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  • Vibrating Media Polisher Thoughts...........

    I have several sections of drawn aluminum tube of various diameters, ranging from 3/16" solid and 3/8" through 3" tubular and the longest lengths are about 8'. I need to polish them back to a bright mill finish and clean up the ID's a little as well.
    Forget the hand polishing and that stuff.
    My idea is to make a plywood box big enough to accommodate the longest tube and maybe 12" x 12", like a tank sort of so I can put a few pieces in at a time. I'll have to find a polishing media that will do the job and I'm looking for ways to vibrate the box. I don't want to shake it, I want to vibrate it.
    Just like a vibratory cleaner that you would use to polish spent brass cartridges when you reload. Any ideas?????

    I have a small vibrating polisher that I use to polish my brass. I use crushed walnut shells and some red powdered jewelers rouge and the brass comes out shiny and bright.

    JL....................
    Last edited by JoeLee; 07-27-2016, 02:19 PM.

  • #2
    You think a plywood box is going to hold up to the polishing media? An easy way to impart vibration on a structure is to bolt a motor to it that has an unbalanced flywheel on the shaft. You'll need a large motor for an 8' long box. The other way to go is to make it a tumbling box, which I think will work better and be easier on the equipment and can be done with a 1/2hp motor. Maybe a shaft out each end running in a bearing and a circular support of some sort in the middle if needed. I use a rotary tumbler and stainless steel pins for my reloading brass and they come out brilliant in a couple hours.

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    • #3
      Not sure how much luck you will have doing aluminum dry. I think the media will quickly load up. We used to tumble with water mixed with some sort of cleaner and even dirty water was enough to prevent the media from working.
      George
      Traverse City, MI

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      • #4
        I suspect that coarse sand is going to be what you want to use for a media. This isn't a pound or so of dirty brass cases and you need something far more aggresive than corn cob media.

        To get at all the surfaces equally I'm also thinking that a larger pipe section and rolling it with the rods, tubes and coarse sand inside would be both easier and give better results than a plywood box. Besides, by the time you get enough energy into that heavy a box filled with the metal and media you WILL have to shake it. It may be a rapid and short stroke sort of shaking but it'll be shaking all the same. The wood will simply soak up any lesser amplitude and higher frequency energy such as a basic vibrator would provide.

        The other way to vibrate it would be with three or four air operated vibrators such as mold makers use in foundry work. You'd need more than one because here again outside of a couple or three feet away from the vibrator the wood box and loose media would soak up and damp out the energy.

        If you make a smaller size box it would also be much easier to shake it correctly. It means doing the work in smaller batches but it would be more effective with less power into it.

        Frankly I like the idea of a tumbling box. If you make it octagonal and make the 8 side segments such that the final product fits snuggly into a sturdy mountain bike wheel rim you could use the rims as both binding and shape holding hoops and at two locations put tires on them and run the tires against a set of rollers or similar to let the whole works turn without end shafts and bearings. If you opt for this be aware that the rims will need to all be of the same type or measured to ensure the inside diameters are all the same. I'd likely use 5 or 6 of them on an 8 something foot long drum. And even then I'd wrap the form with lots of strapping tape or similar to bind the joints.
        Chilliwack BC, Canada

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        • #5
          IMHO I'd make one out of a 15 or 30 gallon steel drum & make it turn not vibrate. You can make driven rollers it sets in. Easy to make & will clean better & last longer.

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          • #6
            Originally posted by gzig5 View Post
            You think a plywood box is going to hold up to the polishing media? An easy way to impart vibration on a structure is to bolt a motor to it that has an unbalanced flywheel on the shaft. You'll need a large motor for an 8' long box. The other way to go is to make it a tumbling box, which I think will work better and be easier on the equipment and can be done with a 1/2hp motor. Maybe a shaft out each end running in a bearing and a circular support of some sort in the middle if needed. I use a rotary tumbler and stainless steel pins for my reloading brass and they come out brilliant in a couple hours.
            I could line it with heavy plastic perhaps....... I don't know about tumbling, if done that way I wold have to make a top for the box.
            Tumbling several pieces at once would probably result in a lot of little dings and abrasion marks.
            I thought of the motor with an off set weight but that would be more like a shaker rather than a vibrator.

            JL....................

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            • #7
              Originally posted by JoeLee View Post
              I could line it with heavy plastic perhaps....... I don't know about tumbling, if done that way I wold have to make a top for the box.
              Tumbling several pieces at once would probably result in a lot of little dings and abrasion marks.
              I thought of the motor with an off set weight but that would be more like a shaker rather than a vibrator.

              JL....................
              I don't think there is a difference between shaking and vibrating, other than some arbitrary choice of transition frequency.

              If you want higher frequency, use the motor to drive an unbalanced shaft at a higher speed by belt, chain or gear.

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              • #8
                If the box were set up so it's on springs and then a link shaft to a motor with an offest shaft was used that would shake/vibrate it well.

