I’ve been watching your videos for about a year now. The first one I watched you deburred a part on the lathe in my opinion backwards. I thought to myself no Joe no. I kept watching your videos and realized we were running neck and neck with our skill level. I was a lazy student in school and skated by with basic math. I never graduated. Then I picked machinist for a career. I got by using a trigeasy book. Geometry was my huckleberry. After 46 years I retired yesterday. Thanks to you I now have to go to sleep tonight knowing I’m second best. Keep up the great videos because I need the entertainment in my twilight years. Take care and God bless you.
Hi Joe, Great video! At one point you comment that the result is '... going to floor you!'. It's even better than you showed. r = d/3, where d is the depth of the dovetail!!! This is true for (and _only_ for) a 60 degree dovetail, see below. This is about the simplest result that mathematicians would refer to as 'pretty'. In this video, you demonstrate the importance of paying attention in math classes. Clearly, you did. I'm biased here, as I'm a retired industrial mathematician. I grew up in a very hands-on family: my father was a plumbing and heating contractor and I did plumbing and tin-knocker's apprenticeships with him during high school, college, and graduate school. His older brother founded a machine/fabrication/millwright/erection shop. I always liked hanging around his shop. During my career, all I had to show for a day's work was a pile of papers covered in equations, tables, graphs, maybe a computer program or an Excel spreadsheet, etc. I took up machine work and woodwork to have something tangible to see and touch. When you talked about a pin whose center is in line with the opening of the dovetail, you found the base of the triangle, 0.075, as the tangent of 30 degrees times the 0.130 depth of the dovetail. That is, tan(30) x 0.130 = 1/sqrt(3) x 0.130 = 0.0750. Then, when you found the radius of the pin, using the small triangle, r = tan (30) x 0.0750 = 0.0433. But, this is the same as r = tan(30) x tan(30) x d, where d is the depth of the dovetail. We can write this as r = tan^2(30) x d = (1/sqrt(3))^2 x d = 1/3 d. That is, for a 60 degree dovetail the radius of a pin whose center is in line with the dovetail opening is 1/3 the depth of that dovetail! r = d/3 ! Fellow viewers, remember, r = d/3 _only_ works with a 60 degree dovetail. I would have done this slightly differently. Draw the triangle with the depth and the angle of the dovetail (theta) as specified, just as you did. As you noted, the radius of the pin is tangent to the hypotenuse of that triangle. This radius creates another triangle that is similar to the first triangle. One leg of the triangle is r. The hypotenuse of this triangle is d-r. The acute angle formed by the radius and the dovetail depth of the original triangle is also theta, because these are similar triangles. We know that cosine is the ratio of the adjacent side to the hypotenuse. In our case, r / (d - r) = cos(theta). Multiply both sides of this by (d - r) / cos(theta) to obtain r / cos(theta) = d - r. Add r to both sides to obtain r x (1 + 1/cos(theta)) = d. Finally, r = d / (1 + 1/cos(theta)) = d x cos(theta) / (1 + cos(theta)) = d / (1 + sec(theta)). In your case, theta is 60 degrees. cos(60) = 1/2. Thus, r = d / (1 + 1/(1/2)) = d / 3, as before. Again, r = d/3 _only_ works for a 60 degree dovetail. Be well & Best regards, Gottfried
Joe I have used trig for nearly 50 years in work and play and have never noticed that relationship in the 30-60 triangle. Very useful bit of info I will pluck out when least expected on my poor unsuspecting friends. Loving these vids
I love geometric development. I was crap at mathematics at school, I've learned a whole lot more since I did my trade than I ever could have at school.
You were lucky to even been taught it in school in the mid 60's I had just started high school, ( here in England at the time, that was at aged 11-16) we were the first class to be taught "Modern Maths" and trigonometry was not on the syllabus at all. We had matrices and such . Never once in my entire career have I ever used anything like them so it was a totally useless waste of everyone's time learning it. And don't get me started on Topology lol. Now doing this sort of engineering for a hobby I have to teach myself or let Joe here show me how to do it lol
That dovetail measure demo was great - always worth a detailed reminder because I always have to think hard every time!. That though was for the 'standard' method. However, the second approach to find a pin center was just exotic!! Love it, so elegant. The machining was icing on the cake - what a gorgeous result too. :) Thanks as always Joe.
Back in 1960 I was taught the three legs of a 30/60 triangle were 1, 2, square root of 3, very easy to remember. Sorry no square root symbol on my key board. The other easy one to remember is 45 triangle, 1, 1, square root of 2. And the carpenters favorite, right triangle 3, 4, 5. Great video Joe!
Yes I've used the 3,4,5 triangle hundreds of times even setting out a 20'x12' concrete base to get it nice and square. Need It to be bigger? Just use metres instead of inches
@@swig46 I typed that on my iPad using “the math keyboard” app. Once you install the app it adds an extra math keyboard to your keyboard options. It has all of the typical math symbols, but I wish it let me add limits to my integrals.
I'm gonna have to watch this SO many times....stupid schools cutting shop classes and leaving the teenage me with ZERO proof that those dang math classes would be of ANY use to me later in life. I was in my 30's before I realized how many things I wanted to play with that required basic Trig and Calculus skills...now at 40, my brain can't hold on to the learnin' as good no more. Thanks for schooling me Joe. I genuinely appreciate your thorough explanations and meticulous filming
As a youngster, math (as I'm sure it was for many) was not a subject I was interested in. Couldn't see the point. My trade (electronic and electrical) taught me the math I needed to know for the job which I use for that and understand. Since becoming interested in engineering later in life, trig is now my new hobby. Again, horses for courses. Thanks as always Jo for the homework, and a new appreciation for numbers. Cheers Pete'.
