I knew you would like Randy's cutters. They are awesome along with his scribes. Glad you could use the cutter for this project and thanks for showing us your process. That dovetail fits really good. You do great work, Lee!
Wow memories working for us currently. We had an R&R large back years ago (still brand new) and we bought the scribe brass then as well, we loved them so much we did not use them so we waited to use them on a special machine rebuild, so after we finish rebuilding or Barker Mill to run the cutter on it we will be using the larger dovetail cutter on it. We later this new year 2019 bought the small dovetail and the stainless steel scribe so we have them all now, we will use the large dovetail in our machine testing for this milling machine rebuild. We know Reid he has a really nice workshop metal and wood type work and we really enjoy Randy and his tools, so it is great to be here to see one of these fine dovetail cutter make some cuts and make these cuts correctly. Really nice machine work lesson and that was nice to watch, we can do it to now. Lance & Patrick.
Really like your videos, as a retired machinist of 40 years. In all them years, I only got a chance to cut one set of dovetails which was in two blocks of Lexan, needed as a display show piece at the Offshore Technology Conference.
RR in the Shop makes quality products. To your viewers, if you haven't got one of Randy's scribes or dovetail cutters you should, you will not be disappointed. --- You're doing very good work in the TIN BARN! Very nice matching dovetails, excellent work! Waiting on part 2.
Nice job, very well explained. Cutter RPM is very important to tool life and you provided it, thanks. I was a machinist for the better part of 40 years and trained a few people along the way. The way you explain is how I used to explain and it is very successful. I just subscribed, I may be expereinced but I still like to learn different processes. Besides, I miss taking a peice of raw stock and making somthing useful from it. I'm awaiting your next video. Again, nice job!
That sir is a fantastic piece of machining and math(s) as we say in England nicely explained and well done Randy Richard for making those beautiful dovetail cutters.
Well, I'll be darned if your vid didn't make life easier for me. I'm replacing the entire compound slide of my lathe with one I'm making from scratch and after completing the female top portion with tool post slot and about to start the male under portion with the attendant difficulty in measuring for gib allowance, your simpler method of measuring from inside of pins to outside of pins rather than halving the diameters of pins and constantly doing the math required, had never once occurred to me and I've been a certified general machinist since 1963. Never too old a dog to learn a new trick I guess. Love those insert bit dovetail cutters too. Gonna look for those. Kudos pard.
Nice video, nice well fitting dovetail! One thing to consider when you measure both sides with the pins. Unless the pin is the same diameter as the depth of the dovetail you are not measuring both parts at the same point on the slope face of the dovetail. If the pin diameter is smaller than the depth of the dovetail you would measure the female as indicated but on the male dovetail the pin needs to reference the top of the part (widest part of the dovetail) to measure on the same plane on both parts. Edit: Even this may not be adequate, just realized the pins don't contact the slopes of the dovetail at one radius above the bottom of the dovetail it actually contacts at one radius plus the sine of 30 degrees times the radius 1.5 radii above the bottom.
Oh I think you are right the first time mate - ie pins reference TOP surface of the male part. And this will be tricky to hold in place for measuring. I suggest using pins that are exactly diameter of male dovetail 'height'. Then they can sit on the 'base' of the male part for measuring, at. which time they will line up exactly with the top. Aaarghh. Geometry tells the tale, and a simple sketch shows it clearly. I was just figuring this out when I saw your comment. Thanks to Mr Pragmatic and to you.
The pin diameter for a 60 degree dovetail is 1/3rd of the dovetail depth if you want to use the same dimension for both male and female parts. - drive.google.com/file/d/1GVwxHEvnL8JpYFfUzes3Z2zrhlT1NNAX/view?usp=share_link
Thanks for the video, very interesting and thought provoking. But I think you were lucky, because your pin diameter is the same as the depth of cut, ie the height of the dovetail. Here is my thinking about it: having made the female part and measured it as you do, surely you must now have the (same) pins reference the TOP surface of the male part as you are making it and measuring it to size? And this will be tricky to hold in place for measuring. I suggest using pins that are exactly diameter of male dovetail 'height'. Then they can sit on the 'base' of the male part for measuring, at. which time they will line up exactly with the top. Aaarghh. Geometry tells the tale, and a simple sketch shows it clearly. CraigS was thinking along similar lines 3 months ago. Altogether a fascinating and tricky problem, and I appreciate what. you have done and shared here. Best wishes! Edit one day later: Double AAARGHH I am wrong !!!
