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  • ME Consultant pro



    Ken Shea posted this program in the threading video post.
    Looked interesting but I found that the demo version didn't work with the lathe infeed distance when using BSF and BSW

    So I decided to do my own spreadsheet which i have been doing tonight.
    Decided to cheat and take the figures from this program before it timed out and found some queries.

    I posted before about the 27 thread being deeper but look at the pic above.
    This is for 3/8" x 16 UNC now from various books including screw threads of the worldd and MH, the depth of this thread is 0.0406"

    [ Nowhere on this chart does it tell you this ]

    Now the infeed depth from the table is 0.0389"

    ?????? how can this be less than the depth?/

    The formula is depth x 1.1433 which should be 0.0464

    Checked some more figures and they are all wrong as well.

    Started posing this and noticed that Kens picture posted at the top shows the infeed of 0.0441 ??

    Mine shows 0.0389



    WTF ???

    Can anyone see any differences between these pics? All you can do is select the thread and inch or imperial

    .
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.




  • #2
    John,

    Michael Rainey, the author, is a frequent poster on PracticalMachinist. You should post this over there.

    I've never tried his software, but his website is here, and his contact information (which I don't want to post) is on the upper right corner:

    http://closetolerancesoftware.com

    Robert
    "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

    Comment


    • #3
      I have that program at work and I dont see any difference. Maybe your demo version is an older one and he updated some values??? He does send out updates a couple times a year, or atleast has since I got a year or two back.

      Comment


      • #4
        Right so last year it was 0.389
        This year it's 0.0441 so will it show the correct figure of 0.464 next year.

        What about leap years.

        Lazlo,
        I have sent Michael an email, I just wondered if it was me doing something silly.

        There are also errors in the UN series compared to the metric series but both use the same formula as they are both 60 degree threads.
        .

        Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



        Comment


        • #5
          so is it just the lathe infeed that has the errors?

          Comment


          • #6
            thanks

            John
            I have the older free one, but seldom use it
            Made up my own chart years ago.
            Made a few copies and stuck then on the wall next to each lathe.
            Not hard to do just some grade seven math
            eddie
            ps Perhaps you should write a program

            pps about that book I email u on. Do you want it?
            please visit my webpage:
            http://motorworks88.webs.com/

            Comment


            • #7
              John, there was a recent update V2.06, click help and about on the demo and see what that it.

              It seems to me that something was said regarding thread data output with the last update, but nothing specific or absolute comes to mind.

              Comment


              • #8
                Ken, Thanks for replying.
                The demo has 2.07 on the top.
                Michael has replied by email and he's looking at it as to why the BSF and BSW don't work.

                He's also explained the reason for the differences but I'm not 100% certain we are both reading off the same hymn sheet but at least he come back prompt enough.

                Eddy,
                I'm in the process of doing a spreadsheet at the moment, that's how I spotted the differences.
                Thanks for the offer of the book but I'll pass thanks.
                I'm in the process of thinning down my collection it's gotten too unmanageable.

                I have sold off two collections of Model Engineer from 1940 to present day.

                That has freed up some much needed space. I have also sold off my collection of vintage aircraft books that I have collected as to be honest I have never had an interest in them, they just kept appearing in job lots and swaps etc.

                Somewhere they are over 500 old motorcycle books, not magazines and to be honest I don't have a clue where they are.
                We have been here 22 years and I have never seen them. It's got to silly proportions.
                After the sort out of the ME's I found I had 8 foot shelf space just on gear cutting books alone.
                .

                Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                Comment


                • #9
                  Does it really help?

                  Thanks John.

                  I was going to address this matter on "the other thread" - but I will do it here.

                  If you look at the tolerances for the major diameter, pitch diameter, minor/root diameter and "distance over (3?)wires" etc. you will see that there is quite a possible range of "in-feed" variations that are within the tolerance band/s.

                  The biggest "feed in" to the root diameter is the from the largest major diameter (aka "OD") to the smallest root diameter and the least is between the smallest OD and the largest root diameter.

                  The "in-feed" at - in this case 29 1/2 degree -which is shown as being to "four decimal places" (eg. 0.0441") is highly problematic as well.

