"Dave" wrote in message
...
ARWadsworth wrote:

"Dave" wrote in message
20 to 25 years ago, I was given a 3.5 mm tap for back boxes,

Not much use in a 4BA hole -)

Ah, I see what you mean. My big mistake. :-(

Dave

I also have a 4BA tap and some 4BA bolts. Guess what I use to fit sockets to
back boxes where the 3.5 thread is totally knackered?

Adam

ARWadsworth wrote:

Maybe, but I have never come across 4BA threads on on backboxes in
houses where the original lighting circuit has an earth. ISTR that
lighting circuits needed an cpc from 1966 onwards.

This did have an earth, not sleeved though. It was a bakery not a house.
Building dates from 1936.

--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

ARWadsworth wrote:

"Dave" wrote in message
...
ARWadsworth wrote:

"Dave" wrote in message
20 to 25 years ago, I was given a 3.5 mm tap for back boxes,

Not much use in a 4BA hole -)

Ah, I see what you mean. My big mistake. :-(

Dave

I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

Do 4 BA bolts/screws have the correct countersink angle for fitting
sockets? If so, what is it? It's something I have never looked at.

Dave

ARWadsworth wrote:

"Dave" wrote in message
...
ARWadsworth wrote:

"Dave" wrote in message
20 to 25 years ago, I was given a 3.5 mm tap for back boxes,

Not much use in a 4BA hole -)

Ah, I see what you mean. My big mistake. :-(

Dave

I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

I forgot to ask, what sort of place sells the 3 and 4 BA C/S
bolts/screws? Electrical wholesaler, or what?

Dave

"Dave" wrote in message
...
ARWadsworth wrote:

"Dave" wrote in message
...
ARWadsworth wrote:

"Dave" wrote in message
20 to 25 years ago, I was given a 3.5 mm tap for back boxes,

Not much use in a 4BA hole -)

Ah, I see what you mean. My big mistake. :-(

Dave

I also have a 4BA tap and some 4BA bolts. Guess what I use to fit sockets
to back boxes where the 3.5 thread is totally knackered?

I forgot to ask, what sort of place sells the 3 and 4 BA C/S bolts/screws?
Electrical wholesaler, or what?

Dave

I have a friend that works for a bolt company. I buy from him.

But any ironmongers, diy store or electrical wholesaler should stock what
you need.


Adam

On Thu, 08 Oct 2009 19:46:52 GMT, ARWadsworth wrote:

I forgot to ask, what sort of place sells the 3 and 4 BA C/S
bolts/screws?

But any ironmongers, diy store or electrical wholesaler should stock
what you need.

I don't think you'll find BA in a diy store, metric only there. A
proper ironmongers may have them but finding a proper ironmongers
might be tricky. Electrical wholesaler, doubtful.

Electronics places such as RS, CPC maybe Maplin might.

Failing those Yellow Pages for a local fastenings specialist.

--
Cheers
Dave.

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

--
*Some people are only alive because it is illegal to kill.

Dave Plowman London SW
To e-mail, change noise into sound.

In article o.uk,
Dave Liquorice wrote:
On Thu, 08 Oct 2009 19:46:52 GMT, ARWadsworth wrote:

I forgot to ask, what sort of place sells the 3 and 4 BA C/S
bolts/screws?

But any ironmongers, diy store or electrical wholesaler should stock
what you need.

I don't think you'll find BA in a diy store, metric only there. A
proper ironmongers may have them but finding a proper ironmongers
might be tricky. Electrical wholesaler, doubtful.

Electronics places such as RS, CPC maybe Maplin might.

Failing those Yellow Pages for a local fastenings specialist.

I'd say trying to source the correct head chrome or brass BA screws for
electrical fittings might be tricky these days.

--
*Never underestimate the power of stupid people in large groups

Dave Plowman London SW
To e-mail, change noise into sound.

On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

--
Frank Erskine

"geoffr" wrote in message
...
On 7 Oct, 15:31, John Rumm wrote:
If you want a set of basic tests to carry out, then post back and I will
list some.

Thanks John. I've read the information in the link you posted, but if
you can provide a set of basic tests then that would be great.

If the tests prove negative then I assume that it's simply a tracking
problem as some of the other posters have suggested. The sockets have
been wiped a few times and there does appear to be a fair amount of
debris around the edges of the switch.

