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Newbie Question: Lathe Leadscrew Handwheel

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  • #16
    Originally posted by Mcgyver View Post
    thats what mine was. As is my horizontal mill, its just not an issue. For all the naysayers - ever had a lathe with one? Until then.....

    ....
    Yes I did.

    It was a big advance to move up to a regular rack feed, the more so as that machine ONLY had the hand wheel or halfnuts as options. With both the rack and the handwheel, might be OK. I have thought about putting on a fine feed attachment. I would NOT go a handwheel.

    The point was not that a handwheel is BAD, just that it is not the only, nor even the best, way to go. If it was so good, it would be a standard feature. But it is not, for the vast majority of lathes ever made.

    It is less accurate than a DRO, less accurate than a micrometer stop. Has a LOT of places for slop and backlash that need to be taken up, and which may kill precision unless all operations are done at one closing of the half nuts. And the dial calibrations are a problem for nearly any imperial leadscrew other than 8 tpi.

    Could be pretty nice as a fine feed, though. THAT feature was good.
    4357 2773 5647 3671 3645 0087 1276

    CNC machines only go through the motions

    "There's no pleasing these serpents"......Lewis Carroll

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    • #17
      The point was not that a handwheel is BAD, just that it is not the only, nor even the best, way to go. If it was so good, it would be a standard feature. But it is not, for the vast majority of lathes ever made.
      Was the handwheel not a very common fitment for small lathes? Seems UK makers used to put them on just about everything except where the bed was so long as to make them impractical?

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      • #18
        If the topside is positioned at an angle, the graduations on the topslide handwheel aren't going to correspond to the actual movement of the tool parallel to the bed ways. That can be solved by using a dial indicator between the carriage and the bed, which will enable you to make precise movements of the carriage using the carriage handwheel.

        If you're really lucky, your lathe will have a graduated dial on the carriage handwheel, like the one on a Jet 1024P and similar machines. It'll spoil you in short order. Of course, it's something you can make for your lathe with your lathe.
        Any products mentioned in my posts have been endorsed by their manufacturer.

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        • #19
          Originally posted by winchman View Post
          If the topside is positioned at an angle, the graduations on the topslide handwheel aren't going to correspond to the actual movement of the tool parallel to the bed ways. ....
          Oh, that's not the issue. at an angle, you can fairly easily and accurately estimate the feed, at least at certain angles. And there is no need to mentally add numbers and fractions to arrive at the travel.

          The issue is that with, say, 16 tpi, which is reasonably common on a leadscrew, you end up with fractional thousandths.... The dial cannot be marked with even increments accurately. In the case of 16 tpi, the advance per turn is 62 1/2 thou. Ylou have a fraction of a thou left over. Same with 6 tpi (used on several brands), which results in a similar situation. The case of 8 tpi is 125 thou per turn, which is reasonably easy to keep track of in your head. Nearly any other leadscrew pitch that has actually been used is basically unworkable for a dial.
          4357 2773 5647 3671 3645 0087 1276

          CNC machines only go through the motions

          "There's no pleasing these serpents"......Lewis Carroll

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          • #20
            Originally posted by winchman View Post
            If the topside is positioned at an angle, the graduations on the topslide handwheel aren't going to correspond to the actual movement of the tool parallel to the bed ways. That can be solved by using a dial indicator between the carriage and the bed, which will enable you to make precise movements of the carriage using the carriage handwheel.

            If you're really lucky, your lathe will have a graduated dial on the carriage handwheel, like the one on a Jet 1024P and similar machines. It'll spoil you in short order. Of course, it's something you can make for your lathe with your lathe.
            If the lathe didn't come stock with them then it was often an option in some cases. But such a hand wheel is only practical on shorter beds. Anything much over 20 to maybe 24 inches and it's too far to reach and still see what you're doing.

            I'd also suggest that a handwheel on the smaller lathes made more sense not so much for the size of the lathe as the small size and travel of the compound. A handwheel on the lead screw gave one a far better range of travel "by the numbers" than would be possible with the shorter compound travel amounts often found on the smaller lathes. And on the larger machines this isn't as much an issue.

            My 12x36 Taiwanese Longem lathe has a graduated handwheel for the rack travel. But it's fairly coarse at .02" per division. I could guess at .005 increments within the rather wide mark spaces but being a rack instead of a screw I'm not sure I could trust it to within plus or minus that same .005. It would only take a small bit of swarf to ruin it.
            Chilliwack BC, Canada

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            • #21
              My 70's Myford Super 7 long bed version came fitted with the leadscrew handwheel accessory. Problem is, with
              the long bed, it takes a step or two away from watching the cut whilst doing so. Never used.
              I visited the UK twice in the 80's and came back with a vernier dial assembly that fits behind the apron handwheel.
              Works similar to the usual crossfeed dial with the added feature of a vernier for really fine movements. Works rather well.
              While it's a nifty gadget, a Mitutoyo digital caliper modded (cut jaws off) into a saddle DRO is the day to day device.
              Cheers, RichD, Canton, Ga
              RichD, Canton, GA

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              • #22
                If your handwheel has some slack or rotational play in the gearing, you can bump it against the gears to lightly tap the carriage forward in tiny increments. Great trick for facing.

                Sent from my XT1053 using Tapatalk

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                • #23
                  Wasn't an option that I know of on many US machines.

