Having just got a 14” rotary table, this was very, very useful. Thanks, Professor. Sharing and teaching is never a waste of time to those of us a-learning.
I have been centering rotary tables on Bridgeports the same way for over fifty years. If you want it closer use the indolent. It is always a good idea,though, to sweep the table first if you are going to raise or lower the knee. Mr. Pete is the best teacher.
I need to do this for a project so I'm doing a refresher course. The wife's mirror that was sitting close to her toothbrush. Mr. Pete, you have a wealth of information in your videos.
thank you for explaining so much the entire time and not just playing music and using simple titles. the tiny things you mention are equally as helpful as the huge ones! awesome stuff, sir!
showing an alternate method of doing something is never a waste of time. it's always good to know different ways of doing something since there are so many variables that influence the progression of a job. being thorough is the hallmark of a good teacher. your videos have been a great help in places where i have hit a wall. thanks for being so thorough and doing a great job of instructing. if the trolls are giving you grief for being thorough they should be shown or told where the cows ate the cabbage...
Mr. Pete. I've been watching your videos for years. They've been extremely useful. Thank you so much for taking the time to make them. Your thoroughness is greatly appreciated. Great job! Keep them coming. :)
At twenty minutes in....did the viewers just get a "Two-bolt Con"? Couldn't resist the pun. Reside in Peoria IL and grew up in Aurora, now retired. I've enjoyed your entire series. Keep 'em coming!
Lyle, what a great lesson !!! Can't tell you were a teacher for over 40 years, Ha Ha Ha. Even, though I already knew this, You can't even know, how cool, and how much fun, this was for me. Your friend, Cliff.
That washer on the morse taper i so simple - never seen that before ! I purchased a second hand last word indicator last year , nice and clear crystal and nice white dial and it is the one i seem to reach for every time - so nimble and easy to use i truly love that little indicator! Thanks for the video mr pete , highly entertaining and educational as we have all come to expect!
Easiest and most accurate way to align rotary table to the machine spindle. Bolt the rotary table to the machine's table. Mount an indicator on the face plate of rotary table using a magnetic holder. Disengage worm drive of rotary table so it is free to turn by hand. Using the milling machine X-Y table adjustments roughly center the rotary table while turning the indicator around nose of machine spindle, with out it touching to get it roughly concentric. Now bring indicator into contact with spindle and dial in while turning the rotary table. This method is a must with a Cross Slide Rotary Table where there is no center hole reference in the table. This aligns the true center axis of the rotary table.
Thank you.I will show that method at the end of (unreleased tips 375). There is no hole reference in the table I am showing. The nose on my mill is damaged--so I use the quill
i dont mean to be so off topic but does anyone know a method to log back into an instagram account..? I stupidly forgot my password. I would appreciate any tips you can give me
BusyBeeTools.com has the straight shank arbors in MT2 and MT3. #B460 and #B461. They only come with a 1" straight shank so may have to be machined down, which is not difficult as this portion is not hardened. They are located in Canada, but will ship to the U.S. The arbors are manufactured by Groz.
For my rotary table chuck adapter plate, I turned a chuck register on one side and a rim on the other that fits snug in the MT2 center bore. This gets me within about 0.0005 every time. And honestly that half thou error might be in the chuck or in the rotary table spindle, not in the chuck to table interface.
Thank you for outstanding instruction. I noticed your small 3-jaw chuck has 3 through holes for mounting to t-nuts on an adapter plate that is then mounted to the rotary table. Except for 3 hole chuck vs. 4 slot table plate, could you have drilled 4 holes in the chuck and mounted it directly? I have a small spare 4 jaw chuck that doesn't fit my lathe spindle and am thinking of extending the mounting holes to be through holes for mounting directly to the t-slots on a rotary table. Is this a hairbrained idea or might it actually work? Thank you again!
This was an excellent lesson and I always enjoy the multiple ways of doing the task. Speaking of the accuracy of the three jaw chuck how is one checked at different diameters and is it possible to repair or rebuild one that is no longer accurate due to wear or damage, if so could that be the subject of another future lesson?
Great video as always Lyle. Just a small comment, why do you not also set your X & Y dials to zero. Handy in the event of a power or DRO failure and also save leaving it switched on all night. We always did this at work before going home as all the power was shut off at night with a padlock fitted to save any unauthorised use by untrained people. Keep up the good tutorials. Have not seen your new Grandchild recently, how is it doing.