I have isolated the circuit by removing the fuse.


I would suggest buying a meter and checking the other switches

--
Michael Chare

"Dave Plowman (News)" wrote in message
...
In article o.uk,
Dave Liquorice wrote:
On Thu, 08 Oct 2009 19:46:52 GMT, ARWadsworth wrote:

I forgot to ask, what sort of place sells the 3 and 4 BA C/S
bolts/screws?

But any ironmongers, diy store or electrical wholesaler should stock
what you need.

I don't think you'll find BA in a diy store, metric only there. A
proper ironmongers may have them but finding a proper ironmongers
might be tricky. Electrical wholesaler, doubtful.

Electronics places such as RS, CPC maybe Maplin might.

Failing those Yellow Pages for a local fastenings specialist.

I'd say trying to source the correct head chrome or brass BA screws for
electrical fittings might be tricky these days.

--
*Never underestimate the power of stupid people in large groups

Dave Plowman London SW

I cannot remember where I got my last lot from. I do not use many these
days.

Adam

In article ,
Frank Erskine wrote:
On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?


Bit late to rail against something which happened a couple of generations
ago?

--
*Never kick a cow pat on a hot day *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

Of course it will cause initial problems for some. But standardising this
sort of thing makes manufacture for export etc easier.

Which is somewhat irrelevant for British plugs and sockets :-)

I know places like Hong Kong use the same ones, but apparently they're
much less strict on quality so have their own local ones rather than
more expensive ones that could actually be sold here.

Pete

Jules wrote:
On Wed, 07 Oct 2009 22:47:27 +0100, Calvin Sambrook wrote:
2. The human tongue is sensitive to electricity and can be used to check
for voltage. Try it first on a 9V battery then progress it higher things.

Nah, doesn't work with AC - it just hurts in alternate directions, back
and forth 50 times a second;

50 hurts?

Pete

On Fri, 09 Oct 2009 01:08:08 +0100, Frank Erskine wrote:

On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

Yup - it was standardised, now it ain't.

Even Thatcher daredn't attack 19" racks - 10s of millions (at least) of
complex units (1.75" IIRC) that would need rewiring if changes needed.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

In article ,
Pete Verdon d wrote:
Of course it will cause initial problems for some. But standardising
this sort of thing makes manufacture for export etc easier.

Which is somewhat irrelevant for British plugs and sockets :-)

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

I know places like Hong Kong use the same ones, but apparently they're
much less strict on quality so have their own local ones rather than
more expensive ones that could actually be sold here.

--
*Money isn't everything, but it sure keeps the kids in touch.

Dave Plowman London SW
To e-mail, change noise into sound.

Pete Verdon wrote:
Jules wrote:

Nah, doesn't work with AC - it just hurts in alternate directions, back
and forth 50 times a second;

50 hurts?


100 actually. Both peaks.

Andy

Frank Erskine wrote:
On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?
Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

I have come across this problem several times in my house, though I can
wait and plan for the next decoration. I am thinking about relatives
that ask for this to be done.

Dave

In article ,
Dave writes:
Frank Erskine wrote:
On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?
Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

I fold in 3 sides against the back with a cold chisel, leaving
only the one with the cable entry. Then it should peel out,
but doesn't always go that smoothly.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Dave wrote:
In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

I have come across this problem several times in my house, though I can
wait and plan for the next decoration. I am thinking about relatives
that ask for this to be done.

Very carefully bend the sides inwards.

--
*If you remember the '60s, you weren't really there

Dave Plowman London SW
To e-mail, change noise into sound.

On Oct 8, 6:38*pm, John Rumm wrote:
more likely, it was hoped to sweep much of the black economy into trade
body membership, whose records could then be used to identify additional
sources of hitherto untapped tax.

and convert mere trade Registration Bodies into Regulation Bodies.
- Charitable front writes regs under guise of false safety statistics
- Commercial backend trots round the companies engineering
"opportunities"

Extension of "MP writes broad law, stakeholder companies write the
detail with a justification page if ever the civil servant is pulled
up". The bog standard modus operandi of business is to fund research
promoting their product/service/strategy once-removed from the
company, which is then pushed by PR as "independent".

