Hi Jeffry, Joe is a great machinist and person, nice to be considered in the same class... ;) Trig is an important part of being a machinist in the upper or advanced class, it will allow you to resolve many situations. Thanks for nice comment and for watching, Pierre
Thank you for teaching me something new. What better a gift could a person give or get? Nothing, nothing better to give or get because knowledge gives you power. Thanks.
A good knowledge makes things so much simpler..... Period... ;) I love to learn new things, it's nice to be able to pass along some of the know how to the next generation also... Thanks for comment, Pierre
Great explanation of the theory for measuring dove tails. This is especially handy when machining and fitting dovetails without a gib strip or other adjustment. A small boring head would be an example of this. I noticed Joe, that you have a shop-made dovetail endmill. If you use a commercial dove tail cutter make sure that its angle matches that of the tool post. Two different cutters may very well have a slightly different angle as I found out to my surprise. Spent an afternoon regrinding a commercial cutter so that its angle matched the tool post's. 30+ years ago I made a complete QCTP & holder set because I could not justify the cost for a home work shop, what with interest rates at that time. I now have 24 tool holders of all descriptions and still use them.
A good knowledge of the basics is the best way to achieve your goals. From there it's possible to adapt any part of a project. This reminds me how I had to force myself to concentrate during trade school in order to learn trig and get good at it, I'm glad I did it... Keep on enjoying your time in the shop........ 🙂👍
This is such a simple exercise and you managed to bungle it and make it super complicated. No wonder there are so many comments about having to watch this multiple times.
These are ALL the steps to start from scratch in order to demonstrate where the results come from, there are also formulas for shortcuts, if you can teach me something simpler, just be my guest... Thanks for viewing and for your comment
@@pierresgarage2687 the simple way is to use rollers of the correct diameter. If you use rollers with a diameter of 1/3rd of the depth then the sizes for both parts are the same. It is as simple as that. Diagram here - drive.google.com/file/d/1L680XDGRHtW_tKYiqxNeCaqYX2ckP_S0/view?usp=sharing
Sometimes it doesn't take much to save you lots of trial and errors ( Also translated by: "Lots of Fucking around" Shtttt... not too loud.... ) Take good care and anxious to see you happily machining soon, Pierre
Well done, Perfessor Pierre, excellent explanation, now nobody has an excuse to measure the wrong way. Oh, and I love how you got the math to come out right even using the wrong hand!
Guess you found me out real fast as a wannabe teacher, I'll have to get used to get the pointer in the right hand.... lol A good basic knowledge of math and trig are a great help in machining complex or even not so complex parts.... ;)
Thank you very much. I've actually got a couple of pieces of scrap in my bin from trying to make tool holders from simple caliper measurements like you showed at the start.
Hi Lee, I had to chuckle at your comment... lol Math and trig are a must in a shop, at least the basic notions, it helps avoid multiple trials and errors that could prove costly and time consuming...
Hello Pierre from Australia. I understood the Math's very well as that was part of the Electronics Engineering I did 35 plus years ago, great presentation and explanation! For those that have a copy, Machinery's Handbook covers this well with examples as well. When it comes to measuring the internal dovetail the method I have used (not having Gauge blocks or an adjustable parallel) is to use a stack of HSS tool bits and feeler gauges. Then measure the stack with mics, end result is a very accurate measurement. This may be of some help to some of your other viewers. Cheers from John.
Hi John, You just proved to yourself that anything that leads to a properly made and measured part is a go, what I love about the trade is that we're always pushed to find creative solutions to get the job done..... A good way to keep the brain cell working like in the younger years...!!! lol Thanks for your input and for taking the time to share, Pierre BTW, I envy the fact you're now in the warm season... Sigh...!
Thanks for the reply Pierre. Yes it is getting a bit warm, soon we can look forward to 40 plus degrees C for our days or well over 100F Cheers from John.
Since getting into machining I've found one that worked out really well for me is that I liked maths in school. Geometry, trig, algebra, all indispensable in some of the trickier measuring problems
Hi Rob, One thing I understood quickly, is the fact that being good in math and trig is a definite asset in machining quality parts... I'm glad I'm glad you also think this way and use it in your trade.... ;) Thanks for your comment, Pierre
Emma Ritson in Australia suggested that I take a look at this video! I did and I am very impressed! I have a project that I have been putting off for years because I was not sure how to do this very thing! Thanks so much for posting this. (I subscribed to your channel so that I can continue to learn from you!) Bob Troxell Virginia, USA
Hi Bob, thanks for subscribing, hope to meet your expectations in the future... ;) Hope your project goes well, if in need of any help, just get in touch and I'll do my best to help... Pierre
Pierre's Garage Thank you! I've been wanting to make some Altria style tool holders for my lathe for a long time! I'll certainly text message you if I get stuck. I think that I will study your video then try to measure what I have.
!3 minutes...!!! On étais plus tuff que ça quand on étais petits, on toffais au moins 15 munutes... Ahhh la vieillesse...!!! J'ai pas hâte d'voir ton age... lol
A caliper is an approximation tool, all depends how precise you need to get, in this case it doesn't take much to be off specs... Thanks for your comment, Pierre
Being able to understand math and trig is a huge plus in the machining world, CAD does lots of the calculations for us but the understanding is, like we could say, priceless... ;)
Good video and illustration of effective math use, BUT, unless the male and female pieces are being made at separate locations there's a much simpler method of measuring the inside of the pins on the male dovetail and the outside of the pins on the female dovetail by having them protrude out of the dovetail. Randy Richards in the Shop demonstrates this in one of his videos about his dovetail cutter
Thank you very much! After assuming it was simple and doing it wrong (and wasting my time and my colleagues' time) I wish I had viewed your detailed video first.
Hi and thanks for a nice comment, it's quite some work to make those videos, very rewarding that someone learns something, your comment is really making me feel great, Pierre
Hi James, When the result is exact, just about any method is a legal mean to get there... Being inventive is a great asset in this trade. Thanks for your comment, Pierre
well, I wasn`t so keen on it.. no indication that the thickness of the parallels needs to be at least 50% of the thickness of the 2 round bars.. If slightly less, the edge wii be touching a curve. making life and calcs difficult.