Hi and thank you for these invaluable videos. Could you explain what / how you are measuring at 9:06? As the dial is mounted on a ball joint, how do you ensure that the gauge itself is aligned with the axis of the mill? Or does its centrality at that point not matter given the task? Thanks for being a great teacher and sharing your knowledge
Lyle, I keep noticing what looks like a crack at the top of the right knee way. It's probably just the paint, but I've seen it in several videos over the past year, or so. -- Tom
Where can I find a morse taper arbor with a straight mount like that one? The only one I've found is on Ebay and its used and expensive for such an item.
Education takes time. I'm a newb and need the long version. About 7:33 in the video you talk about wasting time but I appreciate the details. For your investment of time, I'm grateful. Thank you!
Actually, if one made the MT2 arbor for Mr. Pete's Shop Tips #76 (for lathe alignment) and made sure you machined the end to .750 you'd be able to use it for that as well this.
Hello Mr Pete. Really enjoy your video clips, very indepth and helpfull. I show stationary engines for a hobbie and have just bought myself me very first Lathe. It a very old Dalton Six. All seems to be good but i have no idea how to use it. Your videos are very helpfull but am unsure of how to position the tool and what tool to use for what job. And also speeds (i have rear gears like on you south bend) i assume they for low range so to speak? And do you use with bull pin engaged? Keep up the great work. Adam Fenn England.
+adam fenn Good luck with the new lathe. I have many videos on youtube that might cover that. I also have lathe courses for sale--that would be helpful
MR Pete im concerned about that last part of this video. After you centered the three jaw chuck how do you know the rotary table is centered to the chuck? are there pins that ensure the concentricity of the rotary table to the chuck ? it seams that you only spoke about eyeballing the chuck to the rotary table and that can be off quite a few thou...
I must not know exactly what to look for in my search, but I cannot find an arbor that has a 3MT on the spindle end and a straight shank on the other. I found scads with a JT, but no straight shank. Can you tell me where to buy an arbor like the one you describe? Pardon me if you have answered this question but I did not see it.
Mr Pete.. I REALLY appreciate all your videos. I am learning machining by watching these. I have a 8" Rotary Table (Centech) that I inherited with my used Granite mill. It has a MT3 taper and I am having a tough time finding a arbor that has the MT3 taper and a straight shank. Any suggestions where I should look for one of these?
Great video but wouldn't it be a good thing to check your rotary table accuracy by rotating it with the dial indicator in place? I guess if it was off it would end up in the trash but none the less.....
Hello: where did you get, or can you set a link for the M2T with a 3/4" straight shank? Time 4:36. Have looked in catalogs and on ebay .. but can not find one. Is there a special descriptor, or supplier? Thanks,
Thanks, I looked at number of online suppliers and no one has this item. SO, next best idea is this MT2- to 1/2" tool holder? www.ebay.com/itm/1-2-MT2-MORSE-TAPER-END-MILL-TOOL-HOLDER-ADAPTER-3-8-16-DRAWBAR-END-2MT/112055972721?hash=item1a170e7371%3Ag%3APicAAOSw%7EQRaMEzB&_sacat=0&_nkw=1%2F2%22+MT2+MORSE+TAPER+END+MILL+TOOL+HOLDER+ADAPTER+3%2F8%22-16+DRAWBAR+END+2MT&_from=R40&rt=nc&_trksid=m570.l1313 Then find a precision 1/2" drill rod or blank to insert into a collet of the spindle, or is this a bad idea that would introduce error? Seems like a quick and dirty method, then an indicator if the work requires it?
Why not turn down the diameter of the handle the fraction of an inch it needs so you don't lose so much height when using your rotary table with that plate?
John C I'll admit I don't watch every video so yeah I missed it but I figured I have watched enough videos over the past year I would have seen his face by now.
+mrpete222 don't do it! most laser pointers (and raw laser diodes), do not run true (they do not need to, since the user is just aiming the dot without precision). that said, calibrated laser center/edge finders are available, but are hardly precise nor cheap -- i have had both a calibrated laser finder and wobbler for several years, and the laser went long ago to my sister so she can entertain her cats with it.
