That is a really cool story. Reminded me of my college days.? I grew up in central NY and got a scholarship to go away to school at Wentworth Institute of Technology in Boston.? Those days Wentworth was trying to up its game from its 1904 tech school reputation to a 20th then 21st century university.? They had lots of money so they were buying up all kinds of real estate around Boston.? The old Boston Trade School was across the street so they bought up all the buildings there.? In the basement were several huge lathes.? You had to sit on a chair on the saddle as you turned- with those machines.? I was told that during World War 2 that school and shop were commandeered by the US Navy to make warship cannon barrels.? Turned, gun drilled and bored......same thing...amazing machinery that held an important place in history.?
On Thu, Aug 17, 2023 at 12:31?PM pat goodyear < pgoodyear@...> wrote: So prior to my commercial Nuclear Power plant days, I was an ET (electronics technician) in the Navy, specialty was Reactor Operator in submarines, actually I was the Leading Reactor Operator on both of the submarines I served on, SSN621 and SSN605.? ?So on deployment my submarine damaged the hydraulic ram on the fairwater planes ( the ones on the sail ) and we went back to the tender to have it fixed.? ?This is the second time I had seen a massive lathe at work.? ?The machinists on the tender had to MAKE a new ram?from bar stock on a 20-30 foot long lathe.? No biggie you say.? ?The bar stock in question was a ten" x20 '? chunk of hex K-Monel.? The lathe ran 24/7 for a week straight to shape and not warp the ram, I think the shaft diameter was around 4" and the disc was about 8". I remember chips flying off of the machine red turning blue in flight.? The lathe was turning at a slow speed so as not to heat up the stock.? ?First massive lathe was in the shipyards in Vallejo where they Bored the re-poured babbit out of the submarines's main shaft bearing, it was, 100 feet long 28" in diameter standing 60 feet off of the drydock floor.?
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So prior to my commercial Nuclear Power plant days, I was an ET (electronics technician) in the Navy, specialty was Reactor Operator in submarines, actually I was the Leading Reactor Operator on both of the submarines I served on, SSN621 and SSN605.? ?So on deployment my submarine damaged the hydraulic ram on the fairwater planes ( the ones on the sail ) and we went back to the tender to have it fixed.? ?This is the second time I had seen a massive lathe at work.? ?The machinists on the tender had to MAKE a new ram?from bar stock on a 20-30 foot long lathe.? No biggie you say.? ?The bar stock in question was a ten" x20 '? chunk of hex K-Monel.? The lathe ran 24/7 for a week straight to shape and not warp the ram, I think the shaft diameter was around 4" and the disc was about 8". I remember chips flying off of the machine red turning blue in flight.? The lathe was turning at a slow speed so as not to heat up the stock.? ?First massive lathe was in the shipyards in Vallejo where they Bored the re-poured babbit out of the submarines's main shaft bearing, it was, 100 feet long 28" in diameter standing 60 feet off of the drydock floor.?
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The work hardening issue is common among all austenitic stainless alloys all the way up to the high nickel super alloys like inconels and monels.
The degree of severity seems to be directly correlated to the amount of nickel. Inco 718 in particular if you run it too fast it heats up and abrades the cutter and eats tools.? If you cut it too slow it work hardens and abrades the cutter and eats tools.? This can be alleviated in 304 and 316 with proper tool, feed and cooling.? Selenium in 303 makes it a dream to cut.
I had a friend that was a machine shop owner who ran a lot of inco and other super alloys.? His cutter material of choice interestingly was T15 not carbide.? Back then carbide had sharper edges but did not have the toughness of some of the carbides of today.? Rather fussy to run on aggressive materials.? He would make tools with very positive geometry and sharp edges, almost like an aluminum tool, just massive and rigid then take aggressive cuts peeling heavy chips off the material.? I saw him run turned parts that were shaped completely with high positive plunge cuts.? Just plunge to diameter then move axially and rinse and repeat.? Very counter intuitive since plunge type cutoff tools seem so susceptible to chatter and bad finish.? He would end up with a nice finish then one final light finishing pass with a round nose high positive hand ground tool and very aggressive feed would make a mirror finish.
Incidentally he was the first guy to show me how to take chipped carbide inserts and regrind them on a composite diamond grinder by hand, with high positive geometry for precise special use and great finishes.? Had to be careful with those, not too agressive of cuts....?
