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  • Screw the better mouse trap.

    Screw the better mouse trap, how about a DRO that the home guys can afford. They can build and sell digital calipers for $20.00 bucks. What the hells so damn hard about building a DRO for a cheap home type mill that don't cost as much as the mill? Are there magical components in them? Build a cheap DRO and the world will beat a path to your door.

    Anybody else find these things a bit overpriced in this day and age?
    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

    It is true, there is nothing free about freedom, don't be so quick to give it away.

  • #2
    I tried the cheap route. Ended up with battery powered calipers that didnt work when it was cold in the unheated garage. When it did work the cable connectors sucked and disconnected all the time. All it did was measure. It would not do any calcs, such as holes in a bolt circle, etc.
    so I bit the bullet and bought a $700 setup from china that has glass scales, does calcs, 120vac with battery memory, has connectors that are the same as 9 pin ones on a home computer, has cables that have a metal flexable shield on them.
    I hymed and hawed about spending the $ but now that I have I would do it in an instant again. My only regret is that I didnt do it long ago.

    Comment


    • #3
      Here is a plan for you YOD.

      This would make a decent quill or head encoder as well as axis encoder if it's long enough for your purposes.

      ENCODERS, Linear
      DRC Dynamics Research Corporation Model LB4B-0320

      320 mm 5µ Incremental Optical Linear Encoder used, guaranteed $99/ea

      (Image) These are removed from equipment subject to a "design change" and are used working units. Part of the design change related to the flex cable which has been modified to be 6" in length with a connector for attaching your own flex cable.
      ° Resolution = 5 microns / 0.0002"
      ° Velocity = 350mm/esc. max.
      ° Travel = 320mm / 12.59"
      ° Solid state LED lamps - 100,000 hour life.
      ° Self-Aligning Read Head constrained within track by 5 miniature ball bearing rollers.
      ° Outputs = A quad B TTL levels
      ° Power = 5VDC/200ma
      ° Enclosed, Sealed
      ° Documents: Electrical PDF, Mechanical PDF

      http://www.lasermotion.com/servo.html
      Then scrounge an old laptop with a parallel port and use this software.

      http://www.lindsayengraving.com/othe...rests/dro.html

      A couple of bucks worth of simple parts to interface the encoder is all you need to get 5 micron accuracy.
      Free software for calculating bolt circles and similar: Click Here

      Comment


      • #4
        YOD, their actually less than a quarter of the cost of what they used to be and can also do all kinds of neat little tricks as compared to the older ones, Did I mention far more dependable? What more could you want... I guess you could maybe buy one used and get it for 1/8 the price of what they used to be, I actually cant believe how cheap they are Mine was 1/6th the cost of my mill and easily made my mill twice the machine.

        Comment


        • #5
          The other thing about the cheap caliper method is the update rate kinda sucks. Where my accu-rite is right there.

          But I got my DRO off Craigslist so I didnt pay much which is rare. Mitutoyo DROs are often on same new for around 600 to 700.

          Comes down to you get what you pay for.

          Comment


          • #6
            That's how it is folks

            First of all, Evan has pointed you in the right direction.

            Second, its not the end of the world as we know it if a DRO is not fitted.

            At a pinch, I can get along very well just using my lead-screws.

            I can use my micrometer testing/checking rods as guages to set up a dial indicator either fixed to the machine or mounted on a magnetic base.

            If I am real fussy, I can make spacer blocks to use with the dial indicator. The spacer blocks can be as simple as a drilled and tapped rod (one or both ends - your call). I just insert bolts with a lock-nut on them, set them a bit over length and just face them off in the lathe. Facing off in the mill vice works just as well.

            I do have a good surface plate ("float" glass) and a 300mm very good digital height guage and an 81-piece metric set of slip guages. But I rarely if ever need or use them. The mill table is quite flat enough for most jobs. The "glass plate" does for the rest.

            Do I really need DRO's? - possibly.

            Have I ever seen them? Yep.

            Where? In a catalogue and in my shop - and in boxes on a shelf in my shop. They have been there for (cheap set) 12 months and (dearer set) 6 months.

            Which DRO's?

            These.

            These for the HF-45 mill (bought six monthas ago).
            http://www.hareandforbes.com.au/samp...orking/44.html

            And these too for the mill but might get used on the lathe.
            (bottom of the page) - bought about a year ago.
            http://www.hareandforbes.com.au/samp...orking/43.html

            And when am I going to fit them?

            FIIK - "when ever" I suppose.

            So for those that haven't got DRO's or got them fitted - it ain't the end of the world.

            But they are very nice and handy to have.

            Your machine is just as accurate without DRO's but the machine is definitely easier to use.

            Despite some of the adverse comment from time to time, you can do very well with modifying a simple digital caliper. Just be careful as regards rates of travel and ingress of machine fluids and chips etc.

            If you have a look at the second link I posted, the DRO's are very similar to the digital caliper principle.

