Jim, great to know there's an app. Whats it called? At work I have a hand held tach. that comes with a roll of reflective tape. We check the bench lathes occasionally to be sure they don't exceed marked wheel rpm.
Thank again,
Payson.
|
For my 1942 single lever Heavy 10L I didn’t want to muck up the gear cover so I pressed a rare earth magnet into the opposite end of the bearing clamp hole and then put a small TO-92 size hall sensor in a plastic tube shoved into a bracket.? One pulse per revolution is fine for my Electronic Lead Screw which shows spindle RPM or if the tool tip is calibrated from the centerline it’s possible to read SFM. 
?
toggle quoted message
Show quoted text
From: SouthBendLathe@groups.io [mailto:SouthBendLathe@groups.io] On Behalf Of Gary Johnson via groups.io
Sent: December 20, 2023 3:22 PM
To: SouthBendLathe@groups.io
Subject: Re: [SouthBendLathe] Tach pickup Location? This is for a heavy 10L, but maybe it will give you some ideas. I used 1/8" dia rare earth magnets (four), mounted in 3/8" dia aluminum pucks epoxied to the gear. They are sized so that the magnets would pass very close to the Hall-effect sensor. The sensor was mounted on an aluminum tee bracket affixed to a spot I flattened off and added a tapped hole. This sensor was part of the accessories offered with the old MachTach kit which unfortunately is no longer made.
-Gary
|
The 9Inch and 10K are much smaller than the examples shown. In the morniing I will take/send some photos of mine on my 10K. Works great! Ray
On Wednesday, December 20, 2023 at 04:55:31 PM PST, Andrei <calciu1@...> wrote:
https://www.practicalmachinist.com/forum/threads/digital-tachometer-install-on-13-south-bend-lathe.342824/
Get
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of mike allen <animal@...>
Sent: Wednesday, December 20, 2023 7:52:41 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Tach pickup Location
?
I was thinkin bout the left end of the spindle also , but then would I have to move the magnet if I wanted to put a spyder on ? Don't know . As usual I have been over thinkin this for a while .?
I just finally got my lathe moved over to the new place on Saturday .I have crashed cars,trucks,motorcycles , rolled a water truck & I don't think I have ever had the pucker factor as high as when I turned down my dirt road with the lathe on a trailer? .
Amazingly all the loose hardware I left on the bench is right where I left it . Now I have to get one of my roll-aways moved with all my machine tools . We finally got moisture on the ground , so I gots mud everywhere .
thanks
animal
On 12/20/23 4:27 PM, Andrei wrote:
The ones I have seen have the sensor on the backend of the spindle
Get
Hey folks , I know some of ya have put Tach's on their 9" lathes . Where
did ya put the pickup ?? I'm doin a project/experiment & I will be
needin to put a Tach pickup on my 9A spindle . Rite now I'm leaning?
towards a magnetic pickup cause of the size of the sending unit & magnet .
thanks
animal
|
Re: Dial indicator crystals (new rabbit hole for me!)
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
Sent from Proton Mail mobile
toggle quoted message
Show quoted text
-------- 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
--
-George M.
|
Re: Dial indicator crystals (new rabbit hole for me!)
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
|
https://www.practicalmachinist.com/forum/threads/digital-tachometer-install-on-13-south-bend-lathe.342824/
Get
toggle quoted message
Show quoted text
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of mike allen <animal@...>
Sent: Wednesday, December 20, 2023 7:52:41 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Tach pickup Location
?
I was thinkin bout the left end of the spindle also , but then would I have to move the magnet if I wanted to put a spyder on ? Don't know . As usual I have been over thinkin this for a while .?
I just finally got my lathe moved over to the new place on Saturday .I have crashed cars,trucks,motorcycles , rolled a water truck & I don't think I have ever had the pucker factor as high as when I turned down my dirt road with the lathe on a trailer? .
Amazingly all the loose hardware I left on the bench is right where I left it . Now I have to get one of my roll-aways moved with all my machine tools . We finally got moisture on the ground , so I gots mud everywhere .
thanks
animal
On 12/20/23 4:27 PM, Andrei wrote:
The ones I have seen have the sensor on the backend of the spindle
Get
Hey folks , I know some of ya have put Tach's on their 9" lathes . Where
did ya put the pickup ?? I'm doin a project/experiment & I will be
needin to put a Tach pickup on my 9A spindle . Rite now I'm leaning?
towards a magnetic pickup cause of the size of the sending unit & magnet .
thanks
animal
|
I was thinkin bout the left end of the spindle also , but then
would I have to move the magnet if I wanted to put a spyder on ?
Don't know . As usual I have been over thinkin this for a while .?
I just finally got my lathe moved over to the new place on
Saturday .I have crashed cars,trucks,motorcycles , rolled a water
truck & I don't think I have ever had the pucker factor as
high as when I turned down my dirt road with the lathe on a
trailer? . Amazingly all the loose hardware I left on the bench is
right where I left it . Now I have to get one of my roll-aways
moved with all my machine tools . We finally got moisture on the
ground , so I gots mud everywhere .
thanks
animal
On 12/20/23 4:27 PM, Andrei wrote:
toggle quoted message
Show quoted text
The ones I have seen have the sensor on the
backend of the spindle
Get
Hey folks , I know some of ya have
put Tach's on their 9" lathes . Where
did ya put the pickup ?? I'm doin a project/experiment
& I will be
needin to put a Tach pickup on my 9A spindle . Rite now
I'm leaning?
towards a magnetic pickup cause of the size of the sending
unit & magnet .
thanks
animal
|
Thanks GAry . I have a huge dent in my forehead after lookin at
yer pic . I kept thinklin what am I gonna do with the back gear
plunger . No longer a issue .
animal
On 12/20/23 3:22 PM, Gary Johnson via
groups.io wrote:
toggle quoted message
Show quoted text
This is for a heavy 10L, but maybe it will give you some ideas. I
used 1/8" dia rare earth magnets (four), mounted in 3/8" dia
aluminum pucks epoxied to the gear. They are sized so that the
magnets would pass very close to the Hall-effect sensor. The
sensor was mounted on an aluminum tee bracket affixed to a spot I
flattened off and added a tapped hole. This sensor was part of the
accessories offered with the old MachTach kit which unfortunately
is no longer made.
