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  • how often should a mill be stripped down

    How often do you think you should remove the bed and saddle and clean and inspect oilways leadscrew etc... I know this depends on usage patterns etc but given regular home shop use how often in your opinion should it be stripped down and cleaned? You dont get major service intervals in the operators manual

    After removing the saddle and bed on my old iron mill I have come to the conclusion it has never been taken apart before and its at least 20 years old. It had stickers from a tool firm saying it had been serviced up to 2 years ago but the only evidence of their work seems to be grease in the oil ways and no grease in some of the grease nipples. I dont think I will frequenting their shop.

    All of grubscrew marks on shafts are single indentations with a single exception where some one took a handle off and lost the key out of the key way.

    Derek

  • #2
    In a home shop with good maintenance, and good practices , Never.

    Comment


    • #3
      I'm a firm believer that HSM's do more damage to machinery by "restoring" it than any amount of use.

      So, dust the machines off, lube them and start cutting.

      Comment


      • #4
        Busted??

        Originally posted by DR
        I'm a firm believer that HSM's do more damage to machinery by "restoring" it than any amount of use.

        So, dust the machines off, lube them and start cutting.
        Or to paraphrase DR:
        Them that fixes 'em f**ks 'em

        Which is the reverse of the old shop maxim:
        "Them that f**ks 'em fixes 'em".

        Unless there are compelling reasons otherwise and if it ain't busted - don't fix it.

        Comment


        • #5
          I would sure agree that an ill-informed home shop guy could do more damage than good, but I would like to think that with resources like this, a guy could ask questions and download manuals for some common machinery before going to work. Its certainly important for the novice to understand the careful handling that way surfaces deserve so that they don't go setting way surfaces on a concrete floor, for example.

          A guy knows whether he is prone to moving first and asking questions later and as such could disqualify himself if he is not the type to exercise a lot of care and attention to detail. Given the things I have found in oil passages and embedded in way surfaces, I have to disagree with the general premise that they should not be taken apart and inspected. I took my Bridgeport apart as part of a planned restore just after purchase....I am glad I did and its lead to most of the other machines I have acquired since being taken apart. As a result, I now know all the stuff I would have been rubbing into the ways for the next decade had I not disassembled and cleaned as well as the parts that would have gone unlubricated due to blocked oil passages etc. as the OP noted.

          At the very least, I would encourage the removal and cleaning or replacement of way wipers which eventually become "laps" imbedded with all the swarf and possibly abraisive grit from their previous owners.

          Finding oil zerk fittings with grease in them is a good sign that someone didn't know what they were doing. Grease with swarf and grit in it is lapping compound. It's gotta go.

          Paul
          Paul Carpenter
          Mapleton, IL

          Comment


          • #6
            A guide

            This pdf file is from Arc EuroTrade in the UK and is a good start even though it relates to a new "Seig" X3 milling machine:
            http://www.arceurotrade.co.uk/projec...on%20Guide.pdf

            It is on the following link:
            http://www.arceurotrade.co.uk/Catalo...-X3-Small-Mill

            This sort of planning reinforces what Forrest Addy said - in spades!!

            Blundering around in the dark/fog is at best counter-productive.

            Near enough is not good enough, but when its perfect its near enough.

            I have a new X3 mill still all greased up/preserved waiting to be cleaned up. It is a beautiful machine.

            I intend to retro-fit a CNC package to it - when the bl**dy developer gets back to me with a quote so that I can place an order!!

            Comment


            • #7
              There's a general rule of thumb that few people ever follow and that is every machine tool should have a formal condition survey conducted on it evenry few years. Also part of annual maintenence is a thorough cleaning of all accessible parts, including minor disassembly of sheet metal, pulling gibs, checking out the electrics, tuning and adjusting of leadscrew nuts, endstops, making minor repairs, thorougly cleaning coolant sumps and systems, and so on.

              The home shop user should also conduct a complete machine tool condition survey and round of maintenence/cleaning of every addition to his inventory and probably every five years thereafter depending on annual usage. That goes for brand new machine tools as well as used.

              But there's practicality too. Few have the time, ambition. or the know-how to do all this on theor own even in well-run commercial shops. But a modest annual maintenence cycle will go a long ways to maximizing "up-time" and enhancing longevity of anything including marriages and self image.

              I'm sorry but I didn't address your core question: How much would a bedway and saddle recondition cost? Probably thoudands not hundreds for a commercial job. There's so many variables to consider to give even a ball park guess..
              Last edited by Forrest Addy; 06-06-2008, 12:46 PM.

              Comment


              • #8
                Pro-active

                As Forrest says, it is hard to beat a good pro-active maintenance schedule as it will or should find any real or pending problems in time to attend to them in an orderly manner.

                Re-active maintenance (ie "break-down" or "fubar") is the "pits" if it can be avoided. Even more so if you could have found the faults by being a bit more careful when you bought the machine. A casual "tyre-kicking" session is not much help.

                Machine beds have to be worn one helluva lot to be such that reasonably good work can't be done on it with a good machinist.

                So far the only options considered are grinding or scraping.

                I'd first consider using a planing machine aka planer as they leave a very accurate "soft-ish" finish which is ideal for a "touch up" scraping job.

                Comment


                • #9
                  Test it

                  As the subject OP machine is 20+ years old, and to get an idea of how accurate its is or maybe I'd suggest running this series of tests over it:

                  http://shopswarf.orconhosting.net.nz/hormill.html

                  [Add]
                  (Copied from my post on a coincurrent thread)
                  Machine beds have to be worn one helluva lot to be such that reasonably good work can't be done on it with a good machinist.

