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The old mill/drill vs small knee mill dilemma!

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  • #46
    Click image for larger version  Name:	IMG_2784.PNG Views:	0 Size:	3.13 MB ID:	1871023Click image for larger version  Name:	IMG_2783.PNG Views:	0 Size:	2.95 MB ID:	1871022
    Originally posted by Pfowler67 View Post
    Getting back on topic, does anyone have any input when it comes to mounting DRO to the knee mill? Particularly to quill travel? I have fitted DRO to my current mill/drill on X and Y, but haven't seen any examples of quill mounted DRO on the 8x30 knee mills, so thought i'd ask.
    This is how I mounted all 3 DRO,s on my Gang Drill setup,I tapped derectly into lower part of Quill. Click image for larger version  Name:	IMG_2782.PNG Views:	0 Size:	3.38 MB ID:	1871021

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    • #47
      Originally posted by Pfowler67 View Post
      Getting back on topic, does anyone have any input when it comes to mounting DRO to the knee mill? Particularly to quill travel? I have fitted DRO to my current mill/drill on X and Y, but haven't seen any examples of quill mounted DRO on the 8x30 knee mills, so thought i'd ask.
      That mill design has a scale with a pointer to give a rough idea of the spindle depth. Many DRO quill units are mounted to the pointer with a setup similar to what Tundra Twin track shows in the above post.
      At the end of the project, there is a profound difference between spare parts and left over parts.

      Location: SF East Bay.

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      • #48
        +Damm You guys go off the rails fast.

        I like that drilling machine Doozer posted. Very capable.

        Some folks like myself were actuality looking at small bench top type and I went with an RF-45 clone. Very nice bench top drill. I bought it for drilling, never milling FYI. JR

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        • #49
          Originally posted by Barefoot View Post

          Not trying to jack OP's thread here, but do you have any write ups on this head conversion you can point me to Doozer?

          Neighbor across the street from me has a real nice 8520, except for the bent spindle. Original head with MT2.

          This looks like it'd be a perfect solution....and all the more reason for me to buy it from him.
          I made a plate out of 1-1/2" steel with a 2" kick-up in the bolt pattern centerlines
          to give the M-head some more Z daylight from the table. The spindle can come
          down within 1" or so with the knee fully up. I have a print somewhere, I was
          looking for it last night, will continue to search. But the plate was cake simple.
          Just the bolt pattern of the ram and the bolt pattern of the BP head, and offset by 2".

          Actually I have my old Clausing 8520 head and motor and pulleys.
          I have an extra spindle, which is a little bent, and the bearing nut threads are a
          little screwed up.
          Email me at [email protected] if you want.

          -Doozer
          DZER

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          • #50
            Originally posted by mattthemuppet View Post
            (and Whistler BC never had a whole lot of industry)
            yeah, not much of a used machine market there, but it has other attributes.. Kind of enough that it still wins as the better spot to be.
            Last edited by Mcgyver; 04-24-2020, 01:19 PM.
            in Toronto Ontario - where are you?

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            • #51
              yeah, I'd live in Whistler BC in a heartbeat, that's for sure.

              That is a big azz air can on that shock! I can see why a new linkage was needed. Really impressive work on a manual though. Those travels do sound alot more reasonable - the old ones actually sound alot like my 6x26.

              I have a digital caliper attached to my quill. When funds allow and after fitting the riser block I'll be getting a 3 axis DRO for the knee and table. You can get 4 axis DROs that sum the knee and quill, but they're alot more money and a bit of an overkill in my view.

              here's my quill DRO, works very well (I can see the reading shift 0.0005" when I tighten the quill lock)
              Click image for larger version

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              • #52
                Thanks guys, I like what you’ve made there Tundra Twin Track. I’ll likely puzzle it out once I’ve bought the machine, but great to see what others have done.

                Interesting to hear what DennisCA thinks about the RF45. I’m sure it’s a solid machine. Does anyone else have experience on both machines?
                Just to recap; I’m comparing the RF45 clone mill/drills with square column to the 8x30 knee mill as sold my BusyBee, KBC, Grizzly and others. Figured the knee mill is more rigid but can anyone say any different ?

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                • #53
                  I think you will be pleased whichever mill you end up with, they will undoubtedly both suit your needs very well. You might as well put the names into a hat and buy the one that comes out first. As I said before, I like the knee mill best but that's only because I like its looks more than the other one. I recon it boils down to money, adding a DRO to the knee mill adds to its cost. As for rigidity, who knows, without running both side by side, it is difficult to say. I can run a round column drill mill next to a comparable size knee mill, but I really couldn't say which is more rigid.

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                  • #54
                    Originally posted by mattthemuppet View Post
                    yeah, I'd live in Whistler BC in a heartbeat, that's for sure.

                    That is a big azz air can on that shock! I can see why a new linkage was needed. Really impressive work on a manual though. Those travels do sound alot more reasonable - the old ones actually sound alot like my 6x26.

                    I have a digital caliper attached to my quill. When funds allow and after fitting the riser block I'll be getting a 3 axis DRO for the knee and table. You can get 4 axis DROs that sum the knee and quill, but they're alot more money and a bit of an overkill in my view.

                    here's my quill DRO, works very well (I can see the reading shift 0.0005" when I tighten the quill lock)
                    I've always viewed 3 axis as a bit overkill since the knee has near zero backlash. Better than counting turns I guess, but not worth the money to me. 2 axis and quill is a golden combination.

