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  • #16
    Scraping is cool, but in the proper application.
    I do not know how to scrape. I would like to, but have not had time to learn.
    One project, I re-milled the dovetails on a Hardinge X-Y slide for a 59 lathe. I milled 10 thou off the undersides of the dovetails to remove the belly. Now the gibs are consistently tight and not loose in the middle as before. I have not scraped anything, and it is worlds better than before. So, I think scraping is great, just not the religion that it seems to be. Yes I also pulled the dowel pins and moved the leadscrew locations.
    --Doozer
    DZER

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    • #17
      Doozer-- your point is certainly well taken. You took something worn out and improved on it merely by machining. You could make it better still by improving the bearing on the now-flat way surfaces.

      Machining has its place for roughing things in...especially when new, but also when rebuilding. I could have saved myself quite a bit of time scraping in my Bridgeport knee by having it fly cut first. I didn't have anything big enough to do that work myself (about 25") on a knee that weighs maybe 400# and is the size of a v-8 engine block. I went to a shop locally that was certainly tooled to do work much bigger than that and they figured close to $1000 to flycut the flat and dovetail ways...mostly due to setup time to get it all square before cutting. I can scrape a lot for that kind of money. I spent maybe a couple hundred for scraping tools etc, and *many* hours practicing. Just think if it had been the column ways....the column way faces are maybe 40" long and the column weighs maybe 800#.....I won't be doing that on a machine either. I would venture to guess that most guys here don't have a planer...much less one of scale large enough to do lathe beds as Tiffie proposed. I would also wager that most don't want to pay what it would cost to have planed in two prismatic and two flat ways on a lathe bed.

      In short, scraping produces a longer lasting surface. Scraping and machining are not so much alternatives to one another. Rather they complement one another. Sometimes its also done instead of the prelimiary machining operation because its "portable".

      Paul
      Paul Carpenter
      Mapleton, IL

      Comment


      • #18
        Well done

        Thanks Paul.

        Good sensible well thought-out down-to-earth posts.

        I think we agree on the fundamentals here.

        It is as you say a "balancing" exercise as to just how good you want a machine to be, how you go about it and the limitations of support, costs, time-frame and the viability of new, re-newed/reconditioned/scraped etc." and "good-enough(??) old/used".

        Despite what I have said earlier, it is a wise course to take to consult/read some of the recognised relevant books and articles first so as to "get a handle" on the task ahead.

        The worst result is to "get into" "doing-up" and older machine and then for what-ever reason abandoning the project.

        But on the positive side of things "scraping" and "bedding-in" are hard to beat in terms of skill levels and satisfaction in a good job well done.

        Comment


        • #19
          I teach this stuff and I've never suggested in all my days of pontification that the machine work didn't come first. The planer hand was the scraper's best friend. If the planer hand did his job well, all the scraper hand had to do was scrape for bearing and touch up the fit a little.

          If the planer hand did poorly then like a carpenter working with an old house a long procedure of establishing initial references and slowly bringing in the alignments and fits was necessary. Careless machine work could quadriple the scraping time.

          I've planed a number of machine tools to remove wear to a "witness mark". I'm glad to say I've only been cursed by the scraper hands a little on a few occasions. My career concided with the de-ephasizing of the reconditioning restoration of machine tools.

          Like Moore's Law for electronics some other law yet unpropounded might be stated asserting a machine tool becomes obsolete some time in its life and has to be replaced with new if the shop is to stay competitive. The old machine is usually destined for the foundry ladle although a few examples may be mechanically re-conditioned and fitted with state of the art controls and axis drives.

          Re-conditioning machine tools was once took a four year apprenticeship to master. It was an outgrowth of the millwright's trade. While machie tool reconditioning may now be thought of as either the apotheosis of the machine arts or an example of puffery applied to an obsolete trade such observations in the absence of historical context is not germaine. Once it was a competitive business where most every activity returned economic value, In an age when machine work was far more expensive per unit than now a man with a scraper in cooperation with a man on the machine cound ressurrect a new machine tool from an old for about half the cost of a replacement.

          Now the manufacturing of most anything cost about 1/4 per unit that it did in the early 50's swaying the pendulum and sending worn (or merely obsolete) machines to the breakers and recyclers.

