This came up on my recommendations, and I'm so glad it did. I'd never heard of a sine bar before, and this is such a great explanation of how it works, how to make one and how to use it. Great stuff. Cheers!
I realize this is an older video, but still interesting and informative as well. If I ever need such precision, a sine bar is in the build. Great video to explain what a since bar is and equally interesting how to use it. Thanks... Thumbs Up!
For that third hand you could soft clamp the sine bar to the miter gauge then do your alignment. Saved this one to my woodworking videos. Definitely a keeper.
Genius. What a great and elegant way to set up the cheap miter which comes with the table say and not having to buy those expensive miter bars! You might try using magnets to hold your square to the table for the third hand. They make welding magnets at low cost.
You are absolutely right, Dan, and indeed, when I actually came to use it in anger when I was building my dining chairs, that is exactly what I did. It worked perfectly.
I was a weldor machinist for 40 years, retired. I always saw sine bars in the tool catalogs, never knew how to use one. Wow i could have used this knowledge then
Very grateful for your excellent video showing how to make and use a Sine bar. I’d heard of them many years ago but never knew what they were for. Now I know. I now need to make a shooting board to make my Sine bar but then I’ll be well equipped. Thank you again.
I remember learning about sine bars in high school machine shop class 50 years ago but have never used one. This is brilliant. Also new subscriber as a result of this video.
I was the guy writing on the desk. 40 years later some trig has finally soaked through my skull. I’m gonna make my sine bar to up my woodworking game a bit. Great explanation and examples of use. With a bit of tweaking the miter gauge bar fit to slots and using the sine bar, even a basic tool should be very accurate. Cheers!
I wasn't writing on te desk but I struggled with geometry in 1970 and struggle with it today. I guess I can blame teaching methods (although I did pass O-level math second try in 73)
This is intriguing. You could also make an adjustable length spacer using a turnbuckle as a jack screw. Various length turnbuckles could comprise a wide range of lengths. One mid size one for example comes with .25"-20 threads which conveniently converts to 0.10" change per turn. One screw would change the length by .05" per turn, but the turnbuckle turns both screws at once. Thus .05" +.05" = 0.10" per turn. Partial turns can produce finer resolution as well. Any thread count can be used as the length adjustment per turn. You measure the length with calipers, or measure a different length and count turns for exact spacing. Further, you can use the % of inclination such as is stated for roads of so much height compared to the length (at 0° setting) and convert the inclination to degrees. The rounded single one I've memorized is 7% = 4° for quick calculations. There are web calculators which will convert inclination % to degrees and vice versa to get exactly what you want.
We always used gauges and trigonometry in machine shops when I was young. Once you learn how it's so easy. Squaring up room layout is also child's play. 1, 1, ✓2. ✓2 = 1.414. Anyone can do it and it's so accurate and you don't need a big fancy square.
Another tool for the toolkit. Thanks for the different way of creating an angle in the shop. I don't know when I would need an angle that accurate but it's good to know how it can be done relatively easily.
Another "Extraordinaire DIY" to Steve Maskery! For, mathematics (especially Geometry and Trigonometry), I rely loved it. Comparing History and Geography, etc; was to me "To hell with those"! And "I will stick with me math. Amen!" But the truth is: I made a horrible mistake. That has bugged me for 70+ yrs of my 90 yrs, on this planet. But I still love math to the "nth" degrees. And to see you take a very difficult "fact absolute"; when it comes to angles (other than 90, 45, 30 and 60 degrees); and make it so simple; proves that you are truly a "Cut Above", kind Sir. Thank you Steve, for sharing your innate talents, with us. Love it! 😍 🤠
YT just suggested I watch this. Very interesting. I would like to see a modification with a spine on both sides and a pivot. The precise spacing bars are far more accurate than any protractor.
I was the one in class not writing on the table. In my day, trigonometry was its own subject in school. I think it’s given cursory mention in modern curricular. Anyway, never heard of a sine bar. That is amazing! When I needed an angle I just used the SOHCAHTOA trig formulas or good ole Law Of Cosines with a ruler and square. Unfortunately I lack your excellent craftsmanship.
> Trig remains essential in many parts of math and science ---not just for solving triangles. That said, I am attracted to the law of cosines myself! Great fun to calculate the angles of a triangle I lay out arbitrarily.
I love that you use traditional methods, kudos. However, you may want to consider a Grr-Ripper+ for those slim cuts on the table saw. Or just make something similar. I have two and I use them all the time for small cuts.
I do love the usage for the sine bar. I'm gonna bookmark this, as Im sure I will forget by the time I need to apply what I have learned. Thanks, I really enjoyed this presentation.
@agn855 and yet metric is a much closer and way more accurate way to measure, which throws this sine bar angle accuratecy out the window. Particularly after half-pie guessing the near enough centers between the two brass inserts. Waste of time to make and use, especially when you can download a super accurate angle app on ya phone these days
But at 10cm between centers any error in the length of the spacer will have 2.54 times as much effect on the angle, and at 100cm the whole thing is cumbersome. He could have used 25cm but then he'd have to multiply by 25 and while not hard, is not as easy as by ten. Also, he was using decimal inches and never mentioned feet, yards, fathoms or other screwy "Imperial" units. "Half a league, half a league, Half a league onward"
@@PennsPens How is metric a *"way more accurate"* way to measure? When someones reasoning is flawed, I think they lose credibility in what they have to say. I grew up with imperial and metric in my engineering days, each were as accurate as each other Compare the graduations on a metric and imperial micrometer, you won't find much difference, I have both. I prefer metric myself.
@@briannewton3535 I think maybe this is wrong... let's see: in the metric system there is something called "decimals" and it is just a matter of adding decimals until you get the precise value required; while in the imperial system there would be between 5/32" and 11/64"? (11/64????)
Great job! I plan on making one but have always found that just working with trig functions is the easiest way to find angles. I may have missed it but when you asked Google for the sine of 6.7 degrees I missed you mentioning tha the block needs to be 10 times longer. Oops, just saw the note you put on the screen. Great stuff for making making accurate angles!