                  If the in-feed is by the "scratch to set zero on the OD" method is used, I can't see it "all happening" as it seems to presume that the angle (60 degree) and the radius of the end of the screwing tool are extremely accurate. I might assume that the angle is OK but given that many use the same tool with the same radius for all or most screw-threading, it sort of makes the whole process a bit "suspect". Calculating the "slope feed" (at 29.5 degree) is a PITA and prone to error as well.

                  I cannot see why a short "spigot" about 1/4" to 1/2" long can't be turned on the end of the job (tail-stock end). The diameter can be in two parts - "right on" the root diameter and the other about 0.010" (10 "thou") larger so that I can see where the tool is. The +0.010" diameter will soon let me know when the tool depth is getting "close" as the thread will "show" as a "scratch". After that it can be either a case of "make it fit" a mating or known part and then take note of the "required" diameter as set the top and cross-slide dials to "zero". That way I will know "how far to go to zero" and I don't have to be too fussy about the 29 1/2 degree top-slide setting either.

                  Some times - but certainly not always - some of these "aids" are more hindrance than help.

                  An "aid" should be just that. It should not be the end in itself but only a means to an/the end.
                  Last edited by oldtiffie; 12-17-2008, 04:13 AM.

                  Comment


                  • #10
                    Good morning, John.

                    I've updated the program again, by adding "Ref" to the labels for thread height and infeed distance. As oldtiffie explained quite well, there are too many variables in play for height values to be precise. Tolerance on the major and pitch diameters (external), vague published values for minimum minor diameter (external), and variations in tool geometry all have an effect.

                    I wish you had written me before starting a thread that implied that my program was full of errors, but I guess MEPro came out just a little bit better in the end, hopefully with no damage done.


                    Mike
                    Software For Metalworking
                    http://closetolerancesoftware.com

                    Comment


                    • #11
                      john

                      John
                      Check your mail
                      as well if you have an interesting book or two and you want to
                      send it my way...
                      I paypal the post
                      please visit my webpage:
                      http://motorworks88.webs.com/

                      Comment


                      • #12
                        Mrainey, the link in your signature is not working properly because it's buggered up.

                        The link goes to:
                        Code:
                         http://www.\"http.com//closetolerancesoftware.com\"
                        To enter correctly, change it to:
                        http://closetolerancesoftware.com


                        .
                        Thomas

                        Problems worthy of attack prove their worth by hitting back
                        - Piet Hein

                        Comment


                        • #13
                          Screw-threading without getting screwed

                          Originally posted by mrainey
                          Good morning, John.

                          I've updated the program again, by adding "Ref" to the labels for thread height and infeed distance. As oldtiffie explained quite well, there are too many variables in play for height values to be precise. Tolerance on the major and pitch diameters (external), vague published values for minimum minor diameter (external), and variations in tool geometry all have an effect.

                          I wish you had written me before starting a thread that implied that my program was full of errors, but I guess MEPro came out just a little bit better in the end, hopefully with no damage done.
                          Mike
                          Hi Mike.

                          First - back to the subject:



                          First of all, I feel that I should and do offer an apology for seemingly "tearing into" your program. If it happened, and it may well have at least seemed to have happened, I am sorry.

                          I don't want to "pick a fight" with John S or "all and sundry", but I thought - and still think - that I needed to make what I intended to be "fair comment".

                          I certainly did not intend to use your software as a stick or a weapon to beat anyone over the head with either.

                          What really raised my eye-brows was the tolerance ranges for "measurement over (3?) wires" given that in recent threads and posts that some had been quoting dimensions or measurements "over the wires" in the range of "tenths" - +/_ 0.000?" based on tables that come with sets of "3 wires" such as:




                          I would agree that if the form/angle of the threading tool was very accurate as regards angle and symmetry and that the axis of symmetry was accurately normal to the axis of the work-piece/job and the lathe head-stock spindle axis and that a minimal maximum radius at the tool tip were provided, that the "Measurement of (3) wires" at the pitch diameter - or for that matter any points of tangency - on the flanks of the thread that the accuracy of the thread would have been defined.

