Re: What is the 'BEST' Unimat ?
Bringing the discussion back to Unimats.
Re-read the Unimat manuals written for the U.S. market (Miniature Machining Techniques). The 1963 version, at least, speaks of the .04" you mentioned.
Though most camera, optical and
instrument parts are setup with metric
system threads, you may prefer to work
in inches. One millimeter equals .03937
inch. For all but the most exacting
work, you can round off this decimal to
.04", the amount of feed in one turn of
the handwheel. In inches, each small
mark is a feed of .002'" It is important to
remember that when you are cutting
across the lathe bed, that you reduce
both sides of the workpiece at once.
Thus, turning one calibration actually
removes double the feed, 004": a complete
turn of the handwheel, .08".
On Thursday, September 14, 2023 at 12:49:03 PM EDT, Charles Kinzer <ckinzer@...> wrote:
Here is how they have "English" units on a lathe that is natively metric.? One turn of the handwheel is 1 mm or 0.0394 inches.? That's pretty close to 0.040 inches, so they just mark the wheel in 40 increments as being "close enough."? It seems that most buying these (amateurs and hobbyists) are not bothered as they tend to measure otherwise for the final cut otherwise or something.? Or spend most of their hobby trying to improve the lathe otherwise as an end in itself.? Or don't know.? Or don't care.
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
Hello
Chris:
I just
checked and a pound (US) equals 453.5924 grams.
I do
find package sizes very interesting. Often I think they use
odd sizes to make price comparisons difficult. Different
packages of the same product will be in even ounces, pounds,
kilos or grams and sometimes not an even amount of anything!
Carl.
On 9/15/2023 5:32 AM, Dr Chris Woodcock
wrote:
toggle quoted message
Show quoted text
?
Jam and marmalade is still sold in glass jars of standard size
254 grams (exactly equal to one pound).?
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
The confusion is worse, arguably, in the UK.? Here we measure milk and petrol (gas) in litres but beer in pints.? Jam and marmalade is still sold in glass jars of standard size 254 grams (exactly equal to one pound).? And our road signs always give distances in miles although the media and other "official" reports insist on using kilometres.? Sadly, our delightful?currency of pounds, shillings and pence seems to be long gone!? Fortunately, most engineering tape measures still show an imperial scale on one side and metric on the other, which provides a handy quick conversion. Chris Woodcock
On Thu, 14 Sept 2023 at 18:39, Bill in OKC too via <wmrmeyers= [email protected]> wrote: Nope. Half an inch is 12.7mm. That two tenths of a millimeter is important! Sometimes! ;) I can use either system, but I'm math-challenged despite decades of study, so I use a calculator regardless. And the only time I needed to deal with 1/128" was back when I got my first Vernier caliper. What I hate is things that mix the two systems. Chevrolet vehicles, for example. BASTARDS! :) Had to change out the starter on my mini-van this week. Most everything on it is metric except the starter bolts.?
Once upon a time, digital calculators were expensive. My first was a TI SR-51-II, and I paid $100 for it. That was about a third of my monthly paycheck then. When my teaching career ended, a bit over a decade ago, I could get a MUCH more powerful calculator for $1, with more scientific functions. And the TI-86 graphing calculator was going for about $100, then. It used a processor based on the Z-80 chip that ran my first appliance computer, the TRS-80 Model 1, and had the same graphics capability. Unlike the TRS-80, the TI-86 fit in the palm of my hand. Now I have a cheap Android phone, a MOTO G7 Supra. It has 32gigabytes of storage, and 2gigabytes of program memory. MUCH better graphics capability, too. I have a .5tb or 500gb micro-usb card in it for additional storage. And a scientific calculator app that will about everything BUT graphing. Including all the normal conversions. And another app that will display dwg files.?
THERE IS NO EXCUSE FOR SUCH LACK OF PRECISION!? ;)
Going through a set of drawings and trying to convert every dimension would be tough, though. Which means we need a means of converting on the fly. Digital calipers, anyone? ;)?
Actually, I'll bet that if there is a method that can be used, someone is using it. I actually prefer to use the Imperial system, as modified in the USA, but can get along fine in Metric. Lived for a tad over 5 years in Germany, and 3 in Turkey. I have bought gasoline in litres, and assorted foods in kilograms & grams, so I can get by.?
