I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks

"Staffbull" wrote in message
...
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?


The beds and slideways of most high quality machine tools are made of cast
iron and ground to high precision. Unless it's very poor quality stuff it
should grind beautifully.

"Staffbull" wrote in message
...
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast?

Certainly, either with carbide burrs in a Dremel or similar or with an angle
grinder and ferrous grinding disk.
--
Dave Baker

Staffbull wrote:

I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast?


Yes, you can grind cast iron. But beware.

As a result of the casting method, cast iron has a surface that
resists corrosion to an extent. If you grind it, you will remove that
surface and therefore the corrosion resistance.

So make sure that you protect the ground surfaces against corrosion,
just as you would for mild steel, for example.


or am I just oissing againt the wind trying?


Oissing against the wind must carry its own risks. ;-)

Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC.

"The Natural Philosopher" wrote in message
...
Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC.


Cast iron used in brake discs and flywheels in grey cast iron, or crank
shafts and wheel hubs in nodular cast iron can be machine turned & milled
easily.

Don.

"The Natural Philosopher" wrote in message
...
Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC

You don't, remember correctly that is.
--
Dave Baker

Don wrote:
"The Natural Philosopher" wrote in message
...
Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC.


Cast iron used in brake discs and flywheels in grey cast iron, or crank
shafts and wheel hubs in nodular cast iron can be machine turned & milled
easily.


crankshafts are seldom cast. IIRC they are nearly always forged from
something rather different..steel!

I think we are running into semantics he to me cast iron is the basic
stuff that runs out of an ore processing furnace before its been blast
furnaced!

Not how that part was actually made.

Don.

Dave Baker wrote:
"The Natural Philosopher" wrote in message
...
Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC

You don't, remember correctly that is.
Well, provide examples.

Not of cast steel, but cast *iron*.

"The Natural Philosopher" wrote in message
...
Don wrote:
"The Natural Philosopher" wrote in message
...
Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC.


Cast iron used in brake discs and flywheels in grey cast iron, or crank
shafts and wheel hubs in nodular cast iron can be machine turned & milled
easily.


crankshafts are seldom cast. IIRC they are nearly always forged from
something rather different..steel!

No they aren't!! The vast majority of standard automotive crankshafts are as
you have already been told - cast iron. Only race engines and the occasional
very high output road engine use forged or cast steel for crankshafts which
although having a higher tensile strength is much more notch sensitive than
iron and has a shorter fatigue life.

The vast majority of engine camshafts are also cast iron although in this
case usually chill cast iron to give a high degree of hardness to the cam
lobes. Engine blocks, cylinder heads, brake disks and flywheels are also
commonly made from cast iron in various grades and all of these are readily
machineable except for the hardened chill cast regions of a casting which
must be ground to final shape.

Just putting IIRC after everything doesn't give you the right to blether on
incorrectly about things you haven't actually forgotten because you clearly
never knew anything about them in the first place.
--
Dave Baker
Puma Race Engines

The Natural Philosopher wrote:

Don wrote:
"The Natural Philosopher" wrote in message
...
Staffbull wrote:
can you grind cast?
In fact its about the only sort of machining that works on it IIRC.

Cast iron used in brake discs and flywheels in grey cast iron, or crank
shafts and wheel hubs in nodular cast iron can be machine turned & milled
easily.

crankshafts are seldom cast. IIRC they are nearly always forged from
something rather different..steel!

Having worked for 5 years in an iron foundry, I can assure you that the
vast majority of castings are machined prior to their further use.
We used to make crakshafts for Vauxhall, as well as numerous other
components such as camshafts, exhaust manifolds, and many other small
parts for the motor industry.
Alan
--
To reply by e-mail, change the ' + ' to 'plus'.

In article ,
The Natural Philosopher wrote:
Cast iron used in brake discs and flywheels in grey cast iron, or
crank shafts and wheel hubs in nodular cast iron can be machine
turned & milled easily.


crankshafts are seldom cast. IIRC they are nearly always forged from
something rather different..steel!

********.

Casting this sort of thing gives a more rigid result than forging -
important with a crankshaft for engine refinement. It's also cheaper.
Forging is only normally used where the maximum strength is needed - like
when an existing design is modified or developed to produce more power
than originally intended.

--
*One tequila, two tequila, three tequila, floor.

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

"Dave Plowman (News)" wrote in message
...
In article ,
The Natural Philosopher wrote:
Cast iron used in brake discs and flywheels in grey cast iron, or
crank shafts and wheel hubs in nodular cast iron can be machine
turned & milled easily.


crankshafts are seldom cast. IIRC they are nearly always forged from
something rather different..steel!

********.

Casting this sort of thing gives a more rigid result than forging -

Unfortunately no, not by any measure. Cast iron has a lower modulus of
elasticity (the amount it bends for a given load) than steel as well as
lower ultimate tensile strength. A cast iron crank, of the same shape, is
both more flexible and weaker than a steel one but as I said previously it
is less notch sensitive so less likely to break from stress cracks and has a
longer fatigue life which is important in high mileage engines like truck
diesels.

