Re: Off Topic measuring units
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Try this link:
On 9/17/2023 9:45 AM, old_toolmaker via groups.io wrote:
Hello Carl!
I don’t have a Facebook account so was unable to view your shop and railroad pictures.?
--
forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL
TURRET TOOL POST PLANS?
?LARGE
TURRET TOOL POST PLANS
?MINI-LATHE
CARRIAGE LOCK PLANS
?SMALL
QC TOOL POST PLANS?
?QUICK
CHANGE LATHE TURRET
?MINI
LATHE COMPOUND PIVOT MODIFICATION
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Re: Off Topic measuring units
Try
this link:
On 9/17/2023 9:45 AM, old_toolmaker via
groups.io wrote:
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Hello Carl!
I don’t have a Facebook account so was unable to view your shop
and railroad pictures.?
--
forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST
PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE
LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT
MODIFICATION
|
Re: Headstock spindle spring
If you intend using the machine as a drill press and aren't drilling deep holes, then yes it's a worthwhile addition. Other than that it has no use.
Paul B.
|
Nice display with big numbers. I like it.
Get
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Indispensable. I bought dozens for the student shop I managed for years. Eventually I discovered that the Clockwise branded ones are without a doubt the best value. If you use cheap ones and get frustrated with dead batteries, creeping zeros, and hinky
movement, do yourself a favor and get the best cheap digital caliper available. I just wish they made a 4" one.?
|
Re: Off Topic measuring units
Hello Carl!
I don’t have a Facebook account so was unable to view your shop and railroad pictures.?
--
http://www.homemadetools.net/forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
|
Re: Tips on machining pulley grooves
For
Computers I thought it was the "Keyboard / Chair Interface
Unit" cause all the problems.
On 9/17/2023 5:50 AM, Peter Brooks
wrote:
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On Sun, Sep 17, 2023 at 12:18 AM, Bill in OKC too wrote:
All the problems were the "Stick Actuator" as we Air
Force folks call it. :)
Hahaha...? I worked in IT for many years, both in the commercial
world and in education... Many of the issues raised by 'clients'
were found to be due to 'the nut behind the keyboard'? :-)
|
Re: Tips on machining pulley grooves
Hi
Bill:
You are
right, fancy machines, usually those with CNC, change speed
with diameter. It can be part of the program. And in
production, time matters. The valve seat we were grinding,
they allowed 10 seconds to finish the job.
The
best lathe I've ever run is a Hardinge HVL toolroom lathe. The
head stock was driven by a continuously variable belt drive.
And the carriage feeds were driven by DC motor with a variable
power supply. If something chattered, just twist one of the
knobs until it cut right! Don't get me started about
threading, it was a total cheat on a Hardinge.
For
speeds I just remember 1000 RPM for a 1/4" drill in steel.
Double and Half from there: Double diameter and Half speed:
500 RPM for 1/2", etc. Faster for aluminum and plastic, until
it melts.
Carl.
On 9/17/2023 8:28 AM, Bill in OKC too
via groups.io wrote:
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The formula we used at school is rpm=SPM/d*4.? For
aluminum, SPM is 400-1000 from a chart, 38mm is 1.5"
approximately, and back in the day it was π or 3.14159 or
however many decimals you cared to carry it out. 4 is easier
and still close enough for practical purposes.?
I got 1066rpm, but 1000 or 1100 should be fine, too.
That's with high speed steel tooling. Also on an industrial
lathe. They need to worry about how many parts they can
produce in a day, where a hobbyist usually doesn't. If you
use carbide tooling on a big machine, you can cut about 4x
faster, but you are working on a U3, so forget about that!
:)
Lathes have speeds determined by the gears or pulleys
used to reduce the motor speed, and my experience is that
very few have continuously variable speed, so you use the
closest setting you can to your calculated speed.?
Unless it doesn't work. Then you try the next step. Up or
down, and try it, and see, feel, and heat. If it's better,
carry on, and if not try a different speed! To eliminate
chatter, slower is usually better,? ut not always. Sometimes
you'll need to speed up, sometimes down, and only trying it
will tell you which is better. If it's chattering like mad,
try a different speed. On large stock, and as you get deeper
into it, you may need to change the speed several times,
since your effective diameter changes.?
Some pretty fancy machines will continuously vary the
speed for you. Good luck finding one like that! I've read
about them, but never seen one. ;)
HTH!
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!
Improvise,
Adapt, and Overcome.
Physics
doesn't care about your schedule.
The
only reason I know anything is because I've done
it wrong enough times to START to know better.
Expect in one
hand, expectorate in the other. See which one
gets full first.