Great video, enjoyed it very much. I made my woodworking sine bar some thirty years ago and also maple and also 10 inches between anvil centres but in order to ensure accurate drilling of the two holes I made a jig. The jig was made on my milling machine, it has a 90 Deg angle to locate the true common centre line and the holes in the jig are exactly at 10 inches. I then use transfer punches to mark my piece of maple. It's repeatable and quick once you've got the jig. The jig is one inch thick to ensure the transfer punches are perpendicular to the workpiece.
Interesting description, but I'd prefer buying a sine bar rather than making one. Bound to be more accurate, and they needn't be especially expensive ----$20 would buy one. Still, what you made is likely more than accurate for most purposes. Very creative, too. What do you do to set the height for your sine bar?
Solid point, well done! Lol the entirety of the metric system is based on multiples of 10… hence why the world adopted that system as apposed to the idiotic imperial system that was based on approximate foot and arms lengths, cups of water, comfort temperatures, etc. lol
@@wrenchboostboi8994 > Of course the metric system is based on the meter being one ten millionth of the distance between the equator and the north pole ----- except that it's not that distance and has been arbitrarily revised in length several times. The slightly pear shape of the earth also wasn't know at the time the meter was adopted. Indeed, measures of length are arbitrary. A standard can be any length and measured to whatever degree of accuracy is desired.
@ I had a summer job at Union Carbides Bishop California mine back in 1979. As I was a mining engineering student I was placed in the mine planning department and was given several jobs that required drawing of plans, much to my amusement, I was told that the mine used a metric foot, ie a foot composed 10 1.2 inch long ‘inches’ each of which were broken into tenths etc. They had special scale rules, this being before CAD was a thing. I did ask why they didn’t just go metric, but apparently the miners would not have accepted calling the 8,000 foot level the 2,438m level. So they were making the best of the situation, which made sense.
First thing i noticed watching your video, is how much you sound like Michael Caine the actor. I wasn't 20 seconds into your video and your voice was the first thing that hit me.
Haha! Making a sine bar using a ruler for the length! Wow! That's like doing microsurgery with a sledgehammer. Your precision was out the window from the start. I would instead suggest a vernier protractor, or a digital one. They'll be plenty accurate enough for anything made of wood. If your sine bar works, that means you got REALLY lucky, or more likely, you didn't need that much precision in the first place. Now, all that said, a really neat exercise and interesting build. I suggest that everyone search for a video entitled, "the origins of precision" Have a great week!
That's a bit harsh. As I was watching I was trying to figure out how I would build one using the tools in my average equipped workshop. I also tried to consider the tolerance stack up. No matter how carefully I measured and how much I prevented my drill bit from flexing I would never get exactly 10". Nor would I be able to get the two sides exactly parallel And I would have a slight error on the length of the spacers not to mention that I don't have access to the perfect 6mm anvils. However, even considering all of that I can't think of any woodworking project where this wouldn't be accurate enough. And much more accurate than a protractor.
Making a sine bar using a ruler for the length! A couple of things, firstly it didn't have to be 10" it could have been 5" and be measured digitally, and second if he wanted to make it 10" long I suppose he could have measured 10" digitally by using two pieces of wood (both shorter than the 6" limit) by adopting the method he used for measuring the 45 degree angle where the length of wood was 7.07 inches, which was checked digitally.
@@David-tv3dk You are probably mostly right. Hence my qualification that you probably didn't need to be that accurate in the first place in woodworking. Wood compresses, glue fills minor gaps and there are a multitude of ways to hide imperfections that are in just about every wood project. I don't mean to insult your intelligence with this question, but do you know what a VERNIER protractor is? Many woodworkers cut miters a half or full degree acute so the outside corner is guaranteed to close with little or no visible gap once joined. Most common vernier protractors are accurate to less then 5 min of angle. That's 1/12 of a degree. And if you know how to use them and have a magnifying glass, you can cut the in half. Cheap digital protractors aren't as accurate as vernier models and require those pesky button cells. But they're easy to read close enough for most any wood project. My comment does read harsher than it was intended. My aim was to point out the basic precision error of starting with a very inaccurate foundation length. Those combined with the other things you mention can compound error. But if you're lucky, they can cancel each other out and be very accurate. Maybe. But what do you have to check it against? Again, it's a neat project that may well be good enough, but sine bars can be a real pain in the backside to use, depending on the application. Using one on a vertical surface, for instance. Wood is not the most stable material to make precision measuring devices from. But again, if it's close enough for you, it's close enough. Apologies for the harshness. It's the old Army NCO in me.
@@mikemorgan5015 I am aware of vernier calipers - in fact I own one (or is it a pair?) but I wasn't aware of vernier protractors - although I am not surprised that they exist. I agree that would be a great way to measure angles. My point was that woodworking requires an amount of precision but measuring isn't really the main issue. I believe that it's the lack of precision in the tools that causes the most issues. I have average tools in my shop and I know there is blade deflection and mitre tools or positions that have a small amount of play, I am not sure if my drill press table is exactly perpendicular to the bit etc. But as you suggested wood has a way of hiding errors - even the swelling of the wood when exposed to glue can help fill gaps. I am aware of the trick to cut angles slightly acute so the outside closes but you can also use the same position and cut both sides to ensure that the angle adds to 90 - on a picture frame as an example. I do agree that this isn't overly precise but it is "good enough" for my uses anyway. There's an old saying that "only an amateur blames his tools" and that may be true but many times when I watch a video I think how easy it would be if I had that shop set up...but since I don't I think of ways to hide my errors. I think I was more impressed with the concept more than anything else.
A sine bar is a great way of using basic geometry and trig to solve a problem. I find that satisfying. While your vernier protractor would likely do for a woodworking project as you describe, I'd bet that a sine bar would be superior for a precision setup on a Bridgeport milling machine! Just depends on the precision you need. I'd actually be interested in the precision of a vernier protractor compared with a sine bar and gauge blocks. I wonder how precise each one can lay out an angle when used by a skilled person. .