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, September 14, 2023 at 09:14:11 AM CDT, Andrei < calciu1@...> wrote:
I was too lazy to calculate so i just threw in the closest numbers:
9/16 is greater than half inch. Half inch is 12.5mm so the conclusion was that it is bigger than those two numbers
? the lazy way out ?
Andrei
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
Mike, ? I was hatched in the 1940s, and because most of my classes in school and university were in science-based subjects, I had to learn both imperial and the “old” metric system.? And then around 1960 the S.I. in France got to work and started to reorganize all of the metric units to base them on the Meter-Kilogram-Second (MKS) basic units instead of the centimeter-gram-second (cgs) units.? This, of course, meant learning how to redefine all those combination and special units.? When I became a health physicist, I became very used to dealing with the old radiation units (such as curies for activity, and rads for absorbed dose).? Then in the 1970s, I had to learn the “new” units (such as the Becquerel for activity, and the Gray for absorbed dose – amongst others) and to convert from one to another.? As all work since then used the new units, it made my brain hurt to think in terms of these new units instead of those with which I was already familiar).? For some reason I found this much more difficult for me to do than going from imperial to metric. ? Jerry F. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Mike Gidley
Sent: Thursday, September 14, 2023 10:23 PM
To: [email protected]
Subject: Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?? Hi All
Being old born in the middle of last century. I started life using Imperial Units which is slightly different to the US customary Units and then in the 1970s we (Australia) converted to Metric. I was one year into an Engineering Degree and I had to learn everything in Both Systems. I never convert one system to the other as this causes mistakes and confusion. If you start in one don't try to find a comparison to the other e.g. 1/3 of a metre for 1 foot.? This dosen't apply to Critical measurments for retro fitting a part. When we do designs we just use millimetres (yes Australia uses the French spelling of the units) This avoids decimal places in large projects.The decimal places are for smaller machining size projects.
And my last word The best unimat is what you have or what you can afford to own. My best Unimat is a Unimat3 and an old worn out Sherline, all backed up with a Optiturn1503 TU Chinese made (German lathe).?
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
Hi All
Being old born in the middle of last century. I started life using Imperial Units which is slightly different to the US customary Units and then in the 1970s we (Australia) converted to Metric. I was one year into an Engineering Degree and I had to learn everything in Both Systems. I never convert one system to the other as this causes mistakes and confusion. If you start in one don't try to find a comparison to the other e.g. 1/3 of a metre for 1 foot.? This dosen't apply to Critical measurments for retro fitting a part. When we do designs we just use millimetres (yes Australia uses the French spelling of the units) This avoids decimal places in large projects.The decimal places are for smaller machining size projects.
And my last word The best unimat is what you have or what you can afford to own. My best Unimat is a Unimat3 and an old worn out Sherline, all backed up with a Optiturn1503 TU Chinese made (German lathe).?
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
I have just picked up the very ordinary 18" plastic ruler on my desk. The first 9" are divided into 16ths, with the first three in 32nds. Nine to eighteen are in 10ths, with nine to ten in 50ths, ten to twelve in 20ths.The other edge is, of course, in millimetres, with zero to twenty in 0.5s. All this is what I would expect for a British ruler - I recall similar divisions on the standard school wooden 12" rule.
I also have a Metrinch micrometer, which uses a thread of 0.020" rather than the traditional 0.025". This is very close to 0.5 mm, so it has the usual datum line for inches, but a second one that is a helix round giving a datum that works for millimetres. It took me a moment to work out just what it did. It would be possible to add the equivalent marking to a metric micrometer to read in inches.
As for near misses in material sizes, I like to use 8 mm (5/16") and 4 mm (5/32") - at least, usually near enough. For other things I might call up a part to be made from equal angle, 25 × 4 mm, but by dimensioning from the root of the angle instead of the toe it wouldn't matter if it was 1" rather than 25 mm. Here in the UK we still have a lot of muddle in the dimensioning of materials. Aluminium sections in particular tend to be in inches, while steel is more likely to be metric.
