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How to cut an internal helical oil groove

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  • #16
    Helical grooves are not needed just cut a groove around the I.D. where the oil hole is then using a boring bar to cut grooves lengthwise every 90 degrees from the oil hole that end where the helical grooves ended.

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    • #17
      Originally posted by panhead dave
      Helical grooves are not needed just cut a groove around the I.D. where the oil hole is then using a boring bar to cut grooves lengthwise every 90 degrees from the oil hole that end where the helical grooves ended.
      No oil hole - oil gets in from the ends through the grooves...

      -J

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      • #18
        http://www.oilite.com/bearings.asp

        if you go there, and under "Cast bronze", there is a pdf called "Design Details" and they illustrate and talk about usage for several different groove patterns of internal bushings (nothing about the "how" though)

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        • #19
          I have cut them by hand in my lathe, find the coarsest thread you can cut, if not fast enough change a couple of gears, set up a boring bar with small radius tool in it, move tool into the bore where you want to start, engage half nuts, now this is where you get to play, put head stock in neutral, move tool in close don't touch the bore, now turning the chuck by hand watch where your tool bit is just before you get to the reverse point change from right hand threads to left hand threads, continue turning chuck till tool gets back where you started, switch back to right hand, if you like what you saw, move tool in to the bore and set tool for a chip .010" or .015" start turning the chuck by hand, until you almost get to the end switch to left hand and continue turning till you get back to the beginning if the cut doesn't match open half nuts and turn till your back at the start.

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          • #20
            Mount a cam follower on the saddle, and use hand pressure on the saddle feed handwheel to make the saddle follow a cylindrical cam mounted on the work or on the chuck. At your lowest speed, you should be able to make the saddle follow the cam. If not, you could spring load the saddle against the tailstock (in that case, remember to disengage the saddle feed pinion). If you have enough hands and strength and patience, you might be able to turn the chuck by hand.

            The cam follower can just a piece of drill rod, or aHSS cutter with the business end ground to a rough cylindrical profile. For a one-off or once-in-a while job, you can cut the cam out of a flat piece of sheet metal. Roll or bend it into a cylinder, and weld or rivet tabs to the cam as required to attach it to the chuck. Alternatively, you might also be able to wrap the sheet metal cam around the workpiece and and chuck it with the work. So long as the cam follower is mounted on the saddle or the cross slide, you can use the compound to adjust your depth of cut.
            Last edited by alsinaj; 02-23-2012, 04:20 PM.

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            • #21
              Originally posted by JRouche
              I know you aren't looking for a hack job but here is my hack job
              Well it might not be as slick as auto feed would do, but it's a pretty common way to make an oil groove. I've done several that way and a buddy as done a few dozen that way. It' just needs to be a channel for oil to flow so it doesn't need to be pretty unless a customer demands it.

              Works every time.

              I usually use a die grinder with a small dia. cutoff wheel to make the channel.

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              • #22
                Originally posted by RussZHC
                http://www.oilite.com/bearings.asp

                if you go there, and under "Cast bronze", there is a pdf called "Design Details" and they illustrate and talk about usage for several different groove patterns of internal bushings (nothing about the "how" though)
                Thanks Russ...

                The document states "Small diameter and relatively short-length bearings do not require grooving for oil distribution" Wonder what they mean by small diameter and relatively short? 1" diameter and 2" long could be small diameter and relatively short depending on your perspective.. No groove is the easiest one to cut...

                Looks like they recommend an oval groove - gives me a headache thinking how to cut that on a manual machine..

                Originally posted by duckman
                I have cut them by hand in my lathe, find the coarsest thread you can cut, if not fast enough change a couple of gears, set up a boring bar with small radius tool in it, move tool into the bore where you want to start, engage half nuts, now this is where you get to play, put head stock in neutral, move tool in close don't touch the bore, now turning the chuck by hand watch where your tool bit is just before you get to the reverse point change from right hand threads to left hand threads, continue turning chuck till tool gets back where you started, switch back to right hand, if you like what you saw, move tool in to the bore and set tool for a chip .010" or .015" start turning the chuck by hand, until you almost get to the end switch to left hand and continue turning till you get back to the beginning if the cut doesn't match open half nuts and turn till your back at the start.
                Would using the thread dial accomplish the same thing? I think a variation of this method be able to cut an oval groove?

                Originally posted by alsinaj
                Mount a cam follower on the saddle, and use hand pressure on the saddle feed handwheel to make the saddle follow a cylindrical cam mounted on the work or on the chuck. At your lowest speed, you should be able to make the saddle follow the cam. If not, you could spring load the saddle against the tailstock (in that case, remember to disengage the saddle feed pinion). If you have enough hands and strength and patience, you might be able to turn the chuck by hand.

                The cam follower can just a piece of drill rod, or aHSS cutter with the business end ground to a rough cylindrical profile. For a one-off or once-in-a while job, you can cut the cam out of a flat piece of sheet metal. Roll or bend it into a cylinder, and weld or rivet tabs to the cam as required to attach it to the chuck. Alternatively, you might also be able to wrap the sheet metal cam around the workpiece and and chuck it with the work. So long as the cam follower is mounted on the saddle or the cross slide, you can use the compound to adjust your depth of cut.
                hmmm - let me think about that - sounds repeatable and consistent..

