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  • Face Mill?

    I've had a Seig X3 for a few months now and I think I need a face mill for it. I've been using end mills to get surfaces flat and what I've found is I'm wearing the corners off of the poor little things in an unreasonably short amount of time. Wrong tool for the job?

    My manual says the machine is face mill capable up to 2" dia, but 95% of the time I'm working with mild steel and an X3 is not a behemoth of a mill by any means. Maybe I should tone that down to a 1.5" dia?

    I've looked at the usual places. ENCO, Wholesale Tool, etc. But there's such a crazy amount of info on cutting angles, insert types, and so on that I quite frankly don't know what to pick.

    Any help is greatly appreciated.

    SP

  • #2
    Hi-rake cutters

    I have both a Sieg X3 as well as a Super X3. Both are rated at/for a 2" face milling cutter. I have a "high-rake" 2 1/2" face milling cutter that I bought for my HF-45 square-column mill and it works quite well on the X3's.

    Just take it easy - the X3's are a very good small bench-top mill - but they are not as "big" as my HF-45 which in turn is by no means a "production" mill either.

    This is my 2 1/2" cutter:
    https://www.machineryhouse.com.au/Pr...stockCode=M516

    I am thinking of getting a 2" for my X3's so that I don't "thrash" or over-load them:
    https://www.machineryhouse.com.au/Pr...stockCode=M515

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    • #3
      Face Mill

      Build a simple Fly Cutter Tool and save your money.

      JRW

      Comment


      • #4
        pntrbl,

        I have a RF-31 mill that I use a 2" face mill on with very good results. You just have to adjust your DOC to suit your mill. Also if you face anything wider than your face mill you will wind up with a ridge you will have to fix with a file. I couldn't tell you if my machine is more or less rigid than yours.

        That said, I must agree with J.R.. I bought a cheap set of fly cutters (3) from CDCO and have been using the cheap brazed carbide lathe bits from HF with excellent results. Again you have to set your DOC to suit the Mill and the material you are using (with a flycutter you will want to only take off a few thou at a time). Another advantage to the flycutter is you can adjust you width of cut.

        I had purchased the 2" face mill, then the first project I did on the mill was 3.5" wide.

        The way I have been running at these facing on wider material is to rough with the face mill and then go back and take a final cut with the flycutter.

        Tim

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        • #5
          45 degree face mill like old tiffe said. I think less inserts is better. Sharp inserts take less cutting force. Go with a very light DOC at first, and go heavier until you can hear the spindle being battered. Then back off. I prefer the cutter with an integrated shank, like 3/4", so you can just stick it right in your collet without worrying about getting an arbor. I have a sandvik RA-245 face mill which I like very much, but I know that it causes spindle battering in a Bridgeport knockoff with greater than .02 DOC. (I think that spindle is a little loose anyway, or rather, the interface between the spindle and pulley)

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          • #6
            Climbing and HSS

            The OP's question was about face milling cutters and that is why I answered as I did.

            But I'd always prefer to finish with a fly-cutter - either a TC or HSS tool - HSS preferred.

            If using a HSS cutter I prefer to set it to just a bit wider than the cut and to have it climb milling - it enters with a wider chip instead of "rubbing" - but be careful.

            See:
            Conventional milling versus climb milling

            A milling cutter can cut in two directions, sometimes known as conventional or up and climb or down.

            Conventional milling (left): The chip thickness starts at zero thickness, and increases up to the maximum. The cut is so light at the beginning that the tool does not cut, but slides across the surface of the material, until sufficient pressure is built up and the tooth suddenly bites and begins to cut. This deforms the material (at point A on the diagram, left), work hardening it, and dulling the tool. The sliding and biting behaviour leaves a poor finish on the material.