For calculations, in addition to the desktop PC, the laptop, and the scientific calculator on my phone - which between them probably have more computing power than existed in the whole of Britain in the 1960s - I still use my 1986 Sharp PC 1360 pocket computer. It's very good for complicated calculations, and can have programmed functions written in Basic. I have several special functions built in. Also the Functions on the bottom two rows of the keyboard are chosen by the user. In addition to the normal trig functions I have one button for × 25.4, another for ÷ 25.4 . I have the full complement of two 32 kB memory module fitted, and have never come anywhere near using all of it. My earlier TRS 80, a Sharp PC 1211 in disguise, (from when Radio Shack existed in Britain) has a whole 1.7 kB memory and I never used that up either, but it's not so convenient with a single line display, and it's more complicated for programmed functions. I just switched it on for the first time in at least five years, and it still works. Both of these have proved useful for calculations that are a pain to do on the computer. For example, I thought AutoCad could handle working in mixed units. Now, after many years of pure metric, I'm having to deal with inches again, and I find it doesn't. I'd at least hope for a built in calculator which can handle 2 or 3 coordinates being worked on together, each one as a separate calculation, and which passes the results straight to the CAD as input. I've only wanted it for the last 40 years. I should write it myself but I lack the skills. Maybe if I'd started on it 40 years ago . . .
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
I have one of those in my box of tiny/kit computers.? I used to dumpster dive in the Commodore dumpsters in Santa Clara when I was in high school.? I had an original Commodore PET with the chicklet keyboard, a 40 column CBM, and a 80 column CBM with switchable operation systems and a SuperPet board, along with a top of the line dual floppy drive.? I had a pile of VIC20s too.? All built from dumpster parts.? Good times!
-Dave
On Thursday, September 14, 2023 at 10:43:35 AM PDT, Andrei <calciu1@...> wrote:
Damn, Bill. we had similar computers.
My first PC was the Sinclair Z80, some 43 years ago. Has a whole 16kb of memory and had to load programs from a cassette tape.?
Nope. Half an inch is 12.7mm. That two tenths of a millimeter is important! Sometimes! ;) I can use either system, but I'm math-challenged despite decades of study, so I use a calculator regardless. And the only time I needed
to deal with 1/128" was back when I got my first Vernier caliper. What I hate is things that mix the two systems. Chevrolet vehicles, for example. BASTARDS! :) Had to change out the starter on my mini-van this week. Most everything on it is metric except the
starter bolts.?
Once upon a time, digital calculators were expensive. My first was a TI SR-51-II, and I paid $100 for it. That was about a third of my monthly paycheck then. When my teaching career ended, a bit over a decade ago, I could
get a MUCH more powerful calculator for $1, with more scientific functions. And the TI-86 graphing calculator was going for about $100, then. It used a processor based on the Z-80 chip that ran my first appliance computer, the TRS-80 Model 1, and had the same
graphics capability. Unlike the TRS-80, the TI-86 fit in the palm of my hand. Now I have a cheap Android phone, a MOTO G7 Supra. It has 32gigabytes of storage, and 2gigabytes of program memory. MUCH better graphics capability, too. I have a .5tb or 500gb micro-usb
card in it for additional storage. And a scientific calculator app that will about everything BUT graphing. Including all the normal conversions. And another app that will display dwg files.?
THERE IS NO EXCUSE FOR SUCH LACK OF PRECISION!? ;)
Going through a set of drawings and trying to convert every dimension would be tough, though. Which means we need a means of converting on the fly. Digital calipers, anyone? ;)?
Actually, I'll bet that if there is a method that can be used, someone is using it. I actually prefer to use the Imperial system, as modified in the USA, but can get along fine in Metric. Lived for a tad over 5 years in Germany,
and 3 in Turkey. I have bought gasoline in litres, and assorted foods in kilograms & grams, so I can get by.?
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 Thursday, September 14, 2023 at 09:14:11 AM CDT, Andrei <calciu1@...> wrote:
I was too lazy to calculate so i just threw in the closest numbers:
9/16 is greater than half inch. Half inch is 12.5mm so the conclusion was that it is bigger than those two numbers
? the lazy way out ?
Andrei
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Re: What is the 'BEST' Unimat ?
One of these days I'm going to get a small native metric lathe specifically for metric threading.? ?Eventually...