?
Reminds me of some of the Stainless steels that work harden. I worked it a plant that made Handi Wrap, a plastic food wrap. Everything was either Stainless or Aluminum. The "boys" in the maintaince shop had a habit of rushing a job on the mill and liked to see the blue metal chips a flying. Great with Carbide tools and metal. Not so good with HSS and Stainless. One little pause and a chance for the Stainless to cool down a bit and it would work harden. Then when they would start up again. Instant broken end mill. WD40 sprayed on the cutter was their coolant/lube of choice. Jeff
On Wednesday, August 16, 2023 at 11:36:41 PM EDT, pat goodyear < pgoodyear@...> wrote:
So here is one for the Titanium boys.? I worked as an instrument technician at a Nuclear Generating plant.? The instrument containers for the nuclear detectors were made of aluminum about 8in in diameter, the top plug was secured with 8 1/4-20 x 1" titanium flathead screws, we replaced them each time we serviced the detectors because using a flat blade screwdriver and hand torque you would snap off the screws if they had been used once.? ?very brittle but hard, and didn't like to be cycled.? ?
pat
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Reminds me of some of the Stainless steels that work harden. I worked it a plant that made Handi Wrap, a plastic food wrap. Everything was either Stainless or Aluminum. The "boys" in the maintaince shop had a habit of rushing a job on the mill and liked to see the blue metal chips a flying. Great with Carbide tools and metal. Not so good with HSS and Stainless. One little pause and a chance for the Stainless to cool down a bit and it would work harden. Then when they would start up again. Instant broken end mill. WD40 sprayed on the cutter was their coolant/lube of choice. Jeff
On Wednesday, August 16, 2023 at 11:36:41 PM EDT, pat goodyear <pgoodyear@...> wrote:
So here is one for the Titanium boys.? I worked as an instrument technician at a Nuclear Generating plant.? The instrument containers for the nuclear detectors were made of aluminum about 8in in diameter, the top plug was secured with 8 1/4-20 x 1" titanium flathead screws, we replaced them each time we serviced the detectors because using a flat blade screwdriver and hand torque you would snap off the screws if they had been used once.? ?very brittle but hard, and didn't like to be cycled.? ?
pat
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From my naive bolt queries to nuclear fusion in one thread¡. I just love internet forums! ?:-)
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In a nuclear fusion vessel after producing neutrons and activation of the structural components, half lives of these elements are days or months, not decades¡¡
Also some of the specialized materials are warranted, especially in cryogenic design. I remember a technician recounting a sad accident in a nuclear lab in Harvard¡..someone decided to save a few bucks by making a port cover out of a type of plain steel instead of Austenitic stainless (304). The one most critical property of stainless in cryogenic design is its toughness. It does not transition from ductile to brittle under cryogenic conditions.? The mild steel got cold, became brittle and fractured. As a result people perished. System design is a serious business¡¡
I am just guessing here, (as I missed my chance in school to take the reactor operator class), but aside from being light weight, strong, and corrosion resistant, many of the ¡°exotic¡± metals like titanium and vanadium are used in the nuclear power industry because they show little propensity when exposed to neutrons to become ¡°activated¡±. and become radioactive themselves.? Many of the radioactive materials used in nuclear medicine, for example, are made by placing a precursor (non-radioactive) element in the core of a nuclear reactor where it can be bombarded by neutrons.? After a period of time, many of the nuclei of the precursor atoms absorb one to several neutrons and change into a different element that is radioactive. ? Perhaps someone here who has worked in nuclear power can shed some light on this. ? Jerry F. ? ? Both Titanium and aluminum are extremely susceptible to galling. Most likely they cold welded every time. Anodizing or lube are both good practices. Both aluminum and titanium come from the reactive section of the periodic table. Bad to pair them together.? Incidentally both flat heads and straight blades are not recommended for structural applications. Usually sheet metal or light brackets.? I worked in the nuclear R&D ?industry. I swear they loved specifying exotic stuff just to be exotic¡. ? On Wed, Aug 16, 2023 at 11:36 PM pat goodyear <pgoodyear@...> wrote: So here is one for the Titanium boys.? I worked as an instrument technician at a Nuclear Generating plant.? The instrument containers for the nuclear detectors were made of aluminum about 8in in diameter, the top plug was secured with 8 1/4-20 x 1" titanium flathead screws, we replaced them each time we serviced the detectors because using a flat blade screwdriver and hand torque you would snap off the screws if they had been used once.? ?very brittle but hard, and didn't like to be cycled.? ?