-Gary
|
The ones I have seen have the sensor on the backend of the spindle
Get
toggle quoted message
Show quoted text
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of mike allen <animal@...>
Sent: Wednesday, December 20, 2023 6:00:39 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: [SouthBendLathe] Tach pickup Location
?
Hey folks , I know some of ya have put Tach's on their 9" lathes . Where
did ya put the pickup ?? I'm doin a project/experiment & I will be
needin to put a Tach pickup on my 9A spindle . Rite now I'm leaning?
towards a magnetic pickup cause of the size of the sending unit & magnet .
thanks
animal
|
I started with a bicycle speedometer.? This is a 9”? Magnet super glued to spindle take up nut.?
The sensor was stuck on the headstock near it.?
Requires some calculation to convert mph to rpm
I used it once and the I got a strobe app for my phone. That only requires a piece of white tape and reads direct.?
toggle quoted message
Show quoted text
On Dec 20, 2023, at 6:22?PM, Gary Johnson via groups.io <gwj@...> wrote:
?This is for a heavy 10L, but maybe it will give you some ideas. I used 1/8" dia rare earth magnets (four), mounted in 3/8" dia aluminum pucks epoxied to the gear. They are sized so that the magnets would pass very close to the Hall-effect sensor. The sensor was mounted on an aluminum tee bracket affixed to a spot I flattened off and added a tapped hole. This sensor was part of the accessories offered with the old MachTach kit which unfortunately is no longer made. -Gary <Heavy 10L tach sensor mount.jpeg>
--
Jim B
|
This is for a heavy 10L, but maybe it will give you some ideas. I used 1/8" dia rare earth magnets (four), mounted in 3/8" dia aluminum pucks epoxied to the gear. They are sized so that the magnets would pass very close to the Hall-effect sensor. The sensor was mounted on an aluminum tee bracket affixed to a spot I flattened off and added a tapped hole. This sensor was part of the accessories offered with the old MachTach kit which unfortunately is no longer made. -Gary 
|
Hey folks , I know some of ya have put Tach's on their 9" lathes . Where
did ya put the pickup ?? I'm doin a project/experiment & I will be
needin to put a Tach pickup on my 9A spindle . Rite now I'm leaning?
towards a magnetic pickup cause of the size of the sending unit & magnet .
thanks
animal
|
Re: Dial indicator crystals (new rabbit hole for me!)
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: "SouthBendLathe@groups.io" <SouthBendLathe@groups.io>
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
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of John via groups.io <reproturn@...>
Sent: Wednesday, December 13, 2023 8:52:44 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!) 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 From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of George Meinschein via groups.io
Sent: Thursday, December 14, 2023 12:03 PM
To: SouthBendLathe@groups.io; BridgeportMill@groups.io; OldMachineRestorations@groups.io
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.
--
-George M.
|
Re: 9" model A reversing gear
|
Re: 9" model A reversing gear
Wait a minute! Where are the photos?
;)
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 Saturday, December 16, 2023 at 06:03:27 PM CST, straitsman via groups.io <comynmj@...> wrote:
Thanks to all who made suggestions.? Project completed.? ?
|
Re: 9" model A reversing gear
Thanks to all who made suggestions.? Project completed.? ?
|
Re: Dial indicator crystals (new rabbit hole for me!)
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: "SouthBendLathe@groups.io" <SouthBendLathe@groups.io>
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
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of John via groups.io <reproturn@...>
Sent: Wednesday, December 13, 2023 8:52:44 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!) 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 From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of George Meinschein via groups.io
Sent: Thursday, December 14, 2023 12:03 PM
To: SouthBendLathe@groups.io; BridgeportMill@groups.io; OldMachineRestorations@groups.io
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.
-- -George M.
--
-George M.
|
Re: Dial indicator crystals (new rabbit hole for me!)
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.
|
Re: Dial indicator crystals (new rabbit hole for me!)
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
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of George Meinschein via groups.io <gmeinschein@...>
Sent: Thursday, December 14, 2023 10:04:45 AM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
?
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: "SouthBendLathe@groups.io" <SouthBendLathe@groups.io>
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
From:
SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of John via groups.io <reproturn@...>
Sent: Wednesday, December 13, 2023 8:52:44 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!)
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
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
On Behalf Of George Meinschein via groups.io
Sent: Thursday, December 14, 2023 12:03 PM
To: SouthBendLathe@groups.io;
BridgeportMill@groups.io;
OldMachineRestorations@groups.io
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
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-George M.
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-George M.
--
-George M.
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Re: Dial indicator crystals (new rabbit hole for me!)
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: "SouthBendLathe@groups.io" <SouthBendLathe@groups.io>
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
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of John via groups.io <reproturn@...>
Sent: Wednesday, December 13, 2023 8:52:44 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Dial indicator crystals (new rabbit hole for me!) 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 From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of George Meinschein via groups.io
Sent: Thursday, December 14, 2023 12:03 PM
To: SouthBendLathe@groups.io; BridgeportMill@groups.io; OldMachineRestorations@groups.io
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.
-- -George M.
--
-George M.
|
Payson
Jim_B
Bill in OKC too