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Seeking high-precision milling machine for mild steel, better than Proxxon MF70(!)

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  • Originally posted by ship69 View Post
    Good to hear that I don't need 10,000 rpm to do 0.55mm drilling.
    Presumably the spindle's runout is pretty important though at that size, yes?
    (...)
    @JTiers & @BCRider
    Yes, the runout seems to be THE critical issue if I intend to work at small scale.
    Agreed, spindle runout (actually, the total runout *at the cutting edge*) is a crucially important factor for successful drilling of small holes. Sherline specifies their spindle runout as <.0005" (<~10 μm), measured on the internal Morse taper; of course, any accessories you add between the spindle and cutter may increase (or reduce) this value.

    Originally posted by ship69 View Post
    HOWEVER even if I raise my budget to say GBP1500, and weight limited to 36Kg, the lack of quill on the Sherline & Taigs remains problem for drilling.
    (...)
    Everything is pointing to Sherline except for the lack of quill.
    (...)
    @BCRide - yes, that is an extremely interesting video about 'sensitive drill holders'. That said, he was using a lathe not a milling machine. In order to use on a MILL it sounds like you need to spend $699+ for a name brand version, (maybe $150-200 for a cheap one) on a "micro drill chuck adapter" / (AKA "floating chuck" / "spring-loaded chuck") with a ball-bearing race-type of collar, so that the chuck will spin but the collar can be kept stationary, so that you can feed by hand rather than by using the quill handle. Btw, where does he mention the RPM?
    Ahem. 😉 https://www.sherline.com/product/101...ng-attachment/
    I had honestly forgotten about these, but yes, they're very nice for small hole drilling. I've used them on larger equipment, where it might be easy to break a drill using the standard quill feed handle.

    Originally posted by ship69 View Post
    > Generally with small mills RPM is your limiting factor for production rate.
    What RPM are you proposing that I shoot for? 5,000 RPM? 10,000 RPM? More?
    Emphasis on production. High speeds are not required; a vast deal of outstanding work was done in decades past, when a 10,000 RPM spindle was a special item and, in general, well outside the means of anyone working from home. Slower speeds just mean the operation might take a bit more time. I think that a spindle capable of 5,000 RPM would be ideal for most small-scale manual work. If the exact range you want isn't available, you can always make your own pulleys, provided you don't exceed the speed limit of the bearings.

    Originally posted by ship69 View Post
    Maybe the whole idea of a mill that sits on your desk that can mill mild steel, that can be easily put way over night, just ISN'T POSSIBLE.
    Yes it is. I will make you a video of my Sherline mill cutting 303 stainless. On a side note, if you are able to find an equivalent to 12L14, that is one of the easiest and most enjoyable steels to work with. It contains about 1% lead (Pb) which makes it cut like butter. On another side note, to see actual examples of projects made on Sherline and other small tools, www.craftsmanshipmuseum.com is an excellent rabbit hole to dive into (and, subsequently, to look up and realize it's 2 AM and you have to get up for work in 3 hours).

    Originally posted by ship69 View Post
    - What do watchmakers use? (Do they user huge machines? Or smallish mills like Sherlines?)
    As mentioned below, small machines tend to provide sensitive feedback that is less apparent with larger equipment. For that reason, watchmakers tend to use small machines for actual watch work, and there are tiny special-purpose pinion mills and so forth. While traditionally the bulk of watch- and clock-making work is done on the lathe, the Sherline mill is indeed one of the machines of choice for milling work. W.R. "Bill" Smith (RIP) notably used Sherline tools.

    Originally posted by ship69 View Post
    - what about vintage machines (given that the technology of milling seems very mature)
    Vintage machines can be outstanding, provided that they are in good condition; some are, some aren't. It's sort of a mixed bag - if you know what sorts of things indicate excessive wear or rough usage, versus something that's cosmetically bad but in otherwise good condition, you can do pretty well buying used equipment. It's also possible to buy something that seems decent but is internally worn more than initially realized, or that has some fundamental limitation that makes it less desirable for the work you had intended to do. For example, the spindle bearings may not be up to higher-speed usage, at least not for extended running. That's really a whole other topic and best suited for a different thread - there are good Youtube videos on the subject, such as this one by Tom Lipton.

