I stand by my comment from last month’s video (5K subs now ~58% increase). Superb macro camera work, very effective lighting. Thanks for the inspiration to modify my D-bit grinder index stops. That had been on my list for a long time.
Very interesting design with the 3 staggered inserts👌 I have made some of the single insert type dovetail cutters. If you can find TPMT type inserts they have more flank clearance angle than the TCMT type. You could also increase the flank clearance of your TCMT inserts by grinding more angle on the flanks in you tool and cutter grinder(I have done this). What I have found is the smaller the diameter of the dovetail cutter the more likely it is to rub on the trailing edge of the insert,the larger diameter cutters don't cause this clearance problem at all. Edit to add : if you do grind extra clearance on TCMT inserts don't grind right up to the cutting edge. Increase the flank clearance but stay just beneath the actual cutting edge.
The insert holder mandrel used for locating the hole is a super smart and simple solution. Love stuff like that. Machinists are the best creative problem solvers. and thanks for the adapter idea for the dbit grinder. Brilliant!
The small problem with your cutter is that you cut the seat for the insert with straight cutter but the side of the insert is at 7 degrees. So you only have the cutting edge of the insert braced against the wall of the cutter body. The pressure of the carbide cutting edge against the steel body during the cut will deform the steel just a tiny bit but enough for the cutting force to be transferred onto the screw, rather than the cutter body. That is why commercial indexable dovetail cutters using TCnn or TDnn inserts have the wall of the body cut at the angle matching the angle of the insert. The screw hole is off-set a tiny amount of force the cone of the screw head to push the insert towards the wall of the seat. This way cutting forces are transferred from the cutting edge of the insert onto the cutter body via the entire surface of the opposite side of the insert, never onto the screw holding the insert in place. Your cutter will work for a while but don’t be surprised when the screw comes loose during longer cuts.
@@nbrworksthis video shows how to make the cutter with the seat matching the angle of the insert ruclips.net/video/l3YNf0a7O5E/видео.htmlsi=ho3mjfOVWyUD__NA Another method is to use an endmill ground with a taper matching the insert to cut the very bottom of corner of the seat. You would need to to use the straight endmill to remove material to make room for the shank of the tapered endmill.
I have... *never* jumped while watching a machining video. I usually watch these to relax after a long day at my own machining job. But this moment at 5:11 made me recoil in such a primal fear which i have never experienced outside of a horror game. Every time I rewatch it i flinch. my poor little machinist heart :( In all seriousness, great video. love the cutter!
I hope you have all recovered by now 😄 That was my bad, I should have used the clamp right from the begining. I've been having some trouble with my mill lately when it comes to workspace/travel available. I have the column cover removed in this video because of that, I needed more travel to make a cut (for another project).
@@nbrworks putting some referrnce blocks in the T-slots lets you reposition long parts without majorly affecting the Y axis, So i'd suggest investing in a set/making one. I'm guessing you're making some rails/ways that need higher precision?
Nice video with good machining craftsmanship. However, my gut feeling tells me that if you offset the cutting edge of the cutter away from the center line (or rather the center-plane) your dovetail will not be 60 degrees.
It will,Michel. I have 3 different diameter homemade dovetail insert cutters and they have done lots of work without any failures yet. Mine are the single insert type like the Randy Richards design.
I just found your channel and subscribed, I’m very impressed with your straightforward and concise method of your tutorial. The video and audio is great and I look forward to your other videos! RK
Great job! I want to maybe recut the dovetails on a Vevor mill table, but I need a larger dovetail cutter to do that. Perhaps I may make a similar on to this!
I have made one of these previously and found it chattered badly when the width of engagement was high. In the end I made a new one using a DCMT insert.
Love the content! Can you make the next video brighter? I did everything I could on my end, but it was awfully dark and hard to see some parts of the video.
Hi! I'm sorry this one was dark. I also realized that the day after uploading the video. I exported the file, watched it and it looked fine, then I uploaded it and watched it on my tv. I thought it was dark but also thought it was my tv settings. The next day I compared the exported file next to the youtube page and they were different! I created a poll on the community page asking how bad it was and if I should remove it. Considering other people's opinions I decided to just let it run and make my best to avoid this in the future. Thanks for your constructive comment!
