Revisit the Enco Insert part off tool.

[cybor462]

Hi All
I have been locked in the shop trying to keep up with my new tool. Ok, not that tool you dirty guys gun sight tool. Anyway I bought that Enco blade style insert part off tool. I was never able to keep the insert in one piece. I also trashed one end of the blade. I asked here and most said to speed it up and a few said to power feed it. I tried all that and well that is how I trashed the blade.
Now after spending $45 more on a replacement blade I was determined to see what the heck I was doing wrong. I found some interesting stuff along the way.

1st I thought I had the tool on center but it was not. Let me explain... I have a cheap Brown and Sharpe import square I use to set tool height. I used a center in my tailstock and scribed a mark on the square. Well I used a live center dont you know (shame on me)! The live center was not on center so I was dead from the get go! It was off .010

I inserted a dead center (weird how the words flow) and made one of those neat tools I saw a few post here in the past and re set my tools.

Ok now I was ready to part right? Wrong! I asked my new friend, the guy that is now running my gun sight tool bodies on his cnc machines, and he said when I was sure it was on center (now I am ) and square to the work (it always was) he said run it at 600-800 rpms hold on I said, WHAT!

He said sure we run them all day at that speed. He said Trust Me! So I did, I went home arguing with myself about how I will need to buy another $45 blade after I try parting at 600 rpms. I fired up the lathe, put in a 3" dia bar of 6061 fired up the flood coolant and proceeded to be $45 lighter in the pocket......but wait........heah it cut like butter! And it did not break, squeal, go crunch, or smack or any other of those nasty sounds I never want to hear.

I again trusted the words of 30 years experience and although I doubted it...I learned something.
That is why I like this BBS so much,,there is no end to that type experience. You can't put a price tag on that!

[John Stevenson]

Cybor,
Another thing to try that everyone says is a no no is to support the work with a center.
Everyone says that when it cuts thru to forward forces will snag the blade on the part just cut and snap the blade.

In truth this doesn't happen and the cut part just cocks a bit.

Even if you are not sure you can always remove the center just before you are thru.
I part loads of gear blanks off at 840 rpm in 1-1/4" steel, center supported on the center hole and get a mirror finish both sides.
Just need to use a big countersink to debur as a second op before gearcutting.

.

[cybor462]

John... I may have to go back on what I said about trusting all I have been told.... just kidding...but I would hesitate to use a center when parting but again as I stated in my post I no longer question the opinions of those who have done this work for as long as you No I am not saying your old...well maybe but............. As old as I am anyway..

So far it has worked great without a center. I would try it with one if it seemed it would help. I used up 10 inserts in a couple days at a cost of $40 and a blade at $45. So I am now open to ideas that may go against what the book says should not be done. So far these ideas have me parting without breaking anything.

[Carld]

I have not run that fast a speed but have used the center to "catch" the part and it does work. I don't put much pressure on the center, just touch off lightly. I guess John does that as well.

[BadDog]

I understand you completely cybor. I just bought a Sandvik holder that came with 10 inserts, and I find myself scared to use it. Those holders will run $100 most of the time, and a single (or rather 2) misshap costs $100. Given the number of HSS blades I've gone through, AND the fact that I now have to relearn some parting techniques (higher speed and feed), using that is turning out to be the most intimidating thing I've run across in quite a while. I still have to make an adapter to mount it in my AXA and/or Royal Turret, but I'm starting to think I should have just gotten another couple of HSS blades...

[Tin Falcon]

Klem the way I learned to set the tool on center is to use a 6" rule placed verticly between the tool and the stock in the lathe just gentle pressure. If the tool is high the top of the scale will kick in if low the bottom will kick. A little low is better than high if high the tool will dig in if low deflect away.
Tin

[lane]

At work I stick a bar in the spindle 2-3 ½ dia. make my part and part off at about 645 rpm next speed down is 400 something and too slow. Using an .082 wide insert in sandvik blade . works go and like John said support with center , will make a big difference.

[cybor462]

Klem the way I learned to set the tool on center is to use a 6" rule placed verticly between the tool and the stock in the lathe just gentle pressure.
Tin

Tin... I know that trick but it only gets you close. You could easily be .010 off which I was and that little bit gave me tons of trouble. The tool I just made gets it exact. It did make a big difference. I never had much trouble .010 low with HSS blades but the carbide insert would have no PART of it. HA HA get it PART of it PARTING so funny. I know I will shut up now.

[BadDog]

So how about a pic (or link to original source) of the tool? I generally use the tail stock or center point when it "just has to be right", and the ruler otherwise. But sometimes it's just not convenient, so I've considered making an adjustable height gage for setting tool height.

[cybor462]

Bad Dog which pic would you like the part off tool or the tool height gauge?

[BadDog]

The height gage is what I need to make (so that I don't ruin my $andvik holder, I'll never find another good deal on one...).

[cybor462]

The height gage is what I need to make (so that I don't ruin my $andvik holder, I'll never find another good deal on one...).

Ok let me get a pic tonight. I plan on working in the shop. I will post it later.

[cybor462]

Sorry I did not get this sooner.

It is a tool that had appeared on this board several times. They were slightly different but very simple.

This sets my tool exact and that was what I needed.
Just used a piece of brass for the weight and threaded it to accept the threaded rod. Milled a scrap hunk of CR and was very careful to get the contact section extremely flat. Adjust to your tool center and lock it down. I did thread the CR which makes if much easier to adjust. Just loosen the lock nuts and spin it to get exactly what you need and then lock the nuts down.

For the eagle eye viewers I chamfered the edges of the flat which makes it look uneven but be assured the actual flat section is flat. Also it looks like it is leaning but it is not just the angle the camera was on.
Both ends of the brass are faced and chamfered.

Hope this helps.

[BadDog]

No worries and no rush, thanks for posting. I figured that's the design you used. Nice and simple. The one I saw in the past used caliper points that had been cut off to make a po-boy DRO, and I just happen to have a few of those myself, so that will form the finger on mine. Seems the blade like edge would be more accurate and less sensitive to tilt, but it must be on the cutting edge. Other than that, it will be built very much like yours. Now to just get some time in the shop to catch up on projects...

[dp]

Our friend in Japan shows his version here: http://homepage3.nifty.com/amigos/he...ght_gage-e.htm