Back in the fifties, my Secondary (in what sense secondary?) Modern School didn't teach such things as Algebra. Much of my ignorance remains intact as a result. As an Octogenarian my thirst for understanding is not to be sated. The problem is that I cannot remember what it is that I can understand. Age can be frustrating! Learning is still fun and rewarding though, so thank you Steve Maskery for adding to my joy of living.
Secondary, meaning second. As opposed to Primary, which means first. Except for most of us there was Primary up to age 8, then middle school to 11 or 12, then ' big school'- either secondary to CSE or grammar school to O level, or even A levels. So Secondary is meant to mean your 2nd school. Many people thought it was saying second, as in inferior, to Grammar school, but that wasn't what the sign meant
Machinist would use gauge blocks to very precisely construct the height a sine bar would be set at to get a precise angle. A set of gauge blocks allows pretty much any distance to be constructed up to the limit of the gauge blocks. Gauge blocks are a very precise supplement to a sine bar.
you can also make a sine protractor. just make sonethig like a folding ruler, (one hinge and screw for locking) non hinged side has two half rounds that when together are exactly 1" and as here 10" from hinge center to center of the half rounds, if material of the halves stick up say 1/4" and the two half rounds share the same center, this means you get any sine by just using calipers directly across the ends sticking out, just remove that 1" to get correct sine measurement.
I eas never very good at trigonometry, but my dad was. Old harry simpkins always has cake on a Tuesday. That's o over h = sine, a over h = cosine , o over a = tangent. Opposite, Adjacent, Hypotoneuse. But how you use them still mystifies me. Cheers!
As an apprentice toolmaker I made my own 5 inch sine bar in hardened steel, accurate to less than 0.0002" all over. When I advanced into the design office I swapped it for a decent slide rule (long before the age of calculators). I wonder where it is now!
One of my lecturers used to refer to slide rules as 'guessing sticks'. Ask an engineer with a slide rule and poor eyesight to do 3x2 and the answer is 5.98 ;-)
Interesting Steve, piqued my interest in making one, but I cannot see how the accuracy could be good enough for precision. How thick is a line, how good is a steel rule, one's eyesight, the available light etc. So many variables ! Cheers mate.
A manufactured sine bar and gauge blocks would probably be about the most accurate way to lay out an angle, I would suppose. Such a sine bar can be had foer $20 or more, and a set of gauge blocks for $100 or more, used. If anyone can suggest a more accurate method, I'd be glad to hear it suggested.
Very drole! :) The point is that 10" is a handy size, whereas 10cm is too small to be useful. And as a digital caliper can give me decimal inches, it makes more sense than measuring 250mm.
That's a tool that machinists used for a very long time but that woodworkers have not made good use of. That said, it would make sense to make spacers for commonly used angles such as 30 and 45 degrees and for others that are often used, but for one-offs one could just use the vernier calipers, particularly if the sine bar was integrated as part of a sled..
It's a great way of setting up for angled cuts very accurately. I made mine when I was building a set of dining chairs which had compound angles. You can see the chair legs in the background. The assembly went together perfectly, because the angles were exact.
It is lovely. I call har Lulu, because she was built in 1964, the year she had her first hit with Shout! :( The quill is wonderfull, butto be honest, the pulley arrangement leave s a lot to be desired. There is no Woodruff key, it's just a grub screw onthe shaft. And there is no rack an pinion for rise and fall of the table, which become more of a problem the older I get.
Good video, good tool. BUT, if your caliper is digital or dial it isn't vernier. I don't use digital or dial calipers, I use vernier calipers. Verniers are more robust, less susceptible to incorrect readings. They are a bit fiddly if you're not used to them, but they are "trustworthy" every time. If they close at zero then they are calibrated correctly.
@@SteveMaskeryI would assume that you can just cut off some decently round metal stock. Like an old shaft or similar. If the ends are not nice and perpendicular it can be a little harder to get them properly seated during the glueing but otherwise there is no need for precision at the ends. For a low precision sine bar like this the wood is way less precise than most shafts or other decently round metal round stock.
A more simple idea that doesn't need to make accurate spacers: take a board of MDF with a straight edge. Mark two points 10 or 20 inches apart on that edge. Draw a perpendicular line on one of the points with an acurate square. Calculate the sin of the angle you want in a calculator and multiply it by 10 or 20 depending on the number of inches those points are separated and mark that distance on the perpendicular line. Draw a line between the other point on the edge and this point in the perpendicular line. Now you have a right triangle that has the angle you want on the edge of the board. Transfer this angle to a speed square, and now you can transfer that angle to your project.
For me is so fun to listen someone tells that multiply by 10 makes the things easier while make all the measurement in inches. Wasn't really easier to use metric system?
Yebbut. 10" is a sensible size, whereas 10cm is a bit on the small side. It's easier to multiply by 10 than it is to multiply by 254 (the metric equivalent of 10".
@@SteveMaskery It is comical to hear all the comments elsewhere about decimal inches. The poor ignorant lambs think that inches have to be fractional units 😂. Bless their hearts and cotton socks, I bet they ain't seen even seen an imperial rule with decimal increments. It's been a while since I worked in inches, though still have my imperial micrometers.
Looks like This Old Tony made a sine bar too, with cosine error, let's go have a peek at that. "A Priest, a car salesman and a kangaroo walk into a Sine Bar and..."
That was an interesting watch, thank you. More for engineers rather than woodies, but orses for courses eh? I'm afraid I don't get the joke. Please tell me the punchline! :)
@@SteveMaskery Yeah, it's interesting what sinks in after seeing variations of an explanation. I'm more of a wood guy but always looking for ways to improve accuracy. It's not a real joke. Old Tony said a sine bar walks into a ...wait no uh... There's no punchline sorry.
Could you have not made two five inch pieces and put end to end match the ten inch against those two end to end. With sensitivity of fingertips or feeler gages or a block and feeler gauges, I bet you could have got it to almost within four thou'. A nice job though, and perfectly accurate enough. Not used a sine bar since my engineering days, forty years ago, along with wringing gauge blocks.