New subscriber here. Thanks for the video - - clear to follow and a good demonstration of Randy's dovetail cutter. Well done, thanks. I look forward to watching more of your videos. Joe
Great instructional video, Lee. Thanks for sharing! I've used Randy;s dovetail cutter for a few dovetails, and they always come out great using the same method that you showed in this video.
Thank you for making that so clear. I have been working on making tool holders for my little Chinese lath. I made about 20 holders only 10 are tight enough to use.
Thanks a bunch for explaining very well how to make dovetails, I am very new and have only had a mill and engineering lathe setup for a month, no Dro yet on the mill and not much tooling yet so that his how green I am lol. That pin method of measuring was very well explained and when you first mentioned it I was hoping you would explain it which you did, thanks for that as I would have gone the caliper or worse steel ruler route and got frustrated. You are a lucky man aswel, I have been uploading wood turning vids for a little while and have subscribers but so far have not had anything bought for me 😁 , some wood given to me though at a wood turning symposium by a subscriber which was very appreciated though, hopefully watching your vids and other professionals I should be able to get started up the right way 👍
@@mtraven23 not too bad, I think back then I had a Warco 16b which has been upgraded to a Myford VMC , it gets used quite a bit and I would be lost without it
I have been imagining the geometry of those pins, and it seems to me that this measure-between-pins on female and outside on male gets you close, but it's not clear which measurement should be larger. In a perfect ideal dovetail with zero slop, the outside measurement of the female pins would be smaller than the inside measurement of the male pins--the only way for them to be equal with zero slop would be if the sidewalls were vertical (a groove instead of a dovetail). Conversely, in an exaggerated sloppy dovetail the outside measurement of the female pins would be larger than the inside measurement of the male pins. Hence, the point where the two numbers match is close, but somewhat arbitrary. It's likely going to be just about right, but I think I would want to do a quick sketch and some trig to understand it better.
doesn't the diameter the measuring pins have to be EXACTLY the same as the height of the dovetail? And if there is clearance over the center of the joint, you would put a shim under the pins the same as that clearance?
Two Thumbs up -- I love your technique -- your explanation was excellent . The sequence of events was chronological and easy to follow . This was a Great Video -- you da man !
The only way you can duplicate the clearances is but making the same height dovetail and use the same diameter pins.. For instance, let's say you are using 1/4 inch pins in your example. What kind of measurements do you get if you use 3/16 pins?
Love this video, thanks very much for making it, it is going to help me in my shop for sure! I need to get me a couple of those Randy Richards cutters also.
How much payment to make a small male and female dovetail in either steel or aluminium? I am DIY and currently building a table router fence and need a robust linear sliding function for one of the micro adjusters. No crazy tolerances.
Hi from sunny England! Just found your channel and have spent the evening watching your videos. Thank you for the very informative, educational and entertaining content and for sharing your expertise! You are a really talented guy and I'm really enjoying learning from you. You have a very straightforward, no nonsense approach and a very clear delivery. Thanks again! Subscribed. The main reason I zoned in on this particular video is that I want to build my own CNC milling machine similary to a number of projects seen on RUclips, but instead of using those linear rails, use dovetail ways instead. Seeing how accurately you made those dovetails has given me great confidence that with enough time and practice, I could perhaps do it too. May I ask: are you milling the sort of steel that machine ways are usually made out of? If not, what material would you make machine ways out of and how would you harden them? I'm thinking that milling machine ways require a jib for adjustment?