The most basic precision tool is the flat surface plate. We can make these really good both through machine grinding and then by hand scraping. From that we can make straight edges. Precision-screws and measuring tools arose around this time, mid 18th century. Metals lathes. You can make extremely accurate circular diameters with lathes and even land-lapping. Ultimate precision comes from using light to measure, interferometer-based machines.
+Tommy Hummer They are readily available in the UK. The parallel portion is machinable so you can make them to fit various applications. I use one with a centre drill inserted to centre on the lathe.
Since your hands are plentiful but your face is scarce in these videos i find myself watching for glimpses of the venerable mrpete.. I thought you looked like your moustache was missing/recently shaved in TUBALCAIN TAKES A TRIPLE ROAD TRIP part 1......Now i see at 14:15 of this video, its growing back, or time shifted... My attention to detail catches the randomest things sometimes..
Yan Wo You must have a problem with your computer. I have NO trouble at all watching ANY of his videos, old or new. Both on a Mac and Windows computers.
Yan Wo You have one video with 2 views. If you don't like what others post, then post your own stuff. Why is it that those who complain don't post anything? That said, the interlacing is an issue in some videos, one wonders why youtube does not fix it automatically.
Yan Wo If you demand so perfect from this channel and quit for stupid details, you might miss treasures of excellent teaching and info...... The people appreciating are rushing in more than the people rushing out... ;-)
This video is still helping people over five years later. I'm new at this and recently purchased a small rotary table with a #2 Morse taper, so this was very valuable to me. If anyone is looking for a #2 Morse taper accessory to use the way it's demonstrated in this video, I found this on eBay: www.ebay.com/itm/163614398363 It's a #2MT with a 3/4" straight expanding mandrel shaft. Fits perfectly in a 3/4" collet and even has a built in ridge to function like the washer in the video for using wedges to get the tool out if it's stuck in the rotary table.
Having just got a 14” rotary table, this was very, very useful. Thanks, Professor. Sharing and teaching is never a waste of time to those of us a-learning.
Thanks
As an amateur, self-taught machinist, I am extremely appreciative of your videos. Thank you!
Thank you very much
I have been centering rotary tables on Bridgeports the same way for over fifty years. If you want it closer use the indolent. It is always a good idea,though, to sweep the table first if you are going to raise or lower the knee.
Mr. Pete is the best teacher.
👍👍👍
I always appreciate the multiple methods Mr. Pete.
I need to do this for a project so I'm doing a refresher course. The wife's mirror that was sitting close to her toothbrush. Mr. Pete, you have a wealth of information in your videos.
😄😄😄
thank you for explaining so much the entire time and not just playing music and using simple titles. the tiny things you mention are equally as helpful as the huge ones! awesome stuff, sir!
I am never bored or feel like I'm wasting time listening to my machine shop Teacher! Keep that knowledge coming!
+TAWPTool Thanks for watching
showing an alternate method of doing something is never a waste of time. it's always good to know different ways of doing something since there are so many variables that influence the progression of a job. being thorough is the hallmark of a good teacher.
your videos have been a great help in places where i have hit a wall.
thanks for being so thorough and doing a great job of instructing. if the trolls are giving you grief for being thorough they should be shown or told where the cows ate the cabbage...
I like seeing alternate methods myself so I appreciate the extra time you take to explain them.
Mr. Pete. I've been watching your videos for years. They've been extremely useful. Thank you so much for taking the time to make them. Your thoroughness is greatly appreciated. Great job! Keep them coming. :)
Thank you very much
At twenty minutes in....did the viewers just get a "Two-bolt Con"? Couldn't resist the pun. Reside in Peoria IL and grew up in Aurora, now retired. I've enjoyed your entire series. Keep 'em coming!
+Dave Lammers Thanks for watching
I enjoy your showing of alternate methods of doing things and sincerely hope you continue to do so.
+Doug Rundell Thanks for watching
Yes, there is always more than one way. Just read the comments. LOL
Thank you for this video! The techniques you demonstrated are super helpful!
Lyle, what a great lesson !!!
Can't tell you were a teacher for over 40 years, Ha Ha Ha.
Even, though I already knew this, You can't even know, how cool, and how much fun, this was for me.
Your friend,
Cliff.
+Clifford Fender Thanks for watching
That washer on the morse taper i so simple - never seen that before !
I purchased a second hand last word indicator last year , nice and clear crystal and nice white dial and it is the one i seem to reach for every time - so nimble and easy to use i truly love that little indicator!