On Sunday, September 17, 2023 at 01:46:43 AM CDT,
Peter Brooks <peter@...> wrote:
Bill, thanks for your kind words. I’m sure you are
doing far better than you think you are! ?Life long
learning eh??
Lovely graphic Mike, and I’m sure it would be an
improvement but I don’t have the skill or the
facilities to make it :-)
JHM, thanks for the link to the ME post.
Thanks all for the replies and suggestions. I will
use the ‘thin tool removing waste’ technique first.
My tiny parting tool won’t fit into the space (it is
in a holder which fouls the front of the tool post
as the pulley blank is so large) so I’ll shape and
sharpen a 3mm tool blank.
Most importantly though I’ll draw the thing out at a
10x scale and try to rig up indicators to guide me.
And yes, a round file may come in useful…
One query - when you say ‘slow speed’ what rpm would
be appropriate for a 38mm diameter in aluminium? (I
have yet to get my head around feet per second etc).
|
Re: Off Topic measuring units
Jerry, can you not say essentially the same for fahrenheit? It is repeatable, and consistent. Freezing is not zero only because the medium for freezing was shifted from a specific saline solution to "fresh water".
My point was Celcius does not have the base 10 ease of use of the metric system, so it's inclusion as metric is arbitrary. F, C or K could have been incorporated and little would change. The differences between F and C are jbasically ust points on a scale.
|
Re: Tips on machining pulley grooves
The formula we used at school is rpm=SPM/d*4.? For aluminum, SPM is 400-1000 from a chart, 38mm is 1.5" approximately, and back in the day it was π or 3.14159 or however many decimals you cared to carry it out. 4 is easier and still close enough for practical purposes.?
I got 1066rpm, but 1000 or 1100 should be fine, too. That's with high speed steel tooling. Also on an industrial lathe. They need to worry about how many parts they can produce in a day, where a hobbyist usually doesn't. If you use carbide tooling on a big machine, you can cut about 4x faster, but you are working on a U3, so forget about that! :)
Lathes have speeds determined by the gears or pulleys used to reduce the motor speed, and my experience is that very few have continuously variable speed, so you use the closest setting you can to your calculated speed.?
Unless it doesn't work. Then you try the next step. Up or down, and try it, and see, feel, and heat. If it's better, carry on, and if not try a different speed! To eliminate chatter, slower is usually better,? ut not always. Sometimes you'll need to speed up, sometimes down, and only trying it will tell you which is better. If it's chattering like mad, try a different speed. On large stock, and as you get deeper into it, you may need to change the speed several times, since your effective diameter changes.?
Some pretty fancy machines will continuously vary the speed for you. Good luck finding one like that! I've read about them, but never seen one. ;)
HTH!
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 Sunday, September 17, 2023 at 01:46:43 AM CDT, Peter Brooks <peter@...> wrote:
Bill, thanks for your kind words. I’m sure you are doing far better than you think you are! ?Life long learning eh??
Lovely graphic Mike, and I’m sure it would be an improvement but I don’t have the skill or the facilities to make it :-)
JHM, thanks for the link to the ME post.
Thanks all for the replies and suggestions. I will use the ‘thin tool removing waste’ technique first. My tiny parting tool won’t fit into the space (it is in a holder which fouls the front of the tool post as the pulley blank is so large) so I’ll shape and sharpen a 3mm tool blank.
Most importantly though I’ll draw the thing out at a 10x scale and try to rig up indicators to guide me. And yes, a round file may come in useful…
One query - when you say ‘slow speed’ what rpm would be appropriate for a 38mm diameter in aluminium? (I have yet to get my head around feet per second etc).
|
Re: Headstock spindle spring
Carl,
Thank you for the feedback, so I wont be wasting any money on that.
Dave
On Sun, 17 Sept 2023 at 9:55, Carl <carl.blum@...> wrote:
Hello
David:
My 1973
Unimat came with one, and it was the first thing I took off.
It is nice to have the spring return, but with the spring
there is only 19mm of stroke available. Take it off and you
have 25mm of stroke.
Just
use the quill lever to lift the spindle up and lock it there.
Carl.
On 9/16/2023 8:24 PM, David James via
groups.io wrote:
I saw a headstock spindle spring for sale on ebay. My old cast
iron unimat did not have one when I got it and my manual does not
show one either. Were they only on later models and are they a
worthwhile addition?
