Re: Chassis Types


"Iain Churches" <IainNG@xxxxxxxxxxx> wrote in message
news:g8Wnj.288999$qf7.40143@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx


"Stephen" <jeryn3@xxxxxxxxxxx> wrote in message
news:guAnj.39388$75.10603@xxxxxxxxxxx
Hi Gents, Getting ready for another project and I wanted to solicit
opinions on the pros and cons of an aluminum vs. steel chassis, both
large
and small. I think we discuss this a few years ago but I also think it
would
be nice to do it again. Thanks.


Hi West. A very old friend of mine, the chap who started me off
in tube audio when I was very young, used to work in a smallish
audio prototype shop in the UK. He advised me "Always keep
the prototype.It is usually built in an aluminium chassis and may
perform marginally better than the steel production units"

Of late, I have given up using Hammond-type box chassis,
even though I have access to a metal bender. I prefer the
"slab design" with separate plates top and bottom, sides,
bck and front. I use 10mm anodised alum for the front plate,
6mm for the rear panel, 8mm for the sided, and 3mm for
top and bottom plates, and 3mm stainless steel for the
grilles.

http://www.kolumbus.fi/iain.churches/Pics/203Pics/04A.jpg

You have to remember that anodising insulates one plate
from the other, so screw holes and threads should have
plastric machine screws fitted before the plates go to
be anodised. For practical reasons, I use a copper
U-shaped inner chassis to which the outer panels are
subsequently fixed. You can see the copper in this pic.

http://www.kolumbus.fi/iain.churches/Pics/203Pics/05A.jpg

It's impressive that you are aware of those government rules. I believe that
the Swedes are the best in that area. Long ago, before the advent of APC,
Tripplite, etc. UPS products, I designed a similar product for medical
equipment. In Florida, the lightning capital of the world, the frequent
storms created havoc with all the sensitive medical systems. The design was
initially out of necessity because of all the revenue lost to warranty and
contracted systems. That business flourished and I subsequently sold it for
a tidy sum. My point is that I had to adhere to all those stringent rules in
my products. There was the UL, CSA (for Canada), National Electric Code,
which was especially tough for anything that may come into contact with a
patient or even be in a hospital. Then there was RF generated noise that may
interfere with monitoring systems and heart pacers. So many rules and
testing. Fortunately for hobbyists, we don't need to incorporate those
rules, but I still believe that it's beneficial to at least be aware of
them.

Kindest regards,
west

BTW: I didn't answer you right away because I couldn't remember the
conductor and couldn't find the old program. It was perform at Ruth Eckerd
Hall, Clearwater, Florida - 1983. Perhaps you can help?

Cordially,

Iain








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Relevant Pages

  • Re: Chassis Types
    ... opinions on the pros and cons of an aluminum vs. steel chassis, ... Jon Yaeger, even. ...
    (rec.audio.tubes)
  • Re: Chassis Types
    ... Aluminum is easier to cut holes in, and is a better conductor than steel. ... The chassis would be tied to this star, ... Once the circuits are behaving well, and you are looking at production runs, you can try passing current thru the chassis and see if any ground loops happen. ...
    (rec.audio.tubes)
  • Re: sheet metal screw hazard to aluminum chassis?
    ... Certainly some aluminum shavings /dust ... will fall inside the chassis / case. ... at risk from stray metal dust. ... chassis is a recent thing and steel sheet metal screws, ...
    (uk.comp.homebuilt)
  • Re: Jeffs Movie: Street Freestyle
    ... what kind of bc plates are those? ... Are they custom made or not? ... Aluminum or steel? ...
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  • Re: Chassis Types
    ... opinions on the pros and cons of an aluminum vs. steel chassis, ... "slab design" with separate plates top and bottom, sides, ...
    (rec.audio.tubes)