                          If that is the case, then any accurate round stock (think - "drill rod" (in the USA) or "Silver Steel" in the UK, Australia and New Zealand) - both/either "inch" and/or "mm" of a standard size that can/will contact both flanks should be likewise able to define the thread.

                          I accept that varying the depth at which the "wire/s" form a tangent with the flanks will likewise vary the helix angle at the diameter at/on which the tangents lie/occur and that that can have an effect of widening or narrowing the effective "thread angle" at which the wires contact the flanks as the effective helix angle varies from least at the OD and largest at the root diameter and that "mean" or "pitch" diameter is the best effective compromise.

                          The problem I have with the "Tables" that come with the "3 wire" set/s is that they do not define the limits of the basic outside diameter "D" nor do they give or infer the limits of the measurements over the wires.

                          As I see it, neither your tables nor the ones that come with the 3-wire sets have regard only to the standard US/UN(ified)/metric/ISO 60 degree thread forms and do not address nor define or tabulate anything for the "Brit/UK" 55 degree "Whitworth" form/profile.

                          There is no reason - that I can see - why all thread forms are not or cannot be defined for "3-wire" "treatment". That includes but is not limited to: acme, buttress and all threads with non-parallel sides/flanks - "square" form threads are therefore excluded.

                          The tables that come with the "3-wire" sets are straight out of antiquity in that they are pre-digital/computer.

                          Computers and calculators are as much valid shop tools as are DRO's, digital calipers, height guages, protractors, micrometers etc. and should be regarded and used as such - as they are with CNC.

                          It had occurred to me that any 1, 2 or 3 wires should be able to define a thread if the "angle" of the thread and its symmetry were accurate. The wires need not all be the same diameter although that may make it easier.

                          I had a "stab" at this some time ago with this sketch:


                          I just sketched this on a pad in a matter of minutes after I thought it over. It could easily be drawn or replicated in any 2-D CAD system and the quantities/dimensions etc. extracted from it for any thread or profile (other than "square"). It eliminates any need for accuracy in the OD of need for accuracy in/of "in-feed" whether at "29 1/2 degree (US) or 27 degree (Whitworth - UK), or any other angle - it works for a "straight in" (zero off-set) as well.

                          It originated in a method I've used for a long time to replicate a screw thread from the "mating part" or one that I considered to be a "Pattern" or a "master" for the specific occasion/job. I just accurately grind the screwing tool -usually on a pedestal grinder - with a good protractor and bevel guage. I check the profile against the "master/pattern" screw for "angle" and the "flat" (acme, buttress etc.) or "radius" of the "nose" ("Vee" threads - BSW, Whitworth, UN(ified), "metric" etc) and then I hone it and set it up in the lathe.

                          I turn the new "blank" to accurately be the same diameter as the "Pattern" (or note and make allowance for any difference/s). I use any accurately ground "rod" that "suits" in the shop that will fit in the "groove" in the "pattern" and project above the OD and note that measurement over the single "wire" and the OD on the opposite side of the "pattern". I am now "set to go" and just keep turning that thread until it is near the measurement over the pattern "just in case!!". I try the "nut" from there on to completion.

                          The other method I use is to turn a "spigot" on the end of the job, the diameter of the spigot being in two parts - at the "root diameter" (nearest the tail-stock) and another abutting it being 0.010/0.020" larger. I just keep "screwing" until the tool "touches" and leaves spiral "witness" on the larger diameter. I start trying the "nut" from there on to completion. This method pretty well eliminates any concerns or accuracy as regards off-set angles or in-feed/s in the top/compound slide or the cross-slide.

                          I find that "long-ish" threads (ie "thin" or "skinny" compared to its length, even if supported on a tail-stock centre, some-times have a "barrel" shape/effect as the job is "pushed away" from the cutting tool. A "traveling steady" correctly set up usually fixes this "problem".

                          I have had a good look at the "3 wire" matter in Machinery's Handbook (27). It is "heavy going" and a "slip" is too easily made either in reading the text, extracting infomation from the tables, selecting formulae and applying them. There is all too often no-one else in a HSM shop to run the figures/logic/reasoning/result "past".

