|
Hello all, First off, I apologize for any cross posts. ?Lately, I’ve been fixing a few “parts only”?dial and dial test indicators that I picked up on eBay. ?I’m thinking about getting some 1/25” clear?acrylic sheet and making some nice new?dial crystals. ?Anyone ever worked with acrylic sheet? ?Is this something I’d?knock out with a punch and die setup? ?I did see one guy on YouTube make?his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. ?The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. ?Thoughts and comments from the the collective group?brain power please!
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
-- -George M.
|
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. ? Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. ? That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. ? Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. ? As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. ? Hope that helps. Cheers John Bates Sydney, Australia ? ? ?
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Show quoted text
From: [email protected] < [email protected]> On Behalf Of George Meinschein via groups.io Sent: Thursday, December 14, 2023 12:03 PM To: [email protected]; [email protected]; [email protected]Subject: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!) ? First off, I apologize for any cross posts. ?Lately, I’ve been fixing a few “parts only”?dial and dial test indicators that I picked up on eBay. ?I’m thinking about getting some 1/25” clear?acrylic sheet and making some nice new?dial crystals. ?Anyone ever worked with acrylic sheet? ?Is this something I’d?knock out with a punch and die setup? ?I did see one guy on YouTube make?his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. ?The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. ?Thoughts and comments from the the collective group?brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
|
I concur with John's reply. G-S Supplies is legit. They stock the
common sizes. I think their minimum is 36 total per order and 6 per
size. Maybe they are flexible on the minimums, but I have not tested
that.
Mineral glass is preferred over acrylic. It is also possible to buy
something bigger and turn it down to fit. I have never tried turning
mineral glass, so I do not know if that is an option.
?If you are only doing a few, it might be more economical to buy the
Chicom crystals off ebay. You may need to know the size you need as
they do not always list makes and models of indicator that their
crystals fit. It may just list the diameter and curved or flat. They
charge less than $10 per crystal including shipping. I cannot
imagine it being cheaper in time and labor to buy a sheet of acrylic
and cutting them out yourself.
On 12/13/2023 8:52 PM, John via
groups.io wrote:
toggle quoted message
Show quoted text
Hello
George
I
usually don’t have much to say on the group, but on this
occasion, I may be able to help.
?
Like
you I also repair gauges. Normally I buy replacement
crystals from G-S Supplies in NY
. No commercial connection just a happy overseas customer
for more than 20 years. They are great to deal with. The
website has a lot of data about crystal sizes and types.
Prices are reasonable.
?
That
said, I have made a few crystals because G-S does not
carry/make many of the bigger sizes unless you want to order
500. Biggest problem I have with that here in Australia is
finding acrylic sheet thin enough. But I’m sure there is a
supply in the US.
?
Turning
is the only method I have tried but a punch would probably
do just fine and if necessary you can turn a bevel
afterwards.
?
As
to the bevel edge I can’t speak for every make and type of
gauge, but many regular size gauges made by Mitutoyo,
Starrett, Federal, Standard, etc. use bevel edge crystals.
However, that only applies to domed crystals (by the way
they start out flat and you deform them to fit the bezel).
But (there is always a but) some gauges including ones made
by the above makers have flat crystals and no bevel.
?
Hope
that helps.
Cheers
John
Bates
Sydney,
Australia
?
?
?
?
First off, I apologize for any cross
posts. ?Lately, I’ve been fixing a few “parts only”?dial and
dial test indicators that I picked up on eBay. ?I’m thinking
about getting some 1/25” clear?acrylic sheet and making some
nice new?dial crystals. ?Anyone ever worked with acrylic
sheet? ?Is this something I’d?knock out with a punch and die
setup? ?I did see one guy on YouTube make?his dial crystal
on a lathe. Clamped the acrylic sheet between two silicone
rubber pads and turned the O.D. ?The Mitutoyo crystals have
a beveled edge, so maybe the lathe is the way to go.
?Thoughts and comments from the the collective group?brain
power please!
Thanks,
George H. Meinschein, P.E.
Firearm
and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
|
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
toggle quoted message
Show quoted text
Hello George
I usually don’t have much to say on the group, but on this occasion, I may be able to help.
?
Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY
. No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable.
?
That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m
sure there is a supply in the US.
?
Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards.
?
As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals
(by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel.
?
Hope that helps.
Cheers
John Bates
Sydney, Australia
?
?
?
?
First off, I apologize for any cross posts. ?Lately, I’ve been fixing a few “parts only”?dial and dial test indicators that I picked up on eBay. ?I’m thinking about getting some 1/25” clear?acrylic sheet and making some nice new?dial
crystals. ?Anyone ever worked with acrylic sheet? ?Is this something I’d?knock out with a punch and die setup? ?I did see one guy on YouTube make?his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. ?The
Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. ?Thoughts and comments from the the collective group?brain power please!
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
|
Hello Andrei I have a crystal press with a variety of different sized domed anvils – concave anvil on top and a convex anvil on the bottom. The bezel and the crystal go in and the crystal is distorted enough to allow the rim to fit into the annular groove on the bezel. Once you have a good fit all round the pressure is released and you get a good dust-tight fit. ? That being said I have seen solid brass formers made for use in a vice similar. ? Melt shaping could work but I don’t think that it would produce the long-term joint tension required for a good tight fit. Others may be able to comment on this point. ? You are correct about the distortion, but in practice this is quite minor and does not affect the ability to read the gauge correctly. Also some crystal are preformed and not flat – usually those for the smaller gauges (like the Starrett 711) so the distortion created by fitting is reduced. ? Cheers John Bates Sydney, Australia ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Andrei Sent: Thursday, December 14, 2023 4:59 PM To: [email protected]Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!) ? I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. ? Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. ? That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. ? Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. ? As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. ? Hope that helps. Cheers John Bates Sydney, Australia ? ? ? ? First off, I apologize for any cross posts. ?Lately, I’ve been fixing a few “parts only”?dial and dial test indicators that I picked up on eBay. ?I’m thinking about getting some 1/25” clear?acrylic sheet and making some nice new?dial crystals. ?Anyone ever worked with acrylic sheet? ?Is this something I’d?knock out with a punch and die setup? ?I did see one guy on YouTube make?his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. ?The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. ?Thoughts and comments from the the collective group?brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
|
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
toggle quoted message
Show quoted text
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. Hope that helps. Cheers John Bates Sydney, Australia First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
|
Guys, Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. Hope that helps. Cheers John Bates Sydney, Australia First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
--
-George M.
|
George, I've never done such work. Last I worked with acrylic sheet in anything remotely resembling "fancy" work, I made a cover for a lab scale. That was about 50 years ago or so. I'd be interested in some detail on what and how you're doing on this. I have a couple of indicators that could use a new crystal sitting around here.
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Thursday, December 14, 2023 at 09:05:22 AM CST, George Meinschein via groups.io <gmeinschein@...> wrote:
Guys, Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. Hope that helps. Cheers John Bates Sydney, Australia First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
--
-George M.
|
George, if you do, share some pics or videos. I will never do this, but I sure would like to see it done.
Get
toggle quoted message
Show quoted text
Guys,
Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals
that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours
for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold
the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking,
use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol
(for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George
I usually don’t have much to say on the group, but on this occasion, I may be able to help.
Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY
. No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable.
That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But
I’m sure there is a supply in the US.
Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards.
As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals
(by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel.
Hope that helps.
Cheers
John Bates
Sydney, Australia
First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial
crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo
crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please!
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
--
-George M.
|
Is .040" universal, and has anyone taken a sample measurement of assorted crystals? What about hole saws, diamond?
In 1976 I worked, for several months here in Massachusetts, learning tool repair for Fowler Tool. Best experience. I, too, learned to use dies for curving crystals into shape. They had received many Fowler branded calipers from Helios I think, and most had cracked crystals, BUT - they went down the road of waiting for the customer to return them for repair, and not inspecting before shipping.
Best Holidays to all,
Payson.
|
I second it , when yer through learning yer through . Years back
I had a bud tell me how he had started makin a lense for a
telescope . It sure seemed like a lot of work but was real
interesting . He discovered girls & that was the end of
telescope . I like yer resourcefulness at trying to get the
correct shape .
animal
On 12/14/23 8:42 AM, Andrei wrote:
toggle quoted message
Show quoted text
George, if you do, share some pics or videos. I
will never do this, but I sure would like to see it done.
