How to Bore Soft Jaws on a Lathe

i'm brian warren we're here today at the mcc gene haas advanced manufacturing center at mourinho community college we're partnering up with practical machinists each month to bring educational content in today's video program freshman michael bishop is going to show you how we bore soft jaws [Music] all right guys so the first thing we're going to do is we're going to take our jaws here and we're going to mount them in the chuck now being as this is a college shop one of our first concerns is safety so what we've done is we have pre-milled some material off the bottom to maximize diameter to allow the boiling ring to get through the jaws safely so now we have our chuck here and as you can see on the on the truck here on the master jaws you can see little serrations or teeth and what we're going to do is we're going to line the teeth of the jaw up with the teeth on the chuck here and what we're going to do first is put our t-nut down inside the master jaw and then we're going to take our jaw and a bolt and we're going to line all three of that and the t-nut up on the master gel one thing to remember while you're doing this is that the t-nut should always be down in the jaw you should never have any of that sticking up out of the top we're going to get everything lined up grab a bowl here all right we're going to put everything together another thing to remember is however many teeth you have sticking up off the top of the chuck once you have some once you have everything lined up that same number of teeth should be present on all three jaws so in this case when i line them up i have three teeth exposed sticking up out of the top so i'll have that for the other two jaws as well all right guys so now that our jaws are in we're going to mount our board and ring and there are several different types one like this is the scroll type where the inserts move but in this case i would like to use one that's a little more user friendly where all the inserts move at the same time as you scroll so what we're gonna do is we're gonna take this ring and we're gonna line up the numbers and we're going to mount it inside the outside holes of each jaw all right so we're going to find our number one hole there we go and we're gonna line up each insert with the outside of the hole do some adjustments so we can get the diameter right and one thing to remember when you're mounting the boring ring is to do it with the jaws open so you can adjust them as they close and everything will be clamped by the end of it so we got it in here and we're going to do this in cycles of opening and closing the jaws until we get a little mark which is right by our number one jaw lined up in the center with one of the teeth opening and closing tightening down we get that exactly right and after everything's tightened down and aligned we should be good all right so our jaws are in and our boring bar is in the next thing we're going to do is we're going to take our boring bar and try to find our inner diameter where we're going to start in our program we're going to do that by handle jogging the bar down and then handle jogging over until we're inside of the jaws so we'll come over to our controller here and the first thing we want to do is bring our bring our x down to x to zero so we're going to write a quick little thing in mdi to do that we have our tool t-101 our rapid g00 our work offset g54 and our x0 and for safety we'll put it on 25 rapid we'll hit cycle start once we're down to the zero point then we have a reference point that we can handle jog from and that'll give us our exact position for our inner diameter so we've got a handle job i'm gonna start in tenths or one hundreds and that'll be quicker movements until we get to the boring bar our border ring so we'll handle jog over in z bring x up x positive a little back to z no once we get closer we'll move over to the thousandths increment once we're inside we'll give our jaws a free spin make sure everything's clear and make sure the boring bar is not hitting all right everything's clear so now what we'll do is we will turn our spoon along a couple hundred rpm and then we'll move our x positive slowly by holding down the button until we hear it touch and start to cut and then we'll know exactly where our inner diameter starts all right we're going to close our door turn our spindle on we're going to start moving inward and one thing you can do too is check your position in the operator area we're starting at 1.22 then we'll move in and it touched at 1.51 so we're going to back off of it and turn our spindle off and now we know since our inner diameter starts at 1.51 we're going we'll know in our program to add 100 to that making it 1.61 all right now that we've got our inner diameter the next thing we have to do is actually generate the program to make the up make the operation so instead of handwriting this haas controllers have a what's called a vps which will allow us to put in a put in our measurements in a conversational manner and generate the program that way so we'll go to mdi edit and then we'll go over to vps and we'll we'll go down each one and put in what needs to be put in we'll start with our tool number which in this case is tool number one and where the tool number there's the same offset so tool one offset one we'll have our max rpm this boring ring is rated at about 700 rpm so that's what we'll put our max at don't want to overload the ring after that comes the depth of cut and we're going back 1.8 inches that'll leave just a little bit of material on the back side of the jaw it keeps us from having to hit the uh keeps us from possibly hitting the chuck next is the z rapid approach we're going to put this at and 1.1 know that seems like it's really far away from the material but it is a safety measure it may cut a little layer but it will keep us from uh ramming into the boring ring or the side of the jaw existing hole diameter we have that from our inner diameter which we said was 1.51 and remember you have to subtract 100 from your diameter where you touched that way you're not running straight into material on the first cut just a little safety all right after that we have a finished diameter and now in this case our finished diameter is whatever size jaws we're boring which in this case is 2.5 inches so our finished diameter will be 2.5 and key that in and then we'll just go through and check things like our feed rate which is at about eight thousandths we're taking about 30 thousands off with each cut so nice and slow produces a but produces a better finish and it's safer we'll go down through everything and once everything looks okay got our measurements in we will generate the program one final check here but uh we have our finished pass we have x home and z home so it looks like we're ready to generate so we'll hit f4 and i'm going to output it to mdi which is option number two and there's our program all right we've got one more step before we can hit cycle start and that is our z face measure now being as this doesn't have to be extremely precise what we're going to do is we're going to touch off the face of the jaws like that we're going to get a handle job i'm going to bring z over and you just want the tip of the boring bar tip of the insert to touch the face of the jaws start in larger increments now we're going to switch down to thousandths so we can move in a lot slower now that we're inside the jaw or inside the board ring you just want to move that in until it touches okay once we've got it touched off we'll go to offset we'll go over to work g54 on the z-axis then we'll hit z-face measure all right guys our measurements are in everything's finalized it's time to hit cycle start alright our program's finishing up let's open this thing up and check what our jaws look like do a quick turn here nice smooth surface everything looks good that's how you bore out soft jaws thanks for watching

Channel: Practical Machinist

Views: 21,146

Keywords: lathe, soft jaws, cnc, CNC machine tools, CNC machining, Gene Haas, Haas Automation, Haas CNC, CNC, Haas, haascnc, machining, manufacturing, cnc machines, cnc lathe, milling machine, cnc machine, cnc milling machine, machine tools, cnc machining, cnc machinery, cnc machine tool, cnc machining center, cnc cutting machine, Practical Machinist, Metalworking, haas, boring soft jaws, how to bore soft jaws on a lathe

Id: AbKdFd3nKRQ

Length: 15min 41sec (941 seconds)

Published: Wed Feb 17 2021