# I May Be Starting To Cross Over To The Dark Side



## projectnut (Jan 23, 2021)

As many of you already know I've been attempting to shred metal for quite some time.  I guess some would say I could easily qualify as an "Old Dog".  As such some of us don't learn, or even like to learn new tricks very often.  Having said that I think I'm finally being forced into that corner of either learning new tricks, or fading into the repository of ancient history.

The "new to me" trick is taking on jobs with METRIC measurements.  Just typing the word makes me a bit light headed, let alone actually taking on a job with those types of measurements.  I even went so far as to purchase a Mitutoyo 150 mm (close to 6") scale this week.  I can't yet bring myself to leave my trusty 6" scale in the tool box yet, so I suppose I'll have to carry around both until they finally pry it out of my cold dead hand.

It's not that I feel a bit behind the curve.  I know others have gone before me, and some have even embraced the system.  I'm not sure I can go that far, but at least I'm thinking I may be able to tolerate it.  In reality it won't be that hard.  My 1974 Bridgeport came from the factory with both imperial and metric scales, and the DRO can be switched from one system to the other with a push of a button.   

The lathe may be another story.  One full turn of the compound dial is .125" or 1/8".  It's only the second one I've operated with this scale, and it took me nearly 6 months and a couple dozen botched up parts to get "one full turn equals .100" out of my head.  To further complicate things there is no DRO, so all the conversion is either done in my head or on a calculator.  I'll head down to the shop a little later this evening to see if I can actually make a part measured in millimetrics, multimetars, centimorters, or whatever they are.


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## jmkasunich (Jan 23, 2021)

I would not try to work directly in metric on an inch lathe.  Take the drawing, get your red pen out, and convert all the dimensions to inches and mark up the drawing before you even walk over to the machine.


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## mmcmdl (Jan 23, 2021)

jmkasunich said:


> I would not try to work directly in metric on an inch lathe. Take the drawing, get your red pen out, and convert all the dimensions to inches and mark up the drawing before you even walk over to the machine.


What he said /\/\/\/\ .


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## Mitch Alsup (Jan 23, 2021)

Yes, yes, indeed--convert all measurements into units the machine has on its dials.


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## Lo-Fi (Jan 23, 2021)

I work in metric on an inch lathe (which I hate doing, but you gotta work with what you got) on a regular basis. Unless you're chasing tenths, remember that 1mm = 40 thou and you can't go too far wrong if you take regular measurements. I'm doing my best to purge my workshop of inch stuff, but it's tricky with almost all old industrial stuff being inch. I see a DRO in my future!


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## Boswell (Jan 23, 2021)

all of my 3d Printing stuff is metric from drawing to production. My lathe is CNC so easy to do either and my lathe has DRO that can be switched if needed. I like working in metric but am, as you would expect, more comfortable in imperial. I have a couple of scales that are MM on one site and inches on the other. I am a little more limited on metrology with my favorite micrometers being non-digital imperial. My calipers are digital though so switch easily. 

Good luck as you find a grove on how to work in both that works for you.


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## westerner (Jan 23, 2021)

Tools and conversion formulas are ancient. So is my foundation in Imperial. I work in metric when I must, but I will never look at anything, ever, as long as I live, and say "wow, that thing is xxx millimeters long"


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## mmcmdl (Jan 23, 2021)

Here's the problem with metric anything . They DO NOT make a 10mm wrench or socket that does not go missing after using . If I ever cleaned out my engine bays , I could open up an Ace Hardware franchise .


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## benmychree (Jan 23, 2021)

Only thing I deal with is metric bearing fits; definitely convert metric sizes to imperial.


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## matthewsx (Jan 23, 2021)

I'm one of those people who was in grade school when the US made an attempt to go metric. In many ways I wish it hadn't gotten derailed because it would be so much easier to deal with everything else in the world.

That said, I'm so new to this that I've been contemplating using metric as my primary measurement system for making stuff. My mill/drill is CNC and I've never really gotten used to using the dials for making stuff plus my lathe has both.

John


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## Masterjuggler (Jan 23, 2021)

Basically what Boswell said, I've got some metric intuition from 3d printing. I don't have a problem designing in metric and can eyeball half millimeters on small parts pretty easily. Though being in the US, most old manual tools are imperial as has been mentioned, so that's how I work by default.