In simple terms cast iron is used because it suffices for the job at less
cost than steel. Even with very highly tuned engines putting out several
times their stock power I've never seen a stock cast iron crank break.
There's no reason to change it unless weight is of paramount importance in
which case steel, being stronger, can use smaller lighter sections for a
given loading. However, when weight is pared to the bone, as in a no holds
barred race engine, then steel cranks can need to be changed regularly
because their fatigue life can be quite short.

important with a crankshaft for engine refinement. It's also cheaper.
Forging is only normally used where the maximum strength is needed - like
when an existing design is modified or developed to produce more power
than originally intended.

The other main reason steel is used for race engine cranks is because for
small volume production it's easier to machine the crank from a solid billet
of round forged steel bar than make expensive forging or casting tooling.
Only when volumes reach production vehicle levels does such tooling cost per
item drop to a manageable amount. You might then ask well why not machine
small volume cranks from cast iron continuously cast bar? Mainly because
given the same amount of machining from the solid bar there's not a
sufficient material cost saving in using cast iron rather than forged steel
bar to make it worth the bother when you are also going to get an end
product that's weaker.
--
Dave Baker

In article ,
Dave Baker wrote:
Casting this sort of thing gives a more rigid result than forging -

Unfortunately no, not by any measure. Cast iron has a lower modulus of
elasticity (the amount it bends for a given load) than steel as well as
lower ultimate tensile strength. A cast iron crank, of the same shape,
is both more flexible and weaker than a steel one but as I said
previously it is less notch sensitive so less likely to break from
stress cracks and has a longer fatigue life which is important in high
mileage engines like truck diesels.

Sort of goes against what I was taught - although it could be if designing
both for exactly the same load the cast one becomes in effect more rigid?


In simple terms cast iron is used because it suffices for the job at
less cost than steel. Even with very highly tuned engines putting out
several times their stock power I've never seen a stock cast iron crank
break.

Crikey - broken crankshafts used to be quite common on thrashed engines -
the B series BMC unit was famous for it. Early A series too. Of course
with modern ignition/injection systems it's easy to limit the maximum revs
to a safe limit.

--
*Arkansas State Motto: Don't Ask, Don't Tell, Don't Laugh.

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

"Dave Plowman (News)" wrote in message
...
In article ,
Dave Baker wrote:
Casting this sort of thing gives a more rigid result than forging -

Unfortunately no, not by any measure. Cast iron has a lower modulus of
elasticity (the amount it bends for a given load) than steel as well as
lower ultimate tensile strength. A cast iron crank, of the same shape,
is both more flexible and weaker than a steel one but as I said
previously it is less notch sensitive so less likely to break from
stress cracks and has a longer fatigue life which is important in high
mileage engines like truck diesels.

Sort of goes against what I was taught - although it could be if designing
both for exactly the same load the cast one becomes in effect more rigid?

Quite possibly yes if you have to make the sections very much bigger to
allow for the lower tensile strength. In fact that's why you generally only
see cast iron things in bloody great lumps because it's basically weak and
brittle, especially in thin sections. However in bloody great lumps you
still ain't going to break it and it's cheap.

http://www.engineersedge.com/manufac...s_strength.htm

Even the good stuff, malleable or nodular (SG) cast iron, only has about 70%
of the modulus of elasticity of steel and half or less of the tensile
strength. The crap stuff, basic grey cast which you would use for an engine
block or gearbox casting, is much much weaker than that. If you tried to
make a coathanger out of cast iron wire instead of steel wire it would snap
like a carrot with anything heavier than a shirt on it. Like I say though,
in bloody great lumps it's perhaps understandable that people might think
it's strong but the same size bloody great lumps of steel would be much
stronger and also much more rigid.

In simple terms cast iron is used because it suffices for the job at
less cost than steel. Even with very highly tuned engines putting out
several times their stock power I've never seen a stock cast iron crank
break.

Crikey - broken crankshafts used to be quite common on thrashed engines -
the B series BMC unit was famous for it. Early A series too. Of course
with modern ignition/injection systems it's easy to limit the maximum revs
to a safe limit.

I'm talking 'proper' engines Ya know, like anything designed after the
Ark?

The A series, and the early B series, only had three main bearings on the
crank which is why they bent like bananas under high rpm loadings and broke
so easily. Anything more modern will have five mains and be very hard to
break.
--
Dave Baker

"The Natural Philosopher" wrote in message
...
Dave Baker wrote:
"The Natural Philosopher" wrote in message
...
Staffbull wrote:
I have fitted the fireplace I posted about earilier, all done!!
I have a fire grate front (if thats what you call it!) but it is just
too wide to fit into the opening of the fire so sits proud of the fire
basket (?) can I grind the side down so it will fit?

can you grind cast? or am I just oissing againt the wind trying?

thanks
Yes, you can.