                Jason

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                • #23
                  The document states "Small diameter and relatively short-length bearings do not require grooving for oil distribution" Wonder what they mean by small diameter and relatively short? 1" diameter and 2" long could be small diameter and relatively short depending on your perspective..
                  Can't tell you the number of times I've screamed inwardly when encountering similar statements esp now as I see machinery of hugely different sizes. The factory bronze bushings in my lathe are that figure "8" IIRC and at some point I suspect I will attempt to install new ones and the way I am leaning right now is oil hole (which apparently is not used in your example?) with a single groove along the length of the bearing approximating the point relative to the ends that the "8" does, its less than 1000rpm so I don't think it matters a bunch.
                  If you are interested in a more general discussion/food for thought, try the last posted item here: http://bbs.homeshopmachinist.net/showthread.php?t=52466

                  have not read it all in-depth but shall we say, 'interesting'

                  FWIW, I think the cam idea is worth pursuing (power feed with a rotab on a vertical mill?)

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                  • #24
                    Originally posted by jason.weir
                    ...

                    Can't take credit - not my ideas - stole them from here

                    http://shovelhead.us/forum/showthread.php?t=50023

                    The writer Ray is without a doubt a great machinist hiding on a Harley forum..
                    ...

                    Jason
                    I hang out there once in a while as well Jason and yes, Ray does know his way around a Harley and a machine shop.

                    Don't know if you have seen this thread at the Shoelhead forum but in it Ray vaguely describes his technique in post #13.

                    explain,you want me to explain...hum cannot tell all my secret,

                    Here it is...touch the cutter inside the bushing with lathe turning,take it out,take the depth of cut you want in this case .025 diametral cut,turn the lathe to about 40 RPM,turn the cariage in all the way through at a slow pace and come back at the same speed...voila you have the perfect oil groove.
                    Although it sounds like a bit of finesse is required, with a bit of practice I can definitely see this working. Next time I have a few spare moments in the shop I'll have to give it a whirl on some cheap pieces of steel, aluminum or plastic tubing just to see how long it takes for me to hone my timing down to a consistent level. I have done it externally before with repeatable results. The Helix does not have to meet a designated standard so this last point alone takes the pressure off of getting it "right" .
                    Home, down in the valley behind the Red Angus
                    Bad Decisions Make Good Stories​

                    Location: British Columbia

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                    • #25
                      You can use the turning of the chuck to wind up a steel cable, which would pull the carriage along. The cable would have to go through one right angle, so you'd mount a little pulley temporarily to accommodate this. If the carriage moves too fast because of the diameter available to wind the cable on, then you could get a 2-1 reduction by mounting a snatch block on the carriage and threading the cable through it and bringing the end of the cable back to a fixed point near the headstock.

                      It looks like the OD of your part can be the winch drum. One revolution of the spindle will pull the carriage along pi times d. You'll be in the realm of inches per turn rather than turns per inch.

                      You could possibly arrange a smaller diameter at the other end of the spindle to wind the cable onto. If it was about 3/8 diameter, you'd roughly be getting 1tpi. If the diameter of the makeshift drum was .622, and you used a guitar string of about .030 diameter as the cable, plus you used a snatch block on the carriage, you'd be at almost exactly 1 tpi.

                      Note that you'd have to back the cutter away, then rotate the chuck by hand while moving the carriage to the right to get set up for a second pass.

                      If you used this method, you might want to consider alternatives to steel cable or guitar string. Modern fishing line could be a good option- I just bought some Tuf-Line, which is a very small diameter, very flexible, low stretch, high breaking strength line. What I got you can barely feel in your fingers, but it's rated at 130 lb. Using a snatch block, it would give you a pull of 250 lbs on the carriage before breaking. If you doubled or tripled it, there'd be enough overkill that you could get the job done without fear of it breaking, and it will be a lot easier to wind on a small diameter stub than steel wire. It wouldn't take much effort to turn up an insert to fit the left end of the spindle with the stub drum on it, and you could probably just lay the line around the headstock and on towards the carriage. The line is very slippery and abrasion resistant, so I think it would work well like that.

                      Just another idea that I know will work.
                      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                      • #26
                        For a captured (figure 8) groove, the standard easy method is to simulate the function by cutting a shallow ID groove on either end, then cut the groove with the leadscrew from one groove to the other, then backward from the other end to have two. Difficult to do and not make them cross unless you've got a really fast lead setup. Doesn't make a figure 8, but it's a captured oil groove and it's all done on the machine. I know it can be done that way but I never do it that way myself. I just use a die grinder and cut them by hand. Even if it's squiggly and inconsistent, it's entirely functional. You can make the fairly pretty if you're careful and take your time. Wouldn't hurt to mark a line with a sharpie first to follow if you want a little pattern to follow.

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