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thru boring a 6" chuck for direct bolting to rotary table

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  • #31
    Doozer, I love this Mill and have put a lot of time into it. It's about perfect I think - not really knowing how a mill "should" be but knowing how much better it is since I've cleaned her up. I went to this Rockwell after a few years of using a Rockwell bench drill press with an XY table ( a ****ty one) so you can imagine my appreciation for it. I didn't start out needing a mill I just did a few things that needed the XY table - but once you learn how handy that operation is you start going back to the well.

    Anyway I can hardly believe what a good chuck this is for the money, works fine- good and strong tight pins, jaws close nicely up together. Heavy too. My only gripe is the jaws are several thousands off in height which doesn't matter too too much, it's the steps of the jaws that will matter to me and they are closer- within a couple thou. I stamped the jaws to number them and good god are they hardened! Could barely get an impression with heavy peen hammer and a good thwack. How am I going to lap these down? Is a stone the best way? I don't have diamond laps. I'll need the inner steps of the jaws flat because I'll workhold with them alot - would like to have them all within a thou or better. I thought of parallels but they don't seem right in a chuck. I wonder if chuck jaw compression lifts the work like a mill vise. Easier to to tap with my lead hammer than figure it out!

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    • #32
      Mike, while I can't argue with the truth of what you say- but we do have some pretty good bars here in New Orleans- but I still prefer my shop for a drink. I invite my friends over (all two of em) and it;s pretty much everyones favorite place for a drink. (Everyone being three) Makes you feel like your not wasting time - even when you are ;-)

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      • #33
        New Orleans, you say? I was born there and although I lived in Metarie, I attended high school and college in NO.

        As for good drinking spots, it excels. Bourbon Street, of course, but almost every neighborhood has one or more. And Mardi Gras turns the whole city into one big drinking spot.

        Laissez les bons temps rouler ("Let the good times roll").



        Originally posted by Bill White View Post
        Mike, while I can't argue with the truth of what you say- but we do have some pretty good bars here in New Orleans- but I still prefer my shop for a drink. I invite my friends over (all two of em) and it;s pretty much everyones favorite place for a drink. (Everyone being three) Makes you feel like your not wasting time - even when you are ;-)
        Paul A.
        SE Texas

        And if you look REAL close at an analog signal,
        You will find that it has discrete steps.

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        • #34
          Must be a Jesuit man! I stay well clear of Bourbon St unless friends or clients are in town. Neighborhood bars are the best. its a great place to live, I've only been here since 95. I'm really a yankee from Maine - my son says it best. "Up north you meet a stranger in a bar and you get in a fist fight, in new orleans you meet a stranger in a bar and you got a friend for life!"

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          • #35
            If the steps in the jaws require adjustment, I would first try them out in all the slot combinations, hoping for improvment. If the steps still need attention, then with a mill, you could get a solid carbide endmill for hard metal and take a little off. With the jaws tensioned on a piece of bar, you could mill the steps using the rotary table, or just clamp the chuck directly to the mill bed. Don't touch down on the steel with the cutter stationary, you will chip the end.
            Don't try to stamp the case hardened jaws, you risk ruining the stamps, use a vibro etcher with a carbide tip.
            Last edited by old mart; 05-14-2021, 12:47 PM.

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            • #36
              Originally posted by Bill White View Post
              Doozer, I love this Mill and have put a lot of time into it. It's about perfect I think ....
              I have a Clausing 8520, which is a knee mill just a little smaller than your Rockwell.
              Even though I have a Bridgeport and LOTS bigger milling machines, I find myself
              using the 8520 for all my small stuff. It feels right because the table is smaller and
              easy to move compared to a Bridgeport. Travels are 5x15" I think. It is limited
              to a 1/2" end mill, but I am not in a hurry most times, and if I am, I can use my
              HBM to take off 1" passes at a time.

              -Doozer
              DZER

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              • #37
                yes I played with an 8520, they are very nice, very similar. I started my search for an 8530 before I wandered sideways into this Rockwell. I was just looking for the best available in any of them. I gotta go cut up some delrin on it right now, got a great new 2nd hand Iscar D45 facemill with unpolished inserts that tears up the pea patch like a little red rooster!