Hi Ken, it's great to keep those brain cells active, with a little effort we can all stay young at heart... ;) Thanks for viewing and taking some time to comment, Pierre
Thank you Pierre, for the great lesson. (and a refresher on my math skills! lol) My question is how do you know the angle is 30 deg. on the dove tail? or 60 deg around the dowell?
Hi Jeff, The 60 deg. is a known standard for those dovetails, on some other tools or parts it could be something else, there are ways to make an accurate measurement of the angle, though. Thanks for your comment, Pierre
Ahhh...!!! Don't worry here no punch cards or any exams or controls, so, you can relax..... lol The student is the Boss... ;) Thanks for comment, Pierre
Hello Pierre, Greetings from India, Thank you for this video. I have a doubt though, I am working on a project where we are engaging a change in tooling for which we require a dovetail block change. But in case of our design we leave a clear space between the bottom face of the tool post and the resting face of the support/slide block which has a dovetail groove. Now in your case those depths/lengths were equal but in my case the post would have a lesser length than that of the holder, how much clearance do I consider for (y+clearance) part of my design. Thank you
In Canada we're now using the metric system on most everything, but, when I was learning we used the imperial system, it really takes a long time to convert our mind to another system. Now, I can quite figure metric dimensions when working, it's still more difficult to directly work using the metric system... 😥
I have to grind a male dovetail looking part to a four decimal place dimension. The dimension is given using two dowels like your drawing. My part does not have the bottom part of your male drawing so it's essentially an isosceles trapezoid. I will mount it on a large sine plate on the grinder. I can't take it off to check it with the CMM, it would be too much time consuming. How can I check it accurately ?
In my opinion, it would be possible to use some well calibrated gauge pins, in order to save time when getting closer to your required measure you can use some adjustable parallels, when performing the last cuts you could use some gauge blocks to get a quite rigorous measure for final operation.
Pierre's Garage no problem, I use triganotry everyday in my shop but many people are relying oin technology. Which will enable them from understanding what they are doing completely. It's nice to see you educating others. THANKS
Hey that is a nice cutter. You have a piston type tool post. The wedge type are a bit more tricky, You need the measure the min and max. width. very narrow tolerance.
thats the best dovetail cutter I have. too bad when I was working on the dovetail in the final scene at home, duffus me shattered the insert and had to finish at Pierre's while my new inserts were in the mail.
the cutter its self is fine, i shattered the carbide insert, i figured the screw loosened. the insert got loose and fractured. the cutter is unblemished
I remember a time long ago where it was the same thing, then, I had to force myself to listen better and it finally got in my head... ;) Guess that the words "Never quit" make sense somehow...
wonder if they can make neo magnets precice enough to use as these measuring pins, would make setting them up eazier as they will stick inside the dovetail giving you both hands to operate the measuring tool
I'm sure they can manufacture them to quite close tolerances, since the magnets are only magnetized in the final step after averything is done on them, though, the main problem working with magnets or magnetized parts, is that there is always something that wants to stick to them and you rarely succeed to remove all of the parasite particules...
Hi Pierre....another great video! I only have one question....at the beginning of ur video you used a green elastic to hold the pin.....why green and not a blue elastic? Are you going environmentally friendly now? 😨😨😨😨😨😨😨😨
Just for you, next time I'll use an elastic, I got no idea what to do....!!! lol Got to find myself some multi-colors elastics, maybe at the Dollar store... ;)
great video and drawing, so you just used all Trigonometry in this? why you did not use that formula X=S+D(1+cotangent(angle/2)) or the dovetails with 60 degrees use 2.732 I'm just curious because i tried using that 2.732 with that formula and produced wrong measurements. I'm trying to make an Aloris AXA tool post holder. thanks for your time making this great video with the details in all your Trig angles.
The formula you're using is the common formula used when you look for a way to get the measurements for making a dovetail without having to figure out the trig behint it, all is right, the most common problem isn't the formula most of the time it's the actual angle you get after machining, it only takes a very minute error in order to throw your measurement way out... just try the formula or the calculation with a few values other than 60 degrees, like 60.25, 60.5, or even 61 degrees you'll see that the result is very far from an actual 60 degree angle... Let me know if it solves your problem, Pierre
Try using pins that are 1/3rd the diameter of the depth for 60 degree dovetails. This brings the pins in exactly the same distance apart for both male and female dovetails. The pin centres seat directly above and below the mid point of the angled face if this diameter is used. This eliminates all the trig, just cut the female to approximate size - measure over pins and replicate the dimension for the male.
CLICK! I finally managed to confirm the dimensions of the tool holder I'm working from (that is, confirm the dimensions that Shars supplied), and confirm my layout for the dovetail it will fit to. As usual, I had to come up with my own format of simple steps to get to it. Stare at it, study it, try it, break the parts that were not working for me back down to it's components and put it back together in a way that my brain will accept it. (I not only found my X but now I also know Y ... }|-( ... I know, terrible pun). I still hate what my high school math teachers did to me. 10 hours, which including a two hour nap (because my brain tried to atrophy) and a bout of explosive diarrhea, was the price I paid to get my head wrapped around it. PTSD re-visited???? Now I just need to hope that the notes I have in my little black record book are sufficient to remind me the next time I need to do this...
Math, and trig... lol A couple of things that required teachers to tie me to a chair, guess it kinda paid out in the long run, the main requirement is to be able to concentrate, a good teacher is also one of the best asset in learning harsh stuff. Thanks for viewing and keep on trying until you get it right, Pierre
Well ... you've heard me comment about how well I get along with algebra/trig/calculus (I don't). One of these days I'll figure out a way to describe how I get around that, and I'll have everyone else scratching their heads. I'll watch it again, after my headache subsides, and see if anything gets through. I've been working on a tool post design and at the moment I'm basing the dovetails on the dimensions provided by Shars. I have no idea if Shars/Aloris tool posts and holders will interchange with each other. It would be nice to know if they did, in case I happen to find some Aloris tool holders at a good price. It wouldn't be so good if I couldn't use them ... I'd like to know if I need to be more selective. If anyone can provide the short answer, I'd appreciate it. In the mean time, I'm anticipating the retirement of my Tourrette's tool holder ... the cause of many sudden outbursts of profanity ... in the near future.