Thanks for the video mr pete , highly entertaining and educational as we have all come to expect!
+ian bertenshaw Thanks for watching
I was able to pick up a 6" rotary table at an auction on Monday. Nice lesson on setting it up.
+ILGopher Awesome-Thanks for watching
Great video. I was having a terrible time with my rotary table until now.
👍
3 people are... I just don;t know what they are. This is a perfect explanation how to center a rotary table. Respect Sr.
+I Just Love Football Thanks
yet another educational video from mrpete.. thankyou sir most interesting as always..
+Kevin Willis Thanks for watching
Very Nice Video. Getting ready to get me a rotary table and I came here first.
Another great shop tip! Thank you for sharing your wisdom. Very useful information.
great centering video of the 3 jaw chuck
Neat washer trick, I'd never have thought of that beforehand.
+cyrex686 Thanks for watching
Thank you for another interesting, educational video!
Where did you get the straight shank arbor? I'm looking for one in a #3 morse taper for my rotary table for the same purpose.
Great video, just what I needed
Thank you mrpete, love your work.
Very nice Idea i will also make this check.thanks a lot for this video.
I made a centering cone to get in the proverbial ball park quickly then indicate.
Easiest and most accurate way to align rotary table to the machine spindle. Bolt the rotary table to the machine's table. Mount an indicator on the face plate of rotary table using a magnetic holder. Disengage worm drive of rotary table so it is free to turn by hand. Using the milling machine X-Y table adjustments roughly center the rotary table while turning the indicator around nose of machine spindle, with out it touching to get it roughly concentric. Now bring indicator into contact with spindle and dial in while turning the rotary table. This method is a must with a Cross Slide Rotary Table where there is no center hole reference in the table. This aligns the true center axis of the rotary table.
Thank you.I will show that method at the end of (unreleased tips 375).
There is no hole reference in the table I am showing. The nose on my mill is damaged--so I use the quill
Another great video! I enjoy watching your lessons. I know it is your machine, but I wish you didn't lay tools on the table. Keep up the good work!
i dont mean to be so off topic but does anyone know a method to log back into an instagram account..?
I stupidly forgot my password. I would appreciate any tips you can give me
BusyBeeTools.com has the straight shank arbors in MT2 and MT3. #B460 and #B461. They only come with a 1" straight shank so may have to be machined down, which is not difficult as this portion is not hardened. They are located in Canada, but will ship to the U.S. The arbors are manufactured by Groz.
Thanks for the tip
For my rotary table chuck adapter plate, I turned a chuck register on one side and a rim on the other that fits snug in the MT2 center bore. This gets me within about 0.0005 every time. And honestly that half thou error might be in the chuck or in the rotary table spindle, not in the chuck to table interface.
Thank you for outstanding instruction. I noticed your small 3-jaw chuck has 3 through holes for mounting to t-nuts on an adapter plate that is then mounted to the rotary table. Except for 3 hole chuck vs. 4 slot table plate, could you have drilled 4 holes in the chuck and mounted it directly? I have a small spare 4 jaw chuck that doesn't fit my lathe spindle and am thinking of extending the mounting holes to be through holes for mounting directly to the t-slots on a rotary table. Is this a hairbrained idea or might it actually work? Thank you again!
This was an excellent lesson and I always enjoy the multiple ways of doing the task. Speaking of the accuracy of the three jaw chuck how is one checked at different diameters and is it possible to repair or rebuild one that is no longer accurate due to wear or damage, if so could that be the subject of another future lesson?
Thanks for this video another knowledge for a machinist 👍👍
Thanks
Great video as always Lyle. Just a small comment, why do you not also set your X & Y dials to zero. Handy in the event of a power or DRO failure and also save leaving it switched on all night. We always did this at work before going home as all the power was shut off at night with a padlock fitted to save any unauthorised use by untrained people. Keep up the good tutorials. Have not seen your new Grandchild recently, how is it doing.
Dave Ticehurst Good idea--to set the dials to 0.
Henry is getting big
Great video Pete. I enjoy your stuff. Douglas
MR. PETE,
THE MORE OPTIONS YOU GIVE IN YOUR EXPLANATION THE EASIER IT IS TO APPLY YOUR DIRECTIONS. GREAT LEARNING VIDEO. THANKS.