    Originally posted by ship69 View Post
    PS It seems a shame that nobody seems to have built "feel" feedback (e.g. some sort of acoustic feedback to report changes in torque and/or Z-force to the human operator) into any of these larger machines. But I'm getting ahead of myself.
    Even with large machines, anyone cranking a handwheel will develop a "feel" for the behavior of machine and the cutter. The feedback you're talking about exists, though in a different form; it comes from a wide variety of sources, usually simultaneously. There are quite a few people here who will recognize the nearly-inaudible yet soul-wrenching "tink" of a cutter chipping - even from across a noisy CNC shop! - and although they might not be looking at the cut they'll reflexively stop the machine and check the tool. Or, there's the wonderful "crinkling" sound of a sharp tap cutting steel. There are other audio cues (how does the cutter sound - is it smooth or "crunchy"? Is the motor/gearbox whining under load?), visual cues (finish of the cut, chip formation, direction and 'throw' of the chips leaving the cut), and tactile feedback through the handwheels (vibration, amount of force required to turn the wheel or crank). Small machines tend to give quite a lot of feedback, the 'heavy iron' not so much. It's still there, just reduced.

    To sum up again, if you're leaning that direction, I think you would be well served with the Sherline. Based on what you've said, it feels to me like it's a good fit for your situation. I have no connection with them, other than that I own both a 5400 mill (bought used) and a 4400 lathe (new from the factory), and I have used them with satisfaction for a number of years. There are other worthy machines, of course, and the decision is ultimately yours alone to make.

    Comment



    • Well, one thing for sure- after all this talking and suggesting, the final choice you make will be interesting.

      A couple points- for very small hole drilling with carbide bits, you will need low runout and tight slides. This would be more important than high speeds. The suggestion that you might only need .003 runout is a compromise that I would not accept. Pretty much any spindle of any worth is going to get you under a thou easily- if this were not the case, the bearings would be junk right from the start, and the machine would not be worth buying at any price.

      Another point- rigidity is paramount when it comes to avoiding chatter, and weight obviously helps a lot in that regard. But it isn't the holy grail of chatter-free performance. When I bought the Unimat, it came with the milling attachment. By itself, when mounted on my larger lathe, the milling attachment was fine- the quill play is adjustable and I set it for some drag to eliminate play, and the solid steel mounting bar is strong and rigid enough. But when used on the lathe bed, which has (had) two way bars of about 1/2 inch diameter, there was too much flex overall, and the results were frustrating. The bed of the Unimat lathe was just too flexible to allow for a good machining experience. Since then I've upgraded the bed with a cast iron piece that came from a small mortising machine, and it's way better. So I'll suggest- if it looks flimsy, it probably is- and if it looks solid, it's probably not too bad. If you see a machine with a column that's solid and not hollow, that kind of bodes well for its general usefulness.

      Here's a story about drill presses. I wanted to adapt a drill press to become a tool post machine for my 8x18 lathe. Others had done this, and I thought it wasn't too bad an idea, so I went around and looked at the smallest versions. Most had so much play in the quill that they would have been useless, even if the spindle bearings were fairly tight (which most were, with one glaring exception). I found the Delta to be the best of the lot. They all looked the same except for paint, and were pretty much priced the same, but the Delta castings were machined to a significantly better fit. If at all possible, get your hands on whatever machine you might buy and feel it out.

      I went as far one day as to say to a salesman 'I want this body, but I want this base on it.' He obliged, and let me swap parts from two jigsaws so I had the tight post from one and the tight base from the other. I basically did the same when I bought a Chinese die grinder- I opened three boxes and took the one that ran the best. Nothing beats hands on, so if you can possibly feel out a machine in a showroom, do so. I bought my mill that way- this one, off the showroom floor.