I suppose they are good when using it as a drill press.
|
Re: Tips on machining pulley grooves
On Sun, Sep 17, 2023 at 12:18 AM, Bill in OKC too wrote:
All the problems were the "Stick Actuator" as we Air Force folks call it. :)
Hahaha...? I worked in IT for many years, both in the commercial world and in education... Many of the issues raised by 'clients' were found to be due to 'the nut behind the keyboard'? :-)
|
Re: Tips on machining pulley grooves
Bill, thanks for your kind words. I’m sure you are doing far better than you think you are! ?Life long learning eh??
Lovely graphic Mike, and I’m sure it would be an improvement but I don’t have the skill or the facilities to make it :-)
JHM, thanks for the link to the ME post.
Thanks all for the replies and suggestions. I will use the ‘thin tool removing waste’ technique first. My tiny parting tool won’t fit into the space (it is in a holder which fouls the front of the tool post as the pulley blank is so large) so I’ll shape and sharpen a 3mm tool blank.
Most importantly though I’ll draw the thing out at a 10x scale and try to rig up indicators to guide me. And yes, a round file may come in useful…
One query - when you say ‘slow speed’ what rpm would be appropriate for a 38mm diameter in aluminium? (I have yet to get my head around feet per second etc).
|
Re: Off Topic measuring units
Of course!? I must remember to turn on the brain before I start typing. ? Jerry F. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Andrei
Sent: Saturday, September 16, 2023 9:39 PM
To: [email protected]
Subject: Re: [Unimat] Off Topic measuring units? Kelvin
Aaron, ? “Good” standards should be constant and be able to be reproduced wherever one may need it.? Celsius degrees are the same size as the earlier centigrade degrees and are not arbitrary.? A decent glass blower can make a thermometer anywhere in the world, set zero to the freezing point of water and 100 to the boiling point of water and go from there.? The difference between degrees Celsius and degrees centigrade is that the Celsius numbering begins at absolute zero, which is the exact temperature at which all molecular motion stops and just happens to be approximately 273 degrees below the freezing point of water.?? ?If the basis for units appears arbitrary, it is because the definitions have changed over the years so they may be reproduced WITHOUT having to have a physical standard like a 1 kilogram mass or a bar of Platinum-Iridium alloy on which are scribed two lines 1 meter apart. ?Even the second has been redefined so that with the proper equipment it can be reproduced anywhere in the universe. ? Jerry F. ? ? The core imperial / standard units really are not that weird. Sure not as neat and tidy as metric with its base 10, but really not hard to work with.
Most of the really out there units are very industry specific, hogsheads, bushels, ffurlongs etc, and they are only weird out of context. If you were a 19th century winemaker then Horseheads would seem perfectly reasonable.
Metric is less flexible resulting in its own need to adapt non-metric units in specific cases such as the French system for medical catheters or gauge system for needles.
Don't even get me started on Celsius which in no way follows the rule of 10 of the metric system and is just as arbitrary as ferenheit only using other numbers.
|
Re: Off Topic measuring units
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Aaron,
?
“Good” standards should be constant and be able to be reproduced wherever one may need it.? Celsius degrees are the same size as the earlier centigrade
degrees and are not arbitrary.? A decent glass blower can make a thermometer anywhere in the world, set zero to the freezing point of water and 100 to the boiling point of water and go from there.? The difference between degrees Celsius and degrees
centigrade is that the Celsius numbering begins at absolute zero, which is the exact temperature at which all molecular motion stops and just happens to be approximately 273 degrees below the freezing point of water.?? ?If the basis for units appears arbitrary,
it is because the definitions have changed over the years so they may be reproduced WITHOUT having to have a physical standard like a 1 kilogram mass or a bar of Platinum-Iridium alloy on which are scribed two lines 1 meter apart. ?Even the second has been
redefined so that with the proper equipment it can be reproduced anywhere in the universe.
?
Jerry F.
?
?
The core imperial / standard units really are not that weird. Sure not as neat and tidy as metric with its base 10, but really not hard to work with.
Most of the really out there units are very industry specific, hogsheads, bushels, ffurlongs etc, and they are only weird out of context. If you were a 19th century winemaker then Horseheads would seem perfectly reasonable.
Metric is less flexible resulting in its own need to adapt non-metric units in specific cases such as the French system for medical catheters or gauge system for needles.