-Dave
On Thursday, September 14, 2023 at 09:49:04 AM PDT, Charles Kinzer <ckinzer@...> wrote:
Speaking of Metric vs. English, I once worked with a machinist who HATED metric.? He said, "There are just too many places below the decimal."? What?? That's because at the time he was working on drawings for things designed in English but with all the dimensions converted to metric.? Of course, things designed natively in metric don't typically have that annoyance.
To swing it around to lathes, although not Unimat,? ALL of the Chinese mini-lathes are metric with 1mm pitch lead, cross feed, and compound screws whether they have metric or English marked collars.? (With the exception of Micro-Mark which has English 20 TPI thread screws yielding 0.050 inch per turn.).
Here is how they have "English" units on a lathe that is natively metric.? One turn of the handwheel is 1 mm or 0.0394 inches.? That's pretty close to 0.040 inches, so they just mark the wheel in 40 increments as being "close enough."? It seems that most buying these (amateurs and hobbyists) are not bothered as they tend to measure otherwise for the final cut otherwise or something.? Or spend most of their hobby trying to improve the lathe otherwise as an end in itself.? Or don't know.? Or don't care.
But it gets more nuanced than that.? I have seen some with 40 equal divisions marked.? And some with 39 equal divisions and then one smaller division.? That would be 39 divisions for 0.039 inches and one last smaller division for that remaining 0.0004 inches.? Arguably more honest, but still not helpful if trying to count a number of turns and come up with an accurate total in your head.? But usually, we don't count a lot of turns doing lathe work.? But we might on a mill.? And the mini-mill has the same issue (except for what Micro-Mark sells) and often you DO crank a lot of turns and need to know the actual change.
For those who want to change their metric machine masquerading as English, LittleMachineShop offers conversion kits to make your world right again.
And here's an odd duck.? A while back I bought an assortment of metric thread hex bolts from China, but they had English hex heads (like 3/8 inch).
Charles E. "Chuck" Kinzer
On Thursday, September 14, 2023 at 09:11:54 AM PDT, Martin P. via groups.io <mdupreno1@...> wrote:
To some. Calculation I would agree with. But not visualize and intuit. Depends on what you have done all your life.
It is like saying Spanish is easier to intuit than German.
Martin P.
On Thursday, September 14, 2023 at 10:11:51 AM EDT, Andrei <calciu1@...> wrote:
Metric rocks.?
Everything is easier to calculate, visualize, and intuit.?
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Re: What is the 'BEST' Unimat ?
While I can work in both systems, the one thing I don't like about the metric system is the lack of anything resembling a foot.? 3 decimeters? 1/3 meter? Just doesn't work for me.
-Dave
On Thursday, September 14, 2023 at 06:48:01 AM PDT, Carl <carl.blum@...> wrote:
Hello
Tamra:
I
worked at Bosch for 24 years, a mostly metric company. Since
we used US materials we had to deal with both systems.
At home
I worked mostly with Imperial, then I decided to try to work
mostly in metric, both wood and metal. Measuring and
calculations turned out to be much easier, since there were no
odd fractions to deal with.
First
in metric there are no fractions, other than tenths. Imperial
the fractions include 1/2, 1/3, 1/4, and so on to sometimes
1/128?? and of course 1/1000. So you are dealing with quite a
few different units.
My fun
challenge is how quickly can you tell me the weight of a Cubic
Yard of water? or a Cubic Meter of water?
The
yard is 1685.49 pounds. The meter is 1000 kg or a metric
tonne. ( I did have to look up the cubic yard )
Cubic
foot 62.5 pounds, a 30cm cube would be 27 kg.
Just
get some metric scales and tape measures and you will do
great.
Carl,
at 70 years of age. ( Imperial or metric )
On 9/14/2023 1:01 AM, Tamra wrote:
I don't know where
you reside.... if it is the Metric or Imperial world, I can't see
measurements in metric as easy as I can see them in my brain in
imperial measurements... perhaps this is the first sign of aging,
and inflexible, brain that is in denial that I bought a metric
lathe.? (At least I did tell you if you work in imperial
measurements that ALL unis are metric!)? ?I do know instantly that
3 mm is pretty close to 1/8", but I have to say that to
myself...so all these years later, I'm still whining about
metric... and we don't have as much compatible metric tools in the
shop as imperial tools.? ?If you are doing jewelry, most of that
world in the US is converted to metric... I don't know how it
happened, but it did, so the Uni is quite compatible with the
jewelry world in the USA.