Excellent work. I like the idea of placing the cutting face above center to compensate for insufficient insert side clearance, but doesn’t that introduce negative rake between the cutting face and the workpiece?
@@nbrworks When you mentioned possibly tilting the inserts to get greater clearance the problem that creates is you are no longer producing a true 60 degree angle. It would reduce the cut dovetail to below 60 degrees because the top cutting face is now set at an oblique approach angle.
@@howardosborne8647 if the insert is only tilted outwards (to get more side clearance) then yes, it will cut more near the top of the insert than near the bottom and will not cut a 60° angle. But according to a quick check I made in fusion 360, you can then tilt it backwards to compensate. I might have missed something and there's a chance this might be wrong, of course. I remember the concern was with the bottom of the cutter. If the insert is tilted backwards, then the problem begins to be with the bottom not having clearance. I think simplifying and setting it at 0° works well (as you also mention). Thanks!
Excellent explanation. Some people tilt the piece/ rest the shank on the angle bllck. Because I have swivel vise, I prefer to lay the shank flat, and rotate the vise to form 59 degree. This way the cutter doesn't hit with the whole blade length but rather slices into the material. And a shim undet the shank to achieve 1 deg slope on the horizontal plane. I might experiment with even more than 1 degree slants to see how far I can push my small mill
I personally don't like the type of insert cutters (lathe or any other) that only supports the insert in one direction with the pocket walls. I just can't be sure that the insert would stay exactly where it is.
These type of insert dovetail cutters work very reliably with no fear of the insert moving. I have 3 homemade single insert dovetail cutters using the TPMT 16 and TPMT 11 size inserts. The TPMT inserts have more flank angle clearance than the TCMT type. I have used these homemade cutters a great deal to make 20 of the 250-201 type dovetail lathe tool holders and never had any issue with the insert moving in the dovetail cutter holders.
@@nbrworks My fingers are crossed that your hobby brings you much joy. I will be happy to share some of my 30 years of experience as a turner with you.
Фреза "ласточкин хвост-кукуруза"?) Замечательное решение! Но, с другой стороны, как вы сами убедились, фреза-кукуруза это черновая фреза, и после нее все равно нужен чистовой проход цельной фрезой.
7:31 A brilliant way to set inserts or other position-critical items. I like the way you turn problems upside down and shake them to see what falls out of their pockets. Or in this case, into their pockets! Thanks for the excellent video!
Now that you mention that, I should have started by saying the inserts have 10mm sides and staggering them was a way to get a bigger cutter. Thanks for your comment, it made me realize I missed that (important) bit of information.
I stand by my comment from last month’s video (5K subs now ~58% increase). Superb macro camera work, very effective lighting. Thanks for the inspiration to modify my D-bit grinder index stops. That had been on my list for a long time.
Very interesting design with the 3 staggered inserts👌
I have made some of the single insert type dovetail cutters. If you can find TPMT type inserts they have more flank clearance angle than the TCMT type.
You could also increase the flank clearance of your TCMT inserts by grinding more angle on the flanks in you tool and cutter grinder(I have done this).
What I have found is the smaller the diameter of the dovetail cutter the more likely it is to rub on the trailing edge of the insert,the larger diameter cutters don't cause this clearance problem at all.
Edit to add : if you do grind extra clearance on TCMT inserts don't grind right up to the cutting edge. Increase the flank clearance but stay just beneath the actual cutting edge.
I liked your presentation. Creative way to get make a dovetail cutter for larger dovetails.
Damn, that lathe makes gorgeous cuts!
The insert holder mandrel used for locating the hole is a super smart and simple solution. Love stuff like that. Machinists are the best creative problem solvers. and thanks for the adapter idea for the dbit grinder. Brilliant!
Thanks Derek!
Very clean machinery and corrected setups inspire confidence. Of course, the results speak even more loudly.
Love the power feed on the compound
The small problem with your cutter is that you cut the seat for the insert with straight cutter but the side of the insert is at 7 degrees. So you only have the cutting edge of the insert braced against the wall of the cutter body. The pressure of the carbide cutting edge against the steel body during the cut will deform the steel just a tiny bit but enough for the cutting force to be transferred onto the screw, rather than the cutter body.