There are some interesting dial calipers that have the mechanisms for both metric and imperial in the same dial, with two needles and scales. Like these: https://www.ebay.com/itm/332568970700

I've always thought about getting one of them, but never actually work in metric in my shop, so I never bothered. I just use a digital caliper for 3d printing. There are also dial indicator versions.


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## Jim F (Jan 23, 2021)

Most vernier calipers have both scales, also.


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## Masterjuggler (Jan 23, 2021)

Jim F said:


> Most vernier calipers have both scales, also.


Actually, the only vernier caliper I have has scales for decimal inches and fractional inches, 0.001" and 1/128" lol. It belonged to my great grandfather, a machinist during WWII. Absolutely useless as far as I'm concerned, but he must have thought it was useful for some reason.


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## savarin (Jan 23, 2021)

Got fed up with the imperial dial on my cross slide so I made it a metric one, one complete turn = 1 mm of travel, sooooo much simpler.
Even made a vernier for it but thats just taking the mickey really. 0.01mm per division is close enough for me. or 0.0003936996"


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## MrWhoopee (Jan 23, 2021)

I agree with the others, convert metric to U.S. customary (imperial) before you start. I became quite comfortable with metric measurements while in the trade, but all my tools, including my brain, work in inches. It's kind of like driving on the left when you're used to driving on the right. It doesn't come naturally and you'll make a mistake in a pinch.


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## Aaron_W (Jan 23, 2021)

Relax, metric is an easy system, most of the issues (both ways) come from trying to work with both at the same time. Stick to one or the other and its not a big deal. I'd much prefer to learn metric from scratch than be one of those poor people raised in metric that finds themselves having to work with chains, hogsheads and stone.



matthewsx said:


> I'm one of those people who was in grade school when the US made an attempt to go metric. In many ways I wish it hadn't gotten derailed because it would be so much easier to deal with everything else in the world.
> 
> That said, I'm so new to this that I've been contemplating using metric as my primary measurement system for making stuff. My mill/drill is CNC and I've never really gotten used to using the dials for making stuff plus my lathe has both.
> 
> John



That was in full swing when I was in second grade, so I'm pretty fluent with both, although my brain is calibrated to inches and pounds. I have to convert metric to actually visualize it. Going to Europe I found it so odd getting a soda in a 333ml (11-1/4 ounce) can instead of the standard US 12 oz (355ml) can. You wouldn't think that small difference would be noticeable but it was.


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## savarin (Jan 24, 2021)

Aaron_W said:


> Going to Europe I found it so odd getting a soda in a 333ml (11-1/4 ounce) can instead of the standard US 12 oz (355ml) can. You wouldn't think that small difference would be noticeable but it was.


Ahh but a pint of beer is nice or even better half a litre  
Mind you American shots are better


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## Masterjuggler (Jan 24, 2021)

Funnily enough, how comfortable I am with a unit is very application dependent. Other than freezing at 0⁰C, I have no sense of what celsius means for the weather, but it's the only unit I can think in for computer hardware temperatures and steel heat treating. When machining I definitely think in inches, but for some reason my brain automatically switches to metric when designing parts to be 3d printed. I know tolerances for steel in inches, and 3d printed plastic in millimeters.


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## Larry$ (Jan 24, 2021)

I now will work in metric given a choice. It's a much better system. Back in the 70's Congress failed us, again, by not carrying through with the conversion. In my business most of my equipment was European, so was the hardware we used. So I got to the point of thinking in either system. Now that I'm retired my lathe & mill started life as imperial machines but have DROs that let me use the better system. Send Bernie a message asking to bring the country into  the "modern" world. We've been a two system place long enough.


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## matthewsx (Jan 24, 2021)

savarin said:


> Ahh but a pint of beer is nice or even better half a litre
> Mind you American shots are better


A pint's a pound the world around....

Wait, is that an Imperial Pint?


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## Lo-Fi (Jan 24, 2021)

Fir what it's worth, I use my verniers as a slide rule for converting to inch measurements for lathe work. I never bother drawing in imperial or converting ahead of time, just a pen and verniers are quite adequate.


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## Buffalo21 (Jan 24, 2021)

mmcmdl said:


> Here's the problem with metric anything . They DO NOT make a 10mm wrench or socket that does not go missing after using . If I ever cleaned out my engine bays , I could open up an Ace Hardware franchise .


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## Nogoingback (Jan 24, 2021)

If you don't have them, get a set of Mitutoyo digital calipers.  They convert imperial to metric at the touch of the button, 
so much easier than a calculator.