Yes, but what I should have done is the stepped spacer technique that I used later in the film. Measure one half from one and and the other half from the other end. I cold get anything up to 300mm or 12" pretty accurately that way.
@@SteveMaskery I commented on that before I watched the technique used later (naughty me 😅), though both options work, your half and half option is more accurate I suspect. I have a mediocre mitre fence, but using similar techniques to work from the mitre slot, I'll be able to set more accurate angles, for the few times I need to, as I do have a decent mitre saw.
This seems like an extremely tedious thing to set up. You need all your bits of wood of varying length. they also need to be of precise measurements. what i would do is place a nut in a piece of wood. and put a bolt in it. Then use the bolt to get your different heights. i would also make it so that you can lock the angle.
Or you can just get a digital sliding bevel and spend all that time making stuff you want. I get it, but i just don't need a bunch more stuff to find a place for. And you can get digital tools pretty cheap now.
Good Morning Steve! Brilliant as always. Since I have no degree in engineering (biologist), I wasn't aware of this little gadget, but I will make one as soon as I have built another jig, which would also be helpful for you, to keep at least two hands when cutting this sine-bar parallel on the table saw: just by coincidence, a German woodworking channel yesterday uploaded a video on a jig, that helps cutting thin stripes of wood acurately. I think this might also help to keep the fingers much further away from the blade when cutting the back side of the sine bar parallel to the anvils. Here is a link to that video ruclips.net/video/eVpNTJnkduY/видео.html Jonas is a really cool guy (if you don't judge a book just by the cover 😉). Thanks again for the excellent video
Hi Andreas, glad you liked the video. The problem when trimming the edgeis that, because there are only two points in contact with the fence, it is VERY easy for the workpiece to pivot. A standard feather board does not holp, because it applies pressure in front of the blade, rather than on the blade. It's a really tricky cut. But my blade guard completely covers the blade, riding on the workpiece itself. Even so, I have to concentrate. Thanks for the heads up on the video. I wish I spoke German, he sounds fun. Who has houseplants in his workshop?! And here is my very similar solution to the same problem. The quality is dire (it's from a previous life) and you can skip the first 45s (what was I thinking?!) but you'll get the picture. I still have that jig, I think perhaps I need to remake the film. Enjoy (if you can). ruclips.net/video/lp4ZR5WsL9w/видео.html
In high school you learn all about trigonometry but you learn almost nothing about the practical applications. I was quite good at math and when I watch your videos I often think, so simple why didn't I think of this myself. This is simply because they show far too few practical applications of trigonometry and math. If they would show more practical applications, the lessons would be much more fun, also for those who have more difficulty with math.
Well no, actually. I normally work in metric, but just occasionally it is more convenient to work in inches. This is one such situation, because 10" is a sensible size whereas 10cm is too small to be useful. I'm amphibious, I can swim in both seas.
Fascinating 👏 I am so happy when the RUclips algorithm gets things right once in a while and suggests videos that I actually enjoy and learn from :)
This came up on my recommendations, and I'm so glad it did. I'd never heard of a sine bar before, and this is such a great explanation of how it works, how to make one and how to use it. Great stuff. Cheers!
I realize this is an older video, but still interesting and informative as well. If I ever need such precision, a sine bar is in the build. Great video to explain what a since bar is and equally interesting how to use it. Thanks... Thumbs Up!
I made it when I was making a set of dining chairs and needed to set out compound angles for the side rails. The build went together perfectly.
For that third hand you could soft clamp the sine bar to the miter gauge then do your alignment. Saved this one to my woodworking videos. Definitely a keeper.
Yes, that would work. I've also discovered that using 3 small disk magnets is a very good solution.
I did not know that, every days a school day thank you
Genius. What a great and elegant way to set up the cheap miter which comes with the table say and not having to buy those expensive miter bars! You might try using magnets to hold your square to the table for the third hand. They make welding magnets at low cost.
You are absolutely right, Dan, and indeed, when I actually came to use it in anger when I was building my dining chairs, that is exactly what I did. It worked perfectly.
I was a weldor machinist for 40 years, retired. I always saw sine bars in the tool catalogs, never knew how to use one. Wow i could have used this knowledge then
Very rare to come across a tool I've never heard of or seen before. 👍
Very grateful for your excellent video showing how to make and use a Sine bar. I’d heard of them many years ago but never knew what they were for. Now I know. I now need to make a shooting board to make my Sine bar but then I’ll be well equipped. Thank you again.
I remember learning about sine bars in high school machine shop class 50 years ago but have never used one. This is brilliant. Also new subscriber as a result of this video.
I liked this video so much! You are such a passionate person! Thanks for sharing this tool!
May I suggest adding this video to your Low-Tech playlist? And renaming that list to Low-Tech for High Accuracy?
Or Lotec-Hitec
Retaking those math classes in my early 50's. Oh, how I wish I had been in the frame of mind to pay attention way back in the day.
Ain't that the truth.
I was the guy writing on the desk. 40 years later some trig has finally soaked through my skull. I’m gonna make my sine bar to up my woodworking game a bit. Great explanation and examples of use. With a bit of tweaking the miter gauge bar fit to slots and using the sine bar, even a basic tool should be very accurate. Cheers!
And me. Totally lost me sometime after 6 minutes. 🙂 I went and watched one about a " Tick stick " instead.
@russellwaite5874 then you came back here to comment haha
@@russellwaite5874 me too !
I wasn't writing on te desk but I struggled with geometry in 1970 and struggle with it today.
I guess I can blame teaching methods (although I did pass O-level math second try in 73)
This is intriguing. You could also make an adjustable length spacer using a turnbuckle as a jack screw. Various length turnbuckles could comprise a wide range of lengths. One mid size one for example comes with .25"-20 threads which conveniently converts to 0.10" change per turn. One screw would change the length by .05" per turn, but the turnbuckle turns both screws at once. Thus .05" +.05" = 0.10" per turn. Partial turns can produce finer resolution as well. Any thread count can be used as the length adjustment per turn. You measure the length with calipers, or measure a different length and count turns for exact spacing.
