What would this process be called?
Aluminium heatsink used for mounting electronic components to , to conduct
away heat to the air . Some sort of chisell cutting advance and repeat while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

N_Cook wrote:
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct away heat to the air . Some sort of chisell cutting advance
and repeat while still hot after casting/extruding?, surely not done
cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal must have been about 9mm wide to be cut down, each side, to a
4mm spine.

Milled from both sides simultaneously with gang tooling and then formed.
Small stuff like this is also frequently sintered metal.

--

John R. Carroll
www.machiningsolution.com

John R. Carroll wrote in message
...
N_Cook wrote:
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct away heat to the air . Some sort of chisell cutting advance
and repeat while still hot after casting/extruding?, surely not done
cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal must have been about 9mm wide to be cut down, each side, to a
4mm spine.

Milled from both sides simultaneously with gang tooling and then formed.
Small stuff like this is also frequently sintered metal.

--

John R. Carroll
www.machiningsolution.com



The fins are only 0.7mm thick and no sign of machining marks just a slightly
granualar looking surface on the concave side of each vane and a smooth
surface on the convex side.
I don't see how a milling process can be involved.
Are you saying the original bulk would have been about 4 + (2x27mm ) wide ?
, the fins are about 27mm along the curve.
A milling process would not leave those 5 degree or so off axis cuts along
the spine.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

N_Cook wrote:
John R. Carroll wrote in message
...
N_Cook wrote:
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct away heat to the air . Some sort of chisell cutting advance
and repeat while still hot after casting/extruding?, surely not done
cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal must have been about 9mm wide to be cut down, each side, to a
4mm spine.

Milled from both sides simultaneously with gang tooling and then
formed. Small stuff like this is also frequently sintered metal.

--

John R. Carroll
www.machiningsolution.com



The fins are only 0.7mm thick and no sign of machining marks just a
slightly granualar looking surface on the concave side of each vane
and a smooth surface on the convex side.

Yeah, they are milled straight and then roll formed in place. Bar stock is
pulled through a machine that does both sides and both operations at the
same time.

I don't see how a milling process can be involved.
Are you saying the original bulk would have been about 4 + (2x27mm )
wide ? , the fins are about 27mm along the curve.
A milling process would not leave those 5 degree or so off axis cuts
along the spine.

Sure it would. You form grind the tools/cutters and gang them on an arbor.
You are thinking of this as a milling operation done vertically from the
top. It isn't. It's done horizontally with multiple cutters on an upper and
lower arbor as a long length of stock is pulled through.

I didn't see a ground plane on the heat sink but if there is one it's bonded
after the long bar has been cut to individual lengths and in a furnace.
Like I said, a lot of this stuf is pressed and sintered as well. Depends on
the material and - most importantly - quantities.
Hardened carbide dies aren't cheap whereas wire cutting the forming sections
and grinding the gang tooling is.

--

John R. Carroll
www.machiningsolution.com

I have a heat sink similar to that somewhere. To me it looked like
something done similar to a metal shaper not going through, leaving the chip
attached to base metal. I'm not sure how the process works but I've seen
video of aluminum cans being made by a small piece of aluminum being pressed
in a die and flowing around a punch. Perhaps the fins heat enough to be
formed while being cut?


"N_Cook" wrote in message
...
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

RogerN wrote in message
m...
I have a heat sink similar to that somewhere. To me it looked like
something done similar to a metal shaper not going through, leaving the
chip
attached to base metal. I'm not sure how the process works but I've seen
video of aluminum cans being made by a small piece of aluminum being
pressed
in a die and flowing around a punch. Perhaps the fins heat enough to be
formed while being cut?


"N_Cook" wrote in message
...
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England








This is an end on view
http://home.graffiti.net/diverse:gra..._heatsink3.jpg
showing the granularity which probably suggests a shearing action.
Looks as though the first operation was 4 knife cuts about 2mm deep
(assuming 9mm thick slab to start with ) which when chiselled? up give those
(2 sense) tapering ends to the knife cuts
The lines on the spine probably show a guillotine to chop to length.
The back face of these vanes is quite smooth in appearance mainly.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to conduct
away heat to the air . Some sort of chisell cutting advance and repeat while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

I'm not sure what the process is actually called, but I call it
"shaving." It's probably done on something like a shaper, as one other
poster suggested. It's certainly not milled or sintered.

I've often wondered if heat sinks made like this were any good,
because the integrity of the shaved off material is suspect in my
mind. If the material is cracked, it won't have the same thermal
conductivity. It's possible that this can be okay if the right alloy
is used.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Jim Adney wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

I'm not sure what the process is actually called, but I call it
"shaving." It's probably done on something like a shaper, as one other
poster suggested. It's certainly not milled or sintered.

