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  • RF45 or Knee Mill

    I am looing for input from someone who has experience with both of these mills. I am moving from the RF31 to one of the above. I want the repeatability that the dove tail offers. I am going saturday to pick up a RF45 from Wholesale Tool unless I get feedback that there are major drawbacks to the RF45 vs a knee mill.

    Thanks

    ------------------
    Bob
    Bob
    Pics of shop and some projects
    http://s2.photobucket.com/albums/y39...achine%20Shop/

  • #2
    I would never recommend a mill drill above a knee mill. If you have the room and budget, get a knee mill.
    I am not familiar with the Rong Fu line, and really don't care to be. You are apparently in the Detroit area if you are headed for Wholesale Tools. There are many dealers in the area, down here in Toledo, or Cleveland who can probably fix you up with a good used Bridgeport for the same amount of money.
    You are apparently dissatisfied with the RF31 for some reasons. The RF45 will probably still have many of the shortcomings of the 31, or any other mill drill. It will have some advantages, but will still come up short when compared to a good knee mill.
    Jim H.

    Comment


    • #3
      I also have an RF-31 that I want to replace. You know the story if you own one. I wouldn't put myself through it again with another mill/drill. Why should you?

      After sorting through a whole host of choices I am settled on getting a used Bridgeport Series 1.

      You can get a much better mill for the money if you find the right Bridgeport. There are a large number of them for sale used since the economy has been forcing many shops to downsize or go out of business. It is a buyer's market, but probably not for too much longer.

      Just make sure you evaluate your purchase carefully!

      Good luck.

      Marv

      Comment


      • #4
        Count me on the list as well. I have an RF-30 in the garage waiting to be picked up by it's new owner. It's Bridgeport Series 1 all the way from here on out. Now I just need to find the right one.

        John

        ------------------
        Pursue Excellence and the rest will follow.
        Pursue Excellence and the rest will follow.

        Comment


        • #5
          The only grip I have about the RF31 is the round collumn. Loosing the index anytime you raise or lower the head turned out to be a bigger PITA then I had anticipated. Other than that it has served me well and would have otherwise been quit happy with it.


          <font face="Verdana, Arial" size="2">Originally posted by JCHannum:
          I would never recommend a mill drill above a knee mill. If you have the room and budget, get a knee mill.
          I am not familiar with the Rong Fu line, and really don't care to be. You are apparently in the Detroit area if you are headed for Wholesale Tools. There are many dealers in the area, down here in Toledo, or Cleveland who can probably fix you up with a good used Bridgeport for the same amount of money.
          You are apparently dissatisfied with the RF31 for some reasons. The RF45 will probably still have many of the shortcomings of the 31, or any other mill drill. It will have some advantages, but will still come up short when compared to a good knee mill.
          </font>
          Bob
          Pics of shop and some projects
          http://s2.photobucket.com/albums/y39...achine%20Shop/

          Comment


          • #6
            Using my HF Micro mill, I realized how nice the dovetail column is on it. I allways heard people bash the round columns, something about losing their setup. After using mine to counterbore holes, I realised, Ah thats what they are talking about. I can move my head up, chuck in the bigger drill or endmill, and lower it down and not have to reset the position!

            MAN!, HOw do you guys stand it with those round columns??

            Comment


            • #7
              Bill, your fortunate that you can get away with that minimill. My projects were a little to large for it. I startd with the minilate in March. Bought a 9 x 20 in August and now just set up a new WT 13 x 40 gearhead. This one is a keeper.

              I just did an ebay search for the Bridgeport the others are talking about and all the ones I seen were about twice what I expected to pay. Live and learn.


              <font face="Verdana, Arial" size="2">Originally posted by BillH:
              Using my HF Micro mill, I realized how nice the dovetail column is on it. I allways heard people bash the round columns, something about losing their setup. After using mine to counterbore holes, I realised, Ah thats what they are talking about. I can move my head up, chuck in the bigger drill or endmill, and lower it down and not have to reset the position!

              MAN!, HOw do you guys stand it with those round columns??
              </font>
              Bob
              Pics of shop and some projects
              http://s2.photobucket.com/albums/y39...achine%20Shop/

              Comment


              • #8
                I would not put much faith in eBay. I regularly see BPs going for under $2,000. I am looking at another one or two tonight.

                I don't do large parts, but it isn't hard to exceed the grasp of the mill/drill. Add to that is the fact the mill/drill can't hold a candle to a Bridgeport for robustness and performance. If you can handle the larger machine you should consider doing it and save the RF-31 as a drill press.