As long as you get the normal standards like AXA, BXA, or any thing like it, they will all be interchangeable and pretty universal, on about 18 or 20 of my holders some are from AccuSize, the pendant of Shars in Canada and they do great for a reasonable price... No need to pay hundreds of $$$ to get decent tools holders... ;)
The lathe is 18" swing, so I can use cxa (up to 18") or ca (up to 20). I'll probably use cxa dimensions, which is a better match to the materials I have, unless I happen to nab a slightly larger diameter billet for the body. The chunk of 4" I do have is tough stuff (rail grain car bearing), and has been too handy as a bench block for the last three decades. I don't want to destroy that just yet. And I'm not sure I could if I wanted to. I've recently discovered a problem about using the dimensions from Shars: I laid out the ca dimensions in my cad program, and the resulting dovetail angle was off (not the 60 deg included angle they say it is). So, I might be better off to buy the first holder anyway, and tweak the tool post dovetail to fit that. Otherwise, I risk having a proprietary size of tool holder, and I'd have to make all of them
Just tried to sort it out again ... my head hurts. But I did notice something. Your measurement for "Y" is somewhere around .040 larger than the dimensions provided by Shars for their (CA) tool holders. Of course, they do not tell you how they measured them. Yup. My head really does hurt.... I may have to just try to make mine as close to CXA as I can and plan on making all of my holders if I get the post dovetail undersized. I'll try it again later. One of these days, something will go "click" and I'll have it. I hope.
You could make the readings at min and max extension... Make sure the angle of 60 degrees is constant and accurate or the error will be quite enormous... ( Read in comment to Laurent Thommet ) Easiest possible solution in this case is to get at least one proper holder and start from there it's easy to adjust according to the actual fit...
Possible that Tubalcain had some influence on me, I've watched most of his videos so far... ;) Nice of you to give me such nice feedback, thanks, Pierre
Just remember two triangles: 45/45/90 with sides 1/1/root2. And 30/60/90 with sides 1/root3/2. For simple calculators without square roots, remember root2 = 1.4142 and root 3 = 1.732.
When I remember the numbers it' ok, with age I try more to remember where I last left the digital calculator...... lol Thanks for your input and for your comment...
It all depends on what is the usage, lots of machines are made of cast iron, they purposely make some markings in the ways to allow some lubricant to be trapped there for reducing wear, for some other applications it could be sinply ordinary steel, or in more demanding and wear resistent situations, you could use hardenable steels that you would heat treat and do a grinding finist there afer. For those steels it could be many alloys, for example some D2, 1045, 4140, etc.... Just be careful to use proper speed and feed when machining hardenable materials or it will harden on you before you're finish machining, then, it's quite an ordeal to make soft again... 🙂🙂👍👍
The 60 degrees is a known standard, but, there is a way to measure very accurately using 4 dowel pins and 2 gauge blocks, a little more elaborate but easily doable calculation... And, the 30 degrees from the 60 degree angle is deducted by the fact that a perfect circle inserted in an angle, where a line originating from the corner and passing at the center of that circle will divide the angle exactly in 2 equally. Answer from Mr. Kotter.... lol
Just in case there are any of you that don`t like maths. Try this. ... If you have a toolpost with a fitting toolholder and want more toolholders, simply drop in two small bars as Pierre did, then put a caliper between. this gives you the gap,... As you mill out the dovetail , keep testing with the same two blocks until you are up to measurement.. That`s it. You are not after an accuracy of a tenth of a thou..You need a full thou clearance at least to slide it in and out, Not critical. ..If you do not have an existing toolholder, Well, you`re screwed. and it`s back to the calculations.
It's always the better solution to be able to able to reason the problem from the basics, then, it's easy to just get yourself out of any situation, for almost all of us, when stuck, then, TH-cam is a real life saver.... ;) Thanks for your comment, Pierre
HI PIERRE Thank you very much for your explanations. But don't forget that the results of your calculations are depending (among others) of the accuracy of the angles. Greetings from France Laurent
Hi Laurent, Agreed with you about the accuracy of the angle, a one degree difference, like 31 instead of 30 would make a 0.026" difference on the T measure, so, good idea to check on low quality stuff... Thanks for your input, Pierre
Hi, sorry for the delay to get back... After reviewing the video and the related calculations, we're talking about thousands of an inch, 0.500" minus 0.003" = 0.497" this will be confirmed by the numbers used on the board a little further after that, and you were right about the fact that my explanation at that timing wasn't 100% clear. Thanks for viewing and for taking the time to comment... 🙂👍
How did you know that the angle was 30 degrees? That angle does not appear to be easy to measure. It might be known to be 30 degrees for an aloris style block, but what if we are dealing with something unknown?
You could determine the angle by measuring the width with the two pins, followed by measuring the width again with two identical gauge blocks of known height under the pins. The height of the gauge blocks would be your ∆X and the change of width would be ∆Y. Since ∆Y measures the change of width of both identical tapers, you need to divide it by two when calculating the angle of just the one taper. So the angle would be = arctan(0.5∆Y/∆X). Chris
This method could be also used to control the accuracy of the angle if needed. About the 60 degree angle being suddenly called a two 30 deg. angles, a circle inserted in an angle is going to split that angle in 2 equal parts when you get a line that starts in the corner and go through the center of that circle, this is an admitted fact in trig. I kinda forgot to mention it in the video.
Pierre, I was trying to figure out what "trig rule" you were referencing earlier, but after reading your response here I realized you were talking about a "geometry rule". A bunch of years ago I actually posted a crude cell phone recorded video showing how to determine 30°, 60°, and 90° angles using only a compass and a straight edge to answer a question on a forum. I took it down in the last couple year because it was pretty grainy compared to today videos and no one was watching it anymore. Chris
Actually, the 2 other monkeyteers gave me a hand at elaborating the structure of the video as to make it clear and understandable, this time they were in the background, bur present... ;) Never trust the appearances... lol
You followed pretty closely, it's a mistake about the tenth, the real measure is thousands of inches, the numbers used in the video are right, sorry about it, now it's kinda difficult to make it right, not sure how it can be corrected without uploading a new version... Thanks for pointing it out, Pierre
Majicaly angles or invent your own, i thi k it's funny that simple rations, like 2 to one ,(tan) becomes a ridiculous angle numerically, like 26.565011771. May e w should have been like France and used 400 degrees circle.