pat
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I am just guessing here, (as I missed my chance in school to take the reactor operator class), but aside from being light weight, strong, and corrosion resistant, many of the ¡°exotic¡± metals like titanium and vanadium are used in the nuclear power industry because they show little propensity when exposed to neutrons to become ¡°activated¡±. and become radioactive themselves. ?Many of the radioactive materials used in nuclear medicine, for example, are made by placing a precursor (non-radioactive) element in the core of a nuclear reactor where it can be bombarded by neutrons.? After a period of time, many of the nuclei of the precursor atoms absorb one to several neutrons and change into a different element that is radioactive. ? Perhaps someone here who has worked in nuclear power can shed some light on this. ? Jerry F. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Tool247
Sent: Wednesday, August 16, 2023 8:46 PM
To: [email protected]; pgoodyear@...
Cc: Jkle379184
Subject: Re: [Unimat] Bolt queries? Both Titanium and aluminum are extremely susceptible to galling. Most likely they cold welded every time. Anodizing or lube are both good practices. Both aluminum and titanium come from the reactive section of the periodic table. Bad to pair them together.? Incidentally both flat heads and straight blades are not recommended for structural applications. Usually sheet metal or light brackets.? I worked in the nuclear R&D ?industry. I swear they loved specifying exotic stuff just to be exotic¡. ? On Wed, Aug 16, 2023 at 11:36 PM pat goodyear <pgoodyear@...> wrote: So here is one for the Titanium boys.? I worked as an instrument technician at a Nuclear Generating plant.? The instrument containers for the nuclear detectors were made of aluminum about 8in in diameter, the top plug was secured with 8 1/4-20 x 1" titanium flathead screws, we replaced them each time we serviced the detectors because using a flat blade screwdriver and hand torque you would snap off the screws if they had been used once.? ?very brittle but hard, and didn't like to be cycled.? ?
pat
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Both Titanium and aluminum are extremely susceptible to galling. Most likely they cold welded every time. Anodizing or lube are both good practices. Both aluminum and titanium come from the reactive section of the periodic table. Bad to pair them together.?
Incidentally both flat heads and straight blades are not recommended for structural applications. Usually sheet metal or light brackets.?
I worked in the nuclear R&D ?industry. I swear they loved specifying exotic stuff just to be exotic¡.
On Wed, Aug 16, 2023 at 11:36 PM pat goodyear < pgoodyear@...> wrote: So here is one for the Titanium boys.? I worked as an instrument technician at a Nuclear Generating plant.? The instrument containers for the nuclear detectors were made of aluminum about 8in in diameter, the top plug was secured with 8 1/4-20 x 1" titanium flathead screws, we replaced them each time we serviced the detectors because using a flat blade screwdriver and hand torque you would snap off the screws if they had been used once.? ?very brittle but hard, and didn't like to be cycled.? ?
pat
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So here is one for the Titanium boys.? I worked as an instrument technician at a Nuclear Generating plant.? The instrument containers for the nuclear detectors were made of aluminum about 8in in diameter, the top plug was secured with 8 1/4-20 x 1" titanium flathead screws, we replaced them each time we serviced the detectors because using a flat blade screwdriver and hand torque you would snap off the screws if they had been used once.? ?very brittle but hard, and didn't like to be cycled.? ?
pat
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My apologies. Nitinol wire shrinks when heated or when current passes through it. It does it a lot and with large relative force hence the name muscle wire.?
When you tap titanium it shrinks around its tap. Same is tru for drilling.?
But when heated titanium does expand at a low rate approx 1/2 that of stainless.?
My apologies. Remembered it wrong¡
Sr71 skin is titanium but the air frame is aluminum under it. So the expansion probably acts according to the mixtures rule¡¡expands less than the max for the frame and shrinks less than the max per the titanium skin.? Interesting mix exhibiting almost a neutralizing effect¡. On Wed, Aug 16, 2023 at 5:52 PM Dave Seiter < d.seiter@...> wrote:
I've never heard this about Ti before; is it within a certain temperature range?? I know that the SR-71, which is about 97% titanium, lengthened 3-4 inches in flight due to heating from air friction.