I'd like to point out a couple slight problems with your method of measuring a dovetail. You use pins that have an uspecified diameter. This introduces two problems. The first problem is to not hit the dovetails at the same depth. Think of using pins with a diameter one tenth the depth of the dovetail cut. Lets say the pins then hit the female dovetail at the 5% depth. Then measure the male dovetail the same way, and you will be at a 5% depth again, but relative to the female dovetail, you are at 95% depth. I'll leave it to the reader, to figure out what happpens with pins that are too large. What you want is to have the pins hit at the exact same depth on both male and female dovetails. pick an arbitrary place, I pick the middle point to make it easy. what dowel pin will hit at the middle? you might think a dowel pin with a diameter equal to the depth of the dovetail, you'd be close but still wrong. For a 60 degree dovetail a circle (a round dowel pin) will hit it at 60 degrees, so you need a dowel pin that is sin(60) x depth of dovetail. So .866 x depth of dovetail. Your method was close because you used pins that were close to this size. For those who have tried and had bad results, check the size of your dowel pins and see how close they are to .866 x depth of cut. There should be a correction factor for adjusting measurements using dowel pins equal to the depth of the dovetail. In my younger days I'd figure it out and post it. But, alas, my brain is just too old. I worked out a figure. But I caution you I am old and tired, this could be wrong. Dowel diameter equal to depth of dovetail, multiply the diameter by 1.077 to correct the diameter of the dowel pin so it looks like it is hitting in the center of the dovetail.
I've been thinking along the same lines. Mr Pragmatic was lucky this time, though his method is faulty ! I have a different approach, which now I realise is only good for 45 degree dovetail. Thank you very much for your deep thinking about this. And hell, my further thinking (?) shows I am quite wrong even for 45 degrees. Ha ha ha. Tricky problem!!! I expect the answer is in Machinists Handbook, and it ain't pretty. Best wishes.
For the pins to be directly above each other ie. the same distance apart on both the male and female 60 degree dovetails the diameter needs to be 1/3rd of the depth. Bisect the dovetail angle and construct a vertical line through the true angled length, including sharp corners. The intersection gives the centre of a pin that will rest in the same place on both male and female parts. The pin centre on both parts is always above and below the centre of the angled line. This eliminates trig from cutting dovetails, if it is for yourself, simply make the depth 3x what pin diameter you have. Make the female roughly to size - measure over pins then use this dimension to make the male, just one part needs to be made to a specific size.
I have a question. I'm planning on doing a not so heavy mill, the structure is going to be welded, steel plates, not old like cast iron. I have to choose whether use cast iron dovetail rails or Hiwin like linear sliders.
Is there a meaning at all to the angle of thw dovetail? Is it 60 degrees from horizonatal? Do some producers use some odd specific angle just to brand themselves, or can it be a more important thing? why not use the large radius corrugated pattern used on jet engines now, reducing all the complex vibration at fast speed? Is there a lathe in the world that can do 20000 rpm on large aluminum, for ridiculous surface speed, (that would still be way to fast for AL huh) 2000 surface feet is adequate for rough work.
horizo-natal? At 20,000 rpm? Spectacular!!! Seriously though . . . 45 degrees, 30, 60, are the common angles. It's all about the horizontal and vertical force vectors across the angled surface. Cheers
Lee, this 80 year old guy needs a little help understanding this process. When you place the brass pins in place, then install the adjustable parallels , what part does the pins play in the overall process. Are you adding the diameter of the pins ? If so I didn't see you measure the pins. Can you run that by me again. Thanks Ken Marina California.
If this was a square dovetail (no sloped sides) you could just measure the width of slot and make the matching male part to fit. But the sides are sloped so we use pins to contact the slope at a point one point above the bottom of the female slot. Now if we measure the distance between the pins we can figure the width of the female dovetail at that point. It's more complex than adding the pin diameters but adequate for comparison. This is because the contact point is not at the radius of the pin for a 60 deg dovetail but 1.5 times the radius of the pin above the bottom. The width at that point would be the measured distances between the pins plus two pin radii plus two more pin radii divided by the cosine of 30 deg.
A single insert is fine. It clears chips well and being an indexable insert distrbutes heat well. Putting another insert on a small cutter like this would also weaken it due to the size insert you need to make a dovetail. Nice strong ridgid tool, couldn't ask for more.
I'm doing something wrong? Made matching dovetail, however when I measure as explained in video there is hundred thousands difference and I measured as explained in the video.. Confused.