            Climb milling (right):

            Each tooth engages the material at a definite point, and the width of the cut starts at the maximum and decreases to zero. The chips are disposed behind the cutter, leading to easier swarf removal. The tooth does not rub on the material, and so tool life may be longer. However, climb milling can apply larger loads to the machine, and so is not recommended for older milling machines, or machines which are not in good condition. This type of milling is used predominantly on mills with a backlash eliminator.

            from:
            http://en.wikipedia.org/wiki/Milling..._climb_milling

            at:
            http://en.wikipedia.org/wiki/Milling_cutter

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            • #7
              Originally posted by tmc_31
              pntrbl,
              Also if you face anything wider than your face mill you will wind up with a ridge you will have to fix with a file.
              sounds like your mill is out of tram

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              • #8
                Originally posted by beanbag
                sounds like your mill is out of tram
                Could be just a bit

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                • #9
                  Thanx for all the replies guys. I thought a fly cutter had a drill bit in the center and a bit swinging around the outside. Shows how much I know!

                  I think I'll mosey on over to CDCO now ......

                  Thanx again.

                  SP

                  Comment


                  • #10
                    In the diagram OldTiffe posted, I am a bit puzzled by the statement that in climb milling the 'cutcut starts at the maximum and decreases to zero'.
                    Surely as in the diagram the material will have moved approx half cut depth, and there will be no zero material cut!

                    Puzzled -- peter
                    I have tools I don't know how to use!!

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                    • #11
                      To climb or not to climb? - that is the question

                      Peter.

                      I have repeated the part of my post that you refer to here:

                      Conventional milling versus climb milling:

                      A milling cutter can cut in two directions, sometimes known as conventional or up and climb or down.
                      Conventional milling:


                      The chip thickness starts at zero thickness, and increases up to the maximum. The cut is so light at the beginning that the tool does not cut, but slides across the surface of the material, until sufficient pressure is built up and the tooth suddenly bites and begins to cut. This deforms the material (at point A on the diagram, left), work hardening it, and dulling the tool. The sliding and biting behaviour leaves a poor finish on the material.
                      The description here is perhaps a bit over-simplified as the cutter seems to infer a straight tooth - ie no helix angle or "twist" - as on a router cutter. It also infers that the cutter engages the job along its full length - which it does not. The helix causes the cutter to first engage the job on the end of a clock-wise flute on a very small part of the job - almost like a sheet of paper in a stack - and as it further engages the job it increasingly shears the chip off at angle normal to the cutter helix. As the job advances into the cutter the depth of cut increases until the tooth reaches a maximum depth of cut as it reaches its exit point. All teeth follow successively. If the tooth is blunt it makes vary hard work for both the cutter and the mill. Same applies if the cutter edge misses the "pick-up" and has to rub the job to form a "bulge" that it can start cutting into.


                      Climb milling:


                      Each tooth engages the material at a definite point, and the width of the cut starts at the maximum and decreases to zero. The chips are disposed behind the cutter, leading to easier swarf removal. The tooth does not rub on the material, and so tool life may be longer. However, climb milling can apply larger loads to the machine, and so is not recommended for older milling machines, or machines which are not in good condition. This type of milling is used predominantly on mills with a backlash eliminator.
                      In this case the cutter - still a spiral - engages the job at the maximum depth of cut and some have zero or very little "rub" and engages fully and cleanly. As the cutter rotates and the job is fed into the cutter the chip is still peeling but the depth of cut is reduced so that it is zero at the point of exit. The main problem with climb milling is that as the cutter passes the line of progression it moves from a "pushing" mode to a "pulling" mode and so pulls the job and table through the sum of any lead-screw back-lash and end-play. It can be quite violent - and potentially dangerous with regard to the operator, the machine, the holding medium and the job.

                      Climb milling tends to clear the swarf where-as the conventional milling is inclined to pull it (back) into cut and so fouling and interfering with the cutter starting and maintaining its cutting action.

                      Climb milling is more efficient as regards machine and cutter load and as regards unit material removal in unit time.

                      I normally mill "conventionally" for material bulk removal as my mills have "excessive" back-lash and end-play for climb-milling but I often take a light "spring cut" by climb-milling either at the previous depth of cut setting or with a slight additional depth of cut. This gives a better finish as well as relieving any "spring" in the cutter and/or the milling head due to conventional milling.