                  So far the only options considered are grinding or scraping.

                  I'd first consider using a planing machine aka planer as they leave a very accurate "soft-ish" finish which is ideal for a "touch up" scraping job.
                  [End]
                  Last edited by oldtiffie; 06-06-2008, 01:12 PM.

                  Comment


                  • #10
                    I changed the way felts in my lathe and its self oiling,i.e. so when the saddle moves it automatically oils etc so as chipslinger said never for me.It would be a mamoth task anyway so take care of your machine no grinding over the bed ,no woodturning if soo be meticulous about removing sludge left over as a mixture of woodchips and oiletc good luck Alistair
                    Please excuse my typing as I have a form of parkinsons disease

                    Comment


                    • #11
                      Originally posted by oldtiffie
                      As the subject OP machine is 20+ years old, and to get an idea of how accurate its is or maybe I'd suggest running this series of tests over it:

                      http://shopswarf.orconhosting.net.nz/hormill.html
                      Old Tiffie - Thanks for the link, I'm just doing enough so that I can wind it up and test it without doing more damage. As when I got it home (yes its an ebay bargain) the bed/worm screeched when I moved the X-axis. I sprayed on lubrication and got it moving freely but this warranted inspecting to know why. So after getting a copy of the owner documentation from lathes.co.uk in which only really useful info was the lubrication directions and an exploded parts diagram, I moved into exploring my buy in more detail and finding out what condition it really was in before I turn it on.

                      Luckily apart form the backlash in the worm, there was deposits rather than wear on the table to saddle beds. the only wear I can detect is about 0.00025 wear (dti and surface gauge) in the middle of the saddle to knee beds.

                      I agree, clumsy idiots should not attempt dismantle/reassemble precious equipment, but then what are they doing buying old iron machine tools? or even using machine tools at all? If one doesnt have the sense to take something apart how can one understand how to make something that goes together?

                      While this is only my second machine tool strip/reassemble I have dismantled and rebuilt racing car engines (with the aid of a haynes manual) and built/rebuilt/prepared/crashed/repaired kit racing cars (no useful manuals existing) - even at club level dismantling and inspecting engines, gearboxes and suspension at end of a season wasnt uncommon.

                      The first machine tool was a lathe I stripped, cleaned and rebuilt. It has no extant manuals since it was built sometime between 1947 and 1957. Its a Barker Bar bed 36" with MT4/MT3 and is the only one I know in existence (even Tony of Lathes.co.uk hadnt come across a 36" version). The construction of this lathe means IMHO it needs taking apart every so often to clean out the swarf from its nether regions to stop it jamming its feed system. This was the condition I found it in when I got it. But then this lathe cost me £0

                      Comment


                      • #12
                        The table and saddle on a Bridgeport: removal (and cleaning the grease
                        out of the oilers and pathways) was only a two (short) days job
                        for two of us at school last term. It is definately a two person job.
                        ...lew...

                        Comment


                        • #13
                          Originally posted by Chipslinger
                          In a home shop with good maintenance, and good practices , Never.

                          Amen.

                          A spindle does the real work, if you run big keyways (5/8"-1")you will service it every 6 months.

                          Comment


                          • #14
                            Originally posted by derekm
                            I agree, clumsy idiots should not attempt dismantle/reassemble precious equipment, but then what are they doing buying old iron machine tools? or even using machine tools at all? If one doesnt have the sense to take something apart how can one understand how to make something that goes together?
                            One need not master the intricacies of a tool's design and fabrication in order to use it.

                            It has nothing to do with "clumsy idiots" or "sense" - it's a matter of knowledge. The most elementary bit of "restoration" most machine owners do is replace bearings. And they nearly always do it wrong. I wouldn't label them clumsy idiots just because they don't happen to know enough about bearing manufacture, specifications, and fits to do the job right, or even adequately. It's something which has to be learned, and they haven't learned it. Maybe a better word would be "hubris," though that's not exactly right either.

                            Comment


                            • #15
                              I see some folks living in dreamland.....................

                              "Do more damage by disassembly"? maybe, if you are a fool.

                              HSM types very often ARE the wrong people to do maintenance, and often they do not do any.

                              "Professional" machine shops are WORSE, often doing poorer maintenance and less of it. After all, "we'll clean that after we get these jobs out". Most managers or owners of small shops will repeat that statement forever until the machine breaks down in a larger way and is scrapped or sold. Meantime, whatever tack weld or kludge gets it kinda working again is done.

                              I have taken apart and cleaned up (at least) EVERY machine I have bought used, with one exception. The exception, a Lewis mill, was very well maintained, and had been fairly recently (in machine hours) scraped-in. It came from a small shop with only two machine operators.

                              Aside from that case, invariably I find that the previous owners had put the machine together wrong, or never cleaned it, or broke/lost parts, made some incredible kludge to avoid really fixing it, etc, etc. I have to fix those things as well as dig out 40 years of chips and goo.

                              It has been well worth the expenditure of time to disassemble and clean etc ONCE when I got the machine.....

                              But, after once doing that, if you are reasonably clean in habits, you don't use air to clean chips, etc, it should be many years before you need to tear-down again.

                              A lathe chuck is another story. They get chips in them and need cleaned once a year, if not sooner. The way they are made seems to guarantee chips getting in.

                              But we were discussing mills, and I don't see why they should need that much cleaning if once they are cleaned well, and afterwards treated decently.

                              That said, IMO, anyone who owns machines, and is incapable of at least disassembly for cleaning etc without damage or "getting in over their head" should sell the lot and take up knitting.......with blunt needles.
                              1601

                              Keep eye on ball.
                              Hashim Khan

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