Yes, this method of measuring is wrong! The equal inside/outside result depends on dovetail 'height' (and pin diameter), so in Lee's case it was purely coincidence that he found the same dimension..... Make a simple sketch of it and you can see for yourself.
@@michaelhompus2475 Can you explain a little more? If the dovetails are to fit, don't they have to be the same depth as each other? If they are the same depth and the angle is the same then I think that the same pins should touch at the same height. I can't see the problem of using pins to measure the dovetails. I'm not to proud to learn. If you know a better way I am very interested. Thanks and best wishes.
@@michaelhompus2475 I'm afraid you are right my friend. But the question is, what is the correct approach? I'm sure the pro machinists know, but they have not been following here. Wonder what Joe Pieczynski has to say? This Old Tony knows a few things too.
I would never use a methodology that tries to match an inside mearsurement to an outside measurement. I would only use inside-to-inside or outside-to-outside. You will have to mathematically subtract (or add) the known diameter of the dowel pin.
The inside vs. outside measurement of your pins was just luck in this case. To take this to an extreme for illustration, if you used 1/4" dowels and had a dovetail that was 1" tall, the dowels used to measure the male side are going to be far closer together than the dowels used to measure the female side.
You ccould measure the male also with micrometer by measuring the outside minus twice the diameter of the pins. Now you use the same measurement device to measure only the difference instead of two absoluut distances
camera angle sucks....i guess we will take your word for it, cuz my video shows beautiful side view of a vice, cant see jack squat...daum i relly was looking forward to seeing this too....
I knew you would like Randy's cutters. They are awesome along with his scribes. Glad you could use the cutter for this project and thanks for showing us your process. That dovetail fits really good. You do great work, Lee!
I love the part where you say you choose a 7/16 cutter because it's the sharpest one you got. So true for many of us.
Wow memories working for us currently. We had an R&R large back years ago (still brand new) and we bought the scribe brass then as well, we loved them so much we did not use them so we waited to use them on a special machine rebuild, so after we finish rebuilding or Barker Mill to run the cutter on it we will be using the larger dovetail cutter on it.
We later this new year 2019 bought the small dovetail and the stainless steel scribe so we have them all now, we will use the large dovetail in our machine testing for this milling machine rebuild.
We know Reid he has a really nice workshop metal and wood type work and we really enjoy Randy and his tools, so it is great to be here to see one of these fine dovetail cutter make some cuts and make these cuts correctly.
Really nice machine work lesson and that was nice to watch, we can do it to now.
Lance & Patrick.
Really like your videos, as a retired machinist of 40 years. In all them years, I only got a chance to cut one set of dovetails which was in two blocks of Lexan, needed as a display show piece at the Offshore Technology Conference.
RR in the Shop makes quality products. To your viewers, if you haven't got one of Randy's scribes or dovetail cutters you should, you will not be disappointed. --- You're doing very good work in the TIN BARN! Very nice matching dovetails, excellent work! Waiting on part 2.
Nice job, very well explained. Cutter RPM is very important to tool life and you provided it, thanks. I was a machinist for the better part of 40 years and trained a few people along the way. The way you explain is how I used to explain and it is very successful. I just subscribed, I may be expereinced but I still like to learn different processes. Besides, I miss taking a peice of raw stock and making somthing useful from it. I'm awaiting your next video. Again, nice job!
"Lookie thair"! Your pleasure was felt here. Careful, such success will make you want more and more. Very nice video - again. Thanks for sharing.
I cut dovetails in wood, for drawer boxes, and they are just as pretty in steel! Good machining, sir!☆☆☆
That sir is a fantastic piece of machining and math(s) as we say in England nicely explained and well done Randy Richard for making those beautiful dovetail cutters.
Sorry to say, but I think the math is a bit shoddy.
Thank you for sharing your knowledge! I am just starting out in the home and have no experience.
Very helpful! Thank you so much for this MUCH easier way to calculate and measure dovetails !
Excellent. Never understood how to use the pins. You explained just so clearly. Thanks.
The scrap metal guard with the magnets is brilliant!