Once you get the principle for trigonometry it's quite possible to solve just about any angle problem, it requires some concentration, though... Never heard about the 400 degrees circles...!
Sorry, but using your words. Your calculations are incorrect due to human error. You state in measuring the depth of the dovetail. .500 minus 3 tenths. But write the number .497, but should be .4997. Enjoyed your video.. Thanks
I know, that mistake just slippet out even though I revise the final video at least twice before uploading, onse uploaded it's not possible to modify... ;) Sorry about this, on the other hand it makes it possible for moe to know who's really following and keeping up... Thanks for watching and taking time to comment, Pierre
This is exactly what it sounds like... Trig, the beast for certain machinists, it's always an asset to be able to calculate angles and dimensions with this tool... ;) Thanks for comment, Pierre
This is tha basic calculations in order to make a proper dovetail, you can use other simpler methods to replicate an existing one without going along and calculating the moves...
So you had an ERROR in your T = xxx [(2 x xxx) MINUS! xxx] formula. I captured THAT image to document and it took me 30 min to figure out you screwed up. NEXT TIME redo the whole thing to FIX the error OR at the very least VERBALLY NOTE IT when you see it. You just (off screen) fixed it and said nothing! Come on man!
But you didn't prove the measurements were correct by translating them into real tool holders and testing the fits! Once you do that you can send the"props" down to me. lol
The little bits of machining clips you can see at the beginning and end are from finishing Philippe's block using the calculations and Randy's dovetail cutter.... Not shown, but they fitted perfectly, this is to prove that science worked perfectly again.... lol
All depends on how precise you need to make the parts, for many applications, aproximate measures will do, for machines or appliances, higher presision will require more care and all those complicated calculations and more factors taken into account. For exemple, your car engine requires LOTS of those in order to perform reliably hundred of thousands of kilometers, airplanes as well so they don't fall of the sky in great numbers, etc...
If you can calculate how much material is to be removed or/and how to position your work, then, if you understand the concept, you'll save lots of time and frustrations, like I say it's only my own limited experience... 🙂 You run your shop as you feel...!!!
Something you're not alone with, sometimes, some other TH-camrs with great content puzzle me a little, in the end it's not their fault if I really got to split my brain trying to understand... lol This is a unique occasion to try our best got benefit from all the better content presented... ;) Thanks for viewing and for your comment, Pierre
Thanks for the excellent discussion on measuring dovetails properly.
glad you enjoyed and thanks for your comment... 🙂
Thank you! You and Joe Pi are doing excellent work educating the masses about shop math.
Hi Jeffry,
Joe is a great machinist and person, nice to be considered in the same class... ;)
Trig is an important part of being a machinist in the upper or advanced class, it will allow you to resolve many situations.
Thanks for nice comment and for watching, Pierre
Thank you for teaching me something new. What better a gift could a person give or get? Nothing, nothing better to give or get because knowledge gives you power. Thanks.
A good knowledge makes things so much simpler..... Period... ;)
I love to learn new things, it's nice to be able to pass along some of the know how to the next generation also...
Thanks for comment, Pierre
Great explanation of the theory for measuring dove tails. This is especially handy when machining and fitting dovetails without a gib strip or other adjustment. A small boring head would be an example of this.
I noticed Joe, that you have a shop-made dovetail endmill. If you use a commercial dove tail cutter make sure that its angle matches that of the tool post.
Two different cutters may very well have a slightly different angle as I found out to my surprise. Spent an afternoon regrinding a commercial cutter so that its angle matched the tool post's.
30+ years ago I made a complete QCTP & holder set because I could not justify the cost for a home work shop, what with interest rates at that time. I now have 24 tool holders of all descriptions and still use them.
A good knowledge of the basics is the best way to achieve your goals. From there it's possible to adapt any part of a project. This reminds me how I had to force myself to concentrate during trade school in order to learn trig and get good at it, I'm glad I did it...
Keep on enjoying your time in the shop........ 🙂👍
This is such a simple exercise and you managed to bungle it and make it super complicated. No wonder there are so many comments about having to watch this multiple times.
These are ALL the steps to start from scratch in order to demonstrate where the results come from, there are also formulas for shortcuts, if you can teach me something simpler, just be my guest...
Thanks for viewing and for your comment
@@pierresgarage2687 the simple way is to use rollers of the correct diameter. If you use rollers with a diameter of 1/3rd of the depth then the sizes for both parts are the same. It is as simple as that. Diagram here - drive.google.com/file/d/1L680XDGRHtW_tKYiqxNeCaqYX2ckP_S0/view?usp=sharing
Thank you I just need that right now!
thank you professor Pierre .think ill have to watch all that again a few times.
Maybe not ready to be called a professor yet, sounds like I'm not even using the right hand to hold the pointer.... lol
Thanks, Pierre
Lol, I think I've now watched it 6 times 🤣.
Great video! The best part was the explanation of the math involved.
Excellent Pierre. Always mega useful to run through this as I forget every time!!
Sometimes it doesn't take much to save you lots of trial and errors ( Also translated by: "Lots of Fucking around" Shtttt... not too loud.... )
Take good care and anxious to see you happily machining soon, Pierre
Thanks Pierre. Excellent as usual your presentation.
Well done, Perfessor Pierre, excellent explanation, now nobody has an excuse to measure the wrong way. Oh, and I love how you got the math to come out right even using the wrong hand!
Guess you found me out real fast as a wannabe teacher, I'll have to get used to get the pointer in the right hand.... lol
A good basic knowledge of math and trig are a great help in machining complex or even not so complex parts.... ;)
Thank you very much. I've actually got a couple of pieces of scrap in my bin from trying to make tool holders from simple caliper measurements like you showed at the start.
Hi Lee, I had to chuckle at your comment... lol
Math and trig are a must in a shop, at least the basic notions, it helps avoid multiple trials and errors that could prove costly and time consuming...
Very good workshop teacher Pierre 👍!
Hi, thanks for viewing and for the nice words, Pierre
Thank you very much! Have to watch it few times!!!