Great demonstration both in the geometry / trig and the actual cutting of the test part. I am learning so much from this series! Just getting back into machining after a 6 year break following my fathers passing. Just took the motivation right out of me. This and woodworking are what we talked about all the time. Trying to get back out in the shop and you are an inspiration Joe! Thanks for what you do for the community!
Great video as always Joe.....learn so much from watching them....gives me things to think about and ways to tackle problems...keep up the great work..Brisbane, Australia.
Coach Hagan told me "you're going to need to know this stuff (geometry/trigg) one day"....well played coach Hagan, and well explained Joe Pie! I can't be the only one that gets excited when you go to the white board...I wish 15/16 year old me had paid better attention the first time around.
@@robertoswalt319 I think my biggest issue back then was...um...competing interests 😂. Between football, working on my truck, and young ladies, who has got time to put effort into Sin/Cosine/Tangent/Cotangent relationships?!?! Thankfully the big head prevailed against all odds and I got my EE degree. Herding electrons has always made more sense to me than wrangling triangles. I guess I just wasn't ready, or like you said I didn't see the application for the knowledge.
I'm about to machine a casting for a back plate for my new chuck. I'm gonna make both a male and female part (spindle nose clone) out of aluminum or maybe even Delrin, one for practice before I cut on an expensive casting, and the snoot as a gauge. Love this channel! Nice to see other people do not-so-dry runs!
Thanks again for such an informative video. Lots of machining content out there but you are the only one I have found that actually explains the how and math involved so we can apply to our own jobs. Thank you.
Thanks very much Joe! You have no idea how much help you are to us that are amateur model stationary engine builders. I'm a retired instrument technician but building stationary engines is now my passion.
Pierre did a video on dovetail measuring. I viewed it repeatedly, drew it all out, tried to simplify it, made notes that I hoped to be able to read and get a quick recall of what I'd figured out. Managed to confirm that the commercial tool holder I'd bought was within 0.002 of what they said it would be. And, when I was done, it did make sense. Fast forward to now. It all goes right over me again. I look at those notes, they could be in Greek or Hebrew, they make no sense at all. When it gets to that level, my retention goes to zilch. I just don't use it enough to make it stick. Time for more ibuprofen ... ... I got a few dovetail challenges facing me this summer, maybe it will friction weld or gall itself into place this time.
Another great video from the master Joe Pie! For those of us that only have one gage pin of each size - figure out the diameter you need per Joe's example. The add one thou to that diameter and subtract one thou from that diameter. Use the plus and minus sizes in the dovetail. The overall size will be the same. But be careful if you are locating the centerline - it has moved by one thou.
“No shame in a setup piece....” thanks for those reassuring words from a master machinist. 👍👍😎👍👍. Especially since most of my setup pieces start out as final parts. 🤣😁🤣. Makes much more sense to practice on something easier to machine 😉
5 am trig class. Brill. Thanks Joe for a other very interesting video, best way to learn anything. Class then action works for everything. Regards from Wales
HI Joe thanks for my needed math class, I used your suggestion for finding an angle on the lathe and I was able for the first time to cut a Morris taper accurately. keep it up! Rich
I just realized that trig is trigon-ometry, or measurements using triangles. That all by itself makes this stuff easier. And we both followed your math on both parts. So cool! I feel like I’m actually learning something instead of just watching someone make stuff. Thanks Joe... you make my world a better place. 🤘🏻
Wow if i would have had math teachers that could teach as well as you i might have learned something in school. You are an amazing teacher to the world, keep up the good work and keep safe.
Another amazing lesson! "Hope that makes sense"........ It makes perfect sense since it is math and the answer can be proven to be true. Not that I could have ever figured all that out but learn every time I watch.
What's even easier is simply plug everything into a CAD program. And there are enough free ones out there to fo the job. I used to get drawings that called for specific diameters at the tops of countersinks or chambers on holes. The easiest way I found to check the feature's diameter at the surface was to do a quick layout with a ball of known diameter in the countersink and find the dimension from the top of the ball to a line that was the same dimension as something I had in my box. Typically a 1-2-3 block and check from the top of the ball to 1-2-3 block with a depth mic. CAD is an extremely useful tool not just for designing parts but also for solving shop dimensional questions and how measure or program. When I first started doing CNC work I had to write all my own programs unless it was a part in the machines library that somebody else had done. We had no post processor to run the drawing through so we would need to provide the radius center points on arcs between straight sections. Easy on two edges parallel to the machine axis but between angled surfaces it caused some major head scratching. If you have a computer in your shop (and I think you should) download a free CAD software package and use it. It's a tool.
Great explanation, thanks so much. I never really knew how to do the measurement across a dovetail with pins. You made it very clear and easy to understand.
Nicely explained. I've never made dovetails that small, so it was nice to have a refresher course. These parts would be so fun to make. I got to say, I am jealous.
@@joepie221 Wise decision. I've made the mistake of not double checking the engineer's numbers before I started. I learned just because the print has GE or Milicron on it, doesn't mean it's going to be flawless.