I use the same method but use plexiglass. You can buy small pieces that are 8" by 10" at Lowes, then you can see through it....
Excellent video ..didn't know the correct method to mate and measure dovetails, now I know ..thanks a million..Mr Pragmaticlee..keep em coming.
The dovetail came out very nice, love the fit. Higher rpm is ok.
Reid is a stand up guy... always sending RUclipsr's thoughtful tools.
جزيل الشكر وعظيم التقدير ومزيد من الابداع في ممارسة الشرح بالتفصيل لرفع مهارة الفنيين ونأمل فى المزيد
Well, I'll be darned if your vid didn't make life easier for me. I'm replacing the entire compound slide of my lathe with one I'm making from scratch and after completing the female top portion with tool post slot and about to start the male under portion with the attendant difficulty in measuring for gib allowance, your simpler method of measuring from inside of pins to outside of pins rather than halving the diameters of pins and constantly doing the math required, had never once occurred to me and I've been a certified general machinist since 1963. Never too old a dog to learn a new trick I guess. Love those insert bit dovetail cutters too. Gonna look for those. Kudos pard.
Nice video, nice well fitting dovetail!
One thing to consider when you measure both sides with the pins. Unless the pin is the same diameter as the depth of the dovetail you are not measuring both parts at the same point on the slope face of the dovetail. If the pin diameter is smaller than the depth of the dovetail you would measure the female as indicated but on the male dovetail the pin needs to reference the top of the part (widest part of the dovetail) to measure on the same plane on both parts. Edit: Even this may not be adequate, just realized the pins don't contact the slopes of the dovetail at one radius above the bottom of the dovetail it actually contacts at one radius plus the sine of 30 degrees times the radius 1.5 radii above the bottom.
Oh I think you are right the first time mate - ie pins reference TOP surface of the male part. And this will be tricky to hold in place for measuring. I suggest using pins that are exactly diameter of male dovetail 'height'. Then they can sit on the 'base' of the male part for measuring, at. which time they will line up exactly with the top. Aaarghh. Geometry tells the tale, and a simple sketch shows it clearly.
I was just figuring this out when I saw your comment. Thanks to Mr Pragmatic and to you.
The pin diameter for a 60 degree dovetail is 1/3rd of the dovetail depth if you want to use the same dimension for both male and female parts. - drive.google.com/file/d/1GVwxHEvnL8JpYFfUzes3Z2zrhlT1NNAX/view?usp=share_link
That gift of the smaller cutter from Reid was a real nice thought.
Very enjoyable demo Lee... nice work.
As a machinist myself, I loved the video.
Thanks for the video, very interesting and thought provoking. But I think you were lucky, because your pin diameter is the same as the depth of cut, ie the height of the dovetail. Here is my thinking about it: having made the female part and measured it as you do, surely you must now have the (same) pins reference the TOP surface of the male part as you are making it and measuring it to size? And this will be tricky to hold in place for measuring. I suggest using pins that are exactly diameter of male dovetail 'height'. Then they can sit on the 'base' of the male part for measuring, at. which time they will line up exactly with the top. Aaarghh. Geometry tells the tale, and a simple sketch shows it clearly.
CraigS was thinking along similar lines 3 months ago. Altogether a fascinating and tricky problem, and I appreciate what. you have done and shared here. Best wishes!
Edit one day later: Double AAARGHH I am wrong !!!
That was very well explained and demonstrated. Thanks for sharing. Only problem is that it makes me want to spend money and give Randy a call!
Thanks for another great lesson, RR does make some fine dovetail cutters.Kudos to you both.Thanks.
Excellent work. You make it look so easy.
New subscriber here. Thanks for the video - - clear to follow and a good demonstration of Randy's dovetail cutter. Well done, thanks.
I look forward to watching more of your videos.
Joe
Great instructional video, Lee. Thanks for sharing! I've used Randy;s dovetail cutter for a few dovetails, and they always come out great using the same method that you showed in this video.
I really like your videos, and I am using Randy's dove tail cutters also. I swear by them.
Thank you for making that so clear. I have been working on making tool holders for my little Chinese lath. I made about 20 holders only 10 are tight enough to use.