Thanks for viewing and for taking a moment to leave a comment, Pierre
Ah, second this time, a good old handmade thumbs up to you Pierre
Much appreciated and thanks for watching, Pierre
Very easy to understand... thank you!
Glad it was helpful!
Hello Pierre from Australia. I understood the Math's very well as that was part of the Electronics Engineering I did 35 plus years ago, great presentation and explanation! For those that have a copy, Machinery's Handbook covers this well with examples as well. When it comes to measuring the internal dovetail the method I have used (not having Gauge blocks or an adjustable parallel) is to use a stack of HSS tool bits and feeler gauges. Then measure the stack with mics, end result is a very accurate measurement. This may be of some help to some of your other viewers. Cheers from John.
Hi John,
You just proved to yourself that anything that leads to a properly made and measured part is a go, what I love about the trade is that we're always pushed to find creative solutions to get the job done.....
A good way to keep the brain cell working like in the younger years...!!! lol
Thanks for your input and for taking the time to share, Pierre
BTW, I envy the fact you're now in the warm season... Sigh...!
Thanks for the reply Pierre. Yes it is getting a bit warm, soon we can look forward to 40 plus degrees C for our days or well over 100F Cheers from John.
Taken me 3 years to see this but very useful, thanks for this
Glad it helped you, also, thanks for taking a moment to leave a comment, Pierre
Since getting into machining I've found one that worked out really well for me is that I liked maths in school. Geometry, trig, algebra, all indispensable in some of the trickier measuring problems
Hi Rob,
One thing I understood quickly, is the fact that being good in math and trig is a definite asset in machining quality parts... I'm glad I'm glad you also think this way and use it in your trade.... ;)
Thanks for your comment, Pierre
Wow, thanks so much, Pierre 😅. I knew there was something to the gauge pins just couldn't put my finger on it lol. Your one helluva teacher! 🍎😁🍎
Glad I could help!
Excellent presentation!!
Thank you kindly!
That was a huge help. Thank you Pierre!
It's nice to hear that our efforts are appreciated and help people out and most of all thanks for the nice comment, Pierre
Nice Tutorial Pierre. Good information for those that want to learn.
Hi Dennis, thanks for visit, Pierre
Emma Ritson in Australia suggested that I take a look at this video! I did and I am very impressed! I have a project that I have been putting off for years because I was not sure how to do this very thing! Thanks so much for posting this. (I subscribed to your channel so that I can continue to learn from you!)
Bob Troxell
Virginia, USA
Hi Bob, thanks for subscribing, hope to meet your expectations in the future... ;)
Hope your project goes well, if in need of any help, just get in touch and I'll do my best to help... Pierre
Pierre's Garage Thank you! I've been wanting to make some Altria style tool holders for my lathe for a long time! I'll certainly text message you if I get stuck. I think that I will study your video then try to measure what I have.
Very informative video! Thanks.
Glad it was helpful!
Great explanation. Thank you for sharing.
Thanks for viewing and for taking a moment to leave a comment, Pierre
Greetings Pierre! I never was very good at math, but with your fine explanation, I can do this. Thanks!!
Hi, verry glad if it could help, that's the goal, and, my reward... ;)
Thanks for viewing and leaving a comment, Pierre
That's a great trick, using the screw jack as an adjustable parallel! *making mental note*
need to ensure the threads on the screw jack are a tight fit to prevent any slewing of the screw in section otherwise the ends will not be parallel.
Right about that this is where a counter nut would prove useful...
Excellent diagram & explanation!
Hi Robert, thanks for taking some time to comment, Pierre
WELL DONE, My dovetail worked perfect
Finally got you a decent holder and a good basic learning on how it's done... Priceless... ;)
J'ai retourné sur les bancs d'école pour 13 minutes. Professeur Pierre.
!3 minutes...!!! On étais plus tuff que ça quand on étais petits, on toffais au moins 15 munutes... Ahhh la vieillesse...!!! J'ai pas hâte d'voir ton age... lol
Love your site and this video. Never miss a word with that nice mic you use. Thanks for an informative video.
especially when he switches to french when something doesn't go right ... ;-}
This microphone isn't good enough to do some simultaneous translation, or, isn't trained for certain "Words"...... lol
Great info Pierre! thanks for posting.
You're welcome and thanks for taking time to write a comment, Pierre
Nice work! Love it!
this is very good
Good job ,keep the videos coming a .
Very good tutorial. Even if the calipers has razor blades to measure with, it would still be inaccurate. Thanks, Jerry
A caliper is an approximation tool, all depends how precise you need to get, in this case it doesn't take much to be off specs...
Thanks for your comment, Pierre
great share man ! Thumbs up..
Thanks for writing a comment, Pierre
Use trig all the time at work. Thanks for sharing.
Being able to understand math and trig is a huge plus in the machining world, CAD does lots of the calculations for us but the understanding is, like we could say, priceless... ;)
Good video and illustration of effective math use, BUT, unless the male and female pieces are being made at separate locations there's a much simpler method of measuring the inside of the pins on the male dovetail and the outside of the pins on the female dovetail by having them protrude out of the dovetail. Randy Richards in the Shop demonstrates this in one of his videos about his dovetail cutter
very refreshing. thank u
Thanks for viewing and for taking a moment to leave a comment, Pierre
Hello from iraq well done
Hi, and thanks for your comment..... 🌈👍
Thank you very much! After assuming it was simple and doing it wrong (and wasting my time and my colleagues' time) I wish I had viewed your detailed video first.
Hi and thanks for a nice comment, it's quite some work to make those videos, very rewarding that someone learns something, your comment is really making me feel great, Pierre
comments? just one - Great video!
Hi John, thanks for the nice words, Pierre
I liked the use of the adjustable parallel
Hi James,
When the result is exact, just about any method is a legal mean to get there... Being inventive is a great asset in this trade.
Thanks for your comment, Pierre
well, I wasn`t so keen on it.. no indication that the thickness of the parallels needs to be at least 50% of the thickness of the 2 round bars.. If slightly less, the edge wii be touching a curve. making life and calcs difficult.
Great vid! Very informative
Had a hard time following but finally understood. Too long out of school...