Love the project. I can watch a true craftsman all day long. By the way, I just received the 1100 Lumen Special Edition. It's beautiful. I have a trip to Maui in April and I intend to use the heck out of it. Thanks for the prompt delivery. You are indeed a master craftsman.
Thanks for the compliment and purchase. That light rig is very bright and can sit in the sand flat, or vertical resting on the back of the lights. Please get a safety lanyard for it so you don't loose it.
When I took math I couldn’t picture what it would be good for! If my teachers had an example of building something like this it would of made math my #1 subject!
Kind of funny story. My step sister who is 15 years younger than me was having issues understanding variables in formulas when first starting geometry/algebra. She could do the math or calculations to find area, diameter, or even solve equations and such just fine with real numbers but had a total block if you just presented a formula or had to work backwards. So it wasn't like she was stupid, it was just that a letter instead of a number threw her off. She didn't "get it". Dad wasn't getting through to her and she was getting really frustrated. So unrelated, one Saturday morning I came over to get her and we were supposed to get fertilizer for the garden. I always called fertilizer bullshit for the giggles. So I had her calculate how much bullshit we needed and write it down as she was doing it. I then wrote the formulas above her work and explained how they mostly stood in place of numbers you didn't know at the time but could work also be used to work backwards to figure out somethingif you onlyhad part of the information. Something clicked and she started to get it and within a couple weeks or so, her math grades increased so much the teacher thought she might have been cheating somehow. When confronted about it, my sis blurted out that it was bullshit, all about bullshit. The teacher's reaction made her cry. Needless to say, Dad had to go to school and explain my foul mouth and how she can to her epiphany. To this day we have an inside joke about not getting her started on talking about bullshit.
Hi Joe, many many thanks for all your great videos. I learned so much about machinery and look forward to use one or the other within one of my next projects. I once assembled a 5BI steam engine by PMR which is used on my 1:7.2 scaled logging loco to power the steam winch.
Do you remember when teachers said: You gotta know how to multiply or divide add or subtract manualy -you aint gonna have claculator everywhere you go? Well screw you dinosaurs ! I got it right in the pocket and it comes with camera,FM radio ,flashlight,and the biggest encyclopedia of human knowledge called internet ! Oh how times have changed . . .
You have have some idea what the answer should be before you use a calculator, how else will you know if you put the wrong number in or pressed the wrong function. The same thought works for my days at school before calculators when you used log tables or slide rules. PS i prefer calculators any day.
Hey Joseph, You did it to me again... What I learned is I can still remember there was a time back when we were still using slide rules that I could have figured that out,,,,but there is no way in hell I could still do it today. Don't know if it was the gallons of Black Velvet and Budweiser or the fact that I'm WAY closer to the end of my life then I am to the beginning but the plain fact is I am in no way man enough to figure that out anymore. ,,, There is a reason I travel with a ruggedized lap top with AutoCad on it. - I am totally lost without it in the shop, or even in the field. At least my rusted out brain can still solve graphically. (I think) I do wounder if they even teach things like that in school anymore, if if the kids even want to learn it. ,,, Ahhhh to start over again. Wouldn't it be great? Oh, one more thing I learned. Using guage pins instead of an ID mic to get the dimension between the pins right. Might be why I seldom get a dovetail within better then a few thousandths. Thanks for the tip Joe!
I started watching this, but when you got to the part where you show how to figure the size pin so the center is over the end of the dovetail, I stopped it so I could figure it out myself. I used the tangent of 30 degrees times 0.075 to get 0.0433. No need to figure out the hypotenuse or remember 1.1547. BTW the 1.1547 is also 2 times the tangent of 30 degrees. I love doing this stuff. Thanks Joe! I will do the 1st method using a .125 diameter pin since being 1/8th inch would be more common stock to have if you don't have gauge pins.
I cut a dovetail for a knurling tool I made out of 4140, and I can tell you there was a lot of butt clenching. 60 degree tool cost $160 in Australia! I only once tried to climb mill with it and near shat myself. All worked out in the end. Hope you cover some of the aspects of driving this thing in the follow up video. Nice work so far Joe. 👍🏻
Sorry Joe, you lost me at 'Hey Guys, Joe Pie here...' :-) I will need to seriously build up to watching this. I really appreciate you taking the time to teach it
Well Done! Please keep up the great videos, JoePie. You are making another family heirloom Somewhere on there, use your CNC mill and engrave your name and date.
Another great video Joe. Another dose of cutter envy for me. I also did not know hypotinuse = 2*opersite rule or how to spell them. Yet another blindingly obvious nugget!
Hey Joe thanks again. If I would of had you as an instructor in high school i think more of this would of stuck to the wall. Math would of been a lot easier. Be Safe
Real cool I'm CNC'ing a cross-sliding vise. So this dovetail's with me very well. Yes a cross-sliding vise. Hey Any thing you can machine in soft jaws.... well and the soft jaws themselves. Not in a drill press I'll have to rig some sort of spindle drive above or beside, the handle end looks like a spindle / dremmel could be mounted to a bracket. But starting out the obvious thing is the base lead screw being true to the ways Oh on mine a chainsaw file took most of the distortion out and a lap with hydraulic rod and bushings / laps at either end (it worked ... whatever?) cool stuff keep it up!
