outer protection, for anti-hygroscopic reasons.

 

[N_Cook]

This is the kind of question you could well ask in the newsgroup
uk.rec.sheds. There are a lot of old motorbikey/engineery type folks
hang out in the shed.

Ron

u.r.s added

From the Lucas pdf , under fig 6
http://www.bolsover.com/lucas/sectionL5partA.pdf
"Fit the new slip ring moulding on the shaft, taking care that the wire
enters the hole in the slip ring boss , and that it goes fully home without
bending. Seal the wire into the bosss with varnish"

Sounds a bit odd and don't know what it means yet, pushfit and varnish?.

The contact breaker housing comes off by slackening the central holding bolt
a bit and lightly tapping the bolt head to release a keyed bushing.

It looks as though a roll pin passes through both steel cheeks and through
the coil bobbin to hold the coil in place. I've not managed to shift that
with my usual use of bits of pop-rivet steel pin, so far. One hole is
slightly larger than the other and I'm assuming its a matter of knocking the
pin through the small hole of about 2.2mm diameter to release through the
larger 2.5mm hole.

 

[N_Cook]

This is the kind of question you could well ask in the newsgroup
uk.rec.sheds. There are a lot of old motorbikey/engineery type folks
hang out in the shed.

Ron

u.r.s added

From the Lucas pdf , under fig 6
http://www.bolsover.com/lucas/sectionL5partA.pdf
"Fit the new slip ring moulding on the shaft, taking care that the wire
enters the hole in the slip ring boss , and that it goes fully home without
bending. Seal the wire into the bosss with varnish"

Sounds a bit odd and don't know what it means yet, pushfit and varnish?.

The contact breaker housing comes off by slackening the central holding bolt
a bit and lightly tapping the bolt head to release a keyed bushing.

It looks as though a roll pin passes through both steel cheeks and through
the coil bobbin to hold the coil in place. I've not managed to shift that
with my usual use of bits of pop-rivet steel pin, so far. One hole is
slightly larger than the other and I'm assuming its a matter of knocking the
pin through the small hole of about 2.2mm diameter to release through the
larger 2.5mm hole.

 

[N_Cook]

This is the kind of question you could well ask in the newsgroup
uk.rec.sheds. There are a lot of old motorbikey/engineery type folks
hang out in the shed.

Ron

u.r.s added

From the Lucas pdf , under fig 6
http://www.bolsover.com/lucas/sectionL5partA.pdf
"Fit the new slip ring moulding on the shaft, taking care that the wire
enters the hole in the slip ring boss , and that it goes fully home without
bending. Seal the wire into the bosss with varnish"

Sounds a bit odd and don't know what it means yet, pushfit and varnish?.

The contact breaker housing comes off by slackening the central holding bolt
a bit and lightly tapping the bolt head to release a keyed bushing.

It looks as though a roll pin passes through both steel cheeks and through
the coil bobbin to hold the coil in place. I've not managed to shift that
with my usual use of bits of pop-rivet steel pin, so far. One hole is
slightly larger than the other and I'm assuming its a matter of knocking the
pin through the small hole of about 2.2mm diameter to release through the
larger 2.5mm hole.

 

[N_Cook]

This is the kind of question you could well ask in the newsgroup
uk.rec.sheds. There are a lot of old motorbikey/engineery type folks
hang out in the shed.

Ron

u.r.s added

From the Lucas pdf , under fig 6
http://www.bolsover.com/lucas/sectionL5partA.pdf
"Fit the new slip ring moulding on the shaft, taking care that the wire
enters the hole in the slip ring boss , and that it goes fully home without
bending. Seal the wire into the bosss with varnish"

Sounds a bit odd and don't know what it means yet, pushfit and varnish?.

The contact breaker housing comes off by slackening the central holding bolt
a bit and lightly tapping the bolt head to release a keyed bushing.

It looks as though a roll pin passes through both steel cheeks and through
the coil bobbin to hold the coil in place. I've not managed to shift that
with my usual use of bits of pop-rivet steel pin, so far. One hole is
slightly larger than the other and I'm assuming its a matter of knocking the
pin through the small hole of about 2.2mm diameter to release through the
larger 2.5mm hole.

 

[bobharvey]

knocking the
pin through the small hole of about 2.2mm diameter to release through the
larger 2.5mm hole.

<Sucks teeth>
"There's yer problem right away, guv. You should be measuring yer
hole in 64ths of an inch for a Lucas"
</sucks teeth>

 

[®óñ© © ²°¹°-°²]

From the Lucas pdf , under fig 6
http://www.bolsover.com/lucas/sectionL5partA.pdf

"Fit the new slip ring moulding on the shaft"

Oo-er Missis.

 

[hr(bob) [email protected]]

A pensioner has asked me about possiblity of rewinding some of these magneto
coils.http://home.graffiti.net/diverse:graffiti.net/K2F.jpg
laying on cm/mm graph paper.
Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, nota
trick of the light.
A is aluminium housing for the contact breaker
First comment is he has 5 of these , all not working at all or properly, so
probably not good design anyway, as none were abused in use.
He has one good magneto , he moves around 3 bikes. He can get some or all
nonworkers commercially  reconditioned , at a price each. But of course he
would like all 5 rewound and he knows, like me , that having researched and
set-up for one then the following 4 rewinds are much easier. I use a
coil-winder machine but little experience of these sorts of coils.
No electrical data found on the net for these.
As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
He has some sort of technical data for these , when he can find it, but
first thing is how to (after desolding) slide the laquered-in coil out of
the central section between the 2 steel pole pieces marked S, and because of
the boss marked P that holds the HT wire lead out, coil would have to be
removed from the other open section, underneath in pic. Anyone know the
number of turns, wire gauge to save having to count off ? and details of
interlayer insulation (if any). How is the HT coil output removed from the
boss P or whereabouts is the join to a feedthrough under the output laquer?