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## 7milesup (Jan 24, 2021)

Even though I was born and raised in the good 'ole U.SofA, I HATE the imperial system.  It is so antiquated and outmoded that it I am amazed it is still around.
I mean, seriously, what is half of 11/128".  I dunno.  Have to convert to decimal or if it was metric, it is 2.16mm or 1.13mm.  Holy crap, is that easy or what.
When I flew, we used feet for altitude but knots for speed and Celsius for temperature.  It is all about _what you get used to.  _The only reason the U.S. hasn't converted is because people don't WANT to, not because the metric system is hard, actually just the opposite.  
Remember when the U.S. started an initiative to switch to metric and the road signs had both mph and kph...


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## Lo-Fi (Jan 24, 2021)

I like the actual_ physical_ dimensions of inches. Somehow an inch or a foot is easier to visualise than a meter or centicentimete, but that's absolutely where my love for imperial ends. 

A really useful tool I have is an old Mitutoyo mic that's got vernier in mm and a rolling dial readout for thou. It's super handy for working in my mixed environment.


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## craniac (Jan 24, 2021)

It's drills that finally pushed me over the edge. You've got your fractional set and your numbered set and then the drill sizes for a threaded holes calls for a letter sizes, oh for pity's sake. And I have a huge chart on the wall to convert all of it to thous anyway. The chart is cool, but still the amount of brainpower trickling out all the time converting from fractional sizes, number and letter sizes into thous- at my age I need to conserve all the brainpower I can.  I'd welcome a vernier calculator for that. It's easier to convert from thous to metric in your head. And even without a DRO you can always just attach dial test indicators for short money on your lathe. I can hardly read whats on my ca 1937 lathe dials anyway. It also occurs to me that I can simply switch to using metric indicators if I like. (And switch the change gears to approximate metric on the lathe too.)

I bet I can convert myself to metric and still get an ROI of the time it takes to do it. If it wasn't for working with vintage Imperial machinery I'd of switched long ago. Plus not that much metric stuff is available in the garage sales where I do most of my tools shopping (or did).

Tim


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## Weldingrod1 (Jan 24, 2021)

Ugh. Yeah, I wish we had the gumption to just go ahead and do it. I purely hated working on the car when the blighters had BOTH english and metric bolts! Jeeze, talk about cruel and unusual!

Sent from my SM-G892A using Tapatalk


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## Lo-Fi (Jan 24, 2021)

Try an old Land Rover... A mix of UNF, UNC, BSF, Whitworth (from factory) and often metric here and there when some egit previous owner has thrown whatever they had in.


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## hman (Jan 24, 2021)

I bought a metric tap-and-drill stand recently.  There were several errors, mainly the fact that the specified clearance holes were ALL 2mm larger than the nominal screw size - WAY too big, in my opinion.  It also specified some very obscure tenths-of-millimeters drill sizes.  I decided to calculate the exact drill sizes, convert to ten-thousandths of an inch, and find the nearest "readily available" drill size (fractional, letter, number, metric, whatever).  Here's the spreadsheet I used to do the calculations.  The columns labeled "practical" show the actual drills I bought to populate the stand.


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## davidcarmichael (Jan 24, 2021)

projectnut said:


> As many of you already know I've been attempting to shred metal for quite some time.  I guess some would say I could easily qualify as an "Old Dog".  As such some of us don't learn, or even like to learn new tricks very often.  Having said that I think I'm finally being forced into that corner of either learning new tricks, or fading into the repository of ancient history.
> 
> The "new to me" trick is taking on jobs with METRIC measurements.  Just typing the word makes me a bit light headed, let alone actually taking on a job with those types of measurements.  I even went so far as to purchase a Mitutoyo 150 mm (close to 6") scale this week.  I can't yet bring myself to leave my trusty 6" scale in the tool box yet, so I suppose I'll have to carry around both until they finally pry it out of my cold dead hand.
> 
> ...


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## davidcarmichael (Jan 24, 2021)

It's not the Dark Side. Just move towards the light.


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## SSage (Jan 24, 2021)

I just switch my tools over to metric with a press of a button when needed, my DRO's and my digital measuring tools make it fairly easy. Just buy the lithium batteries in bulk for the dial calibers and such, they go dead right when you in the middle of something. But, I have been buying cheap batteries off eBay, so its not so bad. I get a couple months out of a battery. I really like the digital Shars measuring tools, the premiumn line they call Aventar. Not super cheap, but not that pricey either. Very accurate and consistent so far. I didn't like the cheap ones from Shars, but the Aventar line is fairly good. I've bought two of them so far and they are holding up good.