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Re: What is the 'BEST' Unimat ?
Yep, which is why Starrett makes rules in those graduations. There is a large and very influential segment of our business world involved. And it makes sense in fields where imperial measurements are used but non-decimal fractions aren't at least for relatively short dimensions.?
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, September 14, 2023 at 08:50:54 PM CDT, g steinback via groups.io <gsteinba52@...> wrote:
On Thu, Sep 14, 2023 at 11:03 AM, Peter Brooks wrote:
I would never use tenths of an inch though. No subdivisions on any of the scales or rulers. Boring, like a metric imperial system. An odd attitude looking back on it.
I believe the aviation industry uses/used 10ths and 100ths of inch. Easy math where conversion errors are costly.
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Re: What is the 'BEST' Unimat ?
On Thu, Sep 14, 2023 at 11:03 AM, Peter Brooks wrote:
I would never use tenths of an inch though. No subdivisions on any of the scales or rulers. Boring, like a metric imperial system. An odd attitude looking back on it.
I believe the aviation industry uses/used 10ths and 100ths of inch. Easy math where conversion errors are costly.
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Re: What is the 'BEST' Unimat ?
Metric rocks only if one is used to the system, and especially if one is used to dealing with units of measurement that combine measurement of two or more primary units (time, distance, and mass). ?How much air should I put in my tires?? It give the amount right on the tire, but it is in Pascal.? So we look up Pascal, and find it is 1 Newton per square meter.? So how much is a Newton?? …? OK, I’ve lost interest.? And there are many of these obscure SI units that are used for particular applications.? Pressure can also be expressed in bars or in millimeters of mercury (if talking about atmospheric pressure for example) or in torr (if one is discussing units of vacuum). ? I’m only saying that it depends a lot on what one is used to.? Imperial measurement can be just as bad when it comes to the more obscure units, and I am thankful that the speedometer in my car is shown in miles per hour instead of furlongs per fortnight. ? Jerry F. ? ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Andrei
Sent: Thursday, September 14, 2023 7:12 AM
To: [email protected]; carl.blum@...
Subject: Re: [Unimat] What is the 'BEST' Unimat ?? Everything is easier to calculate, visualize, and intuit.?
Hello Tamra: I worked at Bosch for 24 years, a mostly metric company. Since we used US materials we had to deal with both systems. At home I worked mostly with Imperial, then I decided to try to work mostly in metric, both wood and metal. Measuring and calculations turned out to be much easier, since there were no odd fractions to deal with. First in metric there are no fractions, other than tenths. Imperial the fractions include 1/2, 1/3, 1/4, and so on to sometimes 1/128?? and of course 1/1000. So you are dealing with quite a few different units. My fun challenge is how quickly can you tell me the weight of a Cubic Yard of water? or a Cubic Meter of water? The yard is 1685.49 pounds. The meter is 1000 kg or a metric tonne. ( I did have to look up the cubic yard ) Cubic foot 62.5 pounds, a 30cm cube would be 27 kg. Just get some metric scales and tape measures and you will do great. Carl, at 70 years of age. ( Imperial or metric ) On 9/14/2023 1:01 AM, Tamra wrote: I don't know where you reside.... if it is the Metric or Imperial world, I can't see measurements in metric as easy as I can see them in my brain in imperial measurements... perhaps this is the first sign of aging, and inflexible, brain that is in denial that I bought a metric lathe.? (At least I did tell you if you work in imperial measurements that ALL unis are metric!)? ?I do know instantly that 3 mm is pretty close to 1/8", but I have to say that to myself...so all these years later, I'm still whining about metric... and we don't have as much compatible metric tools in the shop as imperial tools.? ?If you are doing jewelry, most of that world in the US is converted to metric... I don't know how it happened, but it did, so the Uni is quite compatible with the jewelry world in the USA.
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Re: What is the 'BEST' Unimat ?
From Bill in OKC ...>There are rulers that have 10ths of an inch, and 1/100ths of an inch on them. Starrett sells them.?
The Taig Lathe's cross slide dial is divided into 50ths...?
