Re: brass fasteners

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Mddeming@xxxxxxx 

Hi Justin,

    If you want two consistent opinions on this subject ask only one 
person, but ask them twice. ;-))
It is usually a good idea to minimize the amount of metal hardware in 
the TC itself. You can probably get away with some metal fasteners 
some of the time, but if you don't have to - well it's like a 
pack-a-day smoker/biker who rides without a helmet and has 
"unprotected interpersonal congress". You're betting against the 
odds. Also remember that at 10 kV+ wood can be conductive,. even 
varnished wood, if the coating is pierced by hardware.
    I have found that the plastic bolts and nuts used for cheap 
toilet seat hardware works well and is available most places  w/o 
paying shipping.

Matt D.

"If two engineers agree, fire one of them 'cause the other one is 
doing the thinking for both."
                                Old Bell Telephone Labs Motto ca. 1940



In a message dated 11/16/05 1:13:47 P.M. Eastern Standard Time, 
tesla@xxxxxxxxxx writes:
Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Even with non-ferrous metals there can be eddy currents.  Basically
you set up an air core transformer between your driven inductor and
any little bit of metal around.  If the magnetic flux cuts through the
metal piece, then it will generate a current though the virtual
shorted turn that a lump of metal would appear to be... But, for bolts
and small hardware its not usually a problem.  Having said that, on my
DRSSTCs i use steel bolts to connect my secondary to the base, and it
gets HOT, mostly due to the 1" diameter washer as well.  Im not sure
how much heating is from eddy currents vs hysterisis loss and
saturation of the small metal bits.  You wont notice a loss in
performance either way, but be careful of scorching your base!

Steve

On 11/15/05, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Just Justin <rocketfuel@xxxxxxxxxxxxx>
>
> Is it safe to use brass bolts and nuts to secure the primary coil's
> wooden frame
> to a wooden base?
>
> My understanding is that the magnetic field won't affect the brass the way
> ferrous metals would, but is there still concern regarding the
> electric field and
> jumping sparks?
>
>
> Thanks for any comments,
>
> Justin