Joe, I would have said it's safer to reduce the male height not deepen the female feature, that's because the gauge pins sit on the bottom of the female feature as they do on the male part and that is the reference surface. Just my five penneth of input to your wonderful explanation, may one day work up to cutting the circular dovetail that a project I'm working on (for the past twenty years or so) requires. Cheers from across the pond.
Thanks for the great information, it was a great refresher for a project I have coming up. I was a bit confused by the use of aluminum for the cross slide of an engine lathe if going to cutting steel
Joe, I'm confused. At 5:50 you state that the hypotenuse of the right angle triangle is always twice the length of the short side? Surely with a triangle in the ratio of 3:4:5 that's not so. I thought the hypotenuse was the square root of the sum of the squares of the two other sides. Am I missing something?
@@stumccabe I realise now I was barking up the wrong tree. I am one of those mathematically challenged types but if I can draw something on paper I can usually work it out. I had to go to my CAD programme to verify that I was wrong. All sorted now. 😁
@@Preso58 Mark, don’t feel bad. Everything you said in your original post was correct. You just didn’t realize what he said only applied to the 30-60-90 triangle.
for people who don't have a gauge pins, could you do +0.001 on one pin and = 0.001 on the other? I know that on the female dovetail especially you'd introduce a TINY bit of error from the centerlines not being at the same height, but that would probably be in the micron area
Am I misunderstanding, or does this show that the diameter of the perfect pin is simply 2/3 the height of the dovetail? Splitting the inside triangle into 3 equal triangles means that the vertical consists of 1 Short side, and one Hypotenuse, and as the H is twice the S, the vertical is 3*S.
That's how I did it before I started using an ID Mic between them ,,,,,and why I usually blow dovetail dimension. = I'm going to start using gauge pins If I have to turn then on the lathe.
That 1.1547 was throwing me for a loop until I realized it was the Secant of 60 degrees. I never connected the dots on the 30, 60, 90 triangle like you showed. Thanks.
I had to brush up on my trig for that one and I ended up finding it was the secant of 60° after playing around on my laptop's scientific calculator. I may be old but I can still figure a few things out.
try to simplify by calculating the bottom of the dovetail length and the top of pin triangle length only. then subtract the difference, multiply by two and add 1 pin diameter. then subtract from dovetail width.
Joe, So you're saying all the Trig and Geometry classes I took so many years ago are finally becoming useful. BTW, That was a great explanation....next time....use the trig tables or your (ahem) Slide Rule.
I’ve been watching your videos for about a year now. The first one I watched you deburred a part on the lathe in my opinion backwards. I thought to myself no Joe no. I kept watching your videos and realized we were running neck and neck with our skill level. I was a lazy student in school and skated by with basic math. I never graduated. Then I picked machinist for a career. I got by using a trigeasy book. Geometry was my huckleberry. After 46 years I retired yesterday. Thanks to you I now have to go to sleep tonight knowing I’m second best. Keep up the great videos because I need the entertainment in my twilight years. Take care and God bless you.
I had two really good shop teachers in high school and you are doing a great job of picking up where they left off.
Joe and MrPete have replaced my shop teachers in my memory lol
It’s too bad they took shop
Out of schools
@@martintaylor984 Yes sir. Don't get me started....
@@martintaylor984 agreed. It's coming back here and there, but won't look the same. Probably be a lot less manual equipment. Be well my friend.
Hi Joe,
Great video! At one point you comment that the result is '... going to floor you!'. It's even better than you showed. r = d/3, where d is the depth of the dovetail!!! This is true for (and _only_ for) a 60 degree dovetail, see below. This is about the simplest result that mathematicians would refer to as 'pretty'.
In this video, you demonstrate the importance of paying attention in math classes. Clearly, you did. I'm biased here, as I'm a retired industrial mathematician. I grew up in a very hands-on family: my father was a plumbing and heating contractor and I did plumbing and tin-knocker's apprenticeships with him during high school, college, and graduate school. His older brother founded a machine/fabrication/millwright/erection shop. I always liked hanging around his shop. During my career, all I had to show for a day's work was a pile of papers covered in equations, tables, graphs, maybe a computer program or an Excel spreadsheet, etc. I took up machine work and woodwork to have something tangible to see and touch.
When you talked about a pin whose center is in line with the opening of the dovetail, you found the base of the triangle, 0.075, as the tangent of 30 degrees times the 0.130 depth of the dovetail. That is, tan(30) x 0.130 = 1/sqrt(3) x 0.130 = 0.0750. Then, when you found the radius of the pin, using the small triangle, r = tan (30) x 0.0750 = 0.0433. But, this is the same as r = tan(30) x tan(30) x d, where d is the depth of the dovetail. We can write this as r = tan^2(30) x d = (1/sqrt(3))^2 x d = 1/3 d. That is, for a 60 degree dovetail the radius of a pin whose center is in line with the dovetail opening is 1/3 the depth of that dovetail! r = d/3 ! Fellow viewers, remember, r = d/3 _only_ works with a 60 degree dovetail.