      I'm rambling on a bit now, but let me make one more suggestion- try to connect with somebody who is more knowledgeable than you about machines, and willing to go with you if you are at all able to go into a showroom and see the machine you might buy in person. I know that's a tall order, but you might be able to avoid a machine that comes with pre-existing damage, and you might learn valuable things too.
      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

      Comment


      • About that runout thing......

        After you find a mill with low runout (and 0.003" is HORRIBLE, not acceptable), you have to find a way to hold the drill that is better than 0.003" also. Since the spindle is going to be under a thou "out", the drill holder needs to be under a thou also.

        Many drill chucks are not particularly great on runout, since they are often limited to 1/16" drills. There are ones that hold 0-1/4" or so, and which may be better runout, but....
        CNC machines only go through the motions.

        Ideas expressed may be mine, or from anyone else in the universe.
        Not responsible for clerical errors. Or those made by lay people either.
        Number formats and units may be chosen at random depending on what day it is.
        I reserve the right to use a number system with any integer base without prior notice.
        Generalizations are understood to be "often" true, but not true in every case.

        Comment


        • Originally posted by ship69 View Post
          Hello

          I am looking for a small, high speed, high-precision milling machine not unlike the Proxxon MF70, but better made!
          I need to do very precise milling and drilling (e.g. 0.5mm radius) of Mild Steel. I also do larger projects.

          - I need a compact machine with a really good build quality, that is designed to do milling.
          - Speed range: 600 to at least 10,0000 rpm
          - Weight up to 30Kg if necessary, definitely not 50Kg
          - A reasonably powerful motor. (e.g. 150+ watts??)
          - I don't need CNC yet (but that might be useful later??)

          Does such a machine exist?

          Background
          It is for a small/temporary home workshop. So whatever I have needs to be "liftable" out of the way at the end of each day.
          If spending a lot of money, then I would like to be able to mill & drill reasonably wide cuts as well as fine cuts.
          I work in new product development and my projects are hard to predict. I work a lot with mild steel but also with lots of other materials e.g. stainless steel, brass, aluminium, plasics and wood.
          If pushed I could narrow the milling range down to between say 1.0mm and at least 4 or 5 mm.

          I already have a small Proxxon hand drill + stand. It was all very expensive but to be honest, the build quality is pretty average.

          J
          If I already posted this oh well, my bust.

          I was going to mention a high quality vertical mill I was offered when I bought my lathe from the gentleman.

          He had a jewelry shop making castings and fabrication of moulds. I answered an add of his that was for a cnc lathe.

          So I get to this guys shop, probably the year 2001 and see it looks like an office. His vertical cnc mill was up front by the front door and the lathe I was looking at was at the back wall of a 24x60 foot front room. A front room, in dry wall and in operation.

          Would not have bought it if it wasnt shown operational (they had a piece in the vert mill when I walked in). My lathe was and is a solid piece. The vert mill was an Emco as is my lathe. They wanted to sell me the mill as it was running. I wish I had the money..

          Emco (its Europe, not China LOL). Nice stuff. But you said no cnc so I didnt bring it up..

          Oh? Why the sell out in 2001? They were shifting to deposited type molds verses the cutting.. JR

          Comment




          • A) CNC

            No, I have not been giving CNC serious consideration thus far, but I am here to get new information, learn & adapt.


            * NOMAD 3 - yes $ 2,800.00 is c. £2000 - about double my budget.
            Doesn't look particularly rigid and can only cope with 130 watts.
            Spindle speeds (9000 - 24000 RPM) do seem very high.
            i.e. 9000 as a MINIMUM. What would be the maximum cutting with for Mild Steel do you think?

            But being CNC maybe the cutting width (and cutting speed) becomes much less important.


