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.
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! 😍 🤠
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 just got it served as well, and it is beautifully executed. I play with CNC's and I'm certainly no woodworker, but this is great information for any makers trade.
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 don't like many videos. I reserve my like button for my use only. You got a like! Which for me is rare. I appreciate your explanation. Very solid! It's so true the importance of sticking to traditional techniques.
@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????)
Strange I've not been recommended your channel before. Been a joiner for 15 years and a boatbuilder for 5... never come across a sign bar before. Think I'll make one and play around with some angles now! ty for the info, have subscribed!
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.
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.
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.
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.
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 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.
This is (so far) a very interesting video. I'm just halfway thru, and had to pause to write this comment. You've just asked Google to find the sine of 6.7 degrees. Well, I have a Google Nest Hub sitting on my desk next to my PC, and it overheard your query and announced the answer just a half-second behind yours, using a slightly different voice. Now I've spent a good 30 seconds laughing at the hilarity of it all! Ok, time to resume the regular programming...
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.
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?
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.
Well this was 10 minutes of very enjoyable TH-cam thanks, I read mechanical engineering back in the late 70s and have never seen one not even in pretty sophisticated tool rooms, given steel rules are £1 a foot in the local green centre I will cut two inch long pieces and slot them into the sine bar rather than use the brass cylinders won’t look as nice but it’s with in m workshop capabilities sine I don’t have a pillar drill.
This is exactly the kind of precision I've been looking for. I was having trouble getting a good mitre on a picture frame, but this just might solve that.
Glad to be of help. Don't forget that for good mitres, it is necessary, but not sufficient, for the angles to be cut at 45. Opposite sides of the frame also have to be exactly the same length. But I guess you already knew that. :)
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!
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 known 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.
That’s a pretty good trick. I like that idea. Problem is a table saw is only so accurate. I have a sliding T square that will give me angles down to 10th of a degree for miter cuts that is a whole lot easier to set. As for setting the tilt of the blade you can buy digital angle finders that have magnets to hold it to the blade that are more accurate than the table saw/blade combination. I did like the little trick with the wedges in the miter slot. Will have to add that to my bag of woodwork tricks. Thanks for the video, it was worth the watch.
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.
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. .
Great simple technique. I was a kind of misled by the mention of sine and parabolic curve of the inner bar side. In the end you have to have the precisely cut shim for each angle, which leaves me with about 30 thousand shims in my work.
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
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.
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.
6:15 OMFG. How did this part of sines and cosines only NOW click for me?! I'm someone who payed attention in school, yet how did I never realize this? Was I never taught this simple relation between sines, cosines and radius?
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.
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 ;-)
I've never seen a wood sine bar, would not have dreamed a woodworker would ever use one. I assume you use something hard for the bearing rods, so your precision angles stay consistent through the years. Oh. Brass. Umkay. What keeps the wood dimensionally stable?
The wood is maple, which has a very low coeficient of expansion for humidity, even in tangential readings. The only thing that matters here is the longitudial reading. Tables of wood movement give radial and tangential movement, not linear, which is tiny. I'm building dining chairs, not the International Space Station. It's horses for courses. For applications like this, this is more accurate and precise than I could ever need.
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 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..
This is why the trades need to be taught in US high schools. Bringing the theoretical knowledge into practical use. Excellent explanation!
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.
Fascinating 👏 I am so happy when the TH-cam algorithm gets things right once in a while and suggests videos that I actually enjoy and learn from :)
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! 😍
🤠
Out of nowhere came your channel on my feed. This information you provide is “old school” and so fundamentally correct. I’m a fan now! Thank you
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.
I just got it served as well, and it is beautifully executed. I play with CNC's and I'm certainly no woodworker, but this is great information for any makers trade.
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!
This is the first time I've seen this trick - simple and brilliant. thank you
Much more precise than I currently use but was once a day when I worked to this level of precision. I wish the video had been available to me in 1975.
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 don't like many videos. I reserve my like button for my use only. You got a like! Which for me is rare. I appreciate your explanation. Very solid! It's so true the importance of sticking to traditional techniques.
Absolute Genius! I regret sleeping through geometry. Subbed.
Thank you. My HS math teacher would be delighted, as am I. Now I might have a shot at accuracy.
That’s one of the clearest explanations I’ve seen on using a sine bar. Thanks
And now I finally understand what sine actually means
_"…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????)
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!
Very rare to come across a tool I've never heard of or seen before. 👍
Thanks for the wonderful maths lesson, it’s a pleasure watching your videos.
Strange I've not been recommended your channel before. Been a joiner for 15 years and a boatbuilder for 5... never come across a sign bar before. Think I'll make one and play around with some angles now! ty for the info, have subscribed!
Sine bar.
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.
May I suggest adding this video to your Low-Tech playlist? And renaming that list to Low-Tech for High Accuracy?