          We stuck in 1960's technology often lose sight of what's driving changes in the machine shop and part mrnufacturers as a whole. It aint a worship of the past and it aint progress for its own sake. It's return on investment. Once reconditioing was a path to conserving the productivity of plant equipment. Now the emphasis is on upgrading technology.

          The trade of machine tool rebuilder has shrunk to a small percentage of its importance 40 years ago. Only we consumers and operators of 40 year old technology have an stake in it's ressurection. I teach basic hand scraping because that's what I know. Along with the rediments of hand scraping I emphasize time and again that the rudimentary skills learned in two days has to be built on using the Connelly text, the Wayne Moore Foundations of Mechanical Accuracy and other reference etc plus a complete restoration of a small simple project machine as only a first series of steps. Only then should a home shop owner attempt to re-condition a machine for keeps. One should expect to take a couple of years to gett to that stage.

          Most will find the journey to be far more rewarding than arrival at the destination. Learning someting vast and complex will change you. Even the uses of a scraper.
          Last edited by Forrest Addy; 05-14-2008, 12:19 AM.

          Comment


          • #20
            Much of this sounds much like the age-old argument that 'I'm just a hobbyist, and it's plenty good enough for me just as it is. As a hobbyist, I don't need better than a few thou accuracy". ( "I'm just a plain man, and as a plain man ............................")

            The unspoken part of that comment is often "And neither do you"....

            Whether its true or not, if YOU believe it, that's fine.

            Others may not agree, and there is no point in tearing down another's quest for accuracy (to say nothing of plain better working).

            The Connoley book, which I have a copy of, is very good if you are interested in rebuilding machines right.

            If "rebuilding" to you means new paint and rough-sanding the rust off the ways, with maybe a little "flaking" or "frosting" to pretty it up, the book is a total waste of money and time.

            I can tell you that I have applied the information in the book, in partly or completely re-scraping machines and parts of machines. The results of correct alignment and correct procedure in establishing it, have been well worth it for me. As Forrest alludes to, the process is as good for you as the result.

            If you feel it isn't necessary for you, feel free to NOT buy the book or apply the techniques.
            Last edited by J Tiers; 05-14-2008, 12:26 AM.
            1601

            Keep eye on ball.
            Hashim Khan

            Comment


            • #21
              Recon 101

              Thanks Forrest for the sensible and very informative post.

              I am probably in the same age group as you are (71) and as I said in my recent "reconditioning/re-claiming angle plates" thread, that sort of "saving" work was part and parcel of general machine shop works. Machines were very expensive and hard to get and labour was relatively cheap in those days (late 50's and 60's).

              We had a dedicated "Maintenance" Section whose job was to install and repair work-shop and "site" machinery. They were what I think are called "Mill-Wrights" in the USA.

              I have done and see done quite a bit of work described on the planer and the plano-mill. Used effectively, they did excellent restorative work - either as "final stage" or for the "bench-hands" (Fitters) and/or "Maintenance" to hand finish.

              As you say, if done properly, there was comparatively little more to do - but it took a long time to acquire the skills to judge what to do and how to do it (scraping, "bedding" and "fitting"). Not everyone who "tried it" had the required skill-sets, patience or aptitude - and "attitude" - required!! and so a lot of people "fell by the way-side". No place at all for "yappers" or "moody buggers"!!.

              Milling machine beds/ways and table top/side faces as well as lathe beds and carriages were on the agenda after any serious wear, distortion or "dings".

              A really good operator on a planer, plano-mill or boring mill could set up really heavy stuff to very high orders of accuracy while some others were still thinking about it. They "knew" their machines and almost played them like Maestro's. It was remarkable what they could "coach" out of their machines.

              I have nothing against scraping - at all. I've seen some superb work on steam/locomotive work where there are no gaskets - just the scraped finish. Same with rotors and stators in high-pressure hydraulic "swash-plate" motors ands pumps. Some was "done to glass" where an optically flat glass plate with etched grids was used to "see" and "count" the degree of flatness of the scraped parts.

              I agree absolutely with you that it needs a lot of study and practice to get scraping "right". If it broken down into a "10-square-successive" problem/job, then every "square" has to be impeccably planned and executed in strict succession end-to-end. Scraping is not so much a "skill" but an "art" acquired over time as is most art.