            * BANTAM TOOLS Desktop CNC Milling machine
            Says that it's "optimised for aluminium"
            TBH, I find all those slick graphics & shiny, smiling, smug people rather irritating.
            I'd prefer an old-timer machinist who knows his onions any day.
            Amazing little thing... BUT it can't mill mild steel!


            But realistically are ANY desktop CNC machines going to be designed for cutting mild steel or stainless steel?
            If so, (realistically) how much would I need to spend?

            [Yes, I know that you can buy a CNC version of Sherlines, but I can't really afford a manual Sherline as it is! But I am interested in machines that are designed from the ground up as CNC machines, complete with enclosures etc]


            B) RPM
            > High spindle speeds on none tiny cutters requires fast feeds to give correct chipload. Manual handles can’t keep up.
            General question: Is moving the feel too slowly a MAJOR problem, or do you just end up with a less than idea surface and maybe a bit of unwelcome noise?
            What are the rules of thumb re cutting speed & feed rates?
            e.g. Mild steel seem to have a particularly broad range of cutting speeds "3–38 Meters per min (MPM)"
            Does that depend on the steel in question, or doesn't mild steel really care?!



            > Have you actually seen or demoed any of the small mills?
            Obviously not. We have a little thing called Covid lockdown.


            Mcgyver - if watchmakers aren't milling, how on earth are they actually making their watches?
            I presume a lathe would be their first tool. Wire EDM? CNC? How do they make cogs etc?
            What about vintage watch/clock REPAIRERS & clock-makers/horologists?

            Btw, have any of you folks tried wire-EDM?
            It looks absolutely jaw-dropping tech...
            e.g. Did you see this? https://www.youtube.com/watch?v=4iB7kkCy1xM

            But do low-cost/desktop versions exist?
            [I found very little from a few minutes of googling...]

            J

            Comment


            • Originally posted by ship69 View Post

              if watchmakers aren't milling, how on earth are they actually making their watches?

              J
              they don't, make watches that is. Not 1 in 1000 anyway, or maybe 1 in 10,000

              I explained this:

              There's they few like Roger Smith at the top of food chain selling watches for 100's of thousand who do make their own parts... but the 1000's of trained watchmakers you'd take your your watch to none are likely to have a mill. The watchmaking trade isn't what you're thinking it is; there is very little machining except for the odd balance staff. Mostly its repair and servicing (which is plenty challenging on its own)
              Btw, have any of you folks tried wire-EDM?
              It looks absolutely jaw-dropping tech...
              lol, did we increase the budget 250x's? Have a search for BaxEDM....you can make it yourself. Its open source (mostly, you buy the arc controller) amazing wire edm that is good enough do the slow internal part drop demo....does so in one of the videos. There are some challenges to make a good quality wire EDM and this guy has met them in an (imo) impressive fashion
              Last edited by Mcgyver; 04-09-2021, 07:53 AM.
              located in Toronto Ontario