Don't even get me started on Celsius which in no way follows the rule of 10 of the metric system and is just as arbitrary as ferenheit only using other numbers.
|
Kevin Groenke @ PersonMakeObject
Indispensable. I bought dozens for the student shop I managed for years. Eventually I discovered that the Clockwise branded ones are without a doubt the best value. If you use cheap ones and get frustrated with dead batteries, creeping zeros, and hinky movement, do yourself a favor and get the best cheap digital caliper available. I just wish they made a 4" one.? 
|
Re: Off Topic measuring units
Aaron, ? “Good” standards should be constant and be able to be reproduced wherever one may need it.? Celsius degrees are the same size as the earlier centigrade degrees and are not arbitrary.? A decent glass blower can make a thermometer anywhere in the world, set zero to the freezing point of water and 100 to the boiling point of water and go from there.? The difference between degrees Celsius and degrees centigrade is that the Celsius numbering begins at absolute zero, which is the exact temperature at which all molecular motion stops and just happens to be approximately 273 degrees below the freezing point of water.?? ?If the basis for units appears arbitrary, it is because the definitions have changed over the years so they may be reproduced WITHOUT having to have a physical standard like a 1 kilogram mass or a bar of Platinum-Iridium alloy on which are scribed two lines 1 meter apart. ?Even the second has been redefined so that with the proper equipment it can be reproduced anywhere in the universe. ? Jerry F. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Aaron Woods
Sent: Saturday, September 16, 2023 6:46 AM
To: OldToolmaker; [email protected]
Subject: Re: [Unimat] Off Topic measuring units? The core imperial / standard units really are not that weird. Sure not as neat and tidy as metric with its base 10, but really not hard to work with.
Most of the really out there units are very industry specific, hogsheads, bushels, ffurlongs etc, and they are only weird out of context. If you were a 19th century winemaker then Horseheads would seem perfectly reasonable.
Metric is less flexible resulting in its own need to adapt non-metric units in specific cases such as the French system for medical catheters or gauge system for needles.
Don't even get me started on Celsius which in no way follows the rule of 10 of the metric system and is just as arbitrary as ferenheit only using other numbers.
|
Re: Headstock spindle spring
Hello
David:
My 1973
Unimat came with one, and it was the first thing I took off.
It is nice to have the spring return, but with the spring
there is only 19mm of stroke available. Take it off and you
have 25mm of stroke.
Just
use the quill lever to lift the spindle up and lock it there.
Carl.
On 9/16/2023 8:24 PM, David James via
groups.io wrote:
toggle quoted message
Show quoted text
I saw a headstock spindle spring for sale on ebay. My old cast
iron unimat did not have one when I got it and my manual does not
show one either. Were they only on later models and are they a
worthwhile addition?
I suppose they are good when using it as a drill press.
|
I saw a headstock spindle spring for sale on ebay. My old cast iron unimat did not have one when I got it and my manual does not show one either. Were they only on later models and are they a worthwhile addition? I suppose they are good when using it as a drill press. 
|
Re: Tips on machining pulley grooves
This what i was thinking Peter 
|
Re: Tips on machining pulley grooves
I took a machine shop class in high school, finished the class and graduated from high school right around 50 years ago. A bit over 15 years ago, I bought my first lathe. One of the Chinese Mini-lathes, a Harbor Freight 7x10, model 93212. That was around August 2008, IIRC. From then until December of 2014 I had the devil's own time trying to get that lathe to do what I wanted it to do. Got a lot of great help from this and other boards over at Yahoo groups, before they crashed and burned. Still wasn't doing all that good with my life. My wife got tired of my griping about it, and told me to take another class! So I did. Started in February 2015, and I finally completed it in May of 2022. That's 7 years and 3 month, to the day. It was supposed to be an 8 or 9 month class if you attended full time. And I started full time, but was also working full time, and I'm not a teenager anymore. ;)
I think I made it through the first couple of months, but after that, it was two nights a week, 3 hours per night. One of the things I learned in that class was that I had completely forgotten (assuming I had ever learned) how to measure parts accurately. The class taught me that, and a bit of practice with their equipment, including a set of Johannsen blocks to practice on, fixed that in a couple of days. I searched messages for your first questions here. And that was not a whole lot over a year ago. It took me 7 years to figure out I was failing abjectly, and 7 more to do a lot better. I should be a better machinist than you are. But I would be willing to make a small wager that if I am, it won't be for long! You've made tremendous progress in just over a year! I'd have to be blind and stupid to not recognize that! I will admit to being crazy, but I try not to be stupid! ;)
Oh, and there wasn't a single thing wrong with my first lathe that a bit of skill wouldn't have been able to overcome. All the problems were the "Stick Actuator" as we Air Force folks call 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 Saturday, September 16, 2023 at 05:54:06 PM CDT, Julius Henry Marx <sawbona@...> wrote:
On Sat, Sep 16, 2023 at 07:19 PM, Bill in OKC too wrote:
... well done! Congratulations!
Thank you, appreciate your saying so. 8^) Best, JHM
|
Carl
OldToolmaker
Bill in OKC too
David James