Hi Ken, it's great to keep those brain cells active, with a little effort we can all stay young at heart... ;)
Thanks for viewing and taking some time to comment, Pierre
Thank you Pierre, for the great lesson. (and a refresher on my math skills! lol) My question is how do you know the angle is 30 deg. on the dove tail? or 60 deg around the dowell?
Hi Jeff,
The 60 deg. is a known standard for those dovetails, on some other tools or parts it could be something else, there are ways to make an accurate measurement of the angle, though.
Thanks for your comment, Pierre
the nightmares of being late for school and incomplete homework have started again, thank you, (im 47 youd think id be over it)
Ahhh...!!! Don't worry here no punch cards or any exams or controls, so, you can relax..... lol
The student is the Boss... ;)
Thanks for comment, Pierre
Hello Pierre,
Greetings from India,
Thank you for this video. I have a doubt though, I am working on a project where we are engaging a change in tooling for which we require a dovetail block change. But in case of our design we leave a clear space between the bottom face of the tool post and the resting face of the support/slide block which has a dovetail groove. Now in your case those depths/lengths were equal but in my case the post would have a lesser length than that of the holder, how much clearance do I consider for (y+clearance) part of my design.
Thank you
Implement the use of International measuring standards like the main standard.
In Canada we're now using the metric system on most everything, but, when I was learning we used the imperial system, it really takes a long time to convert our mind to another system. Now, I can quite figure metric dimensions when working, it's still more difficult to directly work using the metric system... 😥
@@pierresgarage2687 i understand 👍
Great info!
Hi jster, thanks for comment and what's up with you...??? Hope you're doing good... Pierre
Doing well thanks! Just working like a dog;-)
I have to grind a male dovetail looking part to a four decimal place dimension. The dimension is given using two dowels like your drawing. My part does not have the bottom part of your male drawing so it's essentially an isosceles trapezoid. I will mount it on a large sine plate on the grinder. I can't take it off to check it with the CMM, it would be too much time consuming. How can I check it accurately ?
In my opinion, it would be possible to use some well calibrated gauge pins, in order to save time when getting closer to your required measure you can use some adjustable parallels, when performing the last cuts you could use some gauge blocks to get a quite rigorous measure for final operation.
Try this method for the simplest solution - th-cam.com/video/cIsWsXyLY6k/w-d-xo.html
Nice trig skill
Hi Anthony, Thanks for viewing and for taking time to comment, Pierre
Pierre's Garage no problem, I use triganotry everyday in my shop but many people are relying oin technology. Which will enable them from understanding what they are doing completely. It's nice to see you educating others. THANKS
Hey that is a nice cutter. You have a piston type tool post. The wedge type are a bit more tricky, You need the measure the min and max. width. very narrow tolerance.
thats the best dovetail cutter I have. too bad when I was working on the dovetail in the final scene at home, duffus me shattered the insert and had to finish at Pierre's while my new inserts were in the mail.
I thought the RRITS dovetail cutters were indestructible? How you break one?
the cutter its self is fine, i shattered the carbide insert, i figured the screw loosened. the insert got loose and fractured. the cutter is unblemished
Yes so far no one has destroyed one, They have broke a couple of inserts and broke a couple of screws. That is it so far out of about 300 of them.
Not that I haven't REALLY tried....!!!!
2nd best from canuckistan!
hahahah I hope I'm first
Guesss I'll go back home with a silver medal to show and be proud about... lol
Pierre's Garage i realy like the type of projects you make here and how you present the info. thumbs up from The Netherlands!
meilleure canuk de cote est
I understood everything up to just after "Hi, welcome to the garage again I'm Pierre" can you repeat what you just said? :-)
I remember a time long ago where it was the same thing, then, I had to force myself to listen better and it finally got in my head... ;)
Guess that the words "Never quit" make sense somehow...
wonder if they can make neo magnets precice enough to use as these measuring pins, would make setting them up eazier as they will stick inside the dovetail giving you both hands to operate the measuring tool
I'm sure they can manufacture them to quite close tolerances, since the magnets are only magnetized in the final step after averything is done on them, though, the main problem working with magnets or magnetized parts, is that there is always something that wants to stick to them and you rarely succeed to remove all of the parasite particules...
Pierre make a dovetail 😁
Lots of things Pierre can make if he gets motivated... 😂😉
Hi Pierre....another great video! I only have one question....at the beginning of ur video you used a green elastic to hold the pin.....why green and not a blue elastic? Are you going environmentally friendly now?
😨😨😨😨😨😨😨😨
Just for you, next time I'll use an elastic, I got no idea what to do....!!! lol
Got to find myself some multi-colors elastics, maybe at the Dollar store... ;)
great video and drawing, so you just used all Trigonometry in this? why you did not use that formula X=S+D(1+cotangent(angle/2)) or the dovetails with 60 degrees use 2.732 I'm just curious because i tried using that 2.732 with that formula and produced wrong measurements. I'm trying to make an Aloris AXA tool post holder. thanks for your time making this great video with the details in all your Trig angles.
The formula you're using is the common formula used when you look for a way to get the measurements for making a dovetail without having to figure out the trig behint it, all is right, the most common problem isn't the formula most of the time it's the actual angle you get after machining, it only takes a very minute error in order to throw your measurement way out...
just try the formula or the calculation with a few values other than 60 degrees, like 60.25, 60.5, or even 61 degrees you'll see that the result is very far from an actual 60 degree angle...
Let me know if it solves your problem, Pierre
Try using pins that are 1/3rd the diameter of the depth for 60 degree dovetails. This brings the pins in exactly the same distance apart for both male and female dovetails. The pin centres seat directly above and below the mid point of the angled face if this diameter is used. This eliminates all the trig, just cut the female to approximate size - measure over pins and replicate the dimension for the male.
CLICK! I finally managed to confirm the dimensions of the tool holder I'm working from (that is, confirm the dimensions that Shars supplied), and confirm my layout for the dovetail it will fit to. As usual, I had to come up with my own format of simple steps to get to it. Stare at it, study it, try it, break the parts that were not working for me back down to it's components and put it back together in a way that my brain will accept it. (I not only found my X but now I also know Y ... }|-( ... I know, terrible pun).