                Also, try a Bridgeport and see what you think.

                You also stated that it cost you three lathes to get the keeper you have now. So, what was the total cost of all three? How much did the last lathe you bought cost (the keeper)? The difference between the two numbers is how much you overpaid.

                Were you planning on buying three mills, too?

                Not being a smart-butt, I just wanted to look at it from a different angle.

                Marv

                Comment


                • #9
                  Actualy Marv I got lucky with the first two. Both failed within the 30 day return window with Harbor Frieght.

                  If I got a knee mill it would be in the 8 x 30 table size. I just don't have the room left in my garage/shop for a large BP. And do know where there is an Index for $1000.00 but it is in really rough shape looks wise and is missing some parts plus it is not and R8 Collet.


                  <font face="Verdana, Arial" size="2">Originally posted by debequem:
                  I would not put much faith in eBay. I regularly see BPs going for under $2,000. I am looking at another one or two tonight.

                  I don't do large parts, but it isn't hard to exceed the grasp of the mill/drill. Add to that is the fact the mill/drill can't hold a candle to a Bridgeport for robustness and performance. If you can handle the larger machine you should consider doing it and save the RF-31 as a drill press.

                  Also, try a Bridgeport and see what you think.

                  You also stated that it cost you three lathes to get the keeper you have now. So, what was the total cost of all three? How much did the last lathe you bought cost (the keeper)? The difference between the two numbers is how much you overpaid.

                  Were you planning on buying three mills, too?

                  Not being a smart-butt, I just wanted to look at it from a different angle.

                  Marv
                  </font>
                  Bob
                  Pics of shop and some projects
                  http://s2.photobucket.com/albums/y39...achine%20Shop/

                  Comment


                  • #10
                    Have you looked at the Grizzly G 0519, not
                    a knee mill but a dovetail drill mill with
                    a claimed 18" vertical clearance. Has a
                    "tapping" mode though it is not entirely
                    clear what this amounts to. Also has a
                    3phase motor so a VFD would be essential for
                    most of us, but this seems a clear benefit.
                    Priced about $1500, and at 6-700#, easy to
                    move. This machine appeared on the RongFu
                    web site about 3yrs ago. Steve
                    Steve

                    Comment


                    • #11
                      The knee mill is a true milling machine. The mill drill, regardless of upgrades is a glorified drill press that can be used for milling.
                      There is nothing wrong with a mill drill for what it is, and I am not bashing them. If that is the machine you want, buy it. I am sure it will be capable of doing good work.
                      If you ask which machine is better, the answer is the knee mill.
                      If you do not have the room for a Bridgeport, the smaller knee mills are still better machines than mill drills.
                      Jim H.

                      Comment


                      • #12
                        Thanks SCH, that is what I am referring to as a RF45 or a RF45 clone.

                        <font face="Verdana, Arial" size="2">Originally posted by sch:
                        Have you looked at the Grizzly G 0519, not
                        a knee mill but a dovetail drill mill with
                        a claimed 18" vertical clearance. Has a
                        "tapping" mode though it is not entirely
                        clear what this amounts to. Also has a
                        3phase motor so a VFD would be essential for
                        most of us, but this seems a clear benefit.
                        Priced about $1500, and at 6-700#, easy to
                        move. This machine appeared on the RongFu
                        web site about 3yrs ago. Steve
                        </font>
                        Bob
                        Pics of shop and some projects
                        http://s2.photobucket.com/albums/y39...achine%20Shop/

                        Comment


                        • #13
                          Acutally, I was hoping to find someone that had actuall hands on experience with both and would be able to directly tell me from experience rather than hearsay what would be the benefits/drawbacks to both. I do appreciate all the feedback regardless if its opinion or experience.

                          Thanks All

                          <font face="Verdana, Arial" size="2">Originally posted by JCHannum:
                          The knee mill is a true milling machine. The mill drill, regardless of upgrades is a glorified drill press that can be used for milling.
                          There is nothing wrong with a mill drill for what it is, and I am not bashing them. If that is the machine you want, buy it. I am sure it will be capable of doing good work.
                          If you ask which machine is better, the answer is the knee mill.
                          If you do not have the room for a Bridgeport, the smaller knee mills are still better machines than mill drills.
                          </font>
                          Bob
                          Pics of shop and some projects
                          http://s2.photobucket.com/albums/y39...achine%20Shop/

                          Comment


                          • #14
                            I understand. I have the RF-31 and have 2 years of experience with that mill. My experience with the Bridgeport is long ago. However, I can cite some trade offs.