In fact its about the only sort of machining that works on it IIRC

You don't, remember correctly that is.
Well, provide examples.

Not of cast steel, but cast *iron*.



I accept that modern cranks are made of malleable or SG Iron - but I was
fascinated to see a RR Merlin crankshaft forging die and forging at a museum
in Sheffield, They were forged with the cranks in one plane - then a twist
was applied to each web to give the angular relationship - then machined.
Amazing.

I accept that modern cranks are made of malleable or SG Iron - but I was
fascinated to see a RR Merlin crankshaft forging die and forging at a
museum in Sheffield, They were forged with the cranks in one plane - then
a twist was applied to each web to give the angular relationship - then
machined. Amazing.


Photo of RR Merlin forged and twisted crank - with forging die - all in one
plane

http://picasaweb.google.com/lh/photo...tXF8v8Y0cKFi7Q

In message , "Dave Plowman (News)"
writes
In article ,
Dave Baker wrote:

In simple terms cast iron is used because it suffices for the job at
less cost than steel. Even with very highly tuned engines putting out
several times their stock power I've never seen a stock cast iron crank
break.

Crikey - broken crankshafts used to be quite common on thrashed engines -
the B series BMC unit was famous for it. Early A series too. Of course
with modern ignition/injection systems it's easy to limit the maximum revs
to a safe limit.

Managed that once

I also broke a camshaft on my SD1 in three parts thrashing it down the
autobahn once ... so watch it

--
geoff

In article ,
geoff wrote:
Crikey - broken crankshafts used to be quite common on thrashed engines
- the B series BMC unit was famous for it. Early A series too. Of
course with modern ignition/injection systems it's easy to limit the
maximum revs to a safe limit.

Managed that once

I also broke a camshaft on my SD1 in three parts thrashing it down the
autobahn once ... so watch it

On the V-8? Pretty rare I'd say. The distributor drive usually gives up
first. Which, of course, also drives the oil pump. I'd be less surprised
if it was the 6 cylinder.

--


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

In message , "Dave Plowman (News)"
writes
In article ,
geoff wrote:
Crikey - broken crankshafts used to be quite common on thrashed engines
- the B series BMC unit was famous for it. Early A series too. Of
course with modern ignition/injection systems it's easy to limit the
maximum revs to a safe limit.

Managed that once

I also broke a camshaft on my SD1 in three parts thrashing it down the
autobahn once ... so watch it

On the V-8? Pretty rare I'd say.

Yup, doing a tad above 120 about 50m south of Nuernberg

I heard it go and immediately dropped the clutch and just had enough
momentum to cruise up the ausfahrt which Hitler had conveniently placed
some 60 years earlier in anticipation of the occurrence and onto a
garage forecourt. Miraculously, no further damage was done

The distributor drive usually gives up
first. Which, of course, also drives the oil pump. I'd be less surprised
if it was the 6 cylinder.


--
geoff

Dave Plowman (News) wrote:
In article ,
geoff wrote:
Crikey - broken crankshafts used to be quite common on thrashed engines
- the B series BMC unit was famous for it. Early A series too. Of
course with modern ignition/injection systems it's easy to limit the
maximum revs to a safe limit.

Managed that once

I also broke a camshaft on my SD1 in three parts thrashing it down the
autobahn once ... so watch it

On the V-8? Pretty rare I'd say. The distributor drive usually gives up
first. Which, of course, also drives the oil pump. I'd be less surprised
if it was the 6 cylinder.

Snapped a camshaft on a corsa once. Not sure if the belt went first.

Had to tow it to Calais and onto the ferry home..

"geoff" wrote in message
...

Yup, doing a tad above 120 about 50m south of Nuernberg

Maxie, you tearaway! Where you elephants trunk?

I heard it go and immediately dropped the clutch and just had enough
momentum to cruise up the ausfahrt which Hitler had conveniently placed
some 60 years earlier in anticipation of the occurrence and onto a garage
forecourt. Miraculously, no further damage was done

Maxie, Hitler was such a considerate man indeed.

"geoff" wrote in message
...
In message , "Dave Plowman (News)"
writes
In article ,
Dave Baker wrote:

In simple terms cast iron is used because it suffices for the job at
less cost than steel. Even with very highly tuned engines putting out
several times their stock power I've never seen a stock cast iron crank
break.

Crikey - broken crankshafts used to be quite common on thrashed engines -
the B series BMC unit was famous for it. Early A series too. Of course
with modern ignition/injection systems it's easy to limit the maximum revs
to a safe limit.

Managed that once

Maxie, you a fabulist. You really know how to break things in a big way.

WOW! this post seems to have taken its own tangent :-)

Thanks for the info and the firegrate has ground very niceley! and
fits a treat :-)

been interesting reading though :-)