                      I hope this helps.

                      Comment


                      • #12
                        Wholesale Tool sell one that they advertise as "for smaller machines".
                        The shortest distance between two points is a circle of infinite diameter.

                        Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

                        Southwestern Ontario. Canada

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                        • #13
                          Originally posted by oldtiffie
                          But I'd always prefer to finish with a fly-cutter - either a TC or HSS tool - HSS preferred.
                          I'll take a cheap flycutter over a cheap facemill any day--better finish.

                          I'll take a quality facemill over any flycutter any day--better finish and does it faster.

                          Quality doesn't have to cost the moon, but it likely won't be in the realm of cheap, at least as many people describe it. I like Glacern's cutters, for example. You need one with a modern insert geometry set up to do well with those inserts. You also need one that isn't too crazy big for your milling machine as they eat horsepower like candy.

                          I'm not sure I'd buy a facemill if I couldn't get a pretty nice one. I have 3, and the first one I got was barely better than a flycutter with a lot of fussing. The last two are excellent. One is a 90 degree taking APKT inserts, the other is a Glacern 45 degree.

                          BTW, if you still want a flycutter finish, go for it with the facemill. Just remove all but one insert and you're there. That might be the best yet.

                          Either the flycutter or the facemill will be sensitive to tram, and the bigger the diameter, the more sensitive. A ridge as mentioned is a clear indication of a tramming issue. However, a perfectly "flat" tram isn't necessarily going to give you the ultimate finish due to back cutting. These cutters can often produce a better looking finish if they're ever so slightly out of tram so that only the leading edge is cutting. We're talking 0.001" per foot or so on that.

                          For best finish, climb cut as OldT advises, but also don't take a full pass. Limit it to about 2/3's of the cutter's diameter. You want the forces on the cutter to settle out and predominate on one side. If you're doing a full pass, they will see saw back and forth a bit and the cutter wobbles.

                          The 45 degrees take less cutting force and leave a nicer finish, but you have to give up square shoulders with them.

                          Quite a bit more on milling surface finish here:

                          http://www.cnccookbook.com/MTMillSurfaceFinish.htm

                          Cheers,

                          BW
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                          Try G-Wizard Machinist's Calculator for free:
                          http://www.cnccookbook.com/CCGWizard.html

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                          • #14
                            Point taken

                            Bob,

                            I take your point.

                            If I am finishing I prefer to take a light cut - hence the HSS fly-cutter.

                            But my TC insert facing cutter does very well for heavier work - but I prefer not to use it on lighter cuts on anything that might work-harden.

                            https://www.machineryhouse.com.au/Pr...stockCode=M516

                            It is a pretty good tool.





                            Here is a "used" vehicle brake hub that I faced with it. It went very well indeed - straight through the surface and I was running it at pretty well top speed on my HF-45 mill and winding my 90:1 rotary table as fast as I could go - I could not get it to its limit. I took some finer cuts as well and it came out as well as you suggested that it should.

                            I suspect that one insert may have been just a smidgen lower than the rest and acted as a "scraper tooth". The bottom face of the inserts are flat.





                            In this image the "rust" (I think) was the lanolin preservative I use - but the finish was as good as the others in the pics above.
                            http://i200.photobucket.com/albums/a...ke-disc1-1.jpg

                            I have thought seriously of leaving the inserts in the cutter and sharpening the bottom and side (45*) TC insert faces on my TC grinder so as to get an edge approaching that of a HSS cutter. I might do it later.

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                            • #15
                              Tiffie, it'd be interesting to compare the performance of your face mill with all but one insert removed against your fly cutter.

                              I haven't yet tried the experiment directly as I'm pretty happy with the facemill's "diffraction grating" finish.

                              I will say that the fly cutter I picture on that web page from Widgitmaster gives pretty amazing results on aluminum.

                              Cheers,

                              BW
                              ---------------------------------------------------

                              http://www.cnccookbook.com/index.htm
                              Try G-Wizard Machinist's Calculator for free:
                              http://www.cnccookbook.com/CCGWizard.html

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