              I agree to that starting to "scrape in" a machine with excessive wear or distortion (say more than 1 or 2 thou - or so) is a waste of timer and energy and a road to frustration and abandonment.

              The "uglies" of the shop that are "out of fashion" do have a use and possibly a place too - still. I refer of course to planers, plano-mills, shapers, slotters and the like.

              Despite the repetitive "canting" that I am or maybe of the "she'll be right", "get 'er done" and "that's good enough for hobbyists" "school" etc. that is only partly so.

              If a method, finish, cost, time and accuracy required can justify any or all of them in the eye of the Customer and not the "observer/adviser/critic" then if its OK with the "Customer" then its OK with me.

              Anybody and everybody is free to do as he wills with what he has and what he has or hopes to achieve toward those ends.

              That I do something my does not infer or oblige anyone else to "follow" me.

              Conversely, if I choose to do something differently to some-one else neither means that my way is better or that his wrong - at all.

              Provided we both meet our objectives and out-comes we are both equally "right" as we traverse our similar "journeys" on our separate "roads".

              Everyone must follow his own course and his own "drum".

              So, in summary, I am neither for nor against any method provided that it achieves the "Customers" outcomes within his resources.

              I am not his Judge nor Jury nor his better either.

              Comment


              • #22
                I'm in a very small minority but I found the book hard work and IMHO it didn't give enough practical guidance for an amateur. But the again it wasn't written for someone like me.
                Personally I preferred the Michael Morgan book (with all the usual discliamers - read the archive before ordering)

                Comment


                • #23
                  You're probably right Charles. The Connelly book is a reference. It's not a self-teaching text designed for the beginner. Skilled Craftsmen used it to refresh their memories.

                  One could use its initial chapters to build skill by reading trying and re-reading the skills alluded to but it would be a hard slog. A few moments with a mentor now and then during this process could clarify issues as they evolved and save much straying fromt the path and re-inventing the wheel.

                  The basic tools and their use is bone simple. Their application in re-conditioning a machine tool to gactory origianl condition, operability, and accuracy is roughly equivalent to building a complete wooden boat from lofted lines or a 2 passenger home built airplane.

                  It must be kept in mind at all times that re-consitioning a machine tool while restoring its linearity, alignments etc is a problem in many simultaneous unknowns. I teach my students the important of planning the owrk in detail early in the game. A written list of steps to be taken makes progress deliberate and avoids the mistakes bourne out of impulsiveness.

                  Scraping in a machine tool is not impossible, in fact the individual steps are quite simple. But every one of the hundreds of steps need to be taken in order and that - for a species of corner-cutters like humans - is the rock on which the wave of orderly progress breaks.

                  If one wished to learn scraping the several self teaching scraping texts like Michael Mogan's or Rich King's DVD are good places to start. Another is to scrounge up a mentor near you who once earned his living with a scraper. If you're really shot with luck maybe your local Voc-Tech school has the expertise to pass on to you. Or you could take a course on the topic such as the one Richard King advertizes on eBay or the one I teach in the home town of a volunteer organizer.
                  Last edited by Forrest Addy; 05-14-2008, 05:06 AM.

                  Comment


                  • #24
                    Tiffie, you were not really the target......... You made a point of mentioning that scraping etc has its place, and described that place. And I would never suppose you advocate the "rough sand the ways" re-build.

                    You really just reminded me of the folks who DO trot out the "Plain man" stuff..... They also tend to be against way oil, levels, and maybe any measuring past spring calipers and scales...........

                    I've never figured out why a "hobbyist" should do bad work..... There seems to be an inherent prejudice......

                    To a newspaper, a machinist at work is a professional doing fine commercial work, but what the same man using identical machines in his personal shop makes is described as "home-made". I can't quite figure that out.....

                    perhaps "home-made" to me means crude and done with unsuitable materials...... popsicle sticks and string..... that sort of thing.
                    1601

                    Keep eye on ball.
                    Hashim Khan

                    Comment


                    • #25
                      Originally posted by Charles Ping
                      I'm in a very small minority but I found the book hard work and IMHO it didn't give enough practical guidance for an amateur.
                      It's not you Charles. MTR is painful to read and follow. It was Connelly's personal rebuilding notes that he published as a book, which is hard for someone else to follow.

