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  • #16
    Originally posted by J Tiers View Post

    As many others have said, he cannot know what he needs "exactly" anymore than your employer did when they bought that "too small" mill. Of course it is an important question, but nobody can answer it before they have a mill and start to see it's limits. So as a question, you cannot expect a useful answer.
    Actually that machine was purchased for a specific family of parts that have holes and slots 24" in from any edge, my employer knew exactly what he wanted and bought it.

    This machine is 20 Y 40 X 20 Z
    You can do long narrow parts with the side doors removed and the part hanging out, like so.
    The first of these channels hit the yellow roof column on the left when it made a 200 IPM rapid to the first position, bent the part and moved the 12,000 Lb machine, made quite a racket as well.
    Last edited by Bented; 08-01-2020, 01:24 PM.

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    • #17
      And, while the original idea was perfectly served by it, you now described it as "too small", so it simply supports the idea that needs change and are not anticipated.

      In your example, as in the hobby workshop, it appears that means were found to do the work with the available machine. That also has relevance, since it shows the possibility of adapting the plan to get the job done.

      One cannot know in advance what is going to be required at some unspecified time in the future, not perfectly.

      Consequently, one is best off to get a machine which will do the sort of work needed (milling, in this case), and is, hopefully, not "maxed out" doing it, so that there is room for expansion to larger work. The budget sets the degree of expansion room.

      Note that "expansion" may not be size, it could be precision, accessories, size, tool capacity, etc, or any combination of them. The OP wants a DRO, which is a very good thing to have on a mill. That is smart, and this machine comes with it, or at least it is an option which he intends to add.

      Unless the poster says something definite, such as "I need to be able to deck the head of such and so straight-8 engine of dimensions x and y", asking for details of the work is not super-productive. How would the OP be sure of the exact minimum work envelope?

      The best you can expect is "small model engines", and that still goes from the envelope of a Sherline, to something in the category he is looking at.

      The fact that he quoted off a machine SHOULD be a decent indication of what he expects, and that machine is, in my opinion, a size for good overall work envelope for most model work. The OP seems to think so.
      1601

      Keep eye on ball.
      Hashim Khan

      Comment


      • #18
        Originally posted by J Tiers View Post

        The fact that he quoted off a machine SHOULD be a decent indication of what he expects, and that machine is, in my opinion, a size for good overall work envelope for most model work. The OP seems to think so.
        Consider this, I have not the faintest clue what a "Sherline" is, never used one nor seen one in the wild, am quite familiar with Bridgeport, Cincinnati, Haas, Fadal, Trak, Mazak, Bullard, Makino and several others.

        Just had a peek at the Sherline website, astonishing is the word that comes to mind.
        Are these machines designed specifically for graphite electrode milling?

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        • #19
          Originally posted by Bented View Post

          Consider this, I have not the faintest clue what a "Sherline" is, never used one nor seen one in the wild, am quite familiar with Bridgeport, Cincinnati, Haas, Fadal, Trak, Mazak, Bullard, Makino and several others.

          Just had a peek at the Sherline website, astonishing is the word that comes to mind.
          Are these machines designed specifically for graphite electrode milling?
          People have said about them that "The original design parameters included a rigid bed to avoid twisting" and "Joe recognized the superior rigidity and accuracy of the Sherline design". And by people I mean Sherline themselves because nobody has ever looked at that and had rigidity be the first thing to pop in their mind. Brass bed? Seriously?
          21" Royersford Excelsior CamelBack Drillpress Restoration
          1943 Sidney 16x54 Lathe Restoration

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          • #20
            Originally posted by The Metal Butcher View Post

            People have said about them that "The original design parameters included a rigid bed to avoid twisting" and "Joe recognized the superior rigidity and accuracy of the Sherline design". And by people I mean Sherline themselves because nobody has ever looked at that and had rigidity be the first thing to pop in their mind. Brass bed? Seriously?
            Originally posted by Bented View Post

            Consider this, I have not the faintest clue what a "Sherline" is, never used one nor seen one in the wild, am quite familiar with Bridgeport, Cincinnati, Haas, Fadal, Trak, Mazak, Bullard, Makino and several others.