+ROBERT HORNER Thanks for watching
Mrpete, Any suggestions for centering a rotary table vertically on a Bridgeport mill?
Hi and thank you for these invaluable videos. Could you explain what / how you are measuring at 9:06? As the dial is mounted on a ball joint, how do you ensure that the gauge itself is aligned with the axis of the mill? Or does its centrality at that point not matter given the task? Thanks for being a great teacher and sharing your knowledge
Does anyone know the name designation for the 3/4 straight shank side I can find tons of mt2 arbors but it's hard to tell from a pic if its straight
Lyle, I keep noticing what looks like a crack at the top of the right knee way. It's probably just the paint, but I've seen it in several videos over the past year, or so. -- Tom
That was great! So simple.
Mike
+Oldvet1946 Thanks for watching
Where can I find a morse taper arbor with a straight mount like that one? The only one I've found is on Ebay and its used and expensive for such an item.
mcmaster
Thank you Mr. Pete!
As always, thanks’ for taking the time to make this video! And I support this site. ~M~
Piece of plasticine and a paper clip was how I was taught as an apprentice, took about ten seconds
very good , and well detailed..
Education takes time. I'm a newb and need the long version. About 7:33 in the video you talk about wasting time but I appreciate the details. For your investment of time, I'm grateful. Thank you!
Thank you, I'm glad you like the detail
Actually, if one made the MT2 arbor for Mr. Pete's Shop Tips #76 (for lathe alignment) and made sure you machined the end to .750 you'd be able to use it for that as well this.
how can you tell what size dividing plates you need to fit your rotray table I have a 12" phase ll 221-312 could you tell me what I need. Thank you
Hello Mr Pete. Really enjoy your video clips, very indepth and helpfull. I show stationary engines for a hobbie and have just bought myself me very first Lathe. It a very old Dalton Six. All seems to be good but i have no idea how to use it. Your videos are very helpfull but am unsure of how to position the tool and what tool to use for what job. And also speeds (i have rear gears like on you south bend) i assume they for low range so to speak? And do you use with bull pin engaged? Keep up the great work. Adam Fenn England.
+adam fenn Good luck with the new lathe. I have many videos on youtube that might cover that. I also have lathe courses for sale--that would be helpful
MR Pete im concerned about that last part of this video. After you centered the three jaw chuck how do you know the rotary table is centered to the chuck? are there pins that ensure the concentricity of the rotary table to the chuck ? it seams that you only spoke about eyeballing the chuck to the rotary table and that can be off quite a few thou...
I must not know exactly what to look for in my search, but I cannot find an arbor that has a 3MT on the spindle end and a straight shank on the other. I found scads with a JT, but no straight shank. Can you tell me where to buy an arbor like the one you describe? Pardon me if you have answered this question but I did not see it.
Mr Pete.. I REALLY appreciate all your videos. I am learning machining by watching these. I have a 8" Rotary Table (Centech) that I inherited with my used Granite mill. It has a MT3 taper and I am having a tough time finding a arbor that has the MT3 taper and a straight shank. Any suggestions where I should look for one of these?
Check for that Arbor in the K BC catalog or MSc
Very nice
Great video but wouldn't it be a good thing to check your rotary table accuracy by rotating it with the dial indicator in place? I guess if it was off it would end up in the trash but none the less.....
Where do I get a pink plastic inspection mirror.
What Tenspeed said! Thanks Tubalcain Interesting as always! :o)
O,,,
What kind of rotary table is that, brand?
thank you mrpete 222
Hello: where did you get, or can you set a link for the M2T with a 3/4" straight shank? Time 4:36.
Have looked in catalogs and on ebay .. but can not find one. Is there a special descriptor, or supplier? Thanks,
I have no idea where that came from, I must have got it in an in an auction box?
Thanks,
I looked at number of online suppliers and no one has this item. SO, next best idea is this MT2- to 1/2" tool holder?
www.ebay.com/itm/1-2-MT2-MORSE-TAPER-END-MILL-TOOL-HOLDER-ADAPTER-3-8-16-DRAWBAR-END-2MT/112055972721?hash=item1a170e7371%3Ag%3APicAAOSw%7EQRaMEzB&_sacat=0&_nkw=1%2F2%22+MT2+MORSE+TAPER+END+MILL+TOOL+HOLDER+ADAPTER+3%2F8%22-16+DRAWBAR+END+2MT&_from=R40&rt=nc&_trksid=m570.l1313
Then find a precision 1/2" drill rod or blank to insert into a collet of the spindle, or is this a bad idea that would introduce error? Seems like a quick and dirty method, then an indicator if the work requires it?