I would have done this slightly differently. Draw the triangle with the depth and the angle of the dovetail (theta) as specified, just as you did. As you noted, the radius of the pin is tangent to the hypotenuse of that triangle. This radius creates another triangle that is similar to the first triangle. One leg of the triangle is r. The hypotenuse of this triangle is d-r. The acute angle formed by the radius and the dovetail depth of the original triangle is also theta, because these are similar triangles. We know that cosine is the ratio of the adjacent side to the hypotenuse. In our case, r / (d - r) = cos(theta). Multiply both sides of this by (d - r) / cos(theta) to obtain r / cos(theta) = d - r. Add r to both sides to obtain r x (1 + 1/cos(theta)) = d. Finally, r = d / (1 + 1/cos(theta)) = d x cos(theta) / (1 + cos(theta)) = d / (1 + sec(theta)). In your case, theta is 60 degrees. cos(60) = 1/2. Thus, r = d / (1 + 1/(1/2)) = d / 3, as before. Again, r = d/3 _only_ works for a 60 degree dovetail.
Be well & Best regards, Gottfried
So much knowledge to absorb in a compact video. I’m trying to UNLOOSEN my mind. Thanks, Joe
Another brilliant explanation of how to do something difficult to understand when reading from a book. Thank you again Joe.
Joe I have used trig for nearly 50 years in work and play and have never noticed that relationship in the 30-60 triangle. Very useful bit of info I will pluck out when least expected on my poor unsuspecting friends. Loving these vids
You have a gift for teaching Joe! Delightful as always. Thank you
I love geometric development.
I was crap at mathematics at school, I've learned a whole lot more since I did my trade than I ever could have at school.
You were lucky to even been taught it in school in the mid 60's I had just started high school, ( here in England at the time, that was at aged 11-16) we were the first class to be taught "Modern Maths" and trigonometry was not on the syllabus at all. We had matrices and such . Never once in my entire career have I ever used anything like them so it was a totally useless waste of everyone's time learning it. And don't get me started on Topology lol. Now doing this sort of engineering for a hobby I have to teach myself or let Joe here show me how to do it lol
I was a geometry junkie in school. I loved that class.
That dovetail measure demo was great - always worth a detailed reminder because I always have to think hard every time!. That though was for the 'standard' method. However, the second approach to find a pin center was just exotic!! Love it, so elegant.
The machining was icing on the cake - what a gorgeous result too. :) Thanks as always Joe.
Back in 1960 I was taught the three legs of a 30/60 triangle were 1, 2, square root of 3, very easy to remember. Sorry no square root symbol on my key board. The other easy one to remember is 45 triangle, 1, 1, square root of 2. And the carpenters favorite, right triangle 3, 4, 5.
Great video Joe!
Yes I've used the 3,4,5 triangle hundreds of times even setting out a 20'x12' concrete base to get it nice and square. Need It to be bigger? Just use metres instead of inches
1, 2, 3^.5
You just need to add a math keyboard to your computer. 1,2,√3
@@shadowdog500 I rarely use a computer anymore, but my iPad is always within reach. I’ll have to look for a keyboard app.
@@swig46 I typed that on my iPad using “the math keyboard” app. Once you install the app it adds an extra math keyboard to your keyboard options. It has all of the typical math symbols, but I wish it let me add limits to my integrals.
Everything requires a hook to hang it on or it gets lost in your memory somewhere. Your presentation has become the hook. Great !
WOW! You managed to teach an old dog (61) a new trick! THANKS! I don’t know if I’ll be able to sleep tonight, I feel so smart!
I'm gonna have to watch this SO many times....stupid schools cutting shop classes and leaving the teenage me with ZERO proof that those dang math classes would be of ANY use to me later in life. I was in my 30's before I realized how many things I wanted to play with that required basic Trig and Calculus skills...now at 40, my brain can't hold on to the learnin' as good no more. Thanks for schooling me Joe. I genuinely appreciate your thorough explanations and meticulous filming
Glad to help.
As a youngster, math (as I'm sure it was for many) was not a subject I was interested in. Couldn't see the point. My trade (electronic and electrical) taught me the math I needed to know for the job which I use for that and understand. Since becoming interested in engineering later in life, trig is now my new hobby. Again, horses for courses. Thanks as always Jo for the homework, and a new appreciation for numbers.
Cheers
Pete'.
Nicely done Joe, enjoyed the Trig. You make the machining look easy. Every video is a learning experience. Thanks!
Thanks for checking in John. Always good to see your name here.
Great demonstration both in the geometry / trig and the actual cutting of the test part. I am learning so much from this series! Just getting back into machining after a 6 year break following my fathers passing. Just took the motivation right out of me. This and woodworking are what we talked about all the time.
Trying to get back out in the shop and you are an inspiration Joe! Thanks for what you do for the community!
Great video as always Joe.....learn so much from watching them....gives me things to think about and ways to tackle problems...keep up the great work..Brisbane, Australia.
Coach Hagan told me "you're going to need to know this stuff (geometry/trigg) one day"....well played coach Hagan, and well explained Joe Pie! I can't be the only one that gets excited when you go to the white board...I wish 15/16 year old me had paid better attention the first time around.
I think the biggest challenge we had was trying to see the relevance of what they were trying to teach us.
@@robertoswalt319 I think my biggest issue back then was...um...competing interests 😂. Between football, working on my truck, and young ladies, who has got time to put effort into Sin/Cosine/Tangent/Cotangent relationships?!?!
Thankfully the big head prevailed against all odds and I got my EE degree. Herding electrons has always made more sense to me than wrangling triangles. I guess I just wasn't ready, or like you said I didn't see the application for the knowledge.
I'm about to machine a casting for a back plate for my new chuck. I'm gonna make both a male and female part (spindle nose clone) out of aluminum or maybe even Delrin, one for practice before I cut on an expensive casting, and the snoot as a gauge. Love this channel! Nice to see other people do not-so-dry runs!
