Why I Adjust my Tool Height for Internal Chamfering on the Lathe - Machine Shop Tricks & Hacks
If you saw Saturday's video, you may have noticed how I lift my chamfering tool for internal chamfers and then drop it to do the outside. There is a very good reason for this and I explain it in this video.
This is a trick I came up with years ago, and showed to some old timers. They were all surprised that they had never thought of it. I hope it helps some of you out in your hobby and careers.
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Thanks Josh for explaining why you raise the chamfering tool. A lot of non-machinists now know.
I actually learned this when I was an apprentice in the Max Planck Institute many years ago! It makes instant sense if you think about the geometry of the layout. It was good to see it explained so clearly. Thanks very much.
I find it amazing how many people do not realize this simple concept. It is simple tool geometry.
I have been by the max Planck institute!!
@@marctrossbach6560 There are many. I was in Tübingen.
It's little things like this that make you realize that the learning for a machinists never ends.
I am learning everyday. You will never know it all.
I've known a number of good machinists. One of the better ones used to say, "You've got to make a truckload of scrap before you're a machinist."
@@phlodel I've probably made 5-7 semi loads, and I am still learning. Never give up learning.
I notice it too, but since I'm not a machinist, I assumed it was for better clearance. It is nice you take your time to explain. Regards!
You are effectively changing the angle between the tool and the surface being cut. Also helps with the back relief angle to not touch the internal cut.
Excellent. I've seen a lot of people use a small boring bar or even an internal threading tool for inside chamfers. I guess it's what works for you is the best way. Thank you.
Those tools are set above center. It's the same concept, just that I don't change the tool.
I saw the video on Saturday, ask myself what you were doing, then I realized you were compensating for the internal clearances, and it all made sense. I am not a machinist, but try to learn whatever I can. You explanation was helpful and clear.
I have a chamfering tool set up just as you have, used it for years now. I always ground extra relief on the one side for the extra clearance needed. Your trick there is like magic. I will start using it. Thanks for the tip, Ken
Glad you like it. I used to grind the tools, but I got lazy and started just lifting to get above center.
@@TopperMachineLLCWork smart, not hard :)
You’re dead right and that was well explained 👍👍👍👍
Very clear Josh, thank you so much for posting this.
Morning, I also wondered why the change for internal but did not ask in my reply. Being a self taught hobbyist, I assumed you had good reason and thought I would try it at some point. Thanks for the feedback to all of us.
Yeahhhh I was wondering about that ! Thank you so much for the explanation !
Learned something this morning, Thank You
Excellent. Thank you for sharing ! 👋
Josh, nicely presented! I appreciate and enjoy your channel
Makes perfect senses, Thank you.👍
Thank you Josh!
Thanks for the video. You are a good teacher.
Great explanation thanks for sharing
That's a great tip, Josh. I'm going to try that next time I do an internal chamfer.
I was wondering about that as well. I love learning stuff!
Experience is the best teacher. Not being a machinist I never even noticed you doing this but it makes a lot of sense when you explained it
When I studied Turning at Technical College circa 1977, we were taught that the internal tools had to be above center exactly for the reasons you explained. With one addition, the softer the material, the higher above center the tool had to be offset, with cast aluminium and brass requiring the biggest offset. Thank you for your time explaining these quirks.
I noticed that you were raising the tool for the internal chamfer on the last video and I was thinking that the tool post you are using makes it really easy to do that. Some older lathes don't have that type of tool post, so raising the tool for an internal chamfer is a lot more difficult, as it would involve packing under the tool. Modern conveniences sure help with simple things.
Great explanation. I like the concept of a short video which explains a detail of the longer one. Hope to see more of them.
I plan to do this when it is feasible. Seems like it helps a lot.
I did wonder why you did that and I did not think to ask. Thanks for explaining this so well
Coz I ain’t a machinist in anyway shape or form, i just went on the info and principle of keeping the tooling on centre. But always had a sneaky thought on raising the tool for internal stuff just that little bit. Hmm I might have a play around with this. Awesome and thank you!
fantastic Josh, thank you so much for bringing this up and explaining, cheers, Paul from Florida
Glad you enjoyed it!