                            Besides the obvious (size, weight, and mechanical operation), the RF-31 has a potential for the head to shift laterally if too heavy a cut is made and your registration will change. The square column won't do that, but you can't rotate the head laterally to do special milling operations off of the mill table. That may not be an issue, but you don't have that option with the RF-45.

                            I found the Chinese bearings to be problematic in the RF-31 (just replaced mine after 2 years). I also have problems with the lead screws and the table ways on my Rong-Fu. I was not impressed with the quality. I was concerned that the RF-45 may not offer much improvement since I want to replace my 31. If you are buying a clone I would be concerned that the quality will be even worse. Given that the RF-45 gear head is much more complex, I would expect that the probability of incidents over time will be higher still. No data to support that.

                            You will need to get a spindle wrench (or make one) for the RF-45 since you don’t have a belt to grab or a brake to lock the spindle when you tighten the draw bar. I have heard of a few problems where the collet wasn’t tight on these mills and the end mill creeped out.

                            One large advantage of a heavier mill is stability when making tough cuts. The mass really is your friend. You get better finishes and save time by making deeper cuts. The RF-45 does have a tiny bit more mass, so it should help with rigidity, but I would expect that to be small. The 45 is larger, but only proportionally heavier. The true rigidity may not be a lot more, but got to be better than a round column. Then again, what would be worse, piano wire?

                            There are a number of larger knee mills out there, but you didn’t state your budget. Sounds like it is low. I also don’t really know your short and long term plans.

                            Since I was carefully considering the 45 as an upgrade because I couldn’t fit a full size mill. However, after reviewing all of the options I decided to modify my environment to accept the larger and heavier Bridgeport. I think my total cost will be the same as a Rong-Fu RF-45, but I expect to have a much better mill long term. That is why I am touting the BP solution.

                            Good luck, I hope you get something that works fo ryou.

                            Marv

                            Comment


                            • #15
                              Marv, great response and I appreciate the time you took to post it. Your thinking is pretty much along the lines that I have been fighting with. I am going to look this over a little closer this weekend when I go to Detroit.

                              Bob

                              <font face="Verdana, Arial" size="2">Originally posted by debequem:
                              I understand. I have the RF-31 and have 2 years of experience with that mill. My experience with the Bridgeport is long ago. However, I can cite some trade offs.

                              Besides the obvious (size, weight, and mechanical operation), the RF-31 has a potential for the head to shift laterally if too heavy a cut is made and your registration will change. The square column won't do that, but you can't rotate the head laterally to do special milling operations off of the mill table. That may not be an issue, but you don't have that option with the RF-45.

                              I found the Chinese bearings to be problematic in the RF-31 (just replaced mine after 2 years). I also have problems with the lead screws and the table ways on my Rong-Fu. I was not impressed with the quality. I was concerned that the RF-45 may not offer much improvement since I want to replace my 31. If you are buying a clone I would be concerned that the quality will be even worse. Given that the RF-45 gear head is much more complex, I would expect that the probability of incidents over time will be higher still. No data to support that.

                              You will need to get a spindle wrench (or make one) for the RF-45 since you don’t have a belt to grab or a brake to lock the spindle when you tighten the draw bar. I have heard of a few problems where the collet wasn’t tight on these mills and the end mill creeped out.

                              One large advantage of a heavier mill is stability when making tough cuts. The mass really is your friend. You get better finishes and save time by making deeper cuts. The RF-45 does have a tiny bit more mass, so it should help with rigidity, but I would expect that to be small. The 45 is larger, but only proportionally heavier. The true rigidity may not be a lot more, but got to be better than a round column. Then again, what would be worse, piano wire?

                              There are a number of larger knee mills out there, but you didn’t state your budget. Sounds like it is low. I also don’t really know your short and long term plans.

                              Since I was carefully considering the 45 as an upgrade because I couldn’t fit a full size mill. However, after reviewing all of the options I decided to modify my environment to accept the larger and heavier Bridgeport. I think my total cost will be the same as a Rong-Fu RF-45, but I expect to have a much better mill long term. That is why I am touting the BP solution.

                              Good luck, I hope you get something that works fo ryou.

                              Marv
                              </font>
                              Bob
                              Pics of shop and some projects
                              http://s2.photobucket.com/albums/y39...achine%20Shop/

                              Comment

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