              Comment


              • ship69 That was a 2 second google search for small high speed mills. They exist, they are usually CNC.
                Small Mills for steel exist. You can (I have) cut steel with a proxxon. But it’s not a pleasant experience.
                Your set of limits, mostly the weight one, impose constraints.
                With a high spindle speed you naturally get a high sfpm number. To CUT metal you need to take a minimum slice - which is related to the sharpness of the cutter, the material being cut and a number of other parameters. That’s why a Grinder generally gives a better finish- the cutting tools are the size of a grain of sand and can take a smaller cut. (Danger -massive over simplification)
                If you don’t cut the metal you just rub it. Depending on the metal you can possibly then NOT cut it anymore - Titanium is a bugger in this respect, but stainless and some steels (especially the wear resisting ones - with vanadium in them IIRC) are just as bad.
                So the cutting speed is less important than the chipload - how big a cut are you going to take. If you don’t move fast enough you don’t get the chipload and don’t cut. Then you wear out or break tools.
                Sfpm is directly related to cutter size. So is cutter “idiot proof ness” (for want of a better description) Its much harder to accidentally snap a 16mm cutter than a 1.6mm or a 0.6mm one. I have snapped one 12mm HSS rougher when I accidentally hit the rapid in the wrong direction - that was a “exciting” and not in a good way. I bust a lot more small say 3mm or smaller cutters, But mostly that’s because I’m using them on a 1.7t mill which can happily chew a couple of mm doc on a 100mm diameter face mill by hand. As Bryan said you develop a feel for your machines- I don’t really get through that many given the compromises *I* have chosen - slightly increased tooling costs vs capacity.
                The variation in mild steel cutting speed ( what I have been calling sfpm - surface feet per min) is because there are a lot of variables, even with the same piece of steel. For instance the tooling geometry, machine rigidity, coolant, tool material, etc etc etc.
                A good illustration is hacksawing. You can hacksaw. Now change the blade to a different make with different tech profile- the *optimum* stroke speed will have changes. Change the tooth count and the *optimum* stroke speed will change again. To see the difference in cut vs rub move the saw as fast as you can. You’ll get hot, the work will get hot and likely the teeth on the blade will get hot and knackered. Now do the same but with a slow steady stroke - the cut will proceed cooler all round, and the cutting will go faster.

                Watchmaking is a misused term. Most “watchmakers” are more like garage mechanics - they don’t make parts, they replace them.
                Then there are watchmakers who are watch repairers- they do make the odd part, often balance staffs and similar. That is pure lathe and hand file work.
                Click image for larger version

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                here’s one I made a year or so ago.

                casemaking is also mostly a lathe job, as is a large part of the motion making.
                Watchmakers who actually make a watch from scratch are few and far between. I’m not there yet.
                Small scale watchmakers use the lathe and special attachments for machining, and files, skill and other specialty tools. An individual watchmaker mill is likely to weigh upwards of 100kg and cost way more than you (or I) want to spend. Look at BCA jig borers for an example of a not especially expensive one.
                If the watchmaker is making more than a single watch it’s likely they use a CNC machine to “blank” out the parts before hand finishing them.
                Gear cutting is generally done on the lathe with a live spindle in the tool post.

                EDM is not the solution you are looking for. I have a sinker EDM. It’s not fast, and it’s not small. It’s also smelly, sparky and needs different tending to a mill.

                Dave
                Attached Files
                Just south of Sudspumpwater UK

                Comment


                • Dave - Interesting. Thanks.

                  You raise the topic of grinding. Can you/do you ever use a mill to do grinding to polish a surface? And what about cutting through plate?

                  I ask because I've seen a few Youtube videos where the machinist is using a big, hand-held cutting disk ("hand-held circular saw"?) through steel. It seems pretty fast - faster than hacksawing. But the downside seems to be accuracy.
                  For this purpose I imagine you just spin up a hand-held grinding/cutting disk with a big motor (750+watt?) and away you go. And if you want accuracy you have to finish off your cut by hand with a hand file.

                  e.g. I recently tried cutting a line of 1mm thick steel plate by using a very small (c. 1mm x 20mm) cutting/grinding disk in a 40watt hand drill, but I found that for deeper, longer cuts the REAR of the disk starts to make a mess of things... and I found that cutting rather carefully with a hacksaw was actually much faster way of getting a straight line accurately cut.

                  One of the many things I was hoping that a milling machine would give me was the ability to make accurate straight-line cuts.

                  e.g. Suppose I need to create an accurate cut of say 100mm in length, 20mm away from the edge into some 1mm thick mild steel. Would I best best to:

                  A. Hold the steel sheet in a vice with the steel plate's thin edge pointing upwards and to cut it from one side, with a spining toothed blade?

                  B. Do exactly the same thing but cut it with a thin (1mm?) cutting disk (made of that black grit [carborundum/aluminium oxide/diamond?] + reinforced with fibreglass or similar... etc)?