Further, you can use the % of inclination such as is stated for roads of so much height compared to the length (at 0° setting) and convert the inclination to degrees. The rounded single one I've memorized is 7% = 4° for quick calculations. There are web calculators which will convert inclination % to degrees and vice versa to get exactly what you want.
We always used gauges and trigonometry in machine shops when I was young. Once you learn how it's so easy. Squaring up room layout is also child's play. 1, 1, ✓2. ✓2 = 1.414. Anyone can do it and it's so accurate and you don't need a big fancy square.
Another tool for the toolkit. Thanks for the different way of creating an angle in the shop. I don't know when I would need an angle that accurate but it's good to know how it can be done relatively easily.
I made it when I was cutting compound angles for my dining chairs.
Another "Extraordinaire DIY" to Steve Maskery! For, mathematics (especially Geometry and Trigonometry), I rely loved it. Comparing History and Geography, etc; was to me "To hell with those"! And "I will stick with me math. Amen!"
But the truth is: I made a horrible mistake. That has bugged me for 70+ yrs of my 90 yrs, on this planet. But I still love math to the "nth" degrees. And to see you take a very difficult "fact absolute"; when it comes to angles (other than 90, 45, 30 and 60 degrees); and make it so simple; proves that you are truly a "Cut Above", kind Sir.
Thank you Steve, for sharing your innate talents, with us. Love it! 😍
🤠
YT just suggested I watch this. Very interesting. I would like to see a modification with a spine on both sides and a pivot. The precise spacing bars are far more accurate than any protractor.
I was the one in class not writing on the table. In my day, trigonometry was its own subject in school. I think it’s given cursory mention in modern curricular. Anyway, never heard of a sine bar. That is amazing! When I needed an angle I just used the SOHCAHTOA trig formulas or good ole Law Of Cosines with a ruler and square. Unfortunately I lack your excellent craftsmanship.
I'm so the same 😊
>
Trig remains essential in many parts of math and science ---not just for solving triangles.
That said, I am attracted to the law of cosines myself! Great fun to calculate the angles of a triangle I lay out arbitrarily.
That Sir, is bloody clever. Thank you 😊
That’s one of the clearest explanations I’ve seen on using a sine bar. Thanks
This is the first time I've seen this trick - simple and brilliant. thank you
I love that you use traditional methods, kudos. However, you may want to consider a Grr-Ripper+ for those slim cuts on the table saw. Or just make something similar. I have two and I use them all the time for small cuts.
I do love the usage for the sine bar. I'm gonna bookmark this, as Im sure I will forget by the time I need to apply what I have learned. Thanks, I really enjoyed this presentation.
_"…and multiplying by ten is very easy!"_ (starts using imperial instead of metric. Priceless)
@agn855 and yet metric is a much closer and way more accurate way to measure, which throws this sine bar angle accuratecy out the window. Particularly after half-pie guessing the near enough centers between the two brass inserts. Waste of time to make and use, especially when you can download a super accurate angle app on ya phone these days
@@PennsPens was my thinking as well!
But at 10cm between centers any error in the length of the spacer will have 2.54 times as much effect on the angle, and at 100cm the whole thing is cumbersome. He could have used 25cm but then he'd have to multiply by 25 and while not hard, is not as easy as by ten. Also, he was using decimal inches and never mentioned feet, yards, fathoms or other screwy "Imperial" units. "Half a league, half a league, Half a league onward"
@@PennsPens How is metric a *"way more accurate"* way to measure? When someones reasoning is flawed, I think they lose credibility in what they have to say.
I grew up with imperial and metric in my engineering days, each were as accurate as each other Compare the graduations on a metric and imperial micrometer, you won't find much difference, I have both. I prefer metric myself.
@@briannewton3535 I think maybe this is wrong... let's see: in the metric system there is something called "decimals" and it is just a matter of adding decimals until you get the precise value required; while in the imperial system there would be between 5/32" and 11/64"? (11/64????)
This was exceptionally helpful. Thank you
Thank you! This is brilliant.
Brill Steve, as ever!
Was aware of them in engineering, but hadn't thought of applying them to woodwork, and you make it look so easy!
Great! Perfect education!
Thats class! I probably won't make one...along with the other few hundred "projects" but now I know what it is....
Thanks. 👍
What I might do though is just draw it on paper. Then use a straight edge clamped along the hypotenuse.
Great job! I plan on making one but have always found that just working with trig functions is the easiest way to find angles. I may have missed it but when you asked Google for the sine of 6.7 degrees I missed you mentioning tha the block needs to be 10 times longer. Oops, just saw the note you put on the screen. Great stuff for making making accurate angles!
Great video, enjoyed it very much. I made my woodworking sine bar some thirty years ago and also maple and also 10 inches between anvil centres but in order to ensure accurate drilling of the two holes I made a jig. The jig was made on my milling machine, it has a 90 Deg angle to locate the true common centre line and the holes in the jig are exactly at 10 inches. I then use transfer punches to mark my piece of maple. It's repeatable and quick once you've got the jig. The jig is one inch thick to ensure the transfer punches are perpendicular to the workpiece.
That sounds like a Rolls Royce of a jig! NIce!
Interesting description, but I'd prefer buying a sine bar rather than making one. Bound to be more accurate, and they needn't be especially expensive ----$20 would buy one.
Still, what you made is likely more than accurate for most purposes. Very creative, too.
What do you do to set the height for your sine bar?
11.15.24 I have never heard of this. I love to learn about great ways to measure and create precision. Thanks!!
Thanks for sharing this technique!
Multiplying by ten is easy - so that’s why I’m using inches?
Solid point, well done! Lol the entirety of the metric system is based on multiples of 10… hence why the world adopted that system as apposed to the idiotic imperial system that was based on approximate foot and arms lengths, cups of water, comfort temperatures, etc. lol
@@wrenchboostboi8994 >
Of course the metric system is based on the meter being one ten millionth of the distance between the equator and the north pole ----- except that it's not that distance and has been arbitrarily revised in length several times. The slightly pear shape of the earth also wasn't know at the time the meter was adopted.
