A well done and explained video and something I wish I had available 30+ yrs ago. I'm about 5 months late, but a couple of tips I've picked up for maybe some of the finer details. While I've got decimal equivalent charts and used to use them all the time, I'll now rarely bother to check anything on them I haven't already got memorized since machining almost demands having a a calculator of some type handy. Many don't seem to know that fractional inches are easily converted to there decimal equivalent with a few simple key strokes. Just take the top number in any fraction (the numerator) and divide it by the lower number. (the denominator) it works for every fraction you can come up with, even one's you'd never run across. 37/197ths for example. 37 divided by 197. Rounded off, =.187817" and some change. Or something common, 9/16ths. 9 divided by 16 = .5625". I've also watched quite a few of Mitutoyo's older videos on their YT channel. That thumb wheel on most calipers is really meant for faster and coarser size adjustments. Mit. recommends the best technique for smaller measurements is to use your thumb and forefinger on the back side of each jaw and directly opposite where each caliper jaw will touch a round shaft on each side. That lessens the chance of the small amount of clearances in the calipers slide assembly affecting the measurement. For round or flat sided and parallel parts, then the item to be measured should also be placed as far up in the jaws and as close to the scale bar as you can get. For larger objects, then both hands are used to gently close the jaws against the part. Again and as you said in the video, developing and using the same amount of feel or pressure each time is also important. My Mit digital calipers are the best I've ever used, and I've checked them and my technique on good gauge blocks. But while there accurate, if I need to know I'm measuring to better than about .003" and be sure of that. I'll still use a mike. And what ever accuracy I get on those gauge blocks in the best conditions I can manage, is a whole lot different than measuring parts still in the lathe or mill and under most average shop situations. And for multiple double checks and repeatable measurements to again be 100% sure of the results. Mit also recommends using the same number of clicks on the ratchet each time for consistency. Again I've tried it on those gauge blocks and you can sometimes see a 1/2 10th change between measurements at times. That may or may not be important for most of us, but it is a more consistent technique. So I use 5 slow clicks when I think it really counts on something critical.
A lot of really great tips here. I do think you’re right about people not knowing about where the decimals come from to begin with. I will probably do an entire video on just the chart with tips and tricks as well.
I use that same Mitutoyo digital mic in my shop. It's fast, easy and extremely precise. If I were to do it over again though, I'd get the fast travel version.
They seem like really good micrometers. I enjoyed using them for the video because I could show the scale reading while checking with the digital read out. Truthfully I borrowed these from a friend but I’m really impressed. The 5th decimal place seems a little precarious but if you keep significant figures in mind they’re awesome.
Minus series gage pins are .0002 under size from marked size unless the pins are chinese junk. Minus series gage pins if a qualty brand will mearsure .0002 undersize from marked . Gage pins are measured with a Master Mic or optical comparator when certified. The caliper material is not flexing at the beams , its the gear mechanism being overstressed . 24:26
The gage pin I had could most definitely be Chinese origin so the accuracy could be questionable. I think we could both be right on the caliper part, the gear and the material could be flexing/stressed.
I think that if you were working professionally as a machinist it could take up to a year to get a feel for fits. That does entirely depend upon what kind of work you are doing. If you are making mating parts for an assembly, I think it could be learned more quickly like with mating threads, or with press fits/slip fits. It would depend quite a bit on the frequency you are making parts that go together and experiencing how that feels.
It only took me a few days to get really consistent results with our vernier scale starret micrometers. I had instruction from a master machinist so your mileage may vary
Get yourself a gauge pin or dowel pin, or carbide endmill shank. Something that you know its precise dimension. Then practice the feel of measuring it without looking at the micrometer. Then check the reading on the mic. The key is not looking at it, because otherwise your brain will just stop your hand at the right place. As a hobbyist that doesn't do ultra precision measurements all the time, this is also a good way to sort of re-calibrate your "feel" before measuring a real part.
The whole deal about using nominal drill sizes seems personal. Its almost like you have had to deal with custom size tools when a nominal size would be in spec on a regular basis. 😂
Haha, you found me out. I've been dealing with poorly spec'd parts from customers or internal designs for around 15 years. I've found that if you have a discussion with a designer, be it an engineer or a customer, they can usually change the sizing to be a nominal dimension. There are definitely occasions where engineering requires a strange size and that's ok. I just push using common sense when designing your parts for manufacturing.
Die hard analog guy? I still favor manual micrometers too but the digitals are still pretty cool. In other video comments people have remarked about easily switching to metric which I think could be a big bonus and make these a two for one value in way. Granted you could just convert yourself but everybody has tool preferences.
I have SAE and metric measuring equipment, and don't use a DRO either. I'm an old retired geezer and a hard core Starrett Man. LOL!@@themeandrousengineer
I use calipers during inspection after a tear down but when cutting bushings I use an inch mic and t gauges, 0001" is not as critical as .001" The lathe I use measures in .0002 at the increment from 0
@@gmonynegro595then you must know that starret is no longer the company it once was, but for the most part mitutoyo is. I have both, plus some Interapid, brown and Sharpe. I like mitutoyo, especially my hammered green 0-6 mics. Silky smooth and deadly accurate.
A well done and explained video and something I wish I had available 30+ yrs ago.