                  C. Cut a channel with the steel plate lying horizontally and just use the side of a small milling tool.

                  I have tried cutting my 1mm mild steel (technically car body panel in fact!) carefully with a nibbler but it bends the 1mm steel plate too much. I am guessing that there is probably a high-powered, mounted circular saw machine or band saw designed for the purpose but I am trying to not buy too many tools as my space is extremely tight.

                  With thanks

                  J

                  Comment


                  • For a 4” long cut I would probably just use a hacksaw. Then file off the rough edges, maybe rub on some wet and dry paper on a flattish piece of steel plate. It’s depended on the requirements for accuracy tho. If it had to be quite close to 20mm wide, parallel sided and straight I might bung it in the mill after hacksawing off a slightly larger piece. But my mill vice is 4” wide, so the piece can be supported with minimal stick out and I’d probably just wizz off one side, flip and tap into a parallel then bring to size. If it had to be even more accurate I’d question the spec and then maybe “bung” it in the surface grinder.
                    Of course I have these options and a large workshop full of tools.
                    do you need a piece100 mm long 20mm wide and 1mm thick? Go buy 20x1 steel bar. Chop to length done.
                    A 41/2” angle grinder with a thin cut off disk will also do the job, but by the time I’ve got it out, found the ear defenders and setup I could have probably cut it by hacksaw. The angle grinder won’t be any more accurate.
                    Just south of Sudspumpwater UK

                    Comment


                    • > Do you need a piece100 mm long 20mm wide and 1mm thick?
                      Nope that was just a randon example. Since you ask most recently required 13.1mm with a 45° chamfer on it accurate to +/- aprox 1°.

                      Buy for example if one does mill a surface with a 4inch long cut, how accurate would one reasonably hope to acheive in terms of:
                      a) vertical wobble (over short distances due to cutting tool)
                      b) horizontal wobble (over short distances due to cutting tool)
                      c) end to end accuracy (due to accuracy of the table movements)
                      ...using something like a Sherman/Taig or even a Proxxon?

                      Obviously one can finish off with some wet & dry paper over something flat, but it still would be interesting to know.

                      Comment


                      • 14 or 15mm x 1 bar, 45degree chamfer bit - if your cheap a carbide router one.
                        clamp bar down on a spoil board with one edge parallel to the long travel. So it lies flat - I.e 1mm high.
                        lower head appropriately to give cut all the way through.
                        move short travel to give required width (13.1)
                        Make cut.

                        The end result will be pretty much as straight as the ways, and as parallel as the care in setting up
                        Just south of Sudspumpwater UK

                        Comment


                        • Ship, you asked a few posts back about that Joe Pie video and how it is relevant. I posted it in support of the idea of you being able to do the milling and drilling with lower speeds than you think. The 1350 RPM was not spoken but did show up as a printed overlay just around the beginning of the actual drilling. I posted the link purely as support for the lower RPM option. Nothing to do with drilling in the lathe. Just the lower RPM option.

                          On the idea that the others are mentioning about how a hand wheel can be difficult to keep up I've seen that even with a 1/4" size on my much bigger and certainly not portable mill when cutting aluminium. I run up the speed a little, but still way under the usually found limit, and at that rate I find that to keep the chips looking like fine chips and not dust I have to crank the handwheels pretty fast. Like about a turn every two to three seconds. I could go faster and get chips that were a little more stout too. And I'd still be well within the chip load per tooth for that speed.

                          The risk of feeding too slow or having short pauses is a risk. Even carbide will dull sooner than normal if used in this way. Obviously chips will be different for micro mills but they should still come out as chips and not as dust. Small Planes described the chips as little micro slivers which sounds about right. When doing fine cuts with the side instead of the end I get little rolled slivers like SP described too. Obviously bigger slivers but still slivers.... And they DO love to enter skin easily. So certainly controlling the rain of them as SP did with the shroud would be a wise and prudent accessory if you're doing the milling of this sort in the living area. You don't want that stuff in your feet or in your clothes that then get washed with other clothes and the needle like swarf gets spread around.