                As cameron says it's a highly arbitrary difference between shaking and vibrating. The whole idea is to get the box to move the media and the media to move against the stock.

                Keep in mind that the media needs to be filled higher than the items for this to do a proper job. So again to limit the amount of media needed and the power needed to shake or vibrate that much mass you'll need to limit the size of the box to something more compact and lighter and only do a few pieces at a time. So a 3450rpm motor running from a link rod with a 1/4 inch offset is going to move that stuff in the box pretty well. The motor is going to need to be well secured too or it'll just shake itself. And it likely won't be good for the bearings.
                Chilliwack BC, Canada

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                • #9
                  I'll throw my socks in with flylo so rotation, I normally stick it in the lathe, I borrowed a tube polisher a while back, anyway, 10" plastic pipe like gas or water on rollers, trolley wheels would do, stick a belt round to a motor, blasting grit (cheap) crushed glass gravel whatever, in with the pipes and let it rumble for an hour see how it goes
                  Mark

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                  • #10
                    Sand isn't gonna polish them, it will give a coarse finish similar to sandblaكting. Done it in a rotary polisher to deburr.

                    Finer stuff followed by nut hulls etc with rouge or whatever will clean and polish.

                    Don't do coarse, or you may end up with "highly polished, deeply scratched" as a result.
                    CNC machines only go through the motions.

                    Ideas expressed may be mine, or from anyone else in the universe.
                    Not responsible for clerical errors. Or those made by lay people either.
                    Number formats and units may be chosen at random depending on what day it is.
                    I reserve the right to use a number system with any integer base without prior notice.
                    Generalizations are understood to be "often" true, but not true in every case.

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                    • #11
                      Well, you're likely right and sand would leave a bit of a matt looking finish. But then he didn't say just how degraded they are. If these pieces have heavy corrosion on them it may require a two or three stage process to first roughly clean the pieces. Then something medium in abrasive qualities to smooth the initial cleaning. Then finally to fine finish them back to a freshly bought look. Or if they aren't that bad maybe just the medium then fine or maybe even only the finer stuff.

                      Most of the aluminium stock I've bought seems like the sort of finish I'd get if I tumbled or shook parts for a while in fine silica sand such as used for lighter sandblasting jobs. Shaking or tumbling with the sand would not be as aggresive as actually sandblasting.
                      Chilliwack BC, Canada

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                      • #12
                        It seems like the 8' long sections are going to be a challenge. You say you have several sections to polish. That suggests this is not an on-going need, just a one off? That makes a difference - in durability, and how much capacity you need to have. It sounds like you could do one tube at a time, and that there is no hurry.

                        What happens if you put a piece of aluminum tube in a piece of capped pvc with media and water and tumble it? You could easily test that with a small mock up. The wear on the PVC might be a non-issue for the several tubes you mention.

                        You could put an 8' long structure on springs and vibrate it with a motorized shaft connected at multiple points. What is the natural frequency of the 8' long structure, and does that come into play?

                        I'd check into how the commercial solutions do it, to get an idea what will definitely work.

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                        • #13
                          Originally posted by BCRider View Post
                          Well, you're likely right and sand would leave a bit of a matt looking finish. But then he didn't say just how degraded they are. If these pieces have heavy corrosion on them it may require a two or three stage process to first roughly clean the pieces. Then something medium in abrasive qualities to smooth the initial cleaning. Then finally to fine finish them back to a freshly bought look. Or if they aren't that bad maybe just the medium then fine or maybe even only the finer stuff.

                          Most of the aluminium stock I've bought seems like the sort of finish I'd get if I tumbled or shook parts for a while in fine silica sand such as used for lighter sandblasting jobs. Shaking or tumbling with the sand would not be as aggresive as actually sandblasting.
                          The tubes are just tarnished and discolored. There is no corrosion, pitting or scaling. Like you say I just need to get them back to the freshly bought look.

                          This is more or less just for a one time deal.

                          I don't know if shaking would cause enough rubbing of the media against the tube. I'm thinking that a high frequency vibration would sift the media around the tube where shaking may just shake everything at the same time causing little to know rubbing of the media against the tube.

                          If I were to do this with a motor and an off center weight, the weight would have to be very close to the center of the shaft and spin at a high speed to vibrate, a slower turning motor with a weight positioned further from the shaft wold tend to cause more of a shake.

                          JL..............

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                          • #14
                            I'm thinking rotating drum like a rock polisher. I have no confidence in the vibrating system.
                            CNC machines only go through the motions.

                            Ideas expressed may be mine, or from anyone else in the universe.
                            Not responsible for clerical errors. Or those made by lay people either.
                            Number formats and units may be chosen at random depending on what day it is.
                            I reserve the right to use a number system with any integer base without prior notice.
                            Generalizations are understood to be "often" true, but not true in every case.

                            Comment


                            • #15
                              For a one time deal with sections of such sizes, I'd be using a buffer. You can get a lot done in a short while with a soft buff and compound.
                              Cheers,

                              Frank Ford
                              HomeShopTech

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