I've often wondered if heat sinks made like this were any good,
because the integrity of the shaved off material is suspect in my
mind. If the material is cracked, it won't have the same thermal
conductivity. It's possible that this can be okay if the right alloy
is used.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------


I've never seen such a heatsink with a broken vane.
There is a variant where the tip of each vane is sharply turned into a
spiral before the main run of the curved vane.

I amagine it is all done just immediately after the extrusion, the knife
cuts and then the 5 degree set chisel action on both sides , then chopped to
length.

A very efficient process in the sense of no material loss in machining.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"Jim Adney" wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

If the texture in the photo is accurately portrayed on my computer screen,
it's machined with wirecut EDM. Not cheap, but the best way to do it in
small quantities.

If it's a high-production part, then it's something else.

--
Ed Huntress

Ed Huntress wrote in message
...

"Jim Adney" wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

If the texture in the photo is accurately portrayed on my computer screen,
it's machined with wirecut EDM. Not cheap, but the best way to do it in
small quantities.

If it's a high-production part, then it's something else.

--
Ed Huntress




Would that process give the alternating surface appearance effect?
There's not much point in taking a photo of the other end showing the
appearance of the convex sides of the vanes as it looks like polished
aluminium except for about 5mm at the open end of each vane. That has an
appearance half way between polished and that granular appearance, so
probably won't show up in a pic.

What I don't understand is why the "polished" looking faces look just that.
with not the slightest trace of any striations from a cutting action, I will
try looking under a microscope.

I assumed the process was producing one cut surface and one cleaved process
like a chisel or plane-blade. If it was done at the same time as extrusion
then relatively light forces of a knife through butter.


--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

"N_Cook" wrote in message
...
Ed Huntress wrote in message
...

"Jim Adney" wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

If the texture in the photo is accurately portrayed on my computer
screen,
it's machined with wirecut EDM. Not cheap, but the best way to do it in
small quantities.

If it's a high-production part, then it's something else.

--
Ed Huntress




Would that process give the alternating surface appearance effect?

I'm afraid I don't follow what you mean by alternativing surfaces. If you
explained it earlier in the thread, sorry, I missed it.

There's not much point in taking a photo of the other end showing the
appearance of the convex sides of the vanes as it looks like polished
aluminium except for about 5mm at the open end of each vane. That has an
appearance half way between polished and that granular appearance, so
probably won't show up in a pic.

What I don't understand is why the "polished" looking faces look just
that.
with not the slightest trace of any striations from a cutting action, I
will
try looking under a microscope.

That suggests EDM. The EDMed surface texture is non-directional and just
grainy, looking at it under a microscope. It can range from coarse to the
naked eye, to highly polished.

Do you know if this thing is something made special, in small quantities, or
is it a production piece?


I assumed the process was producing one cut surface and one cleaved
process
like a chisel or plane-blade. If it was done at the same time as extrusion
then relatively light forces of a knife through butter.


--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

Ed Huntress wrote in message
...

"N_Cook" wrote in message
...
Ed Huntress wrote in message
...

"Jim Adney" wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:

That suggests EDM. The EDMed surface texture is non-directional and just
grainy, looking at it under a microscope. It can range from coarse to the
naked eye, to highly polished.

Do you know if this thing is something made special, in small quantities,
or
is it a production piece?



I looked under a x30 microscope and both surfaces show striations, at that
level of viewing, in the sense of chisel cuts if produced like that.

There were 10,000s to millions of them produced for mainlly Sony makes of
domestic hi-fi amplifiers of the 1970s and 80s.


--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

On Jun 1, 2:50 am, "N_Cook" wrote:
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to conduct
away heat to the air . Some sort of chisell cutting advance and repeat while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled cutshttp://home.graffiti.net/diverse:graffiti.net/chisel_vane_heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

--
General electronic repairs, most things repaired, other than TVs and PCshttp://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

It could be a casting using a lost wax process. The wax model is
typically cast in wax from a master mold, then the wax is invested in
a plaster mold, burned out and the aluminum poured in. This shape
would lend itself well to that process.

-Mike

"N_Cook" wrote in message
...
Ed Huntress wrote in message
...

"N_Cook" wrote in message
...
Ed Huntress wrote in message
...

"Jim Adney" wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook"
wrote:

That suggests EDM. The EDMed surface texture is non-directional and just
grainy, looking at it under a microscope. It can range from coarse to the
naked eye, to highly polished.

Do you know if this thing is something made special, in small quantities,
or
is it a production piece?