I still hate what my high school math teachers did to me. 10 hours, which including a two hour nap (because my brain tried to atrophy) and a bout of explosive diarrhea, was the price I paid to get my head wrapped around it. PTSD re-visited????
Now I just need to hope that the notes I have in my little black record book are sufficient to remind me the next time I need to do this...
Math, and trig... lol
A couple of things that required teachers to tie me to a chair, guess it kinda paid out in the long run, the main requirement is to be able to concentrate, a good teacher is also one of the best asset in learning harsh stuff.
Thanks for viewing and keep on trying until you get it right, Pierre
Well ... you've heard me comment about how well I get along with algebra/trig/calculus (I don't). One of these days I'll figure out a way to describe how I get around that, and I'll have everyone else scratching their heads. I'll watch it again, after my headache subsides, and see if anything gets through. I've been working on a tool post design and at the moment I'm basing the dovetails on the dimensions provided by Shars. I have no idea if Shars/Aloris tool posts and holders will interchange with each other. It would be nice to know if they did, in case I happen to find some Aloris tool holders at a good price. It wouldn't be so good if I couldn't use them ... I'd like to know if I need to be more selective. If anyone can provide the short answer, I'd appreciate it.
In the mean time, I'm anticipating the retirement of my Tourrette's tool holder ... the cause of many sudden outbursts of profanity ... in the near future.
As long as you get the normal standards like AXA, BXA, or any thing like it, they will all be interchangeable and pretty universal, on about 18 or 20 of my holders some are from AccuSize, the pendant of Shars in Canada and they do great for a reasonable price...
No need to pay hundreds of $$$ to get decent tools holders... ;)
The lathe is 18" swing, so I can use cxa (up to 18") or ca (up to 20). I'll probably use cxa dimensions, which is a better match to the materials I have, unless I happen to nab a slightly larger diameter billet for the body. The chunk of 4" I do have is tough stuff (rail grain car bearing), and has been too handy as a bench block for the last three decades. I don't want to destroy that just yet. And I'm not sure I could if I wanted to.
I've recently discovered a problem about using the dimensions from Shars: I laid out the ca dimensions in my cad program, and the resulting dovetail angle was off (not the 60 deg included angle they say it is). So, I might be better off to buy the first holder anyway, and tweak the tool post dovetail to fit that. Otherwise, I risk having a proprietary size of tool holder, and I'd have to make all of them
Just tried to sort it out again ... my head hurts. But I did notice something. Your measurement for "Y" is somewhere around .040 larger than the dimensions provided by Shars for their (CA) tool holders. Of course, they do not tell you how they measured them. Yup. My head really does hurt....
I may have to just try to make mine as close to CXA as I can and plan on making all of my holders if I get the post dovetail undersized.
I'll try it again later. One of these days, something will go "click" and I'll have it. I hope.
My tool post is wedge type not plunger type, so when I lay my dowel pins in, how much do I expand the wedge?
You could make the readings at min and max extension... Make sure the angle of 60 degrees is constant and accurate or the error will be quite enormous... ( Read in comment to Laurent Thommet )
Easiest possible solution in this case is to get at least one proper holder and start from there it's easy to adjust according to the actual fit...
thankyou Pierre
Alternate title: Easy doves it!
That's a nice way to say it with humor... lol
Thanks for viewing and taking time to comment, Pierre
Damn, did you get your teaching skills side by side with TubalCain ? :) Nice explanations, even I think I can make new toolholders now :D
Possible that Tubalcain had some influence on me, I've watched most of his videos so far... ;)
Nice of you to give me such nice feedback, thanks, Pierre
Trigonometry. Everyone's favorite. lol
Once understood it's really practical... 🙂👍
Good luck
Thanks... 🌈👍
Just remember two triangles: 45/45/90 with sides 1/1/root2. And 30/60/90 with sides 1/root3/2. For simple calculators without square roots, remember root2 = 1.4142 and root 3 = 1.732.
When I remember the numbers it' ok, with age I try more to remember where I last left the digital calculator...... lol
Thanks for your input and for your comment...
While I basically understand all that math, I'm glad I didn't actually have to do it to make a holder (that fits). :)
Not that difficult, just make a plan and follow the path... After a while it becomes easy enough... ;)
Good day, what material do you recommend using?
It all depends on what is the usage, lots of machines are made of cast iron, they purposely make some markings in the ways to allow some lubricant to be trapped there for reducing wear, for some other applications it could be sinply ordinary steel, or in more demanding and wear resistent situations, you could use hardenable steels that you would heat treat and do a grinding finist there afer. For those steels it could be many alloys, for example some D2, 1045, 4140, etc....
Just be careful to use proper speed and feed when machining hardenable materials or it will harden on you before you're finish machining, then, it's quite an ordeal to make soft again...
🙂🙂👍👍
@@pierresgarage2687 Thanks Pierre, I will take into account your advice, good day
Oooh oooh, Mr. Kotter. I think I missed something... At what point and with what method did you determine the angle of the dovetail?
It is known...
It is a known angle in this example. However, measuring the angle is just as easy. I explained how in my reply to SmartShock's comment. Chris
The 60 degrees is a known standard, but, there is a way to measure very accurately using 4 dowel pins and 2 gauge blocks, a little more elaborate but easily doable calculation...
And, the 30 degrees from the 60 degree angle is deducted by the fact that a perfect circle inserted in an angle, where a line originating from the corner and passing at the center of that circle will divide the angle exactly in 2 equally.
Answer from Mr. Kotter.... lol
👍🏻
Glad you liked... 🙂
Just in case there are any of you that don`t like maths. Try this. ... If you have a toolpost with a fitting toolholder and want more toolholders, simply drop in two small bars as Pierre did, then put a caliper between. this gives you the gap,... As you mill out the dovetail , keep testing with the same two blocks until you are up to measurement.. That`s it. You are not after an accuracy of a tenth of a thou..You need a full thou clearance at least to slide it in and out, Not critical. ..If you do not have an existing toolholder, Well, you`re screwed. and it`s back to the calculations.