It is securitisation of electrical safety - regulation, education,
certification, engineered upgrade cycle, commercial product push
advertising, commercial product endorsement "because it exists you
have to use it to comply with BS7671 correct materials & workmanship",
affiliate advertising. American marketeer's wet dream.

Just like the health & safety engineered market, some good ideas taken
to extreme levels. Then again, consider the VAT, Income Tax & NI,
Business Rates and so on created by the monster H&S industry. Next one
is Green... then food... then water... energy in its various
incentive, penalty, carbon tax trading, goldman sachs is having a
field day.

Who is doing the 18th regs, I thought BS were no longer to be
involved?


Reminds me: that dodgy SWA cable I sent to BASEC about a month or two
back? After useful replies nothing further, no replies to two recent
emails. I suspect the Turkish manufacturer (Demes Kablo) is not
playing ball with BASEC, leaving them in a rather embarassing
position. Worse, I've now seen similar with other cables elsewhere and
Atom Kablo (another Turkish manufacturer). Wonder when the electrical
industry gets a shock :-)

On Oct 9, 11:14*pm, "Dave Plowman (News)"
wrote:
In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

First, hope it was not pushed into a pile of wet plaster, because
plaster holds anything in place better than any screw. Then you might
have the "it might move, lets use cement, SBR, fibreglass flakes or...
epoxy mortar... fischer epoxy fixings". Do not laugh, I have found an
expoxy set backbox in block before now.

Sneak up on the backbox
- Remove the screw, grind off any nail, grind off your finger nails
(hey I got the angle grinder in!)
- Use a HD stanley blade to cut down the box sides so breaking any
bond there, but prefably not the cable.
- If extremely lucky the box will now be loose.

If not...
- Push a thin screwdriver down between plaster & backbox.
- Grind the screwdriver into the wall so you are levering against
brick/block not plaster.
- Bend the screwdriver so the box side folds inwards.
- Bend the screwdriver back into shape or keep for "special tasks".
- If lucky the bond of the box rear to the wall will now be gone.

If not...
- Repeat screwdriver attack on the other sides.
- Eventually the sides will be folded in severely.
- The bond will finally break.

If the box will not fit out through the hole...
- Use the HD stanley blade again to enlarge fractionally.
- The faceplate is larger than the backbox remember.
- Typically it is the corner-fold tabs that prevent easy removal.

Do not yank the box out thinking you are home free.
- If you tilt the box you increase the effective height of the rear.
- Tilting the box on removal rips out the plaster skim at the last
minute.

I suspect wrapping a backbox in masking tape might reduce the surface
bond to the metal so making its future replacement easier. That said,
I always use 25mm for lights, 35mm if any chance of a dimmer, 35mm for
all sockets to provide enough wiring for retermination in the future
and if any chance of grid or wago lever clips I use 47mm. That should
sort out all problems - no doubt they will change the wiring accessory
size :-) MK Grid 2G backboxes of course use 3 holes whereas every
other backbox in the universe (except some cooker) use 4 holes - so
oval/cables will not align :-)

Paper based wallpaper is bad news, because you can never repair it
invisibly.
Vinyl based wallpaper is easy to repair invisibly, just like carpets
avoid hard creases and avoid separating lining paper from the surface.
Likewise layers of lining paper are bad news, hard to repair levels.
Restick wallpaper with proper wallpaper paste.

It is a trial of patience really.

Balls, forgot the trick.

- Bend the backbox sides in a little to create a gap.
- Slide a pair of needle nose pliers over the backbox edge.
- Rotate/bend the pliers to pull the sides in.

Rotation is best because it is more controlled, no chance of ripping
the plaster out.

That is how I replaced 16mm & wood backboxes with 25-35mm for a
colleague.
- Box removed
- Screwdriver used to make wiggle space for cables
- Diamond cutter to deepen the box
- Cables slid through new grommet'd backbox holes, done.

Oh yes, I pushed the new backboxes into wet plaster so the next time
will be just as difficult :-)

Bosch multiconstruction bits are wonderful re easy drill into anything.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

In message , PeterC
writes
On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.

LOL


If they can tap into it.

But they'll have to wait for someone to die.

That's my pitch, anyway.
--
Peter

Ying tong iddle-i po!