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                • #38
                  Originally posted by old mart View Post
                  Don't touch down on the steel with the cutter stationary, you will chip the end.
                  .
                  This happened to me not long ago. When you say don't touch down stationary I guess you mean a plunge cut? it's best to approach from the side, conventional direction? I don't own a carbide mill - I'll look at picking up a 3/8 two flute I guess?

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                  • #39
                    He means don't drag an end mill over the work, while touching the work.
                    Same applies to a lathe toolbit. Don't drag it over the work while not rotating.
                    It may chip the edge. This is because there is always some residual tool
                    pressure, and it can cause edge chipping.

                    -Doozer
                    DZER

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                    • #40
                      Thanks, Doozer, I had assumed that stationary covered it, but forgot that it might be interpreted as not moving in the X or Y axis instead of not rotating. The other thing to be careful with is having a soft pad under the cutter when slackening off an er collet, even a couple of inches drop will chip a cutter, particularly carbide.

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                      • #41
                        Not related but worth mentioning....
                        Nothing is better for seating Morse taper shank
                        drill bits in the spindle than a lead or babbit cast
                        hammer. It does not hurt the point of the bit
                        and does not disintegrate like a urethane hammer.

                        --Doozer
                        DZER

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                        • #42
                          Right Doozer you're seating morse taper bits in that Clausing? I got a lead hammer recently, just under 2lb, nice old ash handle - never been struck on either end! Ive never seen a babbit metal hammer, seems softer than lead, but I dont know why. I have an old lignum vitae caulking hammer (really a mallet) that I use to give a super clean tap. I have a couple and one has a rough face so I don't have any qualms striking metal with it. It's atleast as hard as brass I think. I got the lead hammer to seat work in mill vise, but I have to throw a glove over it at times bc it does bounce a bit. I'll grab a dead blow when I see one cheap.

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                          • #43
                            Originally posted by old mart View Post
                            Thanks, Doozer, I had assumed that stationary covered it, but forgot that it might be interpreted as not moving in the X or Y axis instead of not rotating. The other thing to be careful with is having a soft pad under the cutter when slackening off an er collet, even a couple of inches drop will chip a cutter, particularly carbide.
                            Mart - I really appreciate the thoughts. I need them bc I work quite a bit, pulling long days right now and I'm learning all then time. There is just so much involved, doing anything right takes time and the more you screw up the more you realize the answer is to do it right. Quick cheap or good - pick any two.

                            Today I had to find centers to drill a lot of round stock, turn exact insert plugs, square round socket head screws, heat sink them into delrin with a torch- not breathe the darn smoke- god i forget what all else but by 4pm I called it a day came in, sat down and popped a tylenol! Man machining will get to your lower back!

                            But back to what you say- When I got my mill last year - a few months before Covid hit, I got some old R8 collets that work a charm. I figured I'd buy a cheap set from Shars and every time I use one of them the cutter falls out as I reach for the spindle wrench. Sure they work- but they are a liability. Since Ive been grabbing more old US made ones as I can find them. Neil Skokie are my favorites like them as much as Hardinge.

                            I try to always put a rag under the spindle but you get working and forget stuff .... which one always falls out ? My brand new 5/8 three flute that cost $50 of course. ;-)


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                            • #44
                              Investing in milling cutters that have replacable inserts is safer than risking an expensive solid one. I have indexable cutters from 12mm to 25mm with 1 to 3 inserts. The 25mm has had its shank turned down to 19mm to fit in an R8 collet. They use APMT 11 or 16 type inserts which are double ended and cheap. The inserts are available for steel and aluminium, and also fit in the common shell mills of 40, 50, 63 and 80mm diameters which can be fitted to R8 arbors.
                              I also look out for resharpened solid carbide end mills on ebay, they are excellent for home shop use and cost much less than new ones.

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                              • #45
                                I actually have an 82° countersunk tool that utilizes a 321 carbide triangle bit.
                                I use it to countersink holes and chamfer edges too. Bonus it allows me to
                                work hard steel.

                                -Doozer
                                DZER

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