That is why commercial indexable dovetail cutters using TCnn or TDnn inserts have the wall of the body cut at the angle matching the angle of the insert. The screw hole is off-set a tiny amount of force the cone of the screw head to push the insert towards the wall of the seat. This way cutting forces are transferred from the cutting edge of the insert onto the cutter body via the entire surface of the opposite side of the insert, never onto the screw holding the insert in place.
Your cutter will work for a while but don’t be surprised when the screw comes loose during longer cuts.
I see exactly what you're describing and that makes sense. Thanks, I learned something today! If I ever do another one, I will consider that.
@@nbrworksthis video shows how to make the cutter with the seat matching the angle of the insert
ruclips.net/video/l3YNf0a7O5E/видео.htmlsi=ho3mjfOVWyUD__NA
Another method is to use an endmill ground with a taper matching the insert to cut the very bottom of corner of the seat.
You would need to to use the straight endmill to remove material to make room for the shank of the tapered endmill.
I have... *never* jumped while watching a machining video. I usually watch these to relax after a long day at my own machining job.
But this moment at 5:11 made me recoil in such a primal fear which i have never experienced outside of a horror game. Every time I rewatch it i flinch. my poor little machinist heart :(
In all seriousness, great video. love the cutter!
Yes, I came out with an expletive that questioned the existence of my father.
I hope you have all recovered by now 😄
That was my bad, I should have used the clamp right from the begining.
I've been having some trouble with my mill lately when it comes to workspace/travel available. I have the column cover removed in this video because of that, I needed more travel to make a cut (for another project).
@@nbrworks putting some referrnce blocks in the T-slots lets you reposition long parts without majorly affecting the Y axis, So i'd suggest investing in a set/making one. I'm guessing you're making some rails/ways that need higher precision?
Love your work, love your attention to detail, love your style and I just subscribed!
Hi! Welcome! 😃
Nice work. Clever and creative salutations.
Absolutely beautiful.... BRAVO
Nice video with good machining craftsmanship. However, my gut feeling tells me that if you offset the cutting edge of the cutter away from the center line (or rather the center-plane) your dovetail will not be 60 degrees.
Aha ! I think you are right!
Very clever design.
great Job! 👍👍 Thank you for the inspiration!
Nice work, great job.
Thanks for sharing the process.
Have a great day.
Thanks Ed. Have a great day as well!
@@nbrworksI subscribed to your channel.
Have a great day.
I know this video will be very usefull!! thanks
Very impressive squire. I like the indexing adaptor too.
very nicely done! Great narration and videography!
I think it will work just fine.
Hi Michel. Thanks, I guess I will report back in one of the next videos 😀
It will,Michel. I have 3 different diameter homemade dovetail insert cutters and they have done lots of work without any failures yet. Mine are the single insert type like the Randy Richards design.
I just found your channel and subscribed, I’m very impressed with your straightforward and concise method of your tutorial. The video and audio is great and I look forward to your other videos! RK
Thanks Randall, that's very kind. I have a new video coming up in a couple of hours. Hope you like it. Have a great weekend!
Yes Sir . Send me some of them dovetail cutters to use. Them are some nice pieces
Nice work as always 👏👏
Thanks Masi! 😄
Nice work
You are too smart!
Nice!
I say yes now really want to use one. Lol
Love youre Videos
Thank you!
Great job! I want to maybe recut the dovetails on a Vevor mill table, but I need a larger dovetail cutter to do that. Perhaps I may make a similar on to this!
"I love changing collets..." 😂On a serious note though, really nice project, looks like it turned out well. Thanks for sharing.
Well planned, and built. Would it be worth your time to make an insert setting jig, to reduce insert alignment time to 0?
I haven't thought of that. Maybe that's something I can explore if I start to find that problematic. Thanks for the idea 👍
Is the angle it cut actually 60°? As the cutters aren't on the plane of the shaft axis, the resulting angle won't be correct anymore
Looks like the one RR in the shop makes .
I have made one of these previously and found it chattered badly when the width of engagement was high. In the end I made a new one using a DCMT insert.