                          You're description of your needs for cutting sheet metal helps a lot. And frankly by the time you set up all the cutters and options you mentioned I'd suggest you simply work out a hold down setup that let's you hold the sheet metal and cut it with a hacksaw. It'll be far less time and perhaps a small amount of exercise which I read is good for us. But mostly it is just a lot less fuss and hassle to cut the main body of the part when it's basically sheet metal slightly oversize with a hacksaw and some manner of support.

                          You COULD cut it with an angle grinder and abrasive disc but since you're doing this work in your living area do you really want the crazy spray of steel dust and abrasive particles as the disc wears in use throughout the room? And if you opt for a hand held rotary tool (like Dremel) and the smaller 25 to 30mm discs the same mess but over only about 1/3 of the room? Meanwhile cutting the parts out with a hacksaw only causes low energy particles that politely fall down into a small 50x50cm area and are easily cleaned up. I'd suggest that this is your best option given your need to work within the living area. And a lot less noisy as well.

                          Once cut to something like 1mm or so over size you can then dress the edges in the mill.

                          For this you'll want to make up a "horizontal vise" to hold the metal flat and parallel to the mill table. From there I'd dress the edges with a medium, for this size machine, size end mill. This "flat vise" would be a riser of something like 6x25mm flat ground tool steel stock cut to some suitable length depending on part size. Then the sheet metal part and then a top caul of the same 6x25mm ground flat stock that is slightly longer and has "U" slots on the end to allow it to be clamped down to the table. Probably with 6x1mm flat head allen cap screws so you don't have bolt heads sticking up. The top caul in this case would have the contact surface machined to have a slight crown to it so that it contacts the work piece in the middle of the caul first and is then flexed down into contact at the ends by the screws. The amount of this crowning (or belly since it would be the underside) would be such that it only needs enough pressure to flex to full contact with a reasonable amount of torque on the hold down screws. Some testing to figure that amount out would be needed.

                          This "flat vise" would hold your sheet metal far enough off the table that you can use various portions of the side of the end mill to dress and true the edges of your sheet metal parts. I could see it being quite handy for what you're describing yourself doing.

                          But since you cannot find such things out there you're stuck making such tooling yourself. And this is where you get into a pickle. A long standing recommendation of mine to anyone looking to buy any machines is that they should not buy a machine that only just barely handles the size of work pieces they wish to make. They WILL need to make custom design support tooling and jigs that are then used to make the actual parts for the widgets they produce. And often those tools and jigs will be bigger and stress the machines more than what it takes to make the actual parts.

                          Mind you at this size range it is not out of the question to do a lot of the cutting and drilling for such tooling with hand tools. And then use the mill for some of the more controlled metal removal that is not easily done in as controlled and measured a way with hand tools. Along this line of use the Taig and Sherline and perhaps Proxxon FF230 would be suitable for whittling away at these sort of finishing steps in heavier sections of steel. And to be fair so would the PF70. But consider again SP's comments on how frustrating it might well be depending on the volume of metal needing to be removed with such a light machine. I'm also very concerned over the long term life of the PF70 when used with steel and the resulting fine swarf in contact with anodized aluminium ways. I see the construction of the PF70 as really only being suitable for wood, plastics, industrial waxes and limited use with nonferrous metals. Otherwise the steel swarf is highly likely to result in a rather short tool life span. For this reason I would suggest that you only consider tools that have steel or cast iron ways. And that even then you make up deflectors or way covers to reduce the risk of the fine swarf falling on and being taken into the dovetail joints.