My husband's Mitutoya and my Starrett Imperial Dial Calipers are both in hundredth for 1 full rotation.? I am sure that I'm using the taig lathe because the instructions were made with someone who was teaching using imperial measurements.? I do have one pair of digital calipers that measure in fractions, decimal inches and push the button, I'm measuring in mm.
Light Bulb - I do know where a couple of my unimat books are, but the "Rex" reference is actually Gerald Wingrove... I think.? I suspect the instruction is in metric, so the Uni will come off the shelf at that time.
Tamra
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
? ? Somewhat off topic, but my old Land Rover uses 4 different thread systems (maybe more, some parts never dis-assembled?yet).? Quite a collection of tools necessary to carry in the vehicle.....
On Thu, Sep 14, 2023 at 1:39?PM Bill in OKC too via <wmrmeyers= [email protected]> wrote: Nope. Half an inch is 12.7mm. That two tenths of a millimeter is important! Sometimes! ;) I can use either system, but I'm math-challenged despite decades of study, so I use a calculator regardless. And the only time I needed to deal with 1/128" was back when I got my first Vernier caliper. What I hate is things that mix the two systems. Chevrolet vehicles, for example. BASTARDS! :) Had to change out the starter on my mini-van this week. Most everything on it is metric except the starter bolts.?
Once upon a time, digital calculators were expensive. My first was a TI SR-51-II, and I paid $100 for it. That was about a third of my monthly paycheck then. When my teaching career ended, a bit over a decade ago, I could get a MUCH more powerful calculator for $1, with more scientific functions. And the TI-86 graphing calculator was going for about $100, then. It used a processor based on the Z-80 chip that ran my first appliance computer, the TRS-80 Model 1, and had the same graphics capability. Unlike the TRS-80, the TI-86 fit in the palm of my hand. Now I have a cheap Android phone, a MOTO G7 Supra. It has 32gigabytes of storage, and 2gigabytes of program memory. MUCH better graphics capability, too. I have a .5tb or 500gb micro-usb card in it for additional storage. And a scientific calculator app that will about everything BUT graphing. Including all the normal conversions. And another app that will display dwg files.?
THERE IS NO EXCUSE FOR SUCH LACK OF PRECISION!? ;)
Going through a set of drawings and trying to convert every dimension would be tough, though. Which means we need a means of converting on the fly. Digital calipers, anyone? ;)?
Actually, I'll bet that if there is a method that can be used, someone is using it. I actually prefer to use the Imperial system, as modified in the USA, but can get along fine in Metric. Lived for a tad over 5 years in Germany, and 3 in Turkey. I have bought gasoline in litres, and assorted foods in kilograms & grams, so I can get by.?
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, September 14, 2023 at 09:14:11 AM CDT, Andrei < calciu1@...> wrote:
I was too lazy to calculate so i just threw in the closest numbers:
9/16 is greater than half inch. Half inch is 12.5mm so the conclusion was that it is bigger than those two numbers
? the lazy way out ?
Andrei
|
Re: What is the 'BEST' Unimat ?
There are rulers that have 10ths of an inch, and 1/100ths of an inch on them. Starrett sells them. Has for a long time. Not that they're cheap, though. I found my first one at work, fell out of one of the washing machines years after I got my first lathe. ;)?
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, September 14, 2023 at 01:03:05 PM CDT, Peter Brooks <peter@...> wrote:
You engineering types have all been decimal for years… tenths, hundredths, thous…
Imperial fractions have a certain design aesthetic though. As I’ve said before, when I was a furniture maker in the 80’s I loved to use quarters, eights and sixteenths. No smaller fractions, even youthful eyesight has limitations.
I would never use tenths of an inch though. No subdivisions on any of the scales or rulers. Boring, like a metric imperial system. An odd attitude looking back on it.
Here in the UK we have roughly translated to metric equivalents - 25.4, 12.7, 9.5, 6.35 become 25mm, 12mm, 9mm and 6mm ply. Not good for router cutters when this changeover started happening. Good for router cutter manufacturers no doubt!
Of course in my current fledgling engineering attempts I am solidly metric (couldn’t be anything else really with a U3).
(When you said ‘Metric rocks’ I was imagining perfect 10cm cubes but I get it now).
BTW isn’t age a duo-decimal system? ?:-)
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Re: What is the 'BEST' Unimat ?