-Dave
On Wednesday, August 16, 2023 at 02:20:32 PM PDT, Gerald Feldman < gfeldman2904@...> wrote:
Thanks.? I didn¡¯t know that about Titanium.? On the other hand, most of the low-melting-point alloys (such as Wood¡¯s metal) shrink when they cool, but there are a few others that expand (which makes them good for doing accurate casting. ? Many elements possess unusual? characteristics.? For example, Tin and Zinc will ¡°scream¡± or ¡°cry¡± when bent.? (For that matter, so do I, but I have arthritis.)? Gold can be pounded into sheets until it is just a few atoms thick and one can through it.? Unlike most other solids or liquids, Helium is compressible up to 30% of its volume.? ?? ? And yes, pure aluminum (alloy 1100 if I remember correctly) is soft, gummy, and a PITA to machine (or even cut with a hacksaw.)? When I was just starting, and before I knew this, I spent several hours on my SL trying to machine some small parts for adjusting a pendulum.? ???It was a lesson in frustration. ? Jerry F. ? ? ? ? ? Actually 6061 is the alloy and T6 is the temper from heat treating. 6061-T0 is dead soft and machines crappy. 6061-T4 is bending grade. If you hit T6 with a wide torch for a few seconds it will bend quite nicely. But loses stiffness and strength.? Titanium is a strange material. Not just light and strong¡..it shrinks when it gets hot¡..wrap your brain around that.? That is why it is very difficult to tap (breaks taps) and why Nitinol ¡°muscle wire¡± shrinks with a lot of force when you run current through it.? ? On Wed, Aug 16, 2023 at 1:25 PM Jkle379184 via <jkle379184=aol.com@groupsio> wrote: Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks <peter@...> wrote: Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
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Sr71 skin is titanium but the air frame is aluminum under it. So the expansion probably acts according to the mixtures rule¡¡expands less than the max for the frame and shrinks less than the max per the titanium skin.? Interesting mix exhibiting almost a neutralizing effect¡.
On Wed, Aug 16, 2023 at 5:52 PM Dave Seiter < d.seiter@...> wrote:
I've never heard this about Ti before; is it within a certain temperature range?? I know that the SR-71, which is about 97% titanium, lengthened 3-4 inches in flight due to heating from air friction.
-Dave
On Wednesday, August 16, 2023 at 02:20:32 PM PDT, Gerald Feldman < gfeldman2904@...> wrote:
Thanks.? I didn¡¯t know that about Titanium.? On the other hand, most of the low-melting-point alloys (such as Wood¡¯s metal) shrink when they cool, but there are a few others that expand (which makes them good for doing accurate casting. ? Many elements possess unusual? characteristics.? For example, Tin and Zinc will ¡°scream¡± or ¡°cry¡± when bent.? (For that matter, so do I, but I have arthritis.)? Gold can be pounded into sheets until it is just a few atoms thick and one can through it.? Unlike most other solids or liquids, Helium is compressible up to 30% of its volume.? ?? ? And yes, pure aluminum (alloy 1100 if I remember correctly) is soft, gummy, and a PITA to machine (or even cut with a hacksaw.)? When I was just starting, and before I knew this, I spent several hours on my SL trying to machine some small parts for adjusting a pendulum.? ???It was a lesson in frustration. ? Jerry F. ? ? ? ? ? Actually 6061 is the alloy and T6 is the temper from heat treating. 6061-T0 is dead soft and machines crappy. 6061-T4 is bending grade. If you hit T6 with a wide torch for a few seconds it will bend quite nicely. But loses stiffness and strength.? Titanium is a strange material. Not just light and strong¡..it shrinks when it gets hot¡..wrap your brain around that.? That is why it is very difficult to tap (breaks taps) and why Nitinol ¡°muscle wire¡± shrinks with a lot of force when you run current through it.? ? On Wed, Aug 16, 2023 at 1:25 PM Jkle379184 via <jkle379184=aol.com@groupsio> wrote: Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks <peter@...> wrote: Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
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I've never heard this about Ti before; is it within a certain temperature range?? I know that the SR-71, which is about 97% titanium, lengthened 3-4 inches in flight due to heating from air friction.