            Just had a peek at the Sherline website, astonishing is the word that comes to mind.
            Are these machines designed specifically for graphite electrode milling?
            Graphite milling? Really?

            No point in continuing this discussion, seems fairly obvious that if the machine does not have at least an R8 spindle, and preferably Cat 5, it is not considered useful.

            As a point of information, NO I strongly doubt that milling graphite was ever considered as the "target niche". I do not have a Sherline mill, or lathe, but among the lathes I do have, I have one that swings about 3". Similar size. It is quite useful for parts down in the 0.25 mm area. The needed rigidity of the machines is related to the workpiece (and cutting tool) size.

            You can look at the Sherline site and I believe you will find a link to work done on Sherline machines. It might open BOTH your eyes.
            Last edited by J Tiers; 08-01-2020, 04:54 PM.
            1601

            Keep eye on ball.
            Hashim Khan

            Comment


            • #21
              Originally posted by J Tiers View Post



              Graphite milling? Really?

              .
              Milling graphite is common to make forms for plunge edm work.
              Sherline machines might be ok for milling brass for clockwork
              but not much more.


              -D
              DZER

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              • #22
                Originally posted by J Tiers View Post

                You can look at the Sherline site and I believe you will find a link to work done on Sherline machines. It might open BOTH your eyes.
                And if you had to use a Sherline to mill a part to fix your boat engine, you might be on the island longer than Gilligan.

                -D
                DZER

                Comment


                • #23
                  Originally posted by J Tiers View Post



                  Graphite milling? Really?
                  Yes, as mentioned above many EDM Sinker electrodes are made from graphite, high speed spindles and feeds, low cutting forces and a high degree of accuracy. Machines are made for this purpose only. Turning/milling graphite makes a complete mess if the dust is not contained.

                  In a small EDM shop I can envision such a frail machine for electrode work.

                  Also, I would not take an R8 spindle machine if you gave it to me for free, this is the year 2020 not 1950 as you may have noticed.
                  https://absolutemachine.com/product/...hining-center/

                  Last edited by Bented; 08-01-2020, 05:30 PM.

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                  • #24
                    Originally posted by Bented View Post


                    Also, I would not take an R8 spindle machine if you gave it to me for free, this is the year 2020 not 1950 as you may have noticed.

                    Bented-

                    Those 40 and 50 taper holders that you use were invented in 1927.
                    Just saying.

                    -D
                    DZER

                    Comment


                    • #25
                      Originally posted by Bented View Post
                      Also, I would not take an R8 spindle machine if you gave it to me for free, this is the year 2020 not 1950 as you may have noticed.
                      https://absolutemachine.com/product/...hining-center/
                      you keep showing photos of whats at work....what about home? what tapers do you have on the home shop machines? I've got mills with 40, 30 and R8. I don't find the R8 an issue, when there's lots of removal I use the 40 which is a horizontal (also something you rarely see commercially, but they are great in home shop). If I had only one and it was R8, still not an issue...you take more passes. This is home shop machining, right?
                      in Toronto Ontario - where are you?

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                      • #26
                        When I bought my mill, price was a big concern, and so was my ability to handle it down into the workshop. The machine I bought (a round column mill) was the closest thing that fit the bill. Space was a consideration, but when I made the choice to buy that one, I simply had to push things to either side to make enough space for it. I didn't buy it based on what size work I would be doing with it- it was the biggest one I could handle and afford. If I had had a specific use in mind, I might have gotten a bigger machine, a more expensive one, or one with a dovetail column instead of a round column. The round column has been a bonus several times, but it also led me into making a mechanism to keep the alignment as I moved the head up and down.