You engineering types have all been decimal for years… tenths, hundredths, thous…
Imperial fractions have a certain design aesthetic though. As I’ve said before, when I was a furniture maker in the 80’s I loved to use quarters, eights and sixteenths. No smaller fractions, even youthful eyesight has limitations.
I would never use tenths of an inch though. No subdivisions on any of the scales or rulers. Boring, like a metric imperial system. An odd attitude looking back on it.
Here in the UK we have roughly translated to metric equivalents - 25.4, 12.7, 9.5, 6.35 become 25mm, 12mm, 9mm and 6mm ply. Not good for router cutters when this changeover started happening. Good for router cutter manufacturers no doubt!
Of course in my current fledgling engineering attempts I am solidly metric (couldn’t be anything else really with a U3).
(When you said ‘Metric rocks’ I was imagining perfect 10cm cubes but I get it now).
BTW isn’t age a duo-decimal system? ?:-)
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Re: Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
Damn, Bill. we had similar computers.
My first PC was the Sinclair Z80, some 43 years ago. Has a whole 16kb of memory and had to load programs from a cassette tape.?
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Nope. Half an inch is 12.7mm. That two tenths of a millimeter is important! Sometimes! ;) I can use either system, but I'm math-challenged despite decades of study, so I use a calculator regardless. And the only time I needed
to deal with 1/128" was back when I got my first Vernier caliper. What I hate is things that mix the two systems. Chevrolet vehicles, for example. BASTARDS! :) Had to change out the starter on my mini-van this week. Most everything on it is metric except the
starter bolts.?
Once upon a time, digital calculators were expensive. My first was a TI SR-51-II, and I paid $100 for it. That was about a third of my monthly paycheck then. When my teaching career ended, a bit over a decade ago, I could
get a MUCH more powerful calculator for $1, with more scientific functions. And the TI-86 graphing calculator was going for about $100, then. It used a processor based on the Z-80 chip that ran my first appliance computer, the TRS-80 Model 1, and had the same
graphics capability. Unlike the TRS-80, the TI-86 fit in the palm of my hand. Now I have a cheap Android phone, a MOTO G7 Supra. It has 32gigabytes of storage, and 2gigabytes of program memory. MUCH better graphics capability, too. I have a .5tb or 500gb micro-usb
card in it for additional storage. And a scientific calculator app that will about everything BUT graphing. Including all the normal conversions. And another app that will display dwg files.?
THERE IS NO EXCUSE FOR SUCH LACK OF PRECISION!? ;)
Going through a set of drawings and trying to convert every dimension would be tough, though. Which means we need a means of converting on the fly. Digital calipers, anyone? ;)?
Actually, I'll bet that if there is a method that can be used, someone is using it. I actually prefer to use the Imperial system, as modified in the USA, but can get along fine in Metric. Lived for a tad over 5 years in Germany,
and 3 in Turkey. I have bought gasoline in litres, and assorted foods in kilograms & grams, so I can get by.?
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 Thursday, September 14, 2023 at 09:14:11 AM CDT, Andrei <calciu1@...> wrote:
I was too lazy to calculate so i just threw in the closest numbers:
9/16 is greater than half inch. Half inch is 12.5mm so the conclusion was that it is bigger than those two numbers
? the lazy way out ?
Andrei
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Mensuration, was Re: [Unimat] What is the 'BEST' Unimat ?
Nope. Half an inch is 12.7mm. That two tenths of a millimeter is important! Sometimes! ;) I can use either system, but I'm math-challenged despite decades of study, so I use a calculator regardless. And the only time I needed to deal with 1/128" was back when I got my first Vernier caliper. What I hate is things that mix the two systems. Chevrolet vehicles, for example. BASTARDS! :) Had to change out the starter on my mini-van this week. Most everything on it is metric except the starter bolts.?
Once upon a time, digital calculators were expensive. My first was a TI SR-51-II, and I paid $100 for it. That was about a third of my monthly paycheck then. When my teaching career ended, a bit over a decade ago, I could get a MUCH more powerful calculator for $1, with more scientific functions. And the TI-86 graphing calculator was going for about $100, then. It used a processor based on the Z-80 chip that ran my first appliance computer, the TRS-80 Model 1, and had the same graphics capability. Unlike the TRS-80, the TI-86 fit in the palm of my hand. Now I have a cheap Android phone, a MOTO G7 Supra. It has 32gigabytes of storage, and 2gigabytes of program memory. MUCH better graphics capability, too. I have a .5tb or 500gb micro-usb card in it for additional storage. And a scientific calculator app that will about everything BUT graphing. Including all the normal conversions. And another app that will display dwg files.?