Good thing the bee was there to distract us 😂
Yes. It was a USB......... because it came from America.
Love the content! Can you make the next video brighter? I did everything I could on my end, but it was awfully dark and hard to see some parts of the video.
Hi! I'm sorry this one was dark. I also realized that the day after uploading the video. I exported the file, watched it and it looked fine, then I uploaded it and watched it on my tv. I thought it was dark but also thought it was my tv settings. The next day I compared the exported file next to the youtube page and they were different! I created a poll on the community page asking how bad it was and if I should remove it. Considering other people's opinions I decided to just let it run and make my best to avoid this in the future. Thanks for your constructive comment!
Looking at how long it took to pull in that collet, I'm surprised you haven't made a cordless drill / lathe chuck attachment... 😏
😎👍☘🍺
Can you use three grinder with the diamond wheel to scimitar the inserts.
Excellent work. I like the idea of placing the cutting face above center to compensate for insufficient insert side clearance, but doesn’t that introduce negative rake between the cutting face and the workpiece?
Yes, but the TCMT, being a positive rake insert, helps. My mill is not that powerful and had no problems making the cuts shown in the video.
@@nbrworks When you mentioned possibly tilting the inserts to get greater clearance the problem that creates is you are no longer producing a true 60 degree angle. It would reduce the cut dovetail to below 60 degrees because the top cutting face is now set at an oblique approach angle.
@@howardosborne8647 if the insert is only tilted outwards (to get more side clearance) then yes, it will cut more near the top of the insert than near the bottom and will not cut a 60° angle. But according to a quick check I made in fusion 360, you can then tilt it backwards to compensate. I might have missed something and there's a chance this might be wrong, of course. I remember the concern was with the bottom of the cutter. If the insert is tilted backwards, then the problem begins to be with the bottom not having clearance. I think simplifying and setting it at 0° works well (as you also mention). Thanks!
i think its great
Excellent explanation.
Some people tilt the piece/ rest the shank on the angle bllck.
Because I have swivel vise, I prefer to lay the shank flat, and rotate the vise to form 59 degree. This way the cutter doesn't hit with the whole blade length but rather slices into the material.
And a shim undet the shank to achieve 1 deg slope on the horizontal plane.
I might experiment with even more than 1 degree slants to see how far I can push my small mill
I personally don't like the type of insert cutters (lathe or any other) that only supports the insert in one direction with the pocket walls. I just can't be sure that the insert would stay exactly where it is.
These type of insert dovetail cutters work very reliably with no fear of the insert moving. I have 3 homemade single insert dovetail cutters using the TPMT 16 and TPMT 11 size inserts. The TPMT inserts have more flank angle clearance than the TCMT type.
I have used these homemade cutters a great deal to make 20 of the 250-201 type dovetail lathe tool holders and never had any issue with the insert moving in the dovetail cutter holders.
You have beautiful machinery. Minimum of experience, but maximum of creativity. What's your university degree?
Software engineering. Thanks
@@nbrworks My fingers are crossed that your hobby brings you much joy. I will be happy to share some of my 30 years of experience as a turner with you.
Thanks Stanislav. That's very kind 😃
Szép !
Sweet, a new machinist to ogle on RUclips...
Фреза "ласточкин хвост-кукуруза"?) Замечательное решение! Но, с другой стороны, как вы сами убедились, фреза-кукуруза это черновая фреза, и после нее все равно нужен чистовой проход цельной фрезой.
very best
1:40 - Jeeze what kind of lathe do you have? smooth finishes.
Hi, it's an HBM lathe. I've replied with a link to a similar lathe available in the US in the comment you made on the other video.Thanks
7:31 A brilliant way to set inserts or other position-critical items. I like the way you turn problems upside down and shake them to see what falls out of their pockets. Or in this case, into their pockets! Thanks for the excellent video!
Thanks for the nice comment Greg. I think you might like my next video 🙂 working on it!
cool proj bro
I didn’t quite get why the inserts were staggered until the very end. Great idea using printing an index plate. I’ll try that next time. Great job.
Now that you mention that, I should have started by saying the inserts have 10mm sides and staggering them was a way to get a bigger cutter. Thanks for your comment, it made me realize I missed that (important) bit of information.