PSN-L Email List Message

Subject: Re: A Sticky Question
From: meredith lamb paleoartifact@.........
Date: Wed, 21 Jul 2010 16:00:50 -0600


Hi Jerry,

Actually I've no real recommendations as too material.  As too the
implications of the thickness I'd be more
prone to use as thick a material (i.e., 1/16" or better) as possible just
for pure mechanical long term holding properties.
Once winding begins then the expansion forces naturally begin to try to
"break" the glued material bonds; and
such may well be seen long term.  Realistically; it's like wrapping wire
around your finger, the mounting pressure
begins to hurt with more and more wire wraps.  Coil frame deformation is too
be expected.  Epoxy glass PCB
is pretty tough stuff as is; but the glued joints will be the weakest member
irregardless.

I'm sure I'll hear text "screaming" if I recommended something like 1/8"
thick PCB board; but, it would sure
be much more solid long term than anything else.  Yes; the thickness is
rather ancient electronically, but
it might be found surplus I suppose....or simply glue two 1/16" thick plates
together.  Yes; I suppose it would
likely upset some of the coil dimensions or, of course, the obvious lesser
magnetic field intensity with its use.

Chris's original square coil design is a difficult project for sure.
Sometimes I wonder if a (~pure) copper plate couldn't
achieve the same "coil frame", and with silver solder to the joints (and
cleanup filing), might even be sufficiently strong
and yet also give somewhat of a eddy current motion dampening.  Hopefully in
time; perhaps Chris be feeling better
enough to tell me, us, that; that approach is ~ so and so..........  :>)

Take care, Meredith

On Wed, Jul 21, 2010 at 2:33 PM, GPayton  wrote:

>  Thank you SOOOO much, Meredith!  This input is exactly what I was looking
> for.  Some of my replies got off on the wire and winding, which is still
> good information, but not exactly what I was seeking.
>
> Do you have a preference or recommendations of material to make the coil
> bobbin?  As I mentioned, Chris had suggested the Epoxy Glass PCB material,
> but I had problems trying to construct the spool with such small dimensions
> and the adhesive too.
>
> Thanks again,
> Jerry
>  ------------------------------
>
> ----- Original Message -----
> *From:* meredith lamb 
> *To:* psn-l@..............
> *Sent:* Wednesday, July 21, 2010 3:18 PM
> *Subject:* Re: A Sticky Question
>
> Jerry,
>
> Yes, glue is a real problem over a variety of materials that need to be
> glued.
>
> As far as commercially available brands (USA), there is one plastic glue
> I've come to favor; and that is
> Devcon brand, Plastic Welder.  Its a two part mixing glue that is meant for
> a variety of materials
> like hard plastic, vinyl, pvc piping, fiberglass (and metals and
> concrete).  Net volume 25ml.  Available
> in Ace Hardware stores and likely a variety of other sources; for roughly
> $6.  Its a plunger outlet nozzle.
> A little can go a long ways with your use.  One problem with re-use is
> clearing out the plunger tips
> with a nail (etc.) to allow free flow.  It's flammable, stinky stuff, and
> best to ventilate or use outdoors.
> It makes no mention of being waterproof; but I've used such in a
> magnet/metal holding fixture in a
> bathroom for ~ 3 years; and has seen no failure yet.  This does not bond to
> polyethylene or polypropylene
> plastics.
>
> I've used it on cloth to metal, metal to rubber and once even (clean)
> carbon plate to carbon plate with amazing
> (no failure yet, over ~ 2 years).  Some of these parts come into physical
> force contact and separation;
> but thus far its has been holding well.
>
> Once mixed it begins to harden very fast.  Although tricky to do, removing
> unwanted excess might call
> for another person (or holder) to hold the glued object, and wiping the
> unwanted excess off with a damp cloth.
> I usually let it dry for a full day; but it could be shorter duration.
>
> How well, long term it actually holds is probably dependent somewhat on
> having clean surfaces to begin
> with.  The actual holding force is unknown...I'am not sure at all as to the
> forces exposed to with coil
> winding forms.  One might conceivably try out bonding scrap pieces, letting
> dry, and physically trying
> to separate, bend, torque them; before application into your final project.
>
> Another glue is the same brand; Devcon 2 part "5 minute epoxy", but its
> relegated only to metal & wood,
> concrete, glass & china and ceramics.  Probably good for ~ frame parts
> holding.
>
> Take care, Meredith
> ------------------------------
>
> On Mon, Jul 19, 2010 at 7:42 AM, GPayton  wrote:
>
>>  In years past, I had difficulties in finding a "manual" coil winder and
>> ended up with an old fashioned had drill.  (As you know, you have to search
>> using the correct words or your mouth pursed just right to be successful.)
>>
>> Anyway, that hand drill is what I ended up with.  The EBay choices shown
>> by Barry are interesting.  Thanks, Barry.
>>
>> Never-the-less, in past, I had more trouble finding proper shaped
>> ready-made spools or bobbins to wind a coil.  And, if I tried to construct a
>> rectangular shaped form, I had trouble getting the sandwiched parts to stick
>> together!  I suppose that I did not have the correct adhesive.  I tried
>> several without satisfaction.
>>
>> If anyone knows the secret to building a rectangular form, materials &
>> glue, I'd appreciate knowing it.
>>
>> Regards,
>> Jerry
>>
>>
>>
>
>
Hi Jerry,

Actually I've no real recommendations as too material.= =A0 As too the implications of the thickness I'd be more
prone to us= e as thick a material (i.e., 1/16" or better) as possible just for pur= e mechanical long term holding properties.
Once winding begins then the expansion forces naturally begin to try to &qu= ot;break" the glued material bonds; and
such may well be seen long = term.=A0 Realistically; it's like wrapping wire around your finger, the= mounting pressure
begins to hurt with more and more wire wraps.=A0 Coil frame deformation is = too be expected.=A0 Epoxy glass PCB
is pretty tough stuff as is; but the= glued joints will be the weakest member irregardless.