                      Personally I preferred the Michael Morgan book (with all the usual discliamers - read the archive before ordering)
                      I agree -- Mike's book is really well written, and very easy to follow. It's got great pictures and diagrams on how to sharpen and hone the scraper, how to hold it, and the actual scraping technique, flaking, ... It also has an excellent chapter on machine tool alignment.

                      You can buy the Mike Morgan book and video from any DAPRA distributor. I bought mine from E.S. Dyjak.
                      "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

                      Comment


                      • #26
                        My thoughts on Connelys book, which I read some time back, concern the straight edges and different guages neccessary to check the progress of the work as scraping is being done. Very recently there was a picture on here of some dovetail guages. These straight edges and other tools could be quite heavy and hard to handle for the hobby shop. And expensive for a small job. JIM
                        jim

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                        • #27
                          I'd just like Michael Morgan to finish the Bridgeport book.
                          A whole machine tutorial would be very useful.

                          Comment


                          • #28
                            A great start ot my day!!

                            Originally posted by J Tiers
                            Tiffie, you were not really the target......... You made a point of mentioning that scraping etc has its place, and described that place. And I would never suppose you advocate the "rough sand the ways" re-build.

                            You really just reminded me of the folks who DO trot out the "Plain man" stuff..... They also tend to be against way oil, levels, and maybe any measuring past spring calipers and scales...........

                            I've never figured out why a "hobbyist" should do bad work..... There seems to be an inherent prejudice......

                            To a newspaper, a machinist at work is a professional doing fine commercial work, but what the same man using identical machines in his personal shop makes is described as "home-made". I can't quite figure that out.....

                            perhaps "home-made" to me means crude and done with unsuitable materials...... popsicle sticks and string..... that sort of thing.
                            Thanks JT.

                            That post of yours started my day off just right - with a wry smile and perhaps seeing myself in a different light in some respects.
                            You made a point of mentioning that scraping etc has its place, and described that place. And I would never suppose you advocate the "rough sand the ways" re-build.
                            Yes, scraping does have its place - always has and always will. I do use it on occasion. I still have my scraping set from when I was an Apprentice - flat, bearing and 3-point/triangular. I keep them honed to a very fine edge and all get used here. As example, on the "master squares" that I made for my refinishing of my angle-plate recent post, I used both my bearing and 3-point scrapers to put the internal bevel on the ends - beats the hell out of re-setting a lathe tool to do it and I can put a bevel or radius on at will - very handy.

                            You really just reminded me of the folks who DO trot out the "Plain man" stuff..... They also tend to be against way oil, levels, and maybe any measuring past spring calipers and scales...........
                            Right on again.

                            I do tend to use traditional tools on occasion as they definitely have their place here - when needed. I have a good range of modern tools as well. I use a lanolin-based oil for preservation of my machine and tool surfaces. It is excellent, leaves a stiff "waxy" surface and is easily cleaned off just by hand spraying a new coat which melts/dissolves/softens (??) the first then both are wiped off easily with an old rag (by an old rag?? - me?? - 'fraid so). I use a light machine oil on my ways as I only light machining. "3-in-1" oil gets used sometimes and light machine oil otherwise. I clean off the preservative and re-oil before use and clean up, and re-preserve when finished.

                            I actually prefer to use spring calipers for internal measurements as I can keep to "1/2 a thou" or better quite easily. It is an art but very useful. I transfer the measurement via caliper to my micrometer or digital caliper and get very good results. It is surprising just how well it goes if I say pre-set my digital caliper and lock it and then work between it and my spring calipers. I have a full set of very good 0 - 150mm (0 - 6") outside micrometers but don't have and so far haven't needed a set of inside micrometers.

                            I have a 0 - 150mm set of very good depth micrometers but I quite like the better "feel" I get with using this item CDCO (USA) attached to my digital caliper:
                            http://www.cdcotools.com/item.php?itemid=282
                            The metric depth micrometer has a finer thread than its "inch" equivalent and it has a domed instead of flat end and id much harder to "feel" than the "inch" type with a flat end. (One for the older "inch" tools!!).