Or Lotec-Hitec
Thanks Steve: Very clear as usual... Jerry in Ontario
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.
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 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.
Great video Steve. Simple and practical. Thank you
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.
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.
Thanks for sharing this technique!
This was exceptionally helpful. Thank you
This man has a fire at the local deli!😊
I liked this video so much! You are such a passionate person! Thanks for sharing this tool!
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 did not know that, every days a school day thank you
This is (so far) a very interesting video. I'm just halfway thru, and had to pause to write this comment. You've just asked Google to find the sine of 6.7 degrees. Well, I have a Google Nest Hub sitting on my desk next to my PC, and it overheard your query and announced the answer just a half-second behind yours, using a slightly different voice. Now I've spent a good 30 seconds laughing at the hilarity of it all! Ok, time to resume the regular programming...
WOW...thankyou! that solves some problems for me and I realy love the wedges in the table saw idea.
Incredibly useful, thanks for the instruction and enlightenment
Brilliant, mate! Cheers from Southern California!
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.
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?
Nicely presented 😊
That Sir, is bloody clever. Thank you 😊
Great stuff. Tricks not normally learnt without doing an apprenticeship
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.
Well this was 10 minutes of very enjoyable TH-cam thanks, I read mechanical engineering back in the late 70s and have never seen one not even in pretty sophisticated tool rooms, given steel rules are £1 a foot in the local green centre I will cut two inch long pieces and slot them into the sine bar rather than use the brass cylinders won’t look as nice but it’s with in m workshop capabilities sine I don’t have a pillar drill.
Thank you! This is brilliant.
Useful and informative. Thank you.
Excellent tutorial. Thank you for such a clear explanation.
Wholeheartedly amazing bit of kit. Well presented too, earning you a new subscriber
Very nice explanation and what an incredibly useful and simple tool.
This is exactly the kind of precision I've been looking for. I was having trouble getting a good mitre on a picture frame, but this just might solve that.
Glad to be of help. Don't forget that for good mitres, it is necessary, but not sufficient, for the angles to be cut at 45. Opposite sides of the frame also have to be exactly the same length. But I guess you already knew that. :)
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!
Thanks for the great explanation and 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 known 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.
@@kevinrogan9871unbelievable
@@SeattlePioneervery interesting… i did not know that about the metre/cm
That’s a pretty good trick. I like that idea. Problem is a table saw is only so accurate. I have a sliding T square that will give me angles down to 10th of a degree for miter cuts that is a whole lot easier to set. As for setting the tilt of the blade you can buy digital angle finders that have magnets to hold it to the blade that are more accurate than the table saw/blade combination.
I did like the little trick with the wedges in the miter slot. Will have to add that to my bag of woodwork tricks.
Thanks for the video, it was worth the watch.
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.
Brilliant information! Very helpful. Thank you!
Very helpful. So glad i found this video.
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.
Great video!!!
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?
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. .
Woooood? Next vid we expect "absolute precision from clay bar made by an eye".
Great! Perfect education!
Great simple technique. I was a kind of misled by the mention of sine and parabolic curve of the inner bar side. In the end you have to have the precisely cut shim for each angle, which leaves me with about 30 thousand shims in my work.
Well done, you!
My google mini answered in perfect sync with yours.
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.\
To be more precise on the 10" stick. Make a 6" & 4" or (2) 5" sticks. Those you can measure with your calipers.
What I should have done is make the dog-leg version for the spacer, as I did later on in the video.
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
Cool tool!
Could you use nails driven perpendicular to the board instead of the metal cylinders?
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!
Superb Steve. Im off to make one.
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.
This is very cool.
Love to Stuart.
Great job. Thank you 😊
0:49
"Blimey Steve, that's a big one"
Im sure the engineers aren't the only ones telling you that
I would have Liked to see you proof your concept with known accurate tool.
I’m going to make one right now. Thanks!
Thank you. I've never seen this method.
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 Stuart...
6:15 OMFG. How did this part of sines and cosines only NOW click for me?! I'm someone who payed attention in school, yet how did I never realize this? Was I never taught this simple relation between sines, cosines and radius?
Digital Vernier?
That's a new one on me.
But this was a very good video.
Excellent!
top job, thanks
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.
Rather good. Thank you
Thank you
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.
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 ;-)
That's cool, no batteries, no subscriptions, no planned obsolescence.
I've never seen a wood sine bar, would not have dreamed a woodworker would ever use one. I assume you use something hard for the bearing rods, so your precision angles stay consistent through the years. Oh. Brass. Umkay. What keeps the wood dimensionally stable?
The wood is maple, which has a very low coeficient of expansion for humidity, even in tangential readings. The only thing that matters here is the longitudial reading. Tables of wood movement give radial and tangential movement, not linear, which is tiny. I'm building dining chairs, not the International Space Station. It's horses for courses. For applications like this, this is more accurate and precise than I could ever need.
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.
Brilliant
Awesome!
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..