THERE IS NO EXCUSE FOR SUCH LACK OF PRECISION!? ;)
Going through a set of drawings and trying to convert every dimension would be tough, though. Which means we need a means of converting on the fly. Digital calipers, anyone? ;)?
Actually, I'll bet that if there is a method that can be used, someone is using it. I actually prefer to use the Imperial system, as modified in the USA, but can get along fine in Metric. Lived for a tad over 5 years in Germany, and 3 in Turkey. I have bought gasoline in litres, and assorted foods in kilograms & grams, so I can get by.?
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, September 14, 2023 at 09:14:11 AM CDT, Andrei <calciu1@...> wrote:
I was too lazy to calculate so i just threw in the closest numbers:
9/16 is greater than half inch. Half inch is 12.5mm so the conclusion was that it is bigger than those two numbers
? the lazy way out ?
Andrei
|
Re: What is the 'BEST' Unimat ?
Speaking of Metric vs. English, I once worked with a machinist who HATED metric.? He said, "There are just too many places below the decimal."? What?? That's because at the time he was working on drawings for things designed in English but with all the dimensions converted to metric.? Of course, things designed natively in metric don't typically have that annoyance.
To swing it around to lathes, although not Unimat,? ALL of the Chinese mini-lathes are metric with 1mm pitch lead, cross feed, and compound screws whether they have metric or English marked collars.? (With the exception of Micro-Mark which has English 20 TPI thread screws yielding 0.050 inch per turn.).
Here is how they have "English" units on a lathe that is natively metric.? One turn of the handwheel is 1 mm or 0.0394 inches.? That's pretty close to 0.040 inches, so they just mark the wheel in 40 increments as being "close enough."? It seems that most buying these (amateurs and hobbyists) are not bothered as they tend to measure otherwise for the final cut otherwise or something.? Or spend most of their hobby trying to improve the lathe otherwise as an end in itself.? Or don't know.? Or don't care.
But it gets more nuanced than that.? I have seen some with 40 equal divisions marked.? And some with 39 equal divisions and then one smaller division.? That would be 39 divisions for 0.039 inches and one last smaller division for that remaining 0.0004 inches.? Arguably more honest, but still not helpful if trying to count a number of turns and come up with an accurate total in your head.? But usually, we don't count a lot of turns doing lathe work.? But we might on a mill.? And the mini-mill has the same issue (except for what Micro-Mark sells) and often you DO crank a lot of turns and need to know the actual change.
For those who want to change their metric machine masquerading as English, LittleMachineShop offers conversion kits to make your world right again.
And here's an odd duck.? A while back I bought an assortment of metric thread hex bolts from China, but they had English hex heads (like 3/8 inch).
Charles E. "Chuck" Kinzer
On Thursday, September 14, 2023 at 09:11:54 AM PDT, Martin P. via groups.io <mdupreno1@...> wrote:
To some. Calculation I would agree with. But not visualize and intuit. Depends on what you have done all your life.
It is like saying Spanish is easier to intuit than German.
Martin P.
On Thursday, September 14, 2023 at 10:11:51 AM EDT, Andrei <calciu1@...> wrote:
Metric rocks.?
Everything is easier to calculate, visualize, and intuit.?
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Re: What is the 'BEST' Unimat ?
True. I worked in both systems and preferred metric every time. You still have to work with imperial just because so much around is imperial.?
But getting back to visualization, i can tell what 10mm off would mean in a part, but figuring out how much 35/64th?represents is beyond what I can visualize.?
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To some. Calculation I would agree with. But not visualize and intuit. Depends on what you have done all your life.
It is like saying Spanish is easier to intuit than German.
Martin P.
On Thursday, September 14, 2023 at 10:11:51 AM EDT, Andrei <calciu1@...> wrote:
Metric rocks.?
Everything is easier to calculate, visualize, and intuit.?
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Carl
Bill in OKC too
Tamra