Get
Guys,
Thanks
for the input.? I can get a dozen 4"x6" sheets 0.040" thick
from Amazon for $8.00 and delivered for free.? A dozen 8x10
sheets are $14.00.? I've been using the vise method to bend
the crystals that I have removed and replaced so far.? I seem
to have a 50 year collection (probably a 90 year collection if
I add my father's stuff) of odd and end shaped knobs, buttons,
rubber feet, PVC fittings and so on that allows me to get the
right combo of contours for bending the crystals in the vise.
Now,
I'm thinking of using a mini fly cutter to plunge into the
sheet and cut out the crystal with the proper beveled edge in
one operation.? Double-sided tape or maybe hook up the vaccum
pump to hold the sheets down.? Phones are usually quiet here
between Christmas and New Years Day.? So, I might get a chance
to experiment a bit.
Thanks,
George H. Meinschein, P.E.
Firearm
and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at
04:19, eddie.draper@... via groups.io
<eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of
which both Acrylic & Polycarbonate are examples). If
you want to avoid it breaking or cracking, use
Polycarbonate rather than acrylic, but note that it
scratches nearly as easily. Both machine easily with
normal tools, and quickly take a polish to fully
transparent if the final cut is very fine, followed by
metal polish such as Brasso or Solvol Autosol (for car
chrome) on a cloth. No idea what the equivalents are
outside the UK. You could try machining a convex one out
of a thicker piece without heating, and if you only did
the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George
I usually don’t have much to say on the group, but on this occasion, I may be able to help.
Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY
. No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable.
That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But
I’m sure there is a supply in the US.
Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards.
As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals
(by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel.
Hope that helps.
Cheers
John Bates
Sydney, Australia
First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial
crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo
crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please!
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
--
-George M.
|
The telescope works great for girls. You go out at night, in the middle of a field, with a blanket and a chair. You will not get much stargazing done, though.
Get
toggle quoted message
Show quoted text
I second it , when yer through learning yer through . Years back I had a bud tell me how he had started makin a lense for a telescope . It sure seemed like a lot of work but was real interesting . He discovered girls & that was the end of telescope . I like
yer resourcefulness at trying to get the correct shape .
animal
On 12/14/23 8:42 AM, Andrei wrote:
George, if you do, share some pics or videos. I will never do this, but I sure would like to see it done.
Get
Guys,
Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals
that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours
for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold
the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19,
eddie.draper@... via groups.io
<eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or
cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol
Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------ From: "Andrei"
<calciu1@...> To:
"[email protected]"
<[email protected]> Sent: Thursday, 14 Dec, 23 At 05:58 Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George
I usually don’t have much to say on the group, but on this occasion, I may be able to help.
Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY
. No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable.
That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But
I’m sure there is a supply in the US.
Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards.
As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals
(by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel.
Hope that helps.
Cheers
John Bates
Sydney, Australia
First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial
crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo
crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please!
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive Freehold, NJ 07728
gmeinschein@... Cell#:
732-580-1736
-- -George M.
--
-George M.
|
Bill, I’ll document the whole dial indicator refurb?process somehow. ?It looks slightly different for the various makes and models out there. ?Having said that, Steven Spielberg I ain’t! ?My new Samsung S23Ultra has amazing?video and photo capability. ?I’ll probably just mount that close by and do a series of really short overview, before,?disassembly, cleaning,?reassembly, and after recordings to put up on YouTube. ?The crystal issue can probably be a couple of episodes itself.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
On Thu, Dec 14, 2023 at 11:38 AM, Bill in OKC too via groups.io < wmrmeyers@...> wrote: George, I've never done such work. Last I worked with acrylic sheet in anything remotely resembling "fancy" work, I made a cover for a lab scale. That was about 50 years ago or so. I'd be interested in some detail on what and how you're doing on this. I have a couple of indicators that could use a new crystal sitting around here.
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Thursday, December 14, 2023 at 09:05:22 AM CST, George Meinschein via groups.io <gmeinschein@...> wrote:
Guys, Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. Hope that helps. Cheers John Bates Sydney, Australia First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
-- -George M.