Indeed, measures of length are arbitrary. A standard can be any length and measured to whatever degree of accuracy is desired.
@ I had a summer job at Union Carbides Bishop California mine back in 1979. As I was a mining engineering student I was placed in the mine planning department and was given several jobs that required drawing of plans, much to my amusement, I was told that the mine used a metric foot, ie a foot composed 10 1.2 inch long ‘inches’ each of which were broken into tenths etc. They had special scale rules, this being before CAD was a thing. I did ask why they didn’t just go metric, but apparently the miners would not have accepted calling the 8,000 foot level the 2,438m level. So they were making the best of the situation, which made sense.
First thing i noticed watching your video, is how much you sound like Michael Caine the actor. I wasn't 20 seconds into your video and your voice was the first thing that hit me.
WOW...thankyou! that solves some problems for me and I realy love the wedges in the table saw idea.
Haha! Making a sine bar using a ruler for the length! Wow! That's like doing microsurgery with a sledgehammer. Your precision was out the window from the start.
I would instead suggest a vernier protractor, or a digital one. They'll be plenty accurate enough for anything made of wood. If your sine bar works, that means you got REALLY lucky, or more likely, you didn't need that much precision in the first place.
Now, all that said, a really neat exercise and interesting build.
I suggest that everyone search for a video entitled, "the origins of precision"
Have a great week!
That's a bit harsh.
As I was watching I was trying to figure out how I would build one using the tools in my average equipped workshop. I also tried to consider the tolerance stack up. No matter how carefully I measured and how much I prevented my drill bit from flexing I would never get exactly 10". Nor would I be able to get the two sides exactly parallel And I would have a slight error on the length of the spacers not to mention that I don't have access to the perfect 6mm anvils.
However, even considering all of that I can't think of any woodworking project where this wouldn't be accurate enough. And much more accurate than a protractor.
Making a sine bar using a ruler for the length!
A couple of things, firstly it didn't have to be 10" it could have been 5" and be measured digitally, and second if he wanted to make it 10" long I suppose he could have measured 10" digitally by using two pieces of wood (both shorter than the 6" limit) by adopting the method he used for measuring the 45 degree angle where the length of wood was 7.07 inches, which was checked digitally.
@@David-tv3dk You are probably mostly right. Hence my qualification that you probably didn't need to be that accurate in the first place in woodworking. Wood compresses, glue fills minor gaps and there are a multitude of ways to hide imperfections that are in just about every wood project.
I don't mean to insult your intelligence with this question, but do you know what a VERNIER protractor is? Many woodworkers cut miters a half or full degree acute so the outside corner is guaranteed to close with little or no visible gap once joined. Most common vernier protractors are accurate to less then 5 min of angle. That's 1/12 of a degree. And if you know how to use them and have a magnifying glass, you can cut the in half. Cheap digital protractors aren't as accurate as vernier models and require those pesky button cells. But they're easy to read close enough for most any wood project.
My comment does read harsher than it was intended. My aim was to point out the basic precision error of starting with a very inaccurate foundation length. Those combined with the other things you mention can compound error. But if you're lucky, they can cancel each other out and be very accurate. Maybe. But what do you have to check it against?
Again, it's a neat project that may well be good enough, but sine bars can be a real pain in the backside to use, depending on the application. Using one on a vertical surface, for instance. Wood is not the most stable material to make precision measuring devices from.
But again, if it's close enough for you, it's close enough.
Apologies for the harshness. It's the old Army NCO in me.
@@mikemorgan5015 I am aware of vernier calipers - in fact I own one (or is it a pair?) but I wasn't aware of vernier protractors - although I am not surprised that they exist. I agree that would be a great way to measure angles. My point was that woodworking requires an amount of precision but measuring isn't really the main issue. I believe that it's the lack of precision in the tools that causes the most issues. I have average tools in my shop and I know there is blade deflection and mitre tools or positions that have a small amount of play, I am not sure if my drill press table is exactly perpendicular to the bit etc. But as you suggested wood has a way of hiding errors - even the swelling of the wood when exposed to glue can help fill gaps. I am aware of the trick to cut angles slightly acute so the outside closes but you can also use the same position and cut both sides to ensure that the angle adds to 90 - on a picture frame as an example.
I do agree that this isn't overly precise but it is "good enough" for my uses anyway. There's an old saying that "only an amateur blames his tools" and that may be true but many times when I watch a video I think how easy it would be if I had that shop set up...but since I don't I think of ways to hide my errors.
I think I was more impressed with the concept more than anything else.
A sine bar is a great way of using basic geometry and trig to solve a problem. I find that satisfying.
While your vernier protractor would likely do for a woodworking project as you describe, I'd bet that a sine bar would be superior for a precision setup on a Bridgeport milling machine!
Just depends on the precision you need.
I'd actually be interested in the precision of a vernier protractor compared with a sine bar and gauge blocks. I wonder how precise each one can lay out an angle when used by a skilled person. .
Back in the fifties, my Secondary (in what sense secondary?) Modern School didn't teach such things as Algebra. Much of my ignorance remains intact as a result. As an Octogenarian my thirst for understanding is not to be sated. The problem is that I cannot remember what it is that I can understand. Age can be frustrating! Learning is still fun and rewarding though, so thank you Steve Maskery for adding to my joy of living.
Secondary, meaning second. As opposed to Primary, which means first.
Except for most of us there was Primary up to age 8, then middle school to 11 or 12, then ' big school'- either secondary to CSE or grammar school to O level, or even A levels.
So Secondary is meant to mean your 2nd school.
Many people thought it was saying second, as in inferior, to Grammar school, but that wasn't what the sign meant
Incredibly useful, thanks for the instruction and enlightenment
My only complaint is that when you used your google, it activated mine and paused the video. 😂 Very informative video. Thank you.