-Dave
On Wednesday, August 16, 2023 at 02:20:32 PM PDT, Gerald Feldman <gfeldman2904@...> wrote:
Thanks.? I didn¡¯t know that about Titanium.? On the other hand, most of the low-melting-point alloys (such as Wood¡¯s metal) shrink when they cool, but there are a few others that expand (which makes them good for doing accurate casting. ? Many elements possess unusual? characteristics.? For example, Tin and Zinc will ¡°scream¡± or ¡°cry¡± when bent.? (For that matter, so do I, but I have arthritis.)? Gold can be pounded into sheets until it is just a few atoms thick and one can through it.? Unlike most other solids or liquids, Helium is compressible up to 30% of its volume.? ?? ? And yes, pure aluminum (alloy 1100 if I remember correctly) is soft, gummy, and a PITA to machine (or even cut with a hacksaw.)? When I was just starting, and before I knew this, I spent several hours on my SL trying to machine some small parts for adjusting a pendulum.? ???It was a lesson in frustration. ? Jerry F. ? ? ? ?
From: [email protected] [mailto:[email protected]] On Behalf Of Tool247
Sent: Wednesday, August 16, 2023 10:34 AM
To: [email protected]; jkle379184@...
Subject: Re: [Unimat] Bolt queries ? Actually 6061 is the alloy and T6 is the temper from heat treating. 6061-T0 is dead soft and machines crappy. 6061-T4 is bending grade. If you hit T6 with a wide torch for a few seconds it will bend quite nicely. But loses stiffness and strength.? Titanium is a strange material. Not just light and strong¡..it shrinks when it gets hot¡..wrap your brain around that.? That is why it is very difficult to tap (breaks taps) and why Nitinol ¡°muscle wire¡± shrinks with a lot of force when you run current through it.? ? On Wed, Aug 16, 2023 at 1:25 PM Jkle379184 via <jkle379184=aol.com@groupsio> wrote: Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks <peter@...> wrote: Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
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Superconductors use 5 9s aluminum (99.999% pure). Really mushy.?
While on the subject of strange material properties¡..someone told me that the proof that there is a God is ice¡¡
One of the few materials that gets less dense when it becomes a solid, not more dense. That makes the ice float.?
If ice acted like other materials it would become more dense and then sink to the bottom of a pond progressively freezing the whole pond solid, killing all the fish.? Being less dense and floating protects the aquatic wild life.?
Thanks.? I didn¡¯t know that about Titanium.? On the other hand, most of the low-melting-point alloys (such as Wood¡¯s metal) shrink when they cool, but there are a few others that expand (which makes them good for doing accurate casting. ? Many elements possess unusual? characteristics.? For example, Tin and Zinc will ¡°scream¡± or ¡°cry¡± when bent.? (For that matter, so do I, but I have arthritis.)? Gold can be pounded into sheets until it is just a few atoms thick and one can through it.? Unlike most other solids or liquids, Helium is compressible up to 30% of its volume.? ?? ? And yes, pure aluminum (alloy 1100 if I remember correctly) is soft, gummy, and a PITA to machine (or even cut with a hacksaw.)? When I was just starting, and before I knew this, I spent several hours on my SL trying to machine some small parts for adjusting a pendulum.? ???It was a lesson in frustration. ? Jerry F. ? ? ? ? ? Actually 6061 is the alloy and T6 is the temper from heat treating. 6061-T0 is dead soft and machines crappy. 6061-T4 is bending grade. If you hit T6 with a wide torch for a few seconds it will bend quite nicely. But loses stiffness and strength.? Titanium is a strange material. Not just light and strong¡..it shrinks when it gets hot¡..wrap your brain around that.? That is why it is very difficult to tap (breaks taps) and why Nitinol ¡°muscle wire¡± shrinks with a lot of force when you run current through it.? ? On Wed, Aug 16, 2023 at 1:25 PM Jkle379184 via <jkle379184=aol.com@groupsio> wrote: Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks <peter@...> wrote: Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
|
Thanks.? I didn¡¯t know that about Titanium.? On the other hand, most of the low-melting-point alloys (such as Wood¡¯s metal) shrink when they cool, but there are a few others that expand (which makes them good for doing accurate casting. ? Many elements possess unusual? characteristics.? For example, Tin and Zinc will ¡°scream¡± or ¡°cry¡± when bent.? (For that matter, so do I, but I have arthritis.)? Gold can be pounded into sheets until it is just a few atoms thick and one can through it.? Unlike most other solids or liquids, Helium is compressible up to 30% of its volume.? ?? ? And yes, pure aluminum (alloy 1100 if I remember correctly) is soft, gummy, and a PITA to machine (or even cut with a hacksaw.)? When I was just starting, and before I knew this, I spent several hours on my SL trying to machine some small parts for adjusting a pendulum.? ???It was a lesson in frustration. ? Jerry F. ? ? ? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Tool247
Sent: Wednesday, August 16, 2023 10:34 AM
To: [email protected]; jkle379184@...