On Sat, 10 Oct 2009 10:04:21 +0100, Peter Twydell wrote:

In message , PeterC
writes
On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.

LOL

If they can tap into it.

But they'll have to wait for someone to die.

That's my pitch, anyway.

That's about stripped it.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

In article ,
PeterC wrote:
On Sat, 10 Oct 2009 10:04:21 +0100, Peter Twydell wrote:

In message , PeterC
writes
On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.

LOL

If they can tap into it.

But they'll have to wait for someone to die.

That's my pitch, anyway.

That's about stripped it.

Place is full of nuts again.

--
*A bicycle can't stand alone because it's two tyred.*

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 10 Oct 2009 14:56:54 +0100, Dave Plowman (News) wrote:

In article ,
PeterC wrote:
On Sat, 10 Oct 2009 10:04:21 +0100, Peter Twydell wrote:

In message , PeterC
writes
On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.

LOL

If they can tap into it.

But they'll have to wait for someone to die.

That's my pitch, anyway.

That's about stripped it.

Place is full of nuts again.

Let's put a hex on 'em.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

Andrew Gabriel wrote:
In article ,
Dave writes:
Frank Erskine wrote:
On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?
Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.
It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?
In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

I fold in 3 sides against the back with a cold chisel, leaving
only the one with the cable entry. Then it should peel out,
but doesn't always go that smoothly.

You are not kidding :-(
I have tried this in my house, trying to perfect the technique, but I
always end up ripping some of the decoration off the wall, along with
some of the plaster, usually.

Dave

js.b1 wrote:
On Oct 9, 11:14 pm, "Dave Plowman (News)"
wrote:
In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

First, hope it was not pushed into a pile of wet plaster, because
plaster holds anything in place better than any screw. Then you might
have the "it might move, lets use cement, SBR, fibreglass flakes or...
epoxy mortar... fischer epoxy fixings". Do not laugh, I have found an
expoxy set backbox in block before now.

Sneak up on the backbox
- Remove the screw, grind off any nail, grind off your finger nails
(hey I got the angle grinder in!)
- Use a HD stanley blade to cut down the box sides so breaking any
bond there, but prefably not the cable.
- If extremely lucky the box will now be loose.

If not...
- Push a thin screwdriver down between plaster & backbox.
- Grind the screwdriver into the wall so you are levering against
brick/block not plaster.
- Bend the screwdriver so the box side folds inwards.
- Bend the screwdriver back into shape or keep for "special tasks".
- If lucky the bond of the box rear to the wall will now be gone.

If not...
- Repeat screwdriver attack on the other sides.
- Eventually the sides will be folded in severely.
- The bond will finally break.

If the box will not fit out through the hole...
- Use the HD stanley blade again to enlarge fractionally.
- The faceplate is larger than the backbox remember.
- Typically it is the corner-fold tabs that prevent easy removal.

Do not yank the box out thinking you are home free.
- If you tilt the box you increase the effective height of the rear.
- Tilting the box on removal rips out the plaster skim at the last
minute.

I suspect wrapping a backbox in masking tape might reduce the surface
bond to the metal so making its future replacement easier. That said,
I always use 25mm for lights, 35mm if any chance of a dimmer, 35mm for
all sockets to provide enough wiring for retermination in the future
and if any chance of grid or wago lever clips I use 47mm. That should
sort out all problems - no doubt they will change the wiring accessory
size :-) MK Grid 2G backboxes of course use 3 holes whereas every
other backbox in the universe (except some cooker) use 4 holes - so
oval/cables will not align :-)

Paper based wallpaper is bad news, because you can never repair it
invisibly.
Vinyl based wallpaper is easy to repair invisibly, just like carpets
avoid hard creases and avoid separating lining paper from the surface.
Likewise layers of lining paper are bad news, hard to repair levels.
Restick wallpaper with proper wallpaper paste.

It is a trial of patience really.

Printed and saved. That sounds an interesting way to do it next time.

Thanks

Dave

PeterC wrote:

On Sat, 10 Oct 2009 14:56:54 +0100, Dave Plowman (News) wrote:

In article ,
PeterC wrote:
On Sat, 10 Oct 2009 10:04:21 +0100, Peter Twydell wrote:

In message , PeterC
writes
On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

The standardisation involved more than just electrical things. But it
should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.