                            I am not against using levels at all. I do have a range of levels and I start off with the "roughest/coarsest" and work my way up to the level with the required degree of accuracy for the job at hand. I am 100% in favour of using a level to set a lathe/machine so that all ways etc. are co-planar -as well as other methods mentioened in previous posts. But once "set" I am not obesessed with having the machine "level" as long as it retains its co-planar settings/repationships. I have to admit that there have been (too?) many times that I've wished that the damn machine was dead level!! (Penance/retribution??).

                            I've never figured out why a "hobbyist" should do bad work..... There seems to be an inherent prejudice......
                            I agree with you 100% as that bad attitude is based on prejudice and bull-****!! Just refer anyone with that attitude to this site/forum as it will damn soon set them right - your work and that of Lane and Marv Klotz are good for starters - and there are plenty of others.

                            To a newspaper, a machinist at work is a professional doing fine commercial work, but what the same man using identical machines in his personal shop makes is described as "home-made". I can't quite figure that out.....
                            Again - 100%

                            If you were to say have it revised to be machinists doing professional/"quality" work either or both in a home/hobby or commercial shops .................... it would be better.

                            Not all machinists who work in commercial shops are 100% competent - but I'd guess that 90% are. Some are not much better than process workers. That they got a job in a commercial shop does not imbue them with competence.

                            Only sheer skill and experience - as well as the right frame of mind or "attitude" can or will do that. There are any amount of competent machinist who meet those criteria on this forum - including those who "picked it as as they went along"!!!

                            At least on this forum people ask, discuss, assist and advise where-as some so-called "Professional" machinists are "up themselves" and regard "that sort of sh$t" as beneath them because "they (just) know it" (all?).

                            The people on this forum and many of those who are sudents or Teachers in the Vocational Educational system are good examples of the points I was making regard "good" attitude in my previous paragraphs.

                            perhaps "home-made" to me means crude and done with unsuitable materials...... popsicle sticks and string..... that sort of thing
                            Again - agreed 100%!!

                            That implies "cottage industry".

                            I will wear that badge with pride any time!!!

                            There is heaps of excellent work carried out in "home-based" shops!! Many businesses are attached to the house or in a shed or shop of varying size on this forum and there is some fabulous work comes out of them. Its even better as many achieve extraordinary results with limited resources and sheer grit, determination, versatility, adaptability and ingenuity. They are versatile and "nimble" without the "baggage" (and bureaucracy/"management") of the bigger "commercial" shops.

                            And they help each other!!!

                            Small shops and home shops are the nursery of the economy and the technological edge that we need. The level of skills and dedication is something that "big" shops cannot buy but can only hire.

                            But in all fairness there are some extraordinary people achieving at extraordinary levels in both small and large "developmental" environments.

                            Well, that's it Jerry - thanks heaps - as I said - you "sparked" and "made" my day.

                            Comment


                            • #29
                              Originally posted by oldtiffie
                              I agree with you 100% as that bad attitude is based on prejudice and bull-****!! Just refer anyone with that attitude to this site/forum as it will damn soon set them right - your work and that of Lane and Marv Klotz are good for starters - and there are plenty of others.
                              Tiffie, I'm not sure what you're going on about, since this thread is about Connelly's Machine Tool Reconditioning JTiers took exception when you implied that Connelly's scraping techniques aren't necessary for the home-shop machinist. I agree -- look at the fine scraping examples by McGyver, Paul Carpenter, and Stephen Thomas.

                              But now you're going on about bad attitudes, which we surely have enough of here lately, but I don't see how that relates to Machine Tool Reconditioning.

                              In any event, I don't know if you realize this, but Lane is a professional machinist, and Marv is not -- he's a retired physicist (i.e., a true hobbyist). They couldn't be from more different backgrounds

                              They're both incredible craftsmen though...
                              Last edited by lazlo; 05-16-2008, 10:51 AM.
                              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

                              Comment


                              • #30
                                Originally posted by Charles Ping
                                I'd just like Michael Morgan to finish the Bridgeport book.
                                A whole machine tutorial would be very useful.
                                Funny you should mention that Charles -- when I contacted Mike last Summer about buying his scraping video and book, he replied that "Contrary to popular belief, the Bridgeport book is almost done."

                                I didn't even mention the Bridgeport rebuilding book, so I gather that's a sore point for him
                                "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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