Heh, heh! Good story.
So---- you double checked the math, eh?
Excellent tutorial. Thank you for such a clear explanation.
Thanks for the great explanation and technique !
Great video Steve. Simple and practical. Thank you
Machinist would use gauge blocks to very precisely construct the height a sine bar would be set at to get a precise angle. A set of gauge blocks allows pretty much any distance to be constructed up to the limit of the gauge blocks.
Gauge blocks are a very precise supplement to a sine bar.
Thanks Steve: Very clear as usual... Jerry in Ontario
Brilliant information! Very helpful. Thank you!
This is an awesome use of a sine bar. And it works great on a table saw. I wonder how it might be used on a miter saw.\
Very helpful. So glad i found this video.
you can also make a sine protractor. just make sonethig like a folding ruler, (one hinge and screw for locking) non hinged side has two half rounds that when together are exactly 1" and as here 10" from hinge center to center of the half rounds, if material of the halves stick up say 1/4" and the two half rounds share the same center, this means you get any sine by just using calipers directly across the ends sticking out, just remove that 1" to get correct sine measurement.
When you asked google “what’s the sine of…..” I half expected her to answer Sagittarius. It was really sweet when you acknowledged your passed friend.
I eas never very good at trigonometry, but my dad was. Old harry simpkins always has cake on a Tuesday. That's o over h = sine, a over h = cosine , o over a = tangent. Opposite, Adjacent, Hypotoneuse.
But how you use them still mystifies me. Cheers!
I've never seen that before, what a fantastic way to remember it!
As an apprentice toolmaker I made my own 5 inch sine bar in hardened steel, accurate to less than 0.0002" all over. When I advanced into the design office I swapped it for a decent slide rule (long before the age of calculators). I wonder where it is now!
One of my lecturers used to refer to slide rules as 'guessing sticks'. Ask an engineer with a slide rule and poor eyesight to do 3x2 and the answer is 5.98 ;-)
Interesting Steve, piqued my interest in making one, but I cannot see how the accuracy could be good enough for precision. How thick is a line, how good is a steel rule, one's eyesight, the available light etc. So many variables ! Cheers mate.
A manufactured sine bar and gauge blocks would probably be about the most accurate way to lay out an angle, I would suppose. Such a sine bar can be had foer $20 or more, and a set of gauge blocks for $100 or more, used.
If anyone can suggest a more accurate method, I'd be glad to hear it suggested.
Useful and informative. Thank you.
Wholeheartedly amazing bit of kit. Well presented too, earning you a new subscriber
Digital Vernier?
That's a new one on me.
But this was a very good video.
Superb Steve. Im off to make one.
Never thought of using a sine bar. Thanks for the great idea.
@@terrygoyan Yup! Caught me. Edited my initial comment. Thanks.
@@petec6690 I deleted my first comment. Have a good day!
"Multiplying by ten is very easy, and that's why I'm working in inches."
If only there were a measurement system based on factors of ten......
Very drole! :) The point is that 10" is a handy size, whereas 10cm is too small to be useful. And as a digital caliper can give me decimal inches, it makes more sense than measuring 250mm.
That's a tool that machinists used for a very long time but that woodworkers have not made good use of. That said, it would make sense to make spacers for commonly used angles such as 30 and 45 degrees and for others that are often used, but for one-offs one could just use the vernier calipers, particularly if the sine bar was integrated as part of a sled..
I’m going to make one right now. Thanks!
Thank you. I've never seen this method.
Could you use nails driven perpendicular to the board instead of the metal cylinders?
Love to Stuart.
Great job. Thank you 😊
Maybe make a wedge with different thicknesses marked on the wedge to place under the sine bar so that you don;t need to make all those precise sticks.
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Gauge blocks. The way machinists measure such distance with great accuracy.
Rather good. Thank you
Excellent!
Awesome!
top job, thanks
What is the purpose and need for this tool?
It's a great way of setting up for angled cuts very accurately. I made mine when I was building a set of dining chairs which had compound angles. You can see the chair legs in the background. The assembly went together perfectly, because the angles were exact.
That's a nice drill press. Or pillar drill, I guess you Brits call it, which is a better name, in my opinion.
It is lovely. I call har Lulu, because she was built in 1964, the year she had her first hit with Shout! :(
The quill is wonderfull, butto be honest, the pulley arrangement leave s a lot to be desired. There is no Woodruff key, it's just a grub screw onthe shaft. And there is no rack an pinion for rise and fall of the table, which become more of a problem the older I get.
Brilliant. ❤
Next make a continuous spacer or get a 12" digital electronic protractor.
well that taught an old dog a new trick. thanks
Good video, good tool. BUT, if your caliper is digital or dial it isn't vernier. I don't use digital or dial calipers, I use vernier calipers. Verniers are more robust, less susceptible to incorrect readings. They are a bit fiddly if you're not used to them, but they are "trustworthy" every time. If they close at zero then they are calibrated correctly.
Where would you obtain "anvils" in America for this?
I suspect that you will have to find someone to turn a pair for you. That's what I did.
@@SteveMaskeryI would assume that you can just cut off some decently round metal stock. Like an old shaft or similar.
If the ends are not nice and perpendicular it can be a little harder to get them properly seated during the glueing but otherwise there is no need for precision at the ends.
For a low precision sine bar like this the wood is way less precise than most shafts or other decently round metal round stock.
@@larslindgren3846 Well it wouldn't be as pretty, but it would work.
A more simple idea that doesn't need to make accurate spacers: take a board of MDF with a straight edge. Mark two points 10 or 20 inches apart on that edge. Draw a perpendicular line on one of the points with an acurate square. Calculate the sin of the angle you want in a calculator and multiply it by 10 or 20 depending on the number of inches those points are separated and mark that distance on the perpendicular line. Draw a line between the other point on the edge and this point in the perpendicular line. Now you have a right triangle that has the angle you want on the edge of the board. Transfer this angle to a speed square, and now you can transfer that angle to your project.
Yes, that would work.
@@SteveMaskerybut it wouldn't be that cool, is that what you're implying?