Subject: Re: [Unimat] Bolt queries? Actually 6061 is the alloy and T6 is the temper from heat treating. 6061-T0 is dead soft and machines crappy. 6061-T4 is bending grade. If you hit T6 with a wide torch for a few seconds it will bend quite nicely. But loses stiffness and strength.? Titanium is a strange material. Not just light and strong¡..it shrinks when it gets hot¡..wrap your brain around that.? That is why it is very difficult to tap (breaks taps) and why Nitinol ¡°muscle wire¡± shrinks with a lot of force when you run current through it.? ? On Wed, Aug 16, 2023 at 1:25 PM Jkle379184 via <jkle379184=aol.com@groupsio> wrote: Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks <peter@...> wrote: Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
|
Re: Unimat 3 Milling Head; upgrading the vertical column
Since we are on the subject, this is an SL where I made a vertical guide with a rod on one side, and a threaded rod near side.
Also shown is a 3 set up for milling.? I have not made a vertical guide for this, but have mounted a Chinese milling table.
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Re: Unimat 3 Milling Head; upgrading the vertical column
Take a look at this idea.
It may do what you want.
The author states that there may be too much pressure when
raising or lowering the head so a couple of sets of thrust
bearings may be useful.
Regards,
Brian.
On 16-August-2023 11:08 pm, Herman de
Leeuw via groups.io wrote:
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Show quoted text
Thanks very much for this, Dick!
Any advice and sketches to share on
how to mill an existing vertical column and the milling/boring
head - in my case a Unimat 3 - so as to accommodate the
triangular gib key, and some sketches for the long threaded
screw and hand crank? These being exactly the things that are
missing in the original unimats.?
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Actually 6061 is the alloy and T6 is the temper from heat treating. 6061-T0 is dead soft and machines crappy. 6061-T4 is bending grade. If you hit T6 with a wide torch for a few seconds it will bend quite nicely. But loses stiffness and strength.?
Titanium is a strange material. Not just light and strong¡..it shrinks when it gets hot¡..wrap your brain around that.?
That is why it is very difficult to tap (breaks taps) and why Nitinol ¡°muscle wire¡± shrinks with a lot of force when you run current through it.?
Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. ?Jeff
On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks < peter@...> wrote:
Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
|
Lots of different aluminums out there. Some cut and thread fine and some are soft and gum up the cutters. Some are very strong and do not like to bend and some bend easy but are weak. Normally the closer to pure aluminum, the softer it is. I like to use 6061T6, It machines nice and has the strength, but it does not like to bend. The softer more pure alloys will have a slivery look while the stronger stuff tends to has a more light grey color. Use cutting fluid made for alumin. ?Jeff
On Wednesday, August 16, 2023 at 01:10:12 PM EDT, Peter Brooks <peter@...> wrote:
Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
|
One of my road bikes from the 70's has titanium bottom bracket bolts, but I didn't know that until the first time I took it apart.? Titanium was unusual back then, and I had never actually held a piece.? My first thought was "aluminum!?", but a quick check of some catalogs revealed the truth.? I remember holding them for hours- it was hard for me to accept that bolts that light weight could actually be strong.
-Dave
On Wednesday, August 16, 2023 at 10:10:13 AM PDT, Peter Brooks <peter@...> wrote:
Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
|
Thanks everyone for the very detailed replies and discussion - fascinating.
I found out myself yesterday why bolts aren¡¯t made from aluminium. I might as well have been trying to put a thread on a bar of chocolate. It was not a success. Oh well, you live and learn¡
|
Tool247