I didn’t actually pick up on this first time I watched the bushing video - so went back and watched it again. Thanks for the explanation and demo - I’m going to go and experiment with this. I sometimes end up with a burr when chamfering and I bet this fixes it. 👍
It most likely will.
It did. Result! 👍
Josh, Great hint.....def gonna try it when I get a chance....I dont use cemented carbide hardly at all.....indexable or micro 100 stuff mostly as my parts I work on are usually small....and follow up a chamfer almost always with a quick touch of emery and a cratex polish...overcast and +44 rt now ....grass and lawn are peeking out....driveway down to stone.....YAAAAAYYYYY.... Great instructional vid for the masses...... Don
We had 62° here today. Absolutely beautiful.
That’s a great chamfering tip. Never thought about the clearance issue. Great channel.
Glad it was helpful!
Back in the early 1960 while at a technical college I was tort that. It was never explained to us, I suspect because it was not explained to them. Told to just do it. So thank you for your reading of why, it makes sense. Back in those days it was a case of 'do as you are told, not why.'
Thanks for the demo… I was one of the ones that asked!. The video demonstrates it very well!
Glad it was helpful!
I did not know that. (Johnny Carson). Love that Lion BTW.
Josh your videos are very informative you know your shit
I don't know about that. LOL I do the best I can to get the job done correctly.
useful little tip ...or big tip depending on the size of your lathe .. thanks Josh
Good tip..I do the same thing 👍👍
Definitely works, I’ve done it often. I’ll add raising an OD tool slightly depending on the diameter and clearance angle can help with vibration on slender shafts. Use with caution and consideration.
I have done that also, just don't recommend it for everyone.
Resting a wooden hammer handle on top of a slender shaft while cutting reduces vibration and chatter. Only slight pressure if any is needed.
Thanks
Nice.
Thanks for explaining that. I never knew that it made any difference as long as the tool had clearance.
I am actually surprised by how many didn't know this. Even seasoned veterans.
@@TopperMachineLLC A round boring tool with a 45 degree face rotated slightly will also produce a sharper chamfer due to its positive side rake.
@@ellieprice363 Yes it will, but that is a tool change. I am going for efficiency..
@@TopperMachineLLC Understood. Don’t change tools unless absolutely necessary. Rotating boring bars slightly away from the cut works well if the tool is already inserted. Thanks for sharing so many time saving tricks with your viewers.
I started doing it years ago working with brass. The geometry change affects how the tool deflects. At center or below any deflection causes the tool to cut into the part, above center and the geometry pulls the tool out of the part. On a worn or small machine, the deflection can cause digging in, chatter ect.
Your tool height differences between ID cutting and OD cutting can be somewhat mitigated by leaving your OD tool height set and locked, but cutting in reverse, and on the opposite side of the ID for boring, chamfering, trepanning etc.
Learning on the job, you will find this out soon or later..
By setting the tool high, without resetting the center height nut, it allows a rapid switch to O.D. chamfer height. We do that all the time & I saw that You did that in the bushing video, it's the other 1/2 of Your trick & some might not have caught it.
It is funny how many professionals don't do this, and are absolutely shocked that they didn't know it.
I have been doing that for years particularly with a boing bar. There certainly are a lot of experts out there ready to call you down.
If they really are experts, they will try it first and try to disprove me. Amateurs will whine and complain without testing.
Leave the "poor" keyboard warriors alone. They have nothing else to do. Retired machinist/mechanic.@@TopperMachineLLC
@@bobhudson6659 I have no time for the lazy and useless keyboard warriors. They need to move out of mommy's basement and get a life. Guys like you, on the other hand, I want to talk to and learn from!!!
I have to do the same thing on My HF mini lathe.
Thanks for the tip :) did you ever get a chance to watch that reverse parting tool video?
I did, quite interesting. I would need a different tool holder though, mine runs up at and angle.