"Working out these dovetails is easier than you think"
*me still scratching my head after 35 mins*
Great work btw
Yup, confused I am still 😕
Thanks again for such an informative video. Lots of machining content out there but you are the only one I have found that actually explains the how and math involved so we can apply to our own jobs. Thank you.
I'll be watching this about 5-10 times, and taking notes. Awesome tutorial. Thanks again Joe!
Thanks very much Joe! You have no idea how much help you are to us that are amateur model stationary engine builders. I'm a retired instrument technician but building stationary engines is now my passion.
Glad to help
Pierre did a video on dovetail measuring. I viewed it repeatedly, drew it all out, tried to simplify it, made notes that I hoped to be able to read and get a quick recall of what I'd figured out. Managed to confirm that the commercial tool holder I'd bought was within 0.002 of what they said it would be. And, when I was done, it did make sense.
Fast forward to now. It all goes right over me again. I look at those notes, they could be in Greek or Hebrew, they make no sense at all. When it gets to that level, my retention goes to zilch. I just don't use it enough to make it stick.
Time for more ibuprofen ... ... I got a few dovetail challenges facing me this summer, maybe it will friction weld or gall itself into place this time.
A well fitted dovetail is a real thing of beauty.
I agree
Super way to start my day. Now as we finish cleaning up our shop will mount an ezal board to do Joe's math on,,,thx, great vid,,Bear
Another great video from the master Joe Pie!
For those of us that only have one gage pin of each size - figure out the diameter you need per Joe's example. The add one thou to that diameter and subtract one thou from that diameter. Use the plus and minus sizes in the dovetail. The overall size will be the same. But be careful if you are locating the centerline - it has moved by one thou.
“No shame in a setup piece....” thanks for those reassuring words from a master machinist. 👍👍😎👍👍. Especially since most of my setup pieces start out as final parts. 🤣😁🤣. Makes much more sense to practice on something easier to machine 😉
Its always a personal challenge to turn the setup part into an extra good piece.
5 am trig class. Brill. Thanks Joe for a other very interesting video, best way to learn anything. Class then action works for everything. Regards from Wales
Joe, you make geometry and trig look so easy. My high school shop teacher couldn’t count let alone explain this. 😆
Very well explained, and some beautiful physical proof. Thanks
I’d have taken more mathematical classes in HS if I had a teacher like you. 👍👍👍
agreed
Thank you very much.
Informative and useful, great work Sir thank you as always Joe
Thanks for giving us your angle on measuring dovetails!
I see what ya did there.
I'll never remember this, but this is a fantastic instructional video! Cheers Joe
HI Joe thanks for my needed math class, I used your suggestion for finding an angle on the lathe and I was able for the first time to cut a Morris taper accurately. keep it up!
Rich
I thought you spelled it wrong as I know them as Morse tapers. I looked it up and they are spelled both ways.
@@TinkeringJohn you are right John. I need an English class too
I just realized that trig is trigon-ometry, or measurements using triangles. That all by itself makes this stuff easier. And we both followed your math on both parts. So cool! I feel like I’m actually learning something instead of just watching someone make stuff.
Thanks Joe... you make my world a better place. 🤘🏻
Glad it helped!
Wow if i would have had math teachers that could teach as well as you i might have learned something in school. You are an amazing teacher to the world, keep up the good work and keep safe.
Thank you very much. Thats a great compliment.
Another amazing lesson!
"Hope that makes sense"........ It makes perfect sense since it is math and the answer can be proven to be true. Not that I could have ever figured all that out but learn every time I watch.
What's even easier is simply plug everything into a CAD program. And there are enough free ones out there to fo the job. I used to get drawings that called for specific diameters at the tops of countersinks or chambers on holes. The easiest way I found to check the feature's diameter at the surface was to do a quick layout with a ball of known diameter in the countersink and find the dimension from the top of the ball to a line that was the same dimension as something I had in my box. Typically a 1-2-3 block and check from the top of the ball to 1-2-3 block with a depth mic. CAD is an extremely useful tool not just for designing parts but also for solving shop dimensional questions and how measure or program. When I first started doing CNC work I had to write all my own programs unless it was a part in the machines library that somebody else had done. We had no post processor to run the drawing through so we would need to provide the radius center points on arcs between straight sections. Easy on two edges parallel to the machine axis but between angled surfaces it caused some major head scratching. If you have a computer in your shop (and I think you should) download a free CAD software package and use it. It's a tool.
Great explanation, thanks so much. I never really knew how to do the measurement across a dovetail with pins. You made it very clear and easy to understand.
Poet at work in his chosen field Smother than Silk on the delivery All the kudoos
Nicely explained. I've never made dovetails that small, so it was nice to have a refresher course. These parts would be so fun to make. I got to say, I am jealous.
They are fun, but the prints lack a degree of detail I'm comfortable with, so I'm going slowly looking 10 steps ahead.
@@joepie221 Wise decision. I've made the mistake of not double checking the engineer's numbers before I started. I learned just because the print has GE or Milicron on it, doesn't mean it's going to be flawless.
Love the project. I can watch a true craftsman all day long. By the way, I just received the 1100 Lumen Special Edition. It's beautiful. I have a trip to Maui in April and I intend to use the heck out of it. Thanks for the prompt delivery. You are indeed a master craftsman.