                          For sensitive drilling of very small holes a commonly seen option for drill heads without quills is that the table itself is lifted up and down and the drill held stationary. Although to be fair if you end up with a machine that has a hollow main shaft it should be possible assuming you have a matching micro lathe to make up a lever feed sensitive drilling quill assembly that fits into the head stock of the Taig or Sherline mill and let's you use the head stock as your power source but which gives you the super sensitivity for peck drilling with the smallest of drills.

                          I also looked on YT for Servo Products. I can't find any information on their heavy duty 9000 series models. But there's a few videos showcasing 7000 series drill units which will give you an idea of the size of the drill heads. Comparing the dimensions at their web site for the normal and heavy duty drill heads appear to be the same head size bodies. So I'm guessing the "heavy duty" is just a more powerful motor. It isn't much but it might give you a better feel for what the SP product is like.

                          I still feel that because of the design that the SP product is more of a mill/drill than a dedicated and "proper" 3 axis mill. But if your work is more about small hole drilling with a little sheet metal edge milling then it might be the right tool for you. Clearly the focus even in a milling setup will be on drilling more than milling with the SP unit. But perhaps that's a proper and better fit for your needs? And it would give you the sensitive drill feel. A setup which would require some custom tooling to make up to get for the Taig or Sherline options. But as mills I feel that the better Z axis control with the Taig or Sherline would make them a little better if you do a good share of your parts as more blocky "full bodied" shapes with steps and angles and such.

                          Of course we still don't know what an SP mill drill assembly costs. It may be up in the stratosphere with some of the other things you've seen.

                          (38) Servo Products Company 7000 Drill - YouTube
                          (38) SERVO M7000 DRILL PRESS NJB030310.wmv - YouTube
                          (38) SERVO PRODUCTS TABLE TOP CNC DRILL MODEL 7501 115V - YouTube
                          (38) Servo Products Company Impact Classic CNC Milling Machine - YouTube
                          (38) Servo Drill Press Test - YouTube

                          There's only one video showing it actually cutting anything. And no information on what is being cut. But it appears to be some manner of plastic or G10 fiberglass and resin style board from the nature of the dust that piles up before the operator blows it away.

                          I'd be interested in learning the price on these units. Not the CNC ones, just the manual drill units and the 9000 series with the milling table.
                          Chilliwack BC, Canada

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                          • Originally posted by BCRider View Post
                            I'd be interested in learning the price on these units. Not the CNC ones, just the manual drill units and the 9000 series with the milling table.
                            yeah, stratospheric, several thousand US for a drill press. They are extremely nice, perhaps even the gold standard. I'm fortunate to have one but would not have paid thousands - like most of my stuff; given the fast/high quality/low price pick two thing, I picked quality and low price...waited long enough until a hot deal came along. Mines the chuck vs collets model but it runs so true it hasn't been an issue. I do have an extra Levin 10mm head I thought to make a DP out of so as to have a collet option, but the servo runs so true I'm not yet gotten around to it. Keep in mind with drills this small there is a huge amount of flex and you usually don't go very deep, so the ultimate zero run out isn't strictly required. The tip of drill will concentric on its mark even of the chuck (a loooong way away) has some slight (some # of tenths, not some # of thou) run out. After having it, while the collet is more accurate, I think i prefer the convenience of the drill chuck as it works so well not sure I'd see an advantage with the collet model.
                            Last edited by Mcgyver; 04-09-2021, 05:51 PM.
                            located in Toronto Ontario

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                            • Well, that answers that. Servo Products gets the boot based on price. At least outside of the idea that a used one for cheap might show up over in the UK.
                              Chilliwack BC, Canada

                              Comment


                              • Originally posted by J Tiers View Post

                                Glad to make you happy, Ed.

                                I figured you for a person who could get good work out of a crummy tool. I did not suppose you would enjoy it, but you could do it.
                                An annoying job today, 1/8" wide key seat through a 2" bore 5 3/8" long. It took me 6 hours to do 10 parts including making a bushing and shims. 6061 aluminum weldments so the entry and exit were extra sticky.
                                Part before welding.


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