Great lecture...Please share your cooling/lube set-up...looks efficient
Thanks a bunch for explaining very well how to make dovetails, I am very new and have only had a mill and engineering lathe setup for a month, no Dro yet on the mill and not much tooling yet so that his how green I am lol.
That pin method of measuring was very well explained and when you first mentioned it I was hoping you would explain it which you did, thanks for that as I would have gone the caliper or worse steel ruler route and got frustrated.
You are a lucky man aswel, I have been uploading wood turning vids for a little while and have subscribers but so far have not had anything bought for me 😁 , some wood given to me though at a wood turning symposium by a subscriber which was very appreciated though, hopefully watching your vids and other professionals I should be able to get started up the right way 👍
just watch this video & read your comment 3 years later, curious, hows the mill treating you these days?
@@mtraven23 not too bad, I think back then I had a Warco 16b which has been upgraded to a Myford VMC , it gets used quite a bit and I would be lost without it
That was a very informative Video. Thank's very much for sharing. From a UK Viewer.
Wow very helpful video and information thanks sir 👏👌👍
Well done. Great fit - share your joy in a job well done. Good content - keep going!
_Dan_
that is real cool Thanks for the lesson all the best from John in Texas
Nice job Reid.
very easy to follow your process and nicely done ,just one thing dont sound so surprised when things work the first go ;)
Great video! Thanks so much for sharing this info!
I have been imagining the geometry of those pins, and it seems to me that this measure-between-pins on female and outside on male gets you close, but it's not clear which measurement should be larger.
In a perfect ideal dovetail with zero slop, the outside measurement of the female pins would be smaller than the inside measurement of the male pins--the only way for them to be equal with zero slop would be if the sidewalls were vertical (a groove instead of a dovetail). Conversely, in an exaggerated sloppy dovetail the outside measurement of the female pins would be larger than the inside measurement of the male pins. Hence, the point where the two numbers match is close, but somewhat arbitrary. It's likely going to be just about right, but I think I would want to do a quick sketch and some trig to understand it better.
doesn't the diameter the measuring pins have to be EXACTLY the same as the height of the dovetail? And if there is clearance over the center of the joint, you would put a shim under the pins the same as that clearance?
@@pcbondart No, for 60 degree it is 1/3rd of the height.
Good Stuff Lee, enjoy watching with coffee before work.
Thanks Lee. I personally appreciate the detail . I will save this to my favorites for reference later.
I am curious as to how you precisely set the Z after you change bits. Thanks! GREAT video -- I learned a lot!
Two Thumbs up -- I love your technique -- your explanation was excellent .
The sequence of events was chronological and easy to follow .
This was a Great Video -- you da man !
The only way you can duplicate the clearances is but making the same height dovetail and use the same diameter pins.. For instance, let's say you are using 1/4 inch pins in your example. What kind of measurements do you get if you use 3/16 pins?
If you want to use the same measurement over the pins for both parts, use pins that are 1/3rd diameter of the depth.
Love this video, thanks very much for making it, it is going to help me in my shop for sure! I need to get me a couple of those Randy Richards cutters also.
I really like your video is good work..
Great video and great demonstration.
Excellent video tutorial sir, thank you 😊👍
Will you take an order for a aluminum dove tail design with an offset with a threaded hole on the mail end for an adjustment?
I'd like this video again if I could lol Great job!
Are there small pins on the little removable chip guard to fit inside the holes on the end of the vise?
How much payment to make a small male and female dovetail in either steel or aluminium? I am DIY and currently building a table router fence and need a robust linear sliding function for one of the micro adjusters. No crazy tolerances.
Hi from sunny England! Just found your channel and have spent the evening watching your videos. Thank you for the very informative, educational and entertaining content and for sharing your expertise! You are a really talented guy and I'm really enjoying learning from you. You have a very straightforward, no nonsense approach and a very clear delivery. Thanks again! Subscribed.
The main reason I zoned in on this particular video is that I want to build my own CNC milling machine similary to a number of projects seen on RUclips, but instead of using those linear rails, use dovetail ways instead. Seeing how accurately you made those dovetails has given me great confidence that with enough time and practice, I could perhaps do it too.