                        In general, what everybody says is true- it will turn out to be too small at some point. In a hobby situation you get used to what you can do with it, and you add mods to improve things as the 'need' comes up. Much of my hobby time has been spend making improvements to my machines. I don't regret any of that time spent- it's been satisfying time in the workshop. And I end up with improved machines and honed skills. My lathe was made in Taiwan, at a time when they were a cut above the Chinese stuff- I don't know where the mill was made, so I assume China. It needed some work right away- I pulled the column off the base and cleaned out the paint and filler, re-mounted it, took some test cuts, then determined what thickness of shims were needed and pulled the column again. This would not have been acceptable if it were to be used in business.

                        In any event, you will want to make many test cuts to determine the machines accuracy. It may be good enough out of the box, but you won't know until you use it. I think that goes for any machine, any size and price range.

                        What does this leave you with as a recommendation? Cater to your specific needs if you have them- otherwise get the largest machine you can afford and manage. Don't put your trust in a name- you're probably buying a 'work in progress' anyway, so find out what kind of support you will be getting. That's probably as important as anything.
                        I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                        • #27
                          Originally posted by Doozer View Post

                          Bented-

                          Those 40 and 50 taper holders that you use were invented in 1927.
                          Just saying.

                          -D
                          I realize that, the intention was a taper system that was self releasing thus making tool changers possible, an automatic R8 tool changer would be a complicated mess (-:

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                          • #28
                            Originally posted by Mcgyver View Post

                            you keep showing photos of whats at work....what about home?
                            What do you do for a living?
                            I work 40-50 hours in a machine shop every week, the last thing that I want to do when not working is watch parts/tools rotate, will not do so after leaving work.
                            Have a few close friends that are hobby shop types that I help on occasion, one builds model engines. I lend or give him measuring and cutting tools when needed, when he runs into a process that isn't working for him he will ask.

                            Can you come over to my garage and show me how to do this with my 1940 SB lathe?
                            My answer is always, No, but give me the part and I will make it happen and you can have it in 2 days, this makes everyone happy.

                            I do not keep so much as a tape measure at home.
                            I do not want to measure anything when not working.

                            Last edited by Bented; 08-01-2020, 06:24 PM.

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                            • #29
                              There is another issue, which I hope has been put to rest by now- that of metric vs inch. There was a time when the dial markings didn't correspond to either system, even though they were supposed to be one or the other. Pretty sure that fiasco is gone now.

                              Here's a true story that quite shocked me at the time- I was looking at a combo machine, and I thought hey- this could be good if your space is at a premium- it had a larger diameter capability as a lathe, for a given length capability, and it would be more suitable as a mill than using a milling attachment on a lathe. I played with it in the showroom and something didn't seem right. I decided that next time I went there I'd bring a caliper. So I found that the dial markings did NOT correspond to the actual movement of the slides. At a couple points as I turned the dials, the movement did correspond, but at other points it was way off. The markings did seem to be spaced evenly around the dials, but I could dial in 10 thou and I'd get 17 thou of movement, or I'd get 7 thou of movement. The lead screws were absolutely HORRIBLE on that machine. Who knows if the word 'alignment' would have had any meaning on it either. I know you won't be buying one of these- and people have done some good work on a combo- but the point is make sure you have some recourse with your dealer if you find any similar discrepancies on the machine you buy.
                              I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                              • #30
                                Originally posted by Bented View Post

                                What do you do for a living?
                                I work 40-50 hours in a machine shop every week, the last thing that I want to do when not working is watch parts/tools rotate, will not do so after leaving work.
                                Have a few close friends that are hobby shop types that I help on occasion, one builds model engines. I lend or give him measuring and cutting tools when needed, when he runs into a process that isn't working for him he will ask.

                                Can you come over to my garage and show me how to do this with my 1940 SB lathe?
                                My answer is always, No, but give me the part and I will make it happen and you can have it in 2 days, this makes everyone happy.

                                You hit the nail on the head.
                                I have several friends that works for Conrail. Off the job, they could care less about steam locomotives, rail museums, rail-fan trips,engine spotting, model railroads or anything related to their day job.

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