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R8 - Wimpy or Wonderful

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  • #16
    There are adaptors to take R8, but they use a lot of headroom.

    https://www.arceurotrade.co.uk/Catal...to-R8-Adaptors

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    • #17
      Originally posted by old mart View Post
      There are adaptors to take R8, but they use a lot of headroom.

      https://www.arceurotrade.co.uk/Catal...to-R8-Adaptors
      There are also master holders for KWIK 200 from R8, so I could run my KWIK 200 holders, but it all hangs down below the quill. I had one for a while on an RF45 style mill.
      *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

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      • #18
        FWIW, NT40 tooling is really easy to come by at auctions out here. I bet you could build up a collection of #40 tooling on a shoestring budget if you're willing to run the auction circuit.

        I use R-8 and NT50 tooling. I think of my Bridgeports as drill presses, good for light duty stuff or relatively inaccurate stuff where some flex isn't going to ruin the day. I much prefer working on my 50 taper machines, although they tend to be heavier at the handwheels, slower to setup, and louder to use. I suppose, given the choice, I would take a NT40 mill over an R8 one, but I definitely hear you on wanting to minimize the amount of tooling you need to buy over again.

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        • #19
          Given the option between r8 and a nmtb40 spindle I'd take the 40taper every time. Cat 40 tooling is CHEAP and plentiful and is lightyears ahead of r8 in rigidity, and will work just fine in a nmtb40 spindle. The ONLY way I'd prefer R8 is if it was going to be a strictly drill and tap machine, and I already had a pile of r8 tooling. If you're thinking about serious metal removal rates then a 40taper all the way.

          One of these days I'd love to get a horizontal/vertical machine with a 40 taper. That would be a pretty versatile utility machine. They come up for sale every once in a while at the gov Canada auctions, but the makers name escapes me right now. Seems the Canadian gov had an affinity for them too.

          All that said about r8 machines, I'd make you a good deal on an r8 excello if you were closer right now lol
          Last edited by Dan Dubeau; 02-19-2021, 12:09 PM.

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          • #20
            Using the adapter with the internal drawbolt would sure get old real fast..... Not to mention the crazy overhang it would have.

            Seems to me that if you're looking at big massive heavy machines with over 1.5HP that will convert a lot of metal to chips in a short time and not shake, rattle or roll while doing so that you'd want the 40 taper tooling setup. Otherwise the weak support of the R8 arbor is going to end up being the weak flexible link in an otherwise very sturdy chain. Not to mention the very real risk of spinning the R8 in the spindle when using that amount of power.

            There's also the added rigidity that the 40 taper would give to cutters such as larger face mills. Or during heavier and deeper boring operations.

            And it's not like you NEED to buy 30 or more holders right away. You'll want to buy the specialty tooling like big face mills and boring heads right away along with some end mill holders. But after that? Get 'em as you see the need 'em.
            Chilliwack BC, Canada

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            • #21
              So the 3 hp , R8 mill I just got is no damn good?!
              Sure seems to be handling things OK.
              Crap, I TOLD the old lady that Cincinnati would fit in the basement.
              Len

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              • #22
                Originally posted by JRouche View Post
                Wow. You gave it some balls. I would not use it on a machine above 1.5hp (which they might have been designed for). Just for safety reasons. You dont want to spin yer spindle cause the lil key broke or the friction let go. JR

                ! That 3hp was in reference to the OP's talk of 3-5 hp being available where he was looking. If you read my entire post, you saw that I thought 1hp was enough.
                Southwest Utah

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                • #23
                  Originally posted by eKretz View Post
                  I hate R-8. I have run so many machines in shops that either have a mangled drive key or none at all. . .
                  It isn't a 'drive key'. Its just there to hold the collet while you tighten the drawbar, and to provide repeat indexing for the collets. So many people pull the key, but if you have a collet with a little chip or dirt in the drawbar thread its better to have the key in there.