@@TopperMachineLLC yea that would cause an issue, I think his logic is sound though
@@jetegtmeier71 I agree, the concept has great merit.
Been machining for 45 years , always grind tool to suit the job at center hieght.
I used to do this also, but this is faster. Nothing wrong with grinding to suit the needs, I just like instant gratification. I am young after all. LOL
~ I HAVE DONE uh TON OF BIG FACTORY MACHINE MACHINING ~ AND I WATCH THOSE CLOSE ON U/TUBE...AND I SEE... ~ AS THIS MAN USES HIS YEARS OF EXPERIENCE ~ APPLES IT, AS THAT IS WHAT MAKES HIM A PROFESSIONAL CRAFTSMAN !!! ~ WATCH HIM VERY CLOSE & LEARN...
You either have a specific tool for every conceivable job or you adapt what you have. If lifting the tool stightly for clearance saves me buying a new tool unnecessarily I'm all for it. There are many occasions where clearance is an issue, mainly internal or when trepaning, so when i see you doing it, i dont even think it unusual.
Exactly.
We have to raise up the chamfer tool or make aggressive clearance to avoid crashing the body of the tool
I knew when I seen that in the last video, people would wonder. Lol
Have had to do this with some boring bars also.
Me too. It's all in the tool geometry and being just above center in the bore.
If it feels good, do it! Even though it's not following "convention ".
But it is conventional knowledge. Inside tools.above center.
Works for a wood lathe also.
Raising the cutting tool slightly for internal turning is effectively adding positive rake to the cutting tool. Similar can be achieved by using a positive rake cutting tool on/at center. Note the cutting tooling this video is a brazed carbide zero rake tool. Negative rake tools do not really "cut". Negative rake turning tools remove metal by heating up the contact surface area/point to where the metal becomes soften (plastic) enough to be plowed away from the work. This is why negative rake tools work good when there is enough SFM, rigidity and power from the lathe. Negative rake tools are a LOT tougher, durable and able to remove metal-A-plenty compared to positive rake tools. It is also why negative rake tool don't produce a good surface finish with light cuts and due to the forces involved negative rake tools don't do well at small cuts at all. This is where positive rake tools work better, they are good at light cuts, can deliver a good surface finish, required a lot less power.. except the cutting edge is fragile. There is no ideal turning tool, just the best trade-off for a given need as much as the machine tool will allow coupled with the size of work involved.
Thank you for this great explanation of Negative and Positive rake tooling.
On average, how much are you moving it above centerline? I am going to try this today, but it was unclear on how much. 5 thou? 20 thou? I know it will depend on the board size, but there has to be a limit , right?
Depends on the bore, but I generally lift 1/16-1/8". Which I think I said in the video.
Very leery of internal grip in a jaw chuck, especially with a long part. They just don't hold like external chucking. Be safe! I have most all my chamfer tools relieved for clearance, but lifting is an easy way that also works.
That was for demonstration only.
That piece of tubing in the lathe scared me. I thought you were going to cut on it. Would you machine that with that much hanging past the chuck?
Absolutely, I do it all the time.
@@TopperMachineLLC I've done a fair amount of machine work, but I guess I don't have the experience to know the limits.
@@phlodel with experience, comes wisdom. Maybe what i do sometimes is dumb, but it works. Take your time, never rush. Something like this can go wrong quickly, so triple check your setup and be cautious.
I always had a chamfer tool in it's own holder with the ID side ground for clearance so that I didn't have to do that...
Sounds like an awful waste of time to change tools so much. Being a machinist is about efficiency.
@@TopperMachineLLC It's always on center and takes 5 seconds to change. Machinist with forty years experience...
i've been machining sense 1985 and you are WRONG if you would grind more of a relief on the cutting side of the tool it will cut great and the smaller the part the more important it is to be on center of the part
You are the winner! First person to tell me I am wrong! Guess what, I have been doing this for 25 years. It works. Don't like it, tough!
What in darn tarnation is going on here who turned on the CGI effects? Hello,😅
The best five minutes ever spent❤.