--
-George M.
|
Andrei, That’s my plan!
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
On Thu, Dec 14, 2023 at 11:42 AM, Andrei < calciu1@...> wrote:
George, if you do, share some pics or videos. I will never do this, but I sure would like to see it done.
Get
Guys,
Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals
that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours
for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold
the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking,
use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol
(for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George
I usually don’t have much to say on the group, but on this occasion, I may be able to help.
Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY
. No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable.
That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But
I’m sure there is a supply in the US.
Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards.
As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals
(by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel.
Hope that helps.
Cheers
John Bates
Sydney, Australia
First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial
crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo
crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please!
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
--
-George M.
--
-George M.
|
Payson, 0.040”,?or maybe 1mm, does seem to be a standard. ?The one loose crystal that I had on hand did measure 0.043”.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
On Thu, Dec 14, 2023 at 11:48 AM, Payson < egreene104@...> wrote: Is .040" universal, and has anyone taken a sample measurement of assorted crystals? What about hole saws, diamond?
In 1976 I worked, for several months here in Massachusetts, learning tool repair for Fowler Tool. Best experience. I, too, learned to use dies for curving crystals into shape. They had received many Fowler branded calipers from Helios I think, and most had cracked crystals, BUT - they went down the road of waiting for the customer to return them for repair, and not inspecting before shipping.
Best Holidays to all,
Payson.
--
-George M.
|
That should be more than adequate, and well above what I could do myself. And I was a professional photographer at one time. ;) Many thanks!
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)?
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Friday, December 15, 2023 at 07:05:57 PM CST, George Meinschein via groups.io <gmeinschein@...> wrote:
Bill, I’ll document the whole dial indicator refurb?process somehow. ?It looks slightly different for the various makes and models out there. ?Having said that, Steven Spielberg I ain’t! ?My new Samsung S23Ultra has amazing?video and photo capability. ?I’ll probably just mount that close by and do a series of really short overview, before,?disassembly, cleaning,?reassembly, and after recordings to put up on YouTube. ?The crystal issue can probably be a couple of episodes itself.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
On Thu, Dec 14, 2023 at 11:38 AM, Bill in OKC too via groups.io < wmrmeyers@...> wrote: George, I've never done such work. Last I worked with acrylic sheet in anything remotely resembling "fancy" work, I made a cover for a lab scale. That was about 50 years ago or so. I'd be interested in some detail on what and how you're doing on this. I have a couple of indicators that could use a new crystal sitting around here.
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Thursday, December 14, 2023 at 09:05:22 AM CST, George Meinschein via groups.io <gmeinschein@...> wrote:
Guys, Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. Hope that helps. Cheers John Bates Sydney, Australia First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
--
-George M.
-- -George M.
--
-George M.
|
Update!? Someone on the Bridgeport Mill group suggested using a lathe to make the dial crystals and that is how I saw one person doing it on YouTube.? They rough cut the sheet to size (with a razor knife I think), pinch it between two round plates, and turn the OD.? One plate in the chuck or collet and the other plate brought up tight by the tailstock.? Live center in the tailstock.? I haven't seen a downside to this approach yet.? I also did some calculations to figure out what OD and bevel angle are required for the flat dial crystal to be the correct arc when installed in the bezel.? I thought I could get away with the installed crystal height being a relatively consistent percentage of OD, but after measuring the indicators I have on hand it was obvious that the height/OD ratio varies by manufacturer and model.? Next up, an Excel spreadsheet to run the crystal calculations given specific crystal height and bezel ID values.? I also added a smartphone to tripod adapter to my Christmas list (getting ready to make some totally amateur tutorial videos)!
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 10:04, George Meinschein <gmeinschein@...> wrote:
Guys, Thanks for the input.? I can get a dozen 4"x6" sheets 0.040" thick from Amazon for $8.00 and delivered for free.? A dozen 8x10 sheets are $14.00.? I've been using the vise method to bend the crystals that I have removed and replaced so far.? I seem to have a 50 year collection (probably a 90 year collection if I add my father's stuff) of odd and end shaped knobs, buttons, rubber feet, PVC fittings and so on that allows me to get the right combo of contours for bending the crystals in the vise.