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## jmkasunich (Jan 25, 2021)

Masterjuggler said:


> There are some interesting dial calipers that have the mechanisms for both metric and imperial in the same dial, with two needles and scales. Like these: https://www.ebay.com/itm/332568970700



I have a couple of those (one at work, one at home) and love them.  Most people just make the jump to the electronic ones, but I hate stuff with batteries.


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## Masterjuggler (Jan 25, 2021)

jmkasunich said:


> I have a couple of those (one at work, one at home) and love them.  Most people just make the jump to the electronic ones, but I hate stuff with batteries.


I agree, I have an electronic caliper and it's super handy for things like working in offsets or using the fractional display to sort drill bits, but 99% of the time I go to my dials first. Actually watching the needle move gives so much better visual indication of what's happening.


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## Ischgl99 (Jan 25, 2021)

I worked for a German machinery manufacturer and bearing company, so metric is ingrained in me.  I design everything in metric and convert as needed. Except woodworking, I am still using inches for that, but trying to convert there too. All my micrometers are metric, I needed them for my job, but they were also half the price of inch ones on Ebay since nobody wanted them at the time.  I have a DRO on my mill and the dials on my lathe are inch and metric, so hopefully fewer conversions will be needed.  I would have bought metric lead screw machines if that was an option.  

Like a previous response, I use inch sized drills when drilling holes for tapping metric threads since in many cases you will find an inch drill close enough to the metric size.  Helps save on tooling costs.  I have only bought metric drills when I could not find an inch sized one close enough.


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## Larry$ (Jan 26, 2021)

7milesup said:


> Even though I was born and raised in the good 'ole U.SofA, I HATE the imperial system.  It is so antiquated and outmoded that it I am amazed it is still around.
> I mean, seriously, what is half of 11/128".  I dunno.  Have to convert to decimal or if it was metric, it is 2.16mm or 1.13mm.  Holy crap, is that easy or what.
> When I flew, we used feet for altitude but knots for speed and Celsius for temperature.  It is all about _what you get used to.  _The only reason the U.S. hasn't converted is because people don't WANT to, not because the metric system is hard, actually just the opposite.
> Remember when the U.S. started an initiative to switch to metric and the road signs had both mph and kph...


But knots had nothing to do with the metric system. They stem from the early days of sailing. One knot was = to one minute of longitude. Now redefined as 1152 meters. A minute of longitude is easily measured on a chart (ocean map.) But of course the meter was defined as a unit of the distance from the equator to the poles. I much prefer metric.


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## Boswell (Jan 26, 2021)

when I am doing wood work and working in fractions of a Inch like 3-7/8" and 12 inches to the foot,  it was easy to see the value of metric. But in the machine shop, I work with decimal inches like 1.625 etc and that is just as easy as working in MM. In fact easier because I can visualize an inch easier that a MM. The only issue is when converting between the two systems and calculators have made that a snap. So for me, there is no real pressure to only work in one system or the other. (just not both at the  same time)


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## Winegrower (Jan 26, 2021)

I see a question was asked by 7milesup but not answered, and I believe the answer demonstrates the ease and superiority of the imperial system.



7milesup said:


> I mean, seriously, what is half of 11/128". I dunno. Have to convert to decimal or if it was metric, it is 2.16mm or 1.13mm. Holy crap, is that easy or what.



Half of 11/128” is immediately seen (by any computer guy) to be 11/256”.

I rest my case.


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## jmarkwolf (Feb 2, 2021)

Learn to convert back and forth. The magic number to do so is 25.4.

Multiply inches by 25.4 to get mm, divide mm by 25.4 to get inches.

With a little practice it becomes second nature.

And get a digital caliper with conversion button.


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## Lo-Fi (Feb 2, 2021)

I find that thou to mm the most useful on machining ops when converting "on the fly". 1mm = ~40thou.
The accuracy drops off if you're doing large measurements, of course, but it's more than adequate for roughing and nearly always good enough doing finishing so long as you measure up and reset dials before final pass.


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## Mini Cooper S (Feb 2, 2021)

jmkasunich said:


> I would not try to work directly in metric on an inch lathe.  Take the drawing, get your red pen out, and convert all the dimensions to inches and mark up the drawing before you even walk over to the machine.


And then leave it sit for a bit and come back and do it again!  I have seen too many parts scrapped because of a conversion error, may have even done it once myself. 
Richard


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