May I ask: are you milling the sort of steel that machine ways are usually made out of? If not, what material would you make machine ways out of and how would you harden them? I'm thinking that milling machine ways require a jib for adjustment?
I love this.. great idea.
That was just right. Great work and a great idea.
Are you making a tapered gib? As that would be intresting to see.
Awesome video! Thanks.
Thanks for sharing the technique.
I'd like to point out a couple slight problems with your method of measuring a dovetail. You use pins that have
an uspecified diameter. This introduces two problems.
The first problem is to not hit the dovetails at the same depth. Think of using pins with a diameter one tenth the depth of the dovetail cut. Lets say the pins then hit the female dovetail at the 5% depth. Then measure the male dovetail the same way, and you will be at a 5% depth again, but relative to the female dovetail, you are at 95% depth. I'll leave it to the reader, to figure out what happpens with pins that are too large.
What you want is to have the pins hit at the exact same depth on both male and female dovetails. pick an arbitrary place, I pick the middle point to make it easy. what dowel pin will hit at the middle? you might think a dowel pin with a diameter equal to the depth of the dovetail, you'd be close but still wrong.
For a 60 degree dovetail a circle (a round dowel pin) will hit it at 60 degrees, so you need a dowel pin that is sin(60) x depth of dovetail. So .866 x depth of dovetail. Your method was close because you used pins that were close to this size. For those who have tried and had bad results, check the size of your dowel pins and see how close they are to .866 x depth of cut.
There should be a correction factor for adjusting measurements using dowel pins equal to the depth of the dovetail. In my younger days I'd figure it out and post it. But, alas, my brain is just too old.
I worked out a figure. But I caution you I am old and tired, this could be wrong. Dowel diameter equal to depth of dovetail, multiply the diameter by 1.077 to correct the diameter of the dowel pin so it looks like it is hitting in the center of the dovetail.
I've been thinking along the same lines. Mr Pragmatic was lucky this time, though his method is faulty ! I have a different approach, which now I realise is only good for 45 degree dovetail. Thank you very much for your deep thinking about this. And hell, my further thinking (?) shows I am quite wrong even for 45 degrees. Ha ha ha. Tricky problem!!! I expect the answer is in Machinists Handbook, and it ain't pretty. Best wishes.
For the pins to be directly above each other ie. the same distance apart on both the male and female 60 degree dovetails the diameter needs to be 1/3rd of the depth. Bisect the dovetail angle and construct a vertical line through the true angled length, including sharp corners. The intersection gives the centre of a pin that will rest in the same place on both male and female parts. The pin centre on both parts is always above and below the centre of the angled line. This eliminates trig from cutting dovetails, if it is for yourself, simply make the depth 3x what pin diameter you have. Make the female roughly to size - measure over pins then use this dimension to make the male, just one part needs to be made to a specific size.
Enjoyed Lee!
ATB, Robin
I did get lucky. Thought I used the right method for measuring.
Great Job, like, best regards from Brazil, Ary Prado
This cutter can available in shop.?
Thats a tight fit, nice job !
I guess it’s hard to go to you local industrial supplier and buy one !
just curious if you have a DRO on the z axis???
awesome work
Thanks for the pointers, nicely done
Cool work 👍
Thank you! A to B for and clearly explained!
Where can I purchase the small cutter?
Do you make and sell these dovetail joints?
Good stuff Lee, thanks! Doug
Nicely done. Thank you. BTW, Disturbingly elegant.
Are all dove tails 60 degrees?
I am hearing this correct that dovetail cutter is almost 200bucks????
I have a question.
I'm planning on doing a not so heavy mill, the structure is going to be welded, steel plates, not old like cast iron.
I have to choose whether use cast iron dovetail rails or Hiwin like linear sliders.
I suggest you check out This Old Tony. He knows about that sort of thing . . .
Great video
How much do you sell them for.