                  The old AA did have one, but no dial (the AA had no dials for anything, and used 16 or 24 tpi for lead and feed screws)

                  I don't know of an option for a handwheel on Atlas, Southbend, or Logan, which are the machines that would have been most commonly aimed at the small shop or hobby work. Industrial machines would just not get involved with that sort of thing.
                  4357 2773 5647 3671 3645 0087 1276

                  CNC machines only go through the motions

                  "There's no pleasing these serpents"......Lewis Carroll

                  Comment


                  • #24
                    It may be significant, or it may not, but as you know lathes made in the UK commonly had the carriage wheel to the right of the carriage meaning the operator would have normally stood closer to the tail stock than on machines with the carriage wheel to the left. Standing to the right would bring the lead screw wheel closer to hand.

                    Tiny UK lathes such as my Flexispeed have a lead screw wheel and no wheel on the carriage, my 1908 Drummond had a handwheel on the lead screw and no wheel on the carriage whereas my Grayson lathe has both.

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                    • #25
                      If you have never had a lathe with a handwheel on the right hand end to turn the leadscrew, then you shouldn't be running your mouth about what a terrible idea it is. I found it to be just about one of the handiest features on the lathe.----Brian
                      Brian Rupnow
                      Design engineer
                      Barrie, Ontario, Canada

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                      • #26
                        Just a quick trial.

                        My Myford ML 10 as built had three ways to move the carriage, either a handwheel geared to run on the leadscrew, or a handwheel on the right hand end, or the gear train driven from the mandrel. I had a spare 125 graduated collar and added that to the right hand end of the leadscrew. Given the recent controversy about the usefulness of a graduated handwheel when I needed two spacers about 1 1/8 th long so just for fun I quickly parted them off using the graduated collar and my finger against the parting tool and end of the work to get the length. The two spacers measured 1.123 in and 1.124 in long, plenty good enough for what was needed. I also have dial gauges for cross and lengthwise travel, for circumstances when I need to chase the very last thous. What can be easier and quicker than counting nine turns exactly and parting off ? Regards David Powell.

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                        • #27
                          Originally posted by brian Rupnow View Post
                          If you have never had a lathe with a handwheel on the right hand end to turn the leadscrew, then you shouldn't be running your mouth about what a terrible idea it is. I found it to be just about one of the handiest features on the lathe.----Brian
                          Hey..... Bite me.*

                          I HAVE had one. It was no big deal, not very handy for me, in fact it was a pain. I was HAPPY to get rid of it and have a lathe that did not have one. Never have missed it since. It's not a "terrible" idea..... it just has never been that handy. A way over-rated feature with disadvantages.

                          The GOOD part about it was it gave a fine feed. That was OK.

                          The BAD part about it was that the fine feed was too fine (0.0625 per rev), and so gave almost NO feedback as to cutting forces, so it was possible to mess things up too easily. It had a ratio more appropriate to a heavy lifting jack, resulting in a very slow feed, slower than was ever wanted.

                          Plus, it was too fine to traverse the carrriage any distance before next week. So you had to disengage it, move the carriage, the engage again and do your slooooooooowwwwwww feed again.

                          Many lathes seem to feed at about an inch to an inch and a half per turn with the rack. A feed of maybe a quarter inch per turn would be about right, about 1/6 of the regular rate. That would be plenty fine enough, and yet not so fine as to function more like a house-movers jack than a lathe accessory.

                          I thought of putting a dial on the one I had, but at 62.5 thou per turn, it would have had way too much mental math involved with using it. So I never bothered. If it was a standard decimal rate feed in mm or inches, that would have been OK

                          * Turnabout is fair play
                          Last edited by J Tiers; 03-26-2017, 10:42 AM.
                          4357 2773 5647 3671 3645 0087 1276

                          CNC machines only go through the motions

                          "There's no pleasing these serpents"......Lewis Carroll

                          Comment


                          • #28
                            I wouldn't have wanted one on a lathe with a 30" or 48" carriage. However that lathe in the picture was a 10 x 18" lathe, and I found it to be just fine. I never noticed that it was particularly slow. If I wanted to move the carriage any large amount, I just disengaged the power to the leadscrew (it had a lever for that) and moved it with the big wheel on the front of the apron. So much of the machining I do was short lengths that were best accomplished with that handle on the right hand end. That old green lathe, like my new lathe had a very coarse feed on the apron wheel. It was just awful getting any accuracy of movement with the wheel on the apron.
                            Brian Rupnow
                            Design engineer
                            Barrie, Ontario, Canada

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                            • #29
                              I used to have a little 6x18 Craftsman 109 model, and outside of sliding or tapping the carriage to get to the desired position. Sold it 7 or 8 years ago for $200. I cannot imagine having or using one on a much larger lathe.

                              Dan L
                              Salem, Oregon

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                              • #30
                                I also never had any problem using mine. My Compact 10 has one... and it will get put back on when I do a (planned) conversion to ball screws.

                                My big lathe is a PITA to move the carriage by small desired amounts - yes I use a DTI but the hand wheel is "coarse" so it comes down to dragging the lock and bumping rather then turning it. Hand wheel isn't practical (6 feet away from chuck), but I need a fine adjuster mechanism.
                                Last edited by lakeside53; 03-26-2017, 12:07 PM.

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