I'm sure = I'll hear text "screaming" if I recommended something like 1/= 8" thick PCB board; but, it would sure
be much more solid long term than anything else.=A0 Yes; the thickness is r= ather ancient electronically, but
it might be found surplus I suppose...= ..or simply glue two 1/16" thick plates together.=A0 Yes; I suppose it = would
likely upset some of the coil dimensions or, of course, the obvious lesser = magnetic field intensity with its use.

Chris's original square c= oil design is a difficult project for sure.=A0 Sometimes I wonder if a (~pu= re) copper plate couldn't
achieve the same "coil frame", and with silver solder to the join= ts (and cleanup filing), might even be sufficiently strong
and yet also = give somewhat of a eddy current motion dampening.=A0 Hopefully in time; per= haps Chris be feeling better
enough to tell me, us, that; that approach is ~ so and so..........=A0 :>= ;)

Take care, Meredith=A0

On Wed, Jul 21, 2010 at 2:33 PM, G= Payton <gpayt= on@.............> wrote:
Thank you SOOOO much, Meredith!=A0 This input is exactly what I was=20 looking for.=A0 Some of my replies got off on the wire and winding, which i= s=20 still good information, but not exactly what I was seeking.
=A0
Do you have a preference or recommendations of material to make the co= il=20 bobbin?=A0 As I mentioned, Chris had suggested the Epoxy Glass PCB material= ,=20 but I had problems trying to construct the spool with such small dimensions= and=20 the adhesive too.
=A0
Thanks again,
Jerry

----- Original Message -----
From:=20 meredith lamb
Sent: Wed= nesday, July 21, 2010 3:18=20 PM
Subject: Re: A Sticky Question

Jerry,

Yes,= glue is a real problem over a variety of=20 materials that need to be glued.

As far as commercially available= =20 brands (USA), there is one plastic glue I've come to favor; and that= =20 is
Devcon brand, Plastic Welder.=A0 Its a two part mixing glue that is= =20 meant for a variety of materials
like hard plastic, vinyl, pvc piping,= =20 fiberglass (and metals and concrete).=A0 Net volume 25ml.=A0=20 Available
in Ace Hardware stores and likely a variety of other sources= ; for=20 roughly $6.=A0 Its a plunger outlet nozzle.
A little can go a long way= s=20 with your use.=A0 One problem with re-use is clearing out the plunger=20 tips
with a nail (etc.) to allow free flow.=A0 It's flammable, sti= nky=20 stuff, and best to ventilate or use outdoors.
It makes no mention of b= eing=20 waterproof; but I've used such in a magnet/metal holding fixture in= =20 a
bathroom for ~ 3 years; and has seen no failure yet.=A0 This does no= t=20 bond to polyethylene or polypropylene
plastics.

I've used i= t on=20 cloth to metal, metal to rubber and once even (clean) carbon plate to car= bon=20 plate with amazing
(no failure yet, over ~ 2 years).=A0 Some of these= =20 parts come into physical force contact and separation;
but thus far it= s has=20 been holding well.

Once mixed it begins to harden very fast.=A0=20 Although tricky to do, removing unwanted excess might call
for another= =20 person (or holder) to hold the glued object, and wiping the unwanted exce= ss=20 off with a damp cloth.
I usually let it dry for a full day; but it cou= ld be=20 shorter duration.

How well, long term it actually holds is probabl= y=20 dependent somewhat on having clean surfaces to begin
with.=A0 The actu= al=20 holding force is unknown...I'am not sure at all as to the forces expo= sed to=20 with coil
winding forms.=A0 One might conceivably try out bonding scra= p=20 pieces, letting dry, and physically trying
to separate, bend, torque t= hem;=20 before application into your final project.

Another glue is the sa= me=20 brand; Devcon 2 part "5 minute epoxy", but its relegated only t= o metal &=20 wood,
concrete, glass & china and ceramics.=A0 Probably good for ~= =20 frame parts holding.

Take care, Meredith


On Mon, Jul 19, 2010 at 7:42 AM, GPayton <gpayton@.............>=20 wrote:
In=A0years past, I had difficulties in finding a "manual"= ; coil=20 winder and ended up with an old fashioned had drill.=A0 (As you know, y= ou=20 have to search using the correct words or your mouth pursed just=20 right=A0to be successful.)
=A0
Anyway, that hand drill is what I ended up with.=A0 The EBay choic= es=20 shown by Barry are interesting.=A0 Thanks, Barry.
=A0
Never-the-less, in past, I had more trouble finding proper shaped= =20 ready-made spools or bobbins to wind a coil.=A0 And, if I tried to=20 construct a rectangular shaped form, I had trouble getting the sandwich= ed=20 parts to stick together!=A0 I suppose that I did not have the correct= =20 adhesive.=A0 I tried several without satisfaction.
=A0
If anyone knows the secret to building a rectangular form, materia= ls=20 & glue, I'd appreciate knowing it.
=A0
Regards,
Jerry
=A0
=A0



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