Thanks for the compliment and purchase. That light rig is very bright and can sit in the sand flat, or vertical resting on the back of the lights. Please get a safety lanyard for it so you don't loose it.
@@joepie221 Already have one. It straps to the mount and clips to my BC. that way I can drop it if I need both hands, and it doesn't go anywhere.
When I took math I couldn’t picture what it would be good for! If my teachers had an example of building something like this it would of made math my #1 subject!
Kind of funny story. My step sister who is 15 years younger than me was having issues understanding variables in formulas when first starting geometry/algebra. She could do the math or calculations to find area, diameter, or even solve equations and such just fine with real numbers but had a total block if you just presented a formula or had to work backwards. So it wasn't like she was stupid, it was just that a letter instead of a number threw her off. She didn't "get it".
Dad wasn't getting through to her and she was getting really frustrated. So unrelated, one Saturday morning I came over to get her and we were supposed to get fertilizer for the garden. I always called fertilizer bullshit for the giggles. So I had her calculate how much bullshit we needed and write it down as she was doing it. I then wrote the formulas above her work and explained how they mostly stood in place of numbers you didn't know at the time but could work also be used to work backwards to figure out somethingif you onlyhad part of the information. Something clicked and she started to get it and within a couple weeks or so, her math grades increased so much the teacher thought she might have been cheating somehow. When confronted about it, my sis blurted out that it was bullshit, all about bullshit. The teacher's reaction made her cry.
Needless to say, Dad had to go to school and explain my foul mouth and how she can to her epiphany. To this day we have an inside joke about not getting her started on talking about bullshit.
Fascinating how square circles really are!
I suspect you are having fun doing this lathe. I bought your T-Shirt and am now 10% more accurate, thanks!
Should be 100%. Joe might be upset.
No Joe Pieczynski video is complete without the word unloosen being said at least once!
Amen my friend.
My tongue becomes unloosened after too much alcohol... does that count? 😏😉
Excellent lesson! very clearly explained and demonstrated. Thanks as always for the time and effort you put into sharing your knowledge!
Thanks for watching.
Dovetail geometry demystified, thanks Joe.
Hi Joe,
many many thanks for all your great videos. I learned so much about machinery and look forward to use one or the other within one of my next projects. I once assembled a 5BI steam engine by PMR which is used on my 1:7.2 scaled logging loco to power the steam winch.
hand draws near perfect circle... but i shouldn't be surprised really...
Great refresher in high school geometry and very useful....great video....thanks
Crystal clarity. Thanks Joe!
Thankyou for adding to the series.
Professor Pie.....nicely explained
Thanks Joe, it's been a while since I did dovetails, good refresh.
I always hated trig... but, you make it fun. Nice work!
Trig is lot more fun when it becomes a tool to solve a real problem.
Phenomenal Joe.
Thankyou.
Great explanation of the math Joe.
Thanks Joe!
Do you remember when teachers said: You gotta know how to multiply or divide add or subtract manualy -you aint gonna have claculator everywhere you go?
Well screw you dinosaurs ! I got it right in the pocket and it comes with camera,FM radio ,flashlight,and the biggest encyclopedia of human knowledge called internet !
Oh how times have changed . . .
extended power outage , you're screwed .
You have have some idea what the answer should be before you use a calculator, how else will you know if you put the wrong number in or pressed the wrong function. The same thought works for my days at school before calculators when you used log tables or slide rules. PS i prefer calculators any day.
Hey Joseph, You did it to me again...
What I learned is I can still remember there was a time back when we were still using slide rules that I could have figured that out,,,,but there is no way in hell I could still do it today. Don't know if it was the gallons of Black Velvet and Budweiser or the fact that I'm WAY closer to the end of my life then I am to the beginning but the plain fact is I am in no way man enough to figure that out anymore. ,,, There is a reason I travel with a ruggedized lap top with AutoCad on it. - I am totally lost without it in the shop, or even in the field. At least my rusted out brain can still solve graphically. (I think)
I do wounder if they even teach things like that in school anymore, if if the kids even want to learn it. ,,, Ahhhh to start over again. Wouldn't it be great?
Oh, one more thing I learned. Using guage pins instead of an ID mic to get the dimension between the pins right. Might be why I seldom get a dovetail within better then a few thousandths. Thanks for the tip Joe!
I started watching this, but when you got to the part where you show how to figure the size pin so the center is over the end of the dovetail, I stopped it so I could figure it out myself. I used the tangent of 30 degrees times 0.075 to get 0.0433. No need to figure out the hypotenuse or remember 1.1547. BTW the 1.1547 is also 2 times the tangent of 30 degrees. I love doing this stuff. Thanks Joe! I will do the 1st method using a .125 diameter pin since being 1/8th inch would be more common stock to have if you don't have gauge pins.
Awsome teaching. My trigs are well funded, but your explanation gives an easier side.
It looks like you have learned well grasshopper. Thanks for sharing.
I cut a dovetail for a knurling tool I made out of 4140, and I can tell you there was a lot of butt clenching. 60 degree tool cost $160 in Australia!
I only once tried to climb mill with it and near shat myself. All worked out in the end. Hope you cover some of the aspects of driving this thing in the follow up video. Nice work so far Joe. 👍🏻
very good joe..thanks for your time
Sorry Joe, you lost me at 'Hey Guys, Joe Pie here...' :-) I will need to seriously build up to watching this. I really appreciate you taking the time to teach it
Great stuff Joe.....just got my shirt, love it, thank you?😎😎
Well Done! Please keep up the great videos, JoePie. You are making another family heirloom
Somewhere on there, use your CNC mill and engrave your name and date.