I'm about 5 months late, but a couple of tips I've picked up for maybe some of the finer details. While I've got decimal equivalent charts and used to use them all the time, I'll now rarely bother to check anything on them I haven't already got memorized since machining almost demands having a a calculator of some type handy. Many don't seem to know that fractional inches are easily converted to there decimal equivalent with a few simple key strokes. Just take the top number in any fraction (the numerator) and divide it by the lower number. (the denominator) it works for every fraction you can come up with, even one's you'd never run across. 37/197ths for example. 37 divided by 197. Rounded off, =.187817" and some change. Or something common, 9/16ths. 9 divided by 16 = .5625".
I've also watched quite a few of Mitutoyo's older videos on their YT channel. That thumb wheel on most calipers is really meant for faster and coarser size adjustments. Mit. recommends the best technique for smaller measurements is to use your thumb and forefinger on the back side of each jaw and directly opposite where each caliper jaw will touch a round shaft on each side. That lessens the chance of the small amount of clearances in the calipers slide assembly affecting the measurement. For round or flat sided and parallel parts, then the item to be measured should also be placed as far up in the jaws and as close to the scale bar as you can get. For larger objects, then both hands are used to gently close the jaws against the part. Again and as you said in the video, developing and using the same amount of feel or pressure each time is also important. My Mit digital calipers are the best I've ever used, and I've checked them and my technique on good gauge blocks. But while there accurate, if I need to know I'm measuring to better than about .003" and be sure of that. I'll still use a mike. And what ever accuracy I get on those gauge blocks in the best conditions I can manage, is a whole lot different than measuring parts still in the lathe or mill and under most average shop situations.
And for multiple double checks and repeatable measurements to again be 100% sure of the results. Mit also recommends using the same number of clicks on the ratchet each time for consistency. Again I've tried it on those gauge blocks and you can sometimes see a 1/2 10th change between measurements at times. That may or may not be important for most of us, but it is a more consistent technique. So I use 5 slow clicks when I think it really counts on something critical.
A lot of really great tips here. I do think you’re right about people not knowing about where the decimals come from to begin with. I will probably do an entire video on just the chart with tips and tricks as well.
I use that same Mitutoyo digital mic in my shop. It's fast, easy and extremely precise. If I were to do it over again though, I'd get the fast travel version.
They seem like really good micrometers. I enjoyed using them for the video because I could show the scale reading while checking with the digital read out. Truthfully I borrowed these from a friend but I’m really impressed. The 5th decimal place seems a little precarious but if you keep significant figures in mind they’re awesome.
Digital is fast and convenient but the vernier scale is more durable . Very nice to have both on the same micrometer .
I was really impressed with these micrometers. A friend lent them to me for the video and it was really nice to have both.
Dont forget to lock the mic down
Mic in the shop has been the bane of my existence. Probably going to have to invest in one like others have that clips to my collar
Minus series gage pins are .0002 under size from marked size unless the pins are chinese junk. Minus series gage pins if a qualty brand will mearsure .0002 undersize from marked . Gage pins are measured with a Master Mic or optical comparator when certified. The caliper material is not flexing at the beams , its the gear mechanism being overstressed . 24:26
The gage pin I had could most definitely be Chinese origin so the accuracy could be questionable. I think we could both be right on the caliper part, the gear and the material could be flexing/stressed.
For somebody new to machining, how long would you say it takes to develop "the feel" and be able to know "the feel" is accurate?
I think that if you were working professionally as a machinist it could take up to a year to get a feel for fits. That does entirely depend upon what kind of work you are doing. If you are making mating parts for an assembly, I think it could be learned more quickly like with mating threads, or with press fits/slip fits. It would depend quite a bit on the frequency you are making parts that go together and experiencing how that feels.
It only took me a few days to get really consistent results with our vernier scale starret micrometers. I had instruction from a master machinist so your mileage may vary
Get yourself a gauge pin or dowel pin, or carbide endmill shank. Something that you know its precise dimension. Then practice the feel of measuring it without looking at the micrometer. Then check the reading on the mic.
The key is not looking at it, because otherwise your brain will just stop your hand at the right place.
As a hobbyist that doesn't do ultra precision measurements all the time, this is also a good way to sort of re-calibrate your "feel" before measuring a real part.
The whole deal about using nominal drill sizes seems personal. Its almost like you have had to deal with custom size tools when a nominal size would be in spec on a regular basis. 😂
Haha, you found me out. I've been dealing with poorly spec'd parts from customers or internal designs for around 15 years. I've found that if you have a discussion with a designer, be it an engineer or a customer, they can usually change the sizing to be a nominal dimension. There are definitely occasions where engineering requires a strange size and that's ok. I just push using common sense when designing your parts for manufacturing.
When I use a mechanical micrometer I take a photo and then enlarge it, mainly because my eyes aren't as good as they once were.
Seems like a good strategy to get it done. I haven't gotten there yet, but if/when I do, I will remember this trick.
Digital mics are for amateurs.
Die hard analog guy? I still favor manual micrometers too but the digitals are still pretty cool. In other video comments people have remarked about easily switching to metric which I think could be a big bonus and make these a two for one value in way. Granted you could just convert yourself but everybody has tool preferences.
I have SAE and metric measuring equipment, and don't use a DRO either. I'm an old retired geezer and a hard core Starrett Man. LOL!@@themeandrousengineer
I use calipers during inspection after a tear down but when cutting bushings I use an inch mic and t gauges, 0001" is not as critical as .001" The lathe I use measures in .0002 at the increment from 0
@@gmonynegro595then you must know that starret is no longer the company it once was, but for the most part mitutoyo is. I have both, plus some Interapid, brown and Sharpe. I like mitutoyo, especially my hammered green 0-6 mics. Silky smooth and deadly accurate.