Is there a meaning at all to the angle of thw dovetail? Is it 60 degrees from horizonatal? Do some producers use some odd specific angle just to brand themselves, or can it be a more important thing? why not use the large radius corrugated pattern used on jet engines now, reducing all the complex vibration at fast speed? Is there a lathe in the world that can do 20000 rpm on large aluminum, for ridiculous surface speed, (that would still be way to fast for AL huh) 2000 surface feet is adequate for rough work.
horizo-natal? At 20,000 rpm? Spectacular!!! Seriously though . . . 45 degrees, 30, 60, are the common angles. It's all about the horizontal and vertical force vectors across the angled surface. Cheers
Very Nice.
Great,Job well done
Lee, this 80 year old guy needs a little help understanding this process. When you place the brass pins in place, then install the adjustable parallels , what part does the pins play in the overall process. Are you adding the diameter of the pins ? If so I didn't see you measure the pins. Can you run that by me again. Thanks Ken Marina California.
If this was a square dovetail (no sloped sides) you could just measure the width of slot and make the matching male part to fit. But the sides are sloped so we use pins to contact the slope at a point one point above the bottom of the female slot. Now if we measure the distance between the pins we can figure the width of the female dovetail at that point. It's more complex than adding the pin diameters but adequate for comparison. This is because the contact point is not at the radius of the pin for a 60 deg dovetail but 1.5 times the radius of the pin above the bottom. The width at that point would be the measured distances between the pins plus two pin radii plus two more pin radii divided by the cosine of 30 deg.
Почему ссылку не оставил, где купить?
I wish the dovetail ill be doing for my exam tomorrow will be as low spec.......
Why don't they put two carbide cutters in the dovetail holder? Seem like it would make for easier cutting and a smother cut.
A single insert is fine. It clears chips well and being an indexable insert distrbutes heat well. Putting another insert on a small cutter like this would also weaken it due to the size insert you need to make a dovetail. Nice strong ridgid tool, couldn't ask for more.
I'm doing something wrong? Made matching dovetail, however when I measure as explained in video there is hundred thousands difference and I measured as explained in the video..
Confused.
i don't know maybe you have to compensate for the pin thickness.
Yes, this method of measuring is wrong! The equal inside/outside result depends on dovetail 'height' (and pin diameter), so in Lee's case it was purely coincidence that he found the same dimension..... Make a simple sketch of it and you can see for yourself.
@@michaelhompus2475 Can you explain a little more? If the dovetails are to fit, don't they have to be the same depth as each other? If they are the same depth and the angle is the same then I think that the same pins should touch at the same height.
I can't see the problem of using pins to measure the dovetails. I'm not to proud to learn. If you know a better way I am very interested. Thanks and best wishes.
@@michaelhompus2475 I'm afraid you are right my friend. But the question is, what is the correct approach? I'm sure the pro machinists know, but they have not been following here. Wonder what Joe Pieczynski
has to say? This Old Tony knows a few things too.
The pin diameter needs to be 1/3rd of the dovetail depth for 60 degree dovetails. Only this diameter pin will rest equally on both parts.
Turn your verniers towards you and you can tell if it moves
I would never use a methodology that tries to match an inside mearsurement to an outside measurement. I would only use inside-to-inside or outside-to-outside. You will have to mathematically subtract (or add) the known diameter of the dowel pin.
The inside vs. outside measurement of your pins was just luck in this case. To take this to an extreme for illustration, if you used 1/4" dowels and had a dovetail that was 1" tall, the dowels used to measure the male side are going to be far closer together than the dowels used to measure the female side.
If you want to use the same measurement over the pins for both parts, use pins that are 1/3rd diameter of the depth.
Nice Video:)
You ccould measure the male also with micrometer by measuring the outside minus twice the diameter of the pins. Now you use the same measurement device to measure only the difference instead of two absoluut distances
Thanks for the input, but I don't think so. See my post in the main thread today, and CraigS a few months ago.
I have seen this video two times, 😁
Wow! I wish that I could watch it two times, butI have only seen it twice :-)
Muito bom top demais
👍🏻
Excellent
Very cool
Exelent
camera angle sucks....i guess we will take your word for it, cuz my video shows beautiful side view of a vice, cant see jack squat...daum i relly was looking forward to seeing this too....
There should be no gaps on both sides. So not finish, One more step.