            The big advantage of the "digital caliper" method is that if it gets damaged, you can fit another in less than half an hour.

            So?

            There is a lot of difference between the "nice to have" and the "need to have" stuff - DRO's included.

            So, I'd give very serious consideration of Evan's advice.

            So why don't I do it then?

            Electronics is a complete mystery to me.

            I have yet to advance to the age of the steam radio.

            Perhaps it is an OZ (well, mine anyway) version of self-flagellation.
            http://www.tfd.com/+flagellation

            Or to put it into the OZ vernacular (as from the Australian Slang Dictionary) I am a "whacker"
            Whacker, whacka : Idiot; somebody who talks drivel; somebody with whom you have little patience; a dickhead
            http://www.koalanet.com.au/australian-slang.html#U

            Comment


            • #7
              Iron was being cut long before we had DRO`s Use a dial indicator if you have to.Ran mills and lathes for years using indicators for measurement.yes slow but it works.
              Every Mans Work Is A Portrait of Him Self
              http://sites.google.com/site/machinistsite/TWO-BUDDIES
              http://s178.photobucket.com/user/lan...?sort=3&page=1

              Comment


              • #8
                And you have done a lot of nice stuff in those years,Lane.

                Think of how much easier, faster, and more convenient it could have been done with a DRO.

                BTW, there is a new thing called Electricity,Have you tried it.

                Comment


                • #9
                  why not look into a shumatec DRO? i have 2 one on my lathe and one on my mill. great little things and have all the fancy features the high dollar ones have.

                  Comment


                  • #10
                    Originally posted by IOWOLF
                    And you have done a lot of nice stuff in those years,Lane.

                    Think of how much easier, faster, and more convenient it could have been done with a DRO.

                    BTW, there is a new thing called Electricity,Have you tried it.
                    I never said DRO`s weren't nice and fast . Would not be with out one .just giving options. Anilam 411 for about $ 1200.00 will do just about every thing. nice unit.
                    Every Mans Work Is A Portrait of Him Self
                    http://sites.google.com/site/machinistsite/TWO-BUDDIES
                    http://s178.photobucket.com/user/lan...?sort=3&page=1

                    Comment


                    • #11
                      Simple and cheap

                      Originally posted by Your Old Dog
                      Screw the better mouse trap, how about a DRO that the home guys can afford. They can build and sell digital calipers for $20.00 bucks. What the hells so damn hard about building a DRO for a cheap home type mill that don't cost as much as the mill? Are there magical components in them? Build a cheap DRO and the world will beat a path to your door.

                      Anybody else find these things a bit overpriced in this day and age?
                      Hi YOD.

                      Just re-visiting your post before the thread gets too far away from what I see as your primary requirement.

                      As I see it, it is just a simple digital accurate fluid and swarf-resistant/proof read-out that you can fit to a linear axis on any machine. Say, lathe, mill, grinder etc.

                      Some of the "digital caliper-like" ones will meet those requirements "out of the box".

                      Next "up" will be the sealed "glass-etched" DRO's that will give you a linear displacement without the "bells and whistles".

                      Most if not all of the "features" of the more "up-market" stuff can be done with X-Y off-sets or co-ordinates from any reference/zero point using a basic linear read-out only.

                      The math can either be done from Machinery's Hand-book, if you have one, or simple diagrams on any number of web-sites.

                      You can even draw the job in a simple CAD system and pick off or "detail/dimension" the holes or positions you require and then use those figures to set the DRO's on your machine.

                      There is no doubt that DRO's make it easier and faster to do a job.

                      But not having a DRO does not make doing the job impossible.

                      Having a "zero-set" is a big "plus" as well.

                      The big advantages of any DRO are that you don't need to "count hand-wheel revs" nor do you have to allow for back-lash as the DRO reads the relative movement between the 2 parts that it is mounted to.

                      Its just a matter of what you are willing to pay for what you need.

                      As previously, Evan's suggestion is well worth considering.

                      In all of this of course, you still have to position the table by hand - the DRO only helps you get there.

                      Auto or power setting/location suggests CNC.

                      If I am doing a series of holes on a circle I find it easy to fit my rotary table which has quick indexing plates fitted to it (under-neath and inside). It will do any sub-multiple of 24 (1, 2, 3, 4, 6, 8, 12, 24) holes etc. I just centre the table under the quill, centre the job on the rotab, and then set the radius of the circle. I disengage the worm and wheel and just hand rotate and wait for it to "lock" and away I go. No need to set another pair of ordinates each time I want to move to or position another hole etc.

                      There are any amount of "Quick Indexers" "out there" as well that really don't need a DRO to index a job either.

                      Would I have DRO's? Sure would.

                      When am I gonna fit the one's I've got? When I get around to it or when I really need to I guess.

                      Comment


                      • #12
                        I fully understand what can be done without a DRO. The question is, how much easier would it be with a DRO "for me". The little DRO I fitted to the Z axis on the mill has been a blessing. I know the job can be done without but goes much smoother having it.