It's always the better solution to be able to able to reason the problem from the basics, then, it's easy to just get yourself out of any situation, for almost all of us, when stuck, then, TH-cam is a real life saver.... ;)
Thanks for your comment, Pierre
And I guess that your adjustable parallel is thicker than the radius of the gauge pin + reces :-)
Right about this or else the measures are absolutely useless.... ;)
👍👍👍
Hi Eddy, thanks, Pierre
HI PIERRE Thank you very much for your explanations. But don't forget that the results of your calculations are depending (among others) of the accuracy of the angles. Greetings from France Laurent
Hi Laurent, Agreed with you about the accuracy of the angle, a one degree difference, like 31 instead of 30 would make a 0.026"
difference on the T measure, so, good idea to check on low quality stuff...
Thanks for your input, Pierre
3:40 "500 thousandths minus 3 tenths = 0.497 " ??? The image shows thousandths (thous UK, mils? US), not tenths (of thousandths). Keep consistent units to avoid errors.
Hi, sorry for the delay to get back...
After reviewing the video and the related calculations, we're talking about thousands of an inch, 0.500" minus 0.003" = 0.497" this will be confirmed by the numbers used on the board a little further after that, and you were right about the fact that my explanation at that timing wasn't 100% clear.
Thanks for viewing and for taking the time to comment... 🙂👍
How did you know that the angle was 30 degrees? That angle does not appear to be easy to measure. It might be known to be 30 degrees for an aloris style block, but what if we are dealing with something unknown?
You could determine the angle by measuring the width with the two pins, followed by measuring the width again with two identical gauge blocks of known height under the pins. The height of the gauge blocks would be your ∆X and the change of width would be ∆Y. Since ∆Y measures the change of width of both identical tapers, you need to divide it by two when calculating the angle of just the one taper. So the angle would be = arctan(0.5∆Y/∆X). Chris
This method could be also used to control the accuracy of the angle if needed.
About the 60 degree angle being suddenly called a two 30 deg. angles, a circle inserted in an angle is going to split that angle in 2 equal parts when you get a line that starts in the corner and go through the center of that circle, this is an admitted fact in trig. I kinda forgot to mention it in the video.
Pierre, I was trying to figure out what "trig rule" you were referencing earlier, but after reading your response here I realized you were talking about a "geometry rule". A bunch of years ago I actually posted a crude cell phone recorded video showing how to determine 30°, 60°, and 90° angles using only a compass and a straight edge to answer a question on a forum. I took it down in the last couple year because it was pretty grainy compared to today videos and no one was watching it anymore. Chris
Thanks Chris for taking the time to post that on finding the angle. That's a big help to me.
Great video and no help from the two other musketeers.
Actually, the 2 other monkeyteers gave me a hand at elaborating the structure of the video as to make it clear and understandable, this time they were in the background, bur present... ;)
Never trust the appearances... lol
x=y+clearance yes?
than why calculate Y ???
Guess it depends on what end you got to work with, the mal or the female...
Thanks for waching, Pierre
jemmt
You said .500 - 3 tenths (.0003) then write the answer as .497, shouldn't it be .4997?
You followed pretty closely, it's a mistake about the tenth, the real measure is thousands of inches, the numbers used in the video are right, sorry about it, now it's kinda difficult to make it right, not sure how it can be corrected without uploading a new version...
Thanks for pointing it out, Pierre
Majicaly angles or invent your own, i thi k it's funny that simple rations, like 2 to one ,(tan) becomes a ridiculous angle numerically, like 26.565011771. May e w should have been like France and used 400 degrees circle.
Once you get the principle for trigonometry it's quite possible to solve just about any angle problem, it requires some concentration, though...
Never heard about the 400 degrees circles...!
Sorry, but using your words. Your calculations are incorrect due to human error. You state in measuring the depth of the dovetail. .500 minus 3 tenths. But write the number .497, but should be .4997. Enjoyed your video..
Thanks
I know, that mistake just slippet out even though I revise the final video at least twice before uploading, onse uploaded it's not possible to modify... ;)
Sorry about this, on the other hand it makes it possible for moe to know who's really following and keeping up...
Thanks for watching and taking time to comment, Pierre
you french so you know nothing hahahah Just Joking Thanks for the video.
No worries! 😉🌈👍
Isn;t this Trig ???
This is exactly what it sounds like... Trig, the beast for certain machinists, it's always an asset to be able to calculate angles and dimensions with this tool... ;)
Thanks for comment, Pierre
Trig is probably the most useful thing I learned in school. With the exception of learning to read, which allowed me to learn Trig.
What a load of rubbish, it’s much easier than that ?
This is tha basic calculations in order to make a proper dovetail, you can use other simpler methods to replicate an existing one without going along and calculating the moves...
Way too much math lol...
So you had an ERROR in your T = xxx [(2 x xxx) MINUS! xxx] formula. I captured THAT image to document and it took me 30 min to figure out you screwed up. NEXT TIME redo the whole thing to FIX the error OR at the very least VERBALLY NOTE IT when you see it. You just (off screen) fixed it and said nothing! Come on man!
But you didn't prove the measurements were correct by translating them into real tool holders and testing the fits! Once you do that you can send the"props" down to me. lol
The little bits of machining clips you can see at the beginning and end are from finishing Philippe's block using the calculations and Randy's dovetail cutter....
Not shown, but they fitted perfectly, this is to prove that science worked perfectly again.... lol
Too complicated. I just copy the angles from the old post tool and start cutting. Whay you need so many misures.
All depends on how precise you need to make the parts, for many applications, aproximate measures will do, for machines or appliances, higher presision will require more care and all those complicated calculations and more factors taken into account. For exemple, your car engine requires LOTS of those in order to perform reliably hundred of thousands of kilometers, airplanes as well so they don't fall of the sky in great numbers, etc...
What a total waste of time, we need practical machining videos not maths lessons, total dribble ?
If you can calculate how much material is to be removed or/and how to position your work, then, if you understand the concept, you'll save lots of time and frustrations, like I say it's only my own limited experience... 🙂
You run your shop as you feel...!!!
down vote because you made me feel stupid.... (did not really down vote but thought about it)
Something you're not alone with, sometimes, some other TH-camrs with great content puzzle me a little, in the end it's not their fault if I really got to split my brain trying to understand... lol
This is a unique occasion to try our best got benefit from all the better content presented... ;)
Thanks for viewing and for your comment, Pierre