I looked under a x30 microscope and both surfaces show striations, at that
level of viewing, in the sense of chisel cuts if produced like that.

There were 10,000s to millions of them produced for mainlly Sony makes of
domestic hi-fi amplifiers of the 1970s and 80s.

That wouldn't be wire EDM, then. Fine striations suggest extrusion. And that
quantity suggests they weren't cut, except that they were sliced off from
the extrusion.

--
Ed Huntress

"mlcorson" wrote in message
...
On Jun 1, 2:50 am, "N_Cook" wrote:
What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct
away heat to the air . Some sort of chisell cutting advance and repeat
while
still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg
a steel rule laid across it,
plus a close up showing the slightly angled
cutshttp://home.graffiti.net/diverse:graffiti.net/chisel_vane_heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal
must have been about 9mm wide to be cut down, each side, to a 4mm spine.

--
General electronic repairs, most things repaired, other than TVs and
PCshttp://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

It could be a casting using a lost wax process. The wax model is
typically cast in wax from a master mold, then the wax is invested in
a plaster mold, burned out and the aluminum poured in. This shape
would lend itself well to that process.

-Mike

But not that quantity, Mike. That would be too high for a non-structural
aluminum part. The cost would be at least 20 times the cost of extrusion --
probably more like 100 times the cost.

--
Ed Huntress

N_Cook wrote:
Ed Huntress wrote in message
...
"N_Cook" wrote in message
...
Ed Huntress wrote in message
...
"Jim Adney" wrote in message
...
On Sun, 1 Jun 2008 08:50:02 +0100 "N_Cook" wrote:
That suggests EDM. The EDMed surface texture is non-directional and just
grainy, looking at it under a microscope. It can range from coarse to the
naked eye, to highly polished.

Do you know if this thing is something made special, in small quantities,
or
is it a production piece?



I looked under a x30 microscope and both surfaces show striations, at that
level of viewing, in the sense of chisel cuts if produced like that.

There were 10,000s to millions of them produced for mainlly Sony makes of
domestic hi-fi amplifiers of the 1970s and 80s.




It`s a process called 'Skiving'


Ron(UK)

Ron(UK) wrote in message
...
N_Cook wrote:


It`s a process called 'Skiving'


Ron(UK)


So it does, which begs the philological question - what's the connection
with the work-shy ?


--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

N_Cook wrote:
Ron(UK) wrote in message
...
N_Cook wrote:

It`s a process called 'Skiving'


Ron(UK)


So it does, which begs the philological question - what's the connection
with the work-shy ?

So that means that the dole office is full of orthogonal planers?

Ron

On Sun, 01 Jun 2008 08:50:02 +0100, N_Cook wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct away heat to the air . Some sort of chisell cutting advance and
repeat while still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg a
steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal must have been about 9mm wide to be cut down, each side, to a 4mm
spine.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

I have seen heatsinks done by pressing in fins into a grooved/slotted
base. The grooves are then swaged shut:

direction of the swaging
|F | /
-------+|I |+----------
||N ||
|+--+| BASE
+----+

When you look at the side of such item, you can see the slots and maybe
even the displaced material where the swaging pressure was applied.



--
Przemek Klosowski, Ph.D. przemek.klosowski at gmail

przemek klosowski wrote in message
news:Ls12k.40135$yg6.13962@trnddc01...
On Sun, 01 Jun 2008 08:50:02 +0100, N_Cook wrote:

What would this process be called?
Aluminium heatsink used for mounting electronic components to , to
conduct away heat to the air . Some sort of chisell cutting advance and
repeat while still hot after casting/extruding?, surely not done cold?

http://home.graffiti.net/diverse:gra...e_heatsink.jpg a
steel rule laid across it,
plus a close up showing the slightly angled cuts
http://home.graffiti.net/diverse:gra..._heatsink2.jpg

The remaining uncut spine is about 4mm wide and the original bulk of
metal must have been about 9mm wide to be cut down, each side, to a 4mm
spine.

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

I have seen heatsinks done by pressing in fins into a grooved/slotted
base. The grooves are then swaged shut:

direction of the swaging
|F | /
-------+|I |+----------
||N ||
|+--+| BASE
+----+

When you look at the side of such item, you can see the slots and maybe
even the displaced material where the swaging pressure was applied.



--
Przemek Klosowski, Ph.D. przemek.klosowski at gmail

The roots of the fins are perfectly clean, also the 5 degree or so cut angle
is still evident. I am convinced it is this skiving process, just leaving
the question of whether it is done at the time of billett extrusion , so
still hot, or done cold.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/