I hope you are either doing this as a HUGE favor for the pensioner, or
he/she is rich enough to pay you adequately for your time. No matter
how you get it apart, it will be a large royal pain to rewind with
that fine/small size wire and then reconnect the wire to the slip
rings. Any idea why so many of these hae failed, it might tell you
what not to do when rewinding.

 

[N_Cook]

A pensioner has asked me about possiblity of rewinding some of these magneto
coils.http://home.graffiti.net/diverse:graffiti.net/K2F.jpg
laying on cm/mm graph paper.
Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, not a
trick of the light.
A is aluminium housing for the contact breaker
First comment is he has 5 of these , all not working at all or properly, so
probably not good design anyway, as none were abused in use.
He has one good magneto , he moves around 3 bikes. He can get some or all
nonworkers commercially reconditioned , at a price each. But of course he
would like all 5 rewound and he knows, like me , that having researched and
set-up for one then the following 4 rewinds are much easier. I use a
coil-winder machine but little experience of these sorts of coils.
No electrical data found on the net for these.
As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
He has some sort of technical data for these , when he can find it, but
first thing is how to (after desolding) slide the laquered-in coil out of
the central section between the 2 steel pole pieces marked S, and because of
the boss marked P that holds the HT wire lead out, coil would have to be
removed from the other open section, underneath in pic. Anyone know the
number of turns, wire gauge to save having to count off ? and details of
interlayer insulation (if any). How is the HT coil output removed from the
boss P or whereabouts is the join to a feedthrough under the output laquer?

onhttp://home.graffiti.net/diverse:graffiti.net/

I hope you are either doing this as a HUGE favor for the pensioner, or
he/she is rich enough to pay you adequately for your time. No matter
how you get it apart, it will be a large royal pain to rewind with
that fine/small size wire and then reconnect the wire to the slip
rings. Any idea why so many of these hae failed, it might tell you
what not to do when rewinding.

I was quite happy putting on about 14,000 turns of 45 swg wire onto boat
outboard motor magneto coils, once the traverse rate, reducing
endstop/reversal points etc was set up for my 1920s coilwinder , rusted and
totally seized but now
rescued back into working order after decades in someone's damp and leaking
shed

 

[The Older Gentleman]

I was quite happy putting on about 14,000 turns of 45 swg wire onto boat
outboard motor magneto coils, once the traverse rate, reducing
endstop/reversal points etc was set up for my 1920s coilwinder , rusted and
totally seized but now
rescued back into working order after decades in someone's damp and leaking
shed

Ah! Are you available for alternator rewinds?

 

[N_Cook]

OK this magneto has been in an English shed for years, but "isolating"
secondary and putting a Megger between HT coil and frame shows 5M ohm to
start with
, drifting up to 100M , no good with intended KV around.

The capacitor, sorry, condenser measures 0.36uF which is presumably about
right value, anyone know what value and type of capacitor to replace it with
?

Still not managed to free the bobbin retainer roll pin yet though

 

[SpamTrapSeeSig]

OK this magneto has been in an English shed for years, but "isolating"
secondary and putting a Megger between HT coil and frame shows 5M ohm to
start with
, drifting up to 100M , no good with intended KV around.

You didn't say: I assume from the pics that the wire is merely
varnished, but is it cotton or silk covered too? if so, it may well be
breakdown through damp.

Put it in the oven at around 50deg C for a few hours (days?) and try
again.


Regards,

Simonm.

 

[N_Cook]

Not rollpin , a matter of removing the ballrace and underlying steel rings
and spacer from the brass section marked BR on
http://home.graffiti.net/diverse:graffiti.net/K2F_b.jpg
requiring making up an extractor as standard pullers have no ledge to
purchase on.
The 2 long screws go the length of the steel pieces like an electric drill
housing. Marked the orientation before removing the end cap. Yes the HT wire
marked W just pushes into the boss of the paxolin pulley shown in the third
pic. An excellent site for damp ingress , via capillary action, into the
body of the coil (my excavations exploring how deep the cloth covering was).
Green corrosion on the HT wire is more obvious in the original high
resolution pic, evidencing dampness at the end of the HT sleeving.
http://home.graffiti.net/diverse:graffiti.net/K2F_c.jpg
the capacitor is the square lump covered in greasy mess in the end cap
http://home.graffiti.net/diverse:graffiti.net/K2F_d.jpg
the paxolin pulley-like section that goes on the brass axis at W position.

 

[N_Cook]

Before excavating further decided to take a pic of the now obvious ingress
of damp down the HT wire. Lovely green copper carbonate staining.
http://home.graffiti.net/diverse:graffiti.net/K2F_e.jpghttp://home.graffiti.
net/diverse:graffiti.net/K2F_c.jpg
and the other cap interior where the contact breaker connection is from the
centre fixing , insulated under and around , by what looks like a black RF
coil former
http://home.graffiti.net/diverse:graffiti.net/K2F_f.jpg