LOL

If they can tap into it.

But they'll have to wait for someone to die.

That's my pitch, anyway.

That's about stripped it.

Place is full of nuts again.

Let's put a hex on 'em.

We must all be unified.

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

Chris J Dixon wrote:
PeterC wrote:

On Sat, 10 Oct 2009 14:56:54 +0100, Dave Plowman (News) wrote:

In article ,
PeterC wrote:
On Sat, 10 Oct 2009 10:04:21 +0100, Peter Twydell wrote:

In message , PeterC
writes
On Sat, 10 Oct 2009 04:59:57 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert,
when the drugs began to take hold. I remember "Dave Plowman
(News)" saying something like:

The standardisation involved more than just electrical things.
But it should make things easier for the screw makers.

Blessed are the screwmakers.

For they shall inherit this thread.

LOL

If they can tap into it.

But they'll have to wait for someone to die.

That's my pitch, anyway.

That's about stripped it.

Place is full of nuts again.

Let's put a hex on 'em.

We must all be unified.

We must - careless torque costs lives.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:

We must all be unified.

We must - careless torque costs lives.


That is a new twist on the old saying.

--
David in Normandy.
To e-mail you must include the password FROG on the
subject line, or it will be automatically deleted
by a filter and not reach my inbox.

In message , David in Normandy
writes
The Medway Handyman wrote:

We must all be unified.
We must - careless torque costs lives.


That is a new twist on the old saying.

You picked the right moment to say that.
--
Peter

Ying tong iddle-i po!

PeterC wrote:
On Fri, 09 Oct 2009 01:08:08 +0100, Frank Erskine wrote:

On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

Yup - it was standardised, now it ain't.

Even Thatcher daredn't attack 19" racks - 10s of millions (at least) of
complex units (1.75" IIRC) that would need rewiring if changes needed.

19" Racks have been metricated for donkey's years.

Width of faceplate = 19" = 482.6mm rounded to 483mm

Gap between rack strips (width of opening) = 455mm (typical)

Width of box = 450mm (typical)

Height of faceplate (1U) = 1.75" = 44.45mm rounded to 44.5mm

Height of box = 43mm (i.e. typically slightly less than height of faceplate)

Overall size of conventional floor-standing cabinet typically 600, 800,
900mm wide and typically 600, 700, 800, 900mm deep, etc.

On Wed, 14 Oct 2009 14:05:05 +0100, Dave Osborne wrote:

PeterC wrote:
On Fri, 09 Oct 2009 01:08:08 +0100, Frank Erskine wrote:

On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

Yup - it was standardised, now it ain't.

Even Thatcher daredn't attack 19" racks - 10s of millions (at least) of
complex units (1.75" IIRC) that would need rewiring if changes needed.

19" Racks have been metricated for donkey's years.

Width of faceplate = 19" = 482.6mm rounded to 483mm

Gap between rack strips (width of opening) = 455mm (typical)

Width of box = 450mm (typical)

Height of faceplate (1U) = 1.75" = 44.45mm rounded to 44.5mm

Height of box = 43mm (i.e. typically slightly less than height of faceplate)

Overall size of conventional floor-standing cabinet typically 600, 800,
900mm wide and typically 600, 700, 800, 900mm deep, etc.

Looks as if the metric measurements have been kludged to fit.

Thanks for the info.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

On 14 Oct, 14:05, Dave Osborne wrote:

19" Racks have been metricated for donkey's years.

Don't forget that _inches_ have been metricated for years.

An inch is, by definition, 25.4mm. This is a round number to one dp,
so really not that hard to work with, with accuracy, without even
requiring 4-digit precision.

The losers, if anyone, seem to be the metric "common sizes", such as
19mm

"Dave Osborne" wrote in message
...
PeterC wrote:
On Fri, 09 Oct 2009 01:08:08 +0100, Frank Erskine wrote:

On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

Yup - it was standardised, now it ain't.

Even Thatcher daredn't attack 19" racks - 10s of millions (at least) of
complex units (1.75" IIRC) that would need rewiring if changes needed.

Did she ever metricate the sex industry ?
Going by all the viagra spam it sees not ;-)