Supreme sir!!
No chance ill be making this but interesting video none the less, first woodworking video ive been annoyed at when he FFd it lol
Sorry to hear about your good friend.
Excellent
Thank you very much
"Multiplying numbers by 10 is very easy "
Good thing they invented based 10metric system 😃
"So that's why I'm working in inches"
😒
Why not use the digital calipers as the spacer, saves making so many blocks.
For me is so fun to listen someone tells that multiply by 10 makes the things easier while make all the measurement in inches. Wasn't really easier to use metric system?
Yebbut. 10" is a sensible size, whereas 10cm is a bit on the small side. It's easier to multiply by 10 than it is to multiply by 254 (the metric equivalent of 10".
Usually I work in millimetres. But 10" is a better size than 10 cm.
@@SteveMaskery It is comical to hear all the comments elsewhere about decimal inches. The poor ignorant lambs think that inches have to be fractional units 😂. Bless their hearts and cotton socks, I bet they ain't seen even seen an imperial rule with decimal increments. It's been a while since I worked in inches, though still have my imperial micrometers.
Looks like This Old Tony made a sine bar too, with cosine error, let's go have a peek at that.
"A Priest, a car salesman and a kangaroo walk into a Sine Bar and..."
That was an interesting watch, thank you. More for engineers rather than woodies, but orses for courses eh?
I'm afraid I don't get the joke. Please tell me the punchline! :)
@@SteveMaskery Yeah, it's interesting what sinks in after seeing variations of an explanation. I'm more of a wood guy but always looking for ways to improve accuracy.
It's not a real joke. Old Tony said a sine bar walks into a ...wait no uh...
There's no punchline sorry.
@@BariumCobaltNitrog3n Bummer.
Very kool
Could you have not made two five inch pieces and put end to end match the ten inch against those two end to end. With sensitivity of fingertips or feeler gages or a block and feeler gauges, I bet you could have got it to almost within four thou'. A nice job though, and perfectly accurate enough. Not used a sine bar since my engineering days, forty years ago, along with wringing gauge blocks.
Yes, but what I should have done is the stepped spacer technique that I used later in the film. Measure one half from one and and the other half from the other end. I cold get anything up to 300mm or 12" pretty accurately that way.
@@SteveMaskery I commented on that before I watched the technique used later (naughty me 😅), though both options work, your half and half option is more accurate I suspect. I have a mediocre mitre fence, but using similar techniques to work from the mitre slot, I'll be able to set more accurate angles, for the few times I need to, as I do have a decent mitre saw.
This seems like an extremely tedious thing to set up. You need all your bits of wood of varying length. they also need to be of precise measurements. what i would do is place a nut in a piece of wood. and put a bolt in it. Then use the bolt to get your different heights. i would also make it so that you can lock the angle.
Wood is not as subject to dimensional variation due to temperature change, as long as it is sealed to inhibit moisture movement.
Close enough for horseshoes, anyway!
Or you can just get a digital sliding bevel and spend all that time making stuff you want. I get it, but i just don't need a bunch more stuff to find a place for. And you can get digital tools pretty cheap now.
How are tyou going to calibrate them and test them for accuracy? Or just ASSUME they are accurate?
How do you know where to position the “blunt end”
If you can put it anywhere, the angles could change depending when you place it !
No, that's not right, the angle is always the correct angle. I'm afraid you misunderstand. Watch it again :)
Had to pause the video at 7:06 to wait for my Google to stop talking!
Drilling the holes against a fence would have guaranteed parallel between the edge and the holes. No need to add a process.
It’s his tool, he can add as many steps as he likes.
@chrisb2443 that was about as snotty as it gets. No point helping anybody out when you are around.
When woodworkers do 'precision'.
Seriously, I do like it. But ...
Good Morning Steve! Brilliant as always. Since I have no degree in engineering (biologist), I wasn't aware of this little gadget, but I will make one as soon as I have built another jig, which would also be helpful for you, to keep at least two hands when cutting this sine-bar parallel on the table saw: just by coincidence, a German woodworking channel yesterday uploaded a video on a jig, that helps cutting thin stripes of wood acurately. I think this might also help to keep the fingers much further away from the blade when cutting the back side of the sine bar parallel to the anvils. Here is a link to that video ruclips.net/video/eVpNTJnkduY/видео.html Jonas is a really cool guy (if you don't judge a book just by the cover 😉).
Thanks again for the excellent video
Hi Andreas, glad you liked the video.
The problem when trimming the edgeis that, because there are only two points in contact with the fence, it is VERY easy for the workpiece to pivot. A standard feather board does not holp, because it applies pressure in front of the blade, rather than on the blade. It's a really tricky cut. But my blade guard completely covers the blade, riding on the workpiece itself. Even so, I have to concentrate.
Thanks for the heads up on the video. I wish I spoke German, he sounds fun. Who has houseplants in his workshop?! And here is my very similar solution to the same problem. The quality is dire (it's from a previous life) and you can skip the first 45s (what was I thinking?!) but you'll get the picture. I still have that jig, I think perhaps I need to remake the film. Enjoy (if you can).
ruclips.net/video/lp4ZR5WsL9w/видео.html
Inches! Inches! Inches!!!!!!!!!!!!!!!!!!!
In high school you learn all about trigonometry but you learn almost nothing about the practical applications. I was quite good at math and when I watch your videos I often think, so simple why didn't I think of this myself. This is simply because they show far too few practical applications of trigonometry and math. If they would show more practical applications, the lessons would be much more fun, also for those who have more difficulty with math.
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They have classes in physics to use trig and calculus on.
The British and the yanks stubbornly hanging on to the imperial measuring system.
Well no, actually. I normally work in metric, but just occasionally it is more convenient to work in inches. This is one such situation, because 10" is a sensible size whereas 10cm is too small to be useful. I'm amphibious, I can swim in both seas.
@@SteveMaskery Re "I'm amphibious, I can swim in both seas." My Aunty Dextrus was a keen swimmer and did likewise.