Thank for the video!!!!!!!!!!!
All type job through and rotary tabale
can you tell me where to purchase that mt2 and 3/4 straight arbor? Been looking all over and can't seem to find.
Shars I think
Thanks I will check them out
what make is that rotary table?
thank you
Why not turn down the diameter of the handle the fraction of an inch it needs so you don't lose so much height when using your rotary table with that plate?
+ExtantFrodo2 Thanks for watching-good idea
I just realized that this is probably the first time I have seen your face in a video. And in this case it was in a mirror.
I guess you missed "Tubalcain takes a triple road trip part 1"
John C I'll admit I don't watch every video so yeah I missed it but I figured I have watched enough videos over the past year I would have seen his face by now.
x9x9x9x9x9 =59049 Mr. Peterson VERY RARELY puts his face in view, so, it's easy to miss.... When you see the face you almost disbelieve..... lol
He did a face reveal a few years before that road trip ;-)
Long term viewers will remember
Tim
x9x9x9x9x9 I hope he returned that cute little mirror to Mrs. Tubalcain's makeup table before she finds out he's had it out in the shop again!
thanks Pete
+Joe Shook Thanks for watching
What does DRO mean
Josaljo Won Digital Read Out
Well that was easy. I was thinking it was some sort of automatic control. Thanks.
whu not mount a cheap laser pointer into the spindle and do the same ?
gav Yes. Where do I get a cheap laser?
mrpete222 The office supply store has them.
+mrpete222 don't do it! most laser pointers (and raw laser diodes), do not run true (they do not need to, since the user is just aiming the dot without precision). that said, calibrated laser center/edge finders are available, but are hardly precise nor cheap -- i have had both a calibrated laser finder and wobbler for several years, and the laser went long ago to my sister so she can entertain her cats with it.
One thing that ive been puzzling about lately is how did they build the machinist tools to make machinist tools before they had machinist tools
The most basic precision tool is the flat surface plate. We can make these really good both through machine grinding and then by hand scraping. From that we can make straight edges. Precision-screws and measuring tools arose around this time, mid 18th century. Metals lathes. You can make extremely accurate circular diameters with lathes and even land-lapping. Ultimate precision comes from using light to measure, interferometer-based machines.
Anybody have any luck finding a mt2 to straight shank arbor?
+Tommy Hummer They are readily available in the UK. The parallel portion is machinable so you can make them to fit various applications. I use one with a centre drill inserted to centre on the lathe.
+Tommy Hummer Little Machine--I think
Since your hands are plentiful but your face is scarce in these videos i find myself watching for glimpses of the venerable mrpete..
I thought you looked like your moustache was missing/recently shaved in TUBALCAIN TAKES A TRIPLE ROAD TRIP part 1......Now i see at 14:15 of this video, its growing back, or time shifted...
My attention to detail catches the randomest things sometimes..
+Notso Fresh Thanks for watching
WRONG - you are NOT wasting time by showing us alternate methods!
Your adamant refusal to fix the interlaced video problem has lost you a subscriber. Sorry to go, because I very much like the content.
Yan Wo You must have a problem with your computer. I have NO trouble at all watching ANY of his videos, old or new. Both on a Mac and Windows computers.
Yan Wo You have one video with 2 views. If you don't like what others post, then post your own stuff. Why is it that those who complain don't post anything? That said, the interlacing is an issue in some videos, one wonders why youtube does not fix it automatically.
Yan Wo If you demand so perfect from this channel and quit for stupid details, you might miss treasures of excellent teaching and info...... The people appreciating are rushing in more than the people rushing out... ;-)
This video is still helping people over five years later. I'm new at this and recently purchased a small rotary table with a #2 Morse taper, so this was very valuable to me. If anyone is looking for a #2 Morse taper accessory to use the way it's demonstrated in this video, I found this on eBay: www.ebay.com/itm/163614398363 It's a #2MT with a 3/4" straight expanding mandrel shaft. Fits perfectly in a 3/4" collet and even has a built in ridge to function like the washer in the video for using wedges to get the tool out if it's stuck in the rotary table.
Thank you, I’ve never seen one of these