Now, I'm thinking of using a mini fly cutter to plunge into the sheet and cut out the crystal with the proper beveled edge in one operation.? Double-sided tape or maybe hook up the vaccum pump to hold the sheets down.? Phones are usually quiet here between Christmas and New Years Day.? So, I might get a chance to experiment a bit.
Thanks, George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736
Sent with secure email.
On Thursday, 14 December 2023 at 04:19, eddie.draper@... via groups.io <eddie.draper@...> wrote:
Melt shaping OUGHT to work on any thermoplastic (of which both Acrylic & Polycarbonate are examples). If you want to avoid it breaking or cracking, use Polycarbonate rather than acrylic, but note that it scratches nearly as easily. Both machine easily with normal tools, and quickly take a polish to fully transparent if the final cut is very fine, followed by metal polish such as Brasso or Solvol Autosol (for car chrome) on a cloth. No idea what the equivalents are outside the UK. You could try machining a convex one out of a thicker piece without heating, and if you only did the outside, it would slightly act as a magnifier.
Eddie
------ Original Message ------
From: "Andrei" <calciu1@...>
To: "[email protected]" <[email protected]>
Sent: Thursday, 14 Dec, 23 At 05:58
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
I always wondered how they domed the crystals without optical distortions. The glass ones are ground or melted over a mould, but what about the plastic ones? Does melt shaping work on them, too?
Get
Hello George I usually don’t have much to say on the group, but on this occasion, I may be able to help. Like you I also repair gauges. Normally I buy replacement crystals from G-S Supplies in NY . No commercial connection just a happy overseas customer for more than 20 years. They are great to deal with. The website has a lot of data about crystal sizes and types. Prices are reasonable. That said, I have made a few crystals because G-S does not carry/make many of the bigger sizes unless you want to order 500. Biggest problem I have with that here in Australia is finding acrylic sheet thin enough. But I’m sure there is a supply in the US. Turning is the only method I have tried but a punch would probably do just fine and if necessary you can turn a bevel afterwards. As to the bevel edge I can’t speak for every make and type of gauge, but many regular size gauges made by Mitutoyo, Starrett, Federal, Standard, etc. use bevel edge crystals. However, that only applies to domed crystals (by the way they start out flat and you deform them to fit the bezel). But (there is always a but) some gauges including ones made by the above makers have flat crystals and no bevel. Hope that helps. Cheers John Bates Sydney, Australia First off, I apologize for any cross posts. Lately, I’ve been fixing a few “parts only” dial and dial test indicators that I picked up on eBay. I’m thinking about getting some 1/25” clear acrylic sheet and making some nice new dial crystals. Anyone ever worked with acrylic sheet? Is this something I’d knock out with a punch and die setup? I did see one guy on YouTube make his dial crystal on a lathe. Clamped the acrylic sheet between two silicone rubber pads and turned the O.D. The Mitutoyo crystals have a beveled edge, so maybe the lathe is the way to go. Thoughts and comments from the the collective group brain power please! Thanks, George H. Meinschein, P.E. Firearm and Ballistics Engineering LLC 150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
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-George M.
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-George M.
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I wonder if Long Island Indicator would give you a clue as to the radius of the male and female dies to curve a dial for insertion?
Payson
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Payson,
The concave and convex press inserts are pretty much a "choose what works best" fit from what I can see. I use an assortment of knobs, rubber bushings, and pvc fittings in a vise. That works fine for me and hasn't damaged any crystals yet.
Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736
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-------- Original Message -------- On Dec 20, 2023, 10:17?PM, Payson < egreene104@...> wrote:
I wonder if Long Island Indicator would give you a clue as to the radius of the male and female dies to curve a dial for insertion?
Payson
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-George M.
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IIRC, they have a booklet for DIY types that might have that info? Anyone seen it?
Bill in OKC?
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, December 20, 2023 at 09:17:09 PM CST, Payson <egreene104@...> wrote:
I wonder if Long Island Indicator would give you a clue as to the radius of the male and female dies to curve a dial for insertion?
Payson
|
John
Bill in OKC too
Payson