                    I'm curious as to where you're getting the riser block from for your 6x26. Making it yourself?
                    21" Royersford Excelsior CamelBack Drillpress Restoration
                    1943 Sidney 16x54 Lathe Restoration

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                    • #55
                      I still think you'll be happier in the long run with the RF45 square-column clone with the DRO. Since it already has the DRO and no messing around changing Z height. More rigid because the head *can't* swing around the column. It can only tilt left/right.
                      25 miles north of Buffalo NY, USA

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                      • #56
                        Originally posted by nickel-city-fab View Post
                        I still think you'll be happier in the long run with the RF45 square-column clone with the DRO. Since it already has the DRO and no messing around changing Z height. More rigid because the head *can't* swing around the column. It can only tilt left/right.
                        That swing joint is actually pretty solid. But in my case it turned out to be a source of error in tramming the head. I used shims as a short term solution but obviously shims in a joint that should be movable is not a good solution. But I live with it for now.

                        With the RF45 there would be two possible sources of error that would need closer inspection with suitable equipment. First would be column to table for square in both directions. Second would be the rotating joint that allows the head to tilt side to side since it is a "face" joint. Either could be a source of error in the "nodding" direction for the tramming of the spindle to the table.

                        Having the little knee mill myself and having looked at the RF45 quite closely and with my previous small round column mill drill experience I would second Old Mart's idea that either would make you happy. There's nothing one does better than the other to really swing it one way or the other.

                        Both are relatively low cost items from Asia so you can expect to need to measure and confirm the basic geometry of the machine's setup. And likely you'll need to do some small corrective actions on a few things that are not quite in spec. And these things will require some head scratching on how to test them and consideration of basic geometry and how to expand your present metrology gear to measure various aspects.

                        In a very valid way those that say to buy old used machines have a very good point. The basic geometry on these older machines made with more care is typically excellent. But then possible wear becomes an issue. So it's a tradeoff for sure. And as mentioned above not everyone has room for a full size Bridgeport. And things like that nice little Clausing don't show up every other day. Especially up in this area.

                        For those of you thinking that living in Whistler would be like a dream a stab of reality might be to look up the cost of housing up that way. That'll yank you back to reality in the blink of an eye.... It's a jewel of a place but DARN ! ! ! ! !
                        Chilliwack BC, Canada

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                        • #57
                          Originally posted by old mart View Post
                          As for rigidity, who knows, without running both side by side, it is difficult to say. I can run a round column drill mill next to a comparable size knee mill, but I really couldn't say which is more rigid.
                          I think that it depends on how you define "comparable". If you go by table size, you may end up comparing a 1000 lb 3/4 size turret + knee mill against a 500 lb mill/drill. If you go by weight, you will have a pretty big mill/drill. I found the "Grizzly G0755 10" x 32" 2 HP HD Mill/Drill with Stand and Power Feed" is comparable to the knee mill in size and weight. I don't know who has one. It's big and not a bench top machine.

                          The advantages of the two types have been well discussed on the various forums. As I said, I have the "small" 1000 lb knee mill and find it to be pretty rigid. The knee is a heavy casting that is supported from below by a large screw and does not move when in use. I get good results from it despite it's age (40 years)

                          Dan


                          At the end of the project, there is a profound difference between spare parts and left over parts.

                          Location: SF East Bay.

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                          • #58
                            I myself would definitely prefer the Oxford over the Craftex. Even though you say you'll only work on small stuff, at some point the limitations of table travel will cause you problems. Same thing as quill travel as another poster said. The Oxford table travel is 7x18 vs 6x14-1/2 for the Craftex. You'd be surprised by the differrence an inch makes. The quill travel is 5" for the Oxford vs. 3-1/8" on the Craftex. Plus you get power quill feed on the Oxford, handy for drill large holes.

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                            • #59
                              Forestgnome's post above just encouraged me to go back and look at the opening pictures again and to compare cost. Given that Bell's Oxford comes with power table, DRO, and a nice swiveling switch panel I'd say that hands down the Bell option is the better way to go. Not only a little more table movment, always a good thing as FG points out, but all those other features as well? And the same price?

                              That's a slam dunk easy decision from where I sit. Bell all the way. You'll quickly come to love all those extra features. And as pointed out through this thread there's really nothing that makes the knee mill stand out over this RF 45 clone even if we are just looking at the basic machines.
                              Chilliwack BC, Canada

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                              • #60
                                Originally posted by The Metal Butcher View Post

                                I've always viewed 3 axis as a bit overkill since the knee has near zero backlash. Better than counting turns I guess, but not worth the money to me. 2 axis and quill is a golden combination.

                                I'm curious as to where you're getting the riser block from for your 6x26. Making it yourself?
                                but I wants the digital everywhere! I'm a metric man in an imperial world, so a big plus of digital is being able to use mm or inches. I can work in inches, but I think better in mm

                                Yes, I'll be making my own riser block. I have a couple of random 6" diameter 4" high "wheels" (look like wheels off a belt sander tbh) with 1/2" thick walls - I'm going to turn one of those into a riser blot and make extended bolts to go through the riser to secure the head to the column. Been thinking about it for ages, but lack of Z hasn't ben quite annoying enough yet to move it to the top of the list. Hoping to get to it this summer.

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