                          "Internal" threads are another matter.

                          Comment


                          • #14
                            Thanks Thomas, I fixed the link in my signature.

                            Oldtiffie:
                            I've really enjoyed all your comments.

                            The tolerance on the measurement over wires is identical to the tolerance on the pitch diameter (three-wire method is generally taken for granted, except for tapered pipe threads). The diameter of the wires themselves must be held to an extremely close tolerance to give the expected results.

                            MEPro doesn't allow you to input alternate thread wire sizes - you're stuck with the so-called "best" size (the diameter that's tangent to the flanks at the pitch diameter). In addition to the 60-degree threads, it makes calculations for BSW, BSF, ACME, Buttress, BA, NPT, and NPTF.

                            I agree that it's much too time-consuming and all too easy to make a mistake when making manual threading calculations. That's why I wrote my programs.

                            I also wrote Threadpal, a much more powerful thread data calculator which allows you to enter any major diameter, pitch, or wire diameter you want (okay, there are some limits).

                            I have a lot of customers who make threads for a living and for whom time spent making thread calculations is money down the drain. It's probably overkill for home shop machinists, but I'll invite you to give it a look and come back with comments, positive and negative.

                            http://closetolerancesoftware.com/METhreadPal.html


                            Mike
                            Software For Metalworking
                            http://closetolerancesoftware.com

                            Comment


                            • #15
                              Whew!!!

                              Thanks Mike - heaps - for taking my comment as you did and in the spirit in which it was intended. It takes a "very good man" to take it as you did and to continue the discussion "in public" on an "open forum". I am very impressed - thank you.

                              I've had an initial/cursory "look" and am very impressed, the more so now that I've read your post and had a look at your site instead of being limited (by myself as it happens) to assuming that all that was/is in the posts (two threads) covered all that there is - which it - now - very clearly did not.

                              My impression thus far was that the "Pro" is not for me as I am retired and time is not an issue. I could get very interested in the advanced threading module though.

                              I do have a question as regards portability etc. I have two computers on my desk (W2K Pro and XP Pro) that are fully net-worked. Each is intended as a "hot" clone of the other. I am the only one using them. I will also be buying another computer for (if and) when I get around to getting the Mach3 CNC package up and running in my shop. That shop computer will "live" in the shop. My question is: how do I or can I run the software on any computer with me as the sole user in a "Home Shop" environment that is not used for commercial or "Trade" purposes?

                              As regards your Pro software, I have "rules of thumb" for most machining and I "try" my machine and see "how it feels" on just about every job. That would be very hard to "pin down or to quantify". So I really only need the advanced "threading" module.

                              I will have a better look and make some comment later in the day or tomorrow (perhaps Saturday as tomorrow, Friday, is our wedding anniversary!!). I "live dangerously" - but there are limits!!.

                              I will think about the "internal measurement" as it - like all other/s - is a bit "hit and miss" to the extent that there is no method comparable to or using the principles of the "3 -wires". There was a method I used many years ago that addressed that issue and it works surprisingly well. It was from my time in the Tool-Room and was a Tradesman/Apprentice discussion during a "break" that started it - but is was while ago. I think I have the basics and fundamentals right, I just need to re-think it and check it out. I will "get back" to you.

                              One thought I did have, following on from my previous post, was that for those who only use the "off-set angle" and "in-feed" method and who may relay on the "scratch to set dial zeros" procedure, it may be an idea to specify the maximum tool-nose radius that should be used or alternatively allow an option to input the tool-nose radius if they can accurately determine what it is.

                              [Edit]
                              I would think that rather than have peope look at it as a "(big?) cost" item that they "cannot afford", perhaps if it were addressed as a "show cause" approach it might be better. By that I mean that potential users/buyers should have to ask themselves to "show cause" why they DON"T buy it. ie it should be regarded as an investment to the extent that it is no so much how much it costs to buy it, but rather what it will or may cost them if they dont (buy it)!!!

                              [End edit]

                              Thanks, Mike - later.
                              Last edited by oldtiffie; 12-18-2008, 02:58 AM.

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