                        What is there about a DRO that makes the expense of them stay up there? You can buy scientific calculators for $59.00, gps units for a few hundred accurate to with in 15 meters on the planet. They put electronic time pieces in pens and pencils and still a basic DRO system has to cost nearly a grand?

                        While Evan's idea may be a good one I fear it is above my level of craftsmanship to pull it off. I must say I can visualize Tiffs idea of the rods and see how that might work for me pretty well. Something like that with a hinge arraingment would allow me to go back to original starting points on a project.
                        - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                        Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

                        It is true, there is nothing free about freedom, don't be so quick to give it away.

                        Comment


                        • #13
                          Rods 'n all

                          Originally posted by Your Old Dog
                          I fully understand what can be done without a DRO. The question is, how much easier would it be with a DRO "for me". The little DRO I fitted to the Z axis on the mill has been a blessing. I know the job can be done without but goes much smoother having it.

                          What is there about a DRO that makes the expense of them stay up there? You can buy scientific calculators for $59.00, gps units for a few hundred accurate to with in 15 meters on the planet. They put electronic time pieces in pens and pencils and still a basic DRO system has to cost nearly a grand?

                          While Evan's idea may be a good one I fear it is above my level of craftsmanship to pull it off. I must say I can visualize Tiffs idea of the rods and see how that might work for me pretty well. Something like that with a hinge arraingment would allow me to go back to original starting points on a project.
                          Thanks YOD.

                          I didn't mean to infer that you didn't "know of or about DRO's" - far from it - but I just put that in in case some might have thought otherwise.

                          I agree that DRO's are "way up there" as regards cost. But I'd guess that all in the "supply chain" just charge what the market will bear - aka "market forces".

                          (The "supply chain" includes the "ticket-clippers" who get a "slice of the action" and yet do bugger all except have it pass through their accounts - usually only electronically and not physically).

                          I don't doubt that the "market" and "prices" are being manipulated and there is a lot of "price-gouging" going on. Proving it is hard enough. Getting it prosecuted is all but impossible.

                          In the absence of "ebay-ing" it, I'd guess that someone on this forum will know of a basic DRO at a reasonable price or of someone with one "spare".

                          Perhaps someone on this forum - preferably in your area - who goes to sales etc. might "look out" for you and keep you posted.

                          The "rods" idea was not mine. I was taught it when I was in work-shops as an Apprentice and after. We just had adjustable rods as described set to length and seated in an inverted "V" and a dial indicator on the carriage. It was used on lathes, mills, boring mills, planer-mills, etc. An "upper-level" but similar method (with slip-guages and DTI's) was used on the Tool-Room mills, lathes and even the Jig-Borer on occasion. It works very well and is very durable. Costs nothing and rods can even be threaded together.

                          We also used stuff like the rings from ball/roller bearing rings as parallel strips on the mills, shapers, grinders etc. They are remarkably accurate and flat. We used to "knick" them on a pedestal grinder and break them for smaller pieces. If in doubt we just had them given a "lick" on the magnetic chuck on the surface or Tool & Cutter grinders.

                          Old or substandard vices could be made to hold the work down hard and flat on the base of the vice and hard-up against the fixed jaw just by using a good Engineers ruler or a thin but "sharp-cornered" parallel strip. We had a lot of fun just meeting challenges and "making do" with what ever was handy (or could be borrowed or stolen from somewhere else).

                          Pics of vice (posted previously) follow.

                          Yep. That vice jaw (on my pedestal grinder) lifted 0.037" (37 "thou") as per the feeler gauges, but as you can see, the job is hard down on the vice base and hard-up against the fixed jaw. And if needs be, that is good enought to use on the mills or grinders here as well. Might up-set some of the purists, but it works. Just be careful on the mills that you don't over-load it though!!!

                          The theme here is that very good results can be got from very "ordinary" tools with care.

                          Good work does NOT require the very "best" or "latest and greatest" - but as with DRO's - it sure helps.







                          Comment


                          • #14
                            Originally posted by lane
                            I never said DRO`s weren't nice and fast . Would not be with out one .just giving options. Anilam 411 for about $ 1200.00 will do just about every thing. nice unit.
                            Will it load the parts?
                            Life Is Grand

                            Comment


                            • #15
                              YOD, none of those devices are accurate down to .0001". Linear scales are one part of the expense. Look at the prices on ebay that new in box heidenhain scales go for. I have seen $300+ for some medium sizes scales. List prices are even higher.

                              Also they dont make nearly the amount of these things as they do in any comsumer device so the prices of components and bare circuit boards are much higher. Also since they dont make as many the cost of R&D cant be amortized as thin as they can with say an iphone or gps.

                              I love having a DRO. Cant imagine going back. Wear on lead screws is irrelevant. When I go from .3" dia and turn it to take off .1 in dia it is right there.

                              Comment

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