A 60-30-90 dgrs triangle, has a 1, 2, SQR 3 relation, where the 2 is the hypothenuse. If you know this, than it is even easier to calculate.
45-45-90 is also a nice one, 1, 1, sqrt 2 with the last one the diagonal
Another great video Joe. Another dose of cutter envy for me. I also did not know hypotinuse = 2*opersite rule or how to spell them. Yet another blindingly obvious nugget!
Hey Joe thanks again. If I would of had you as an instructor in high school i think more of this would of stuck to the wall. Math would of been a lot easier. Be Safe
Real cool I'm CNC'ing a cross-sliding vise. So this dovetail's with me very well. Yes a cross-sliding vise. Hey Any thing you can machine in soft jaws.... well and the soft jaws themselves. Not in a drill press I'll have to rig some sort of spindle drive above or beside, the handle end looks like a spindle / dremmel could be mounted to a bracket. But starting out the obvious thing is the base lead screw being true to the ways Oh on mine a chainsaw file took most of the distortion out and a lap with hydraulic rod and bushings / laps at either end (it worked ... whatever?) cool stuff keep it up!
Joe, I would have said it's safer to reduce the male height not deepen the female feature, that's because the gauge pins sit on the bottom of the female feature as they do on the male part and that is the reference surface. Just my five penneth of input to your wonderful explanation, may one day work up to cutting the circular dovetail that a project I'm working on (for the past twenty years or so) requires. Cheers from across the pond.
Thanks for the great information, it was a great refresher for a project I have coming up. I was a bit confused by the use of aluminum for the cross slide of an engine lathe if going to cutting steel
Its a functional scale model, not intended for production.
It's not a working lathe. Most components are aluminum, thus for display only.
But if the motor worked, one could turn wood, perhaps.
Joe, I'm confused. At 5:50 you state that the hypotenuse of the right angle triangle is always twice the length of the short side? Surely with a triangle in the ratio of 3:4:5 that's not so. I thought the hypotenuse was the square root of the sum of the squares of the two other sides. Am I missing something?
That rule only applies to a 30-60-90 triangle, not to a 3:4:5 triangle.
@@dougcollinge6424 OK, my bad! I just drew it out and I am now having a large serve of humble pie!
Mark Presling . The ratio of the lengths of he sides of a 30, 90, 60 triangle are 1:2: root 3. Just remember 1, 2, root 3.
@@stumccabe I realise now I was barking up the wrong tree. I am one of those mathematically challenged types but if I can draw something on paper I can usually work it out. I had to go to my CAD programme to verify that I was wrong. All sorted now. 😁
@@Preso58 Mark, don’t feel bad. Everything you said in your original post was correct. You just didn’t realize what he said only applied to the 30-60-90 triangle.
Great video Joe, thanks for sharing
Thanks for the video Joe.
As always, Great explanation!
Thanks for sharing and showing the math.
Superb! Thanks Joe.
Joe. Pi. Rocks!
Well, that answered those questions. Many thanks.
for people who don't have a gauge pins, could you do +0.001 on one pin and = 0.001 on the other? I know that on the female dovetail especially you'd introduce a TINY bit of error from the centerlines not being at the same height, but that would probably be in the micron area
Why don't you run the numbers and tell us what you find out?
Best hack would be to use two pieces off a common piece of drill rod. Just make the pieces longer than the dovetail and clean up the cut ends.
@@wwilcox2726 because I remember nothing of high school trig
@@Rx7man and you just watched all the trig in the video....
Which was why Joe took the time to spell it out for those who don't remember their trig.
My math skills runs out when I run out of fingers. Your really great teacher!
Am I misunderstanding, or does this show that the diameter of the perfect pin is simply 2/3 the height of the dovetail? Splitting the inside triangle into 3 equal triangles means that the vertical consists of 1 Short side, and one Hypotenuse, and as the H is twice the S, the vertical is 3*S.
Thanks again Joe!
Best maths lesson ever.
Thanks for sharing Joe...
Thanks,
John
Great video. I suppose one could also measure the distance between the pins externally on either or both ends, using a micrometer in the first set-up.
That's how I did it before I started using an ID Mic between them ,,,,,and why I usually blow dovetail dimension. = I'm going to start using gauge pins If I have to turn then on the lathe.
That 1.1547 was throwing me for a loop until I realized it was the Secant of 60 degrees. I never connected the dots on the 30, 60, 90 triangle like you showed. Thanks.
Glad it clicked.
I had to brush up on my trig for that one and I ended up finding it was the secant of 60° after playing around on my laptop's scientific calculator. I may be old but I can still figure a few things out.
This Dude is a mad genius.
Thank you.
try to simplify by calculating the bottom of the dovetail length and the top of pin triangle length only. then subtract the difference, multiply by two and add 1 pin diameter. then subtract from dovetail width.
Thanks Joe
Wow, I'm amazed at your knowledge of math, I'm still counting apples and oranges.
Joe, So you're saying all the Trig and Geometry classes I took so many years ago are finally becoming useful. BTW, That was a great explanation....next time....use the trig tables or your (ahem) Slide Rule.
Very nice. You were right (angle) many times. 😍