                  Southwest Utah

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                  • #24
                    Originally posted by Doozer View Post
                    NMTB40 has drive tangs. R-8 does not. Torque drive capacity has your answer. -Doozer
                    This will come as a surprise to you, but not everyone has the desire or need to push everything to the max. Huge amounts of quality work have come from R8 machines for many, many decades. Bigger, faster & more expensive is often not the best choice.

                    Southwest Utah

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                    • #25
                      I'm running 2, 3HP CNC mills every day as a business. They both have a Bridgeport type R8 head, as I bought them for prototype mills, not production. They are both 2001 machines, and I've had one of them since new. They are both very capable machines, and so far I haven't had anything I needed to do that they wouldn't do in 20 years. They have air powered drawbars, which makes tool changes quick and easy. I took the key for the collet out of both spindles right off the bat and have only spun a collet a few times. With the key out, it didn't hurt anything. It seems to me it would be a lot more tiring to change out 40 taper tool holders by hand all day than R8.

                      I also have a KWIK 200 spindle from a 1984 Hurco that is surplus, if anyone is interested. It will fit a Bridgeport type head. Right now the best BP type mill value seems to be an Acer 3VS E-mill.
                      Kansas City area

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                      • #26
                        Originally posted by Bob La Londe View Post

                        There are also master holders for KWIK 200 from R8, so I could run my KWIK 200 holders, but it all hangs down below the quill. I had one for a while on an RF45 style mill.
                        Yes, there are many flavors of master holders. Here are a few I have, one in R-8 even. Those long ones are not masters, they are spindles JR

                        Click image for larger version

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                        My old yahoo group. Bridgeport Mill Group

                        https://groups.yahoo.com/neo/groups/...port_mill/info

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                        • #27
                          Hi,

                          Ain't nobody here running their Bridgeport/clone hard enough to have a real concern over what type of spindle you should get. If it's that big of a deal, get a real mill with a Cat50 spindle and be done with it.

                          If you already own R8 tooling and it has done the job for all the years you have had it, you really need to ask yourself if it's really worth all the new money you will spend to replace all of it.

                          Just get the R8 spindle and be happy. For those really rare times you think you want to spin a 4" facemill or 12" flycutter, just use that Weldon flat tool holder on the R8 you got.............
                          If you think you understand what is going on, you haven't been paying attention.

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                          • #28
                            At one time we had a Bridgeport with a spring loaded retention knob system that did not work terribly well, these are solid holders.
                            There were also modified R8 collets with a nut clamping device on the end like an ER. Do not recall the name of the system but it made for fast tool changes but not robust tool holding.

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                            • #29
                              I wish I only had two systems to keep track of.

                              ISO20, TTS/R8, Kwik-200, for primary. I also have a baby mill drill with a Morse taper (using a morse to er25 collet chuck). Then there are the collets. ER11, ER16, ER20, ER25, ER32, 3C, 5C, and AcuraFlex (2 sizes). Lots of freaking collets. I also have a 16C pull back chuck, but currently no collets for it.

                              Looks like I am going to start to collect more R8 stuff again now too. I gave away a lot of the R8 stuff I had before when I sold the RF30 and tore down the RF45 for parts. I have a few R8 tools I missed and a couple I bought for the Tormach. I never use them on the Tormach so...

                              I was torn about the spindle taper, but the one machine that had everything else I wanted without having to do a bunch of addons comes with an R8 taper. (1-3 inverter, coolant, DRO, power feed, power knee, PDB, true variable speed, etc all included (not cheap))

                              I think in the case of fixed pulley variable speed inverter machines the 5HP motor isn't about providing 5HP, but about providing "some" horsepower when only turning 60-70 rpm at the spindle.
                              *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

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                              • #30
                                This new machine arrived 3 or 4 years ago, 7 1/ 2 HP variable speed spindle with no gearbox.
                                At a suitable speed it will not drive a 1" HSS twist drill in mild steel without stalling. In order to prevent the Z axis drive from trying to push a non-rotating drill through the work it simply shuts down.

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