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1000 pieces, whats the best way to tackle this?

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  • #16
    Agree, after about 250 pc that is going to be like carrying bricks for the Babylonians.

    It would not be so bad except that every drilling operation has almost no tolerance, you have a 1/16" wall to stay out of. I think you almost have to do that in the lathe to ensure it goes straight.

    It might pay you to find a couple drills like the pics below (solid gun drills), they drill straight and do not wander, but you need to have a starting recess for them, they will not start on a surface. And they do not get chips out very well, unless they are "coolant through" types, which is what you really need, they would blow out chips and make it easier.

    Getting the workpiece centered, and straight, within about 25 thou is going to be key.... even if you drill straight, you need that to be straight doen the middle, not straight out the side......

    Possible to see a pic from the side with a ruler? Might make the hard part a little clearer, showing the distance between flanges.





    Last edited by J Tiers; 12-12-2017, 02:12 PM.
    1601

    Keep eye on ball.
    Hashim Khan

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    • #17
      More pictures.

      I've got high hopes the drills will work better with cutting fluid, ill know later today. It's definitely not going to be fun doing 1000.

      Sent from my SM-G930W8 using Tapatalk

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      • #18
        However you end up doing them now, I suggest that YOU suggest to revise the part to use an aluminum extrusion WITH a through hole for an insert next time.

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        • #19
          Originally posted by Dan Dubeau View Post
          However you end up doing them now, I suggest that YOU suggest to revise the part to use an aluminum extrusion WITH a through hole for an insert next time.
          I agree. It may not be offered by the manufacturer presently, and this 1000 piece quantity is a 6 year supply, so they probably wouldn't be interested enough to do custom extrusions for this one part. A common small company problem.

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          • #20
            Ow..... You got yourself a pup there........

            The thin area is shorter than I thought, though. That's a good thing. Gives you a better chance.

            I'd have suggested a smaller dia drill, but they are worse on chip removal, and I do not know of solid gun drills under 1/8".

            Originally posted by Dan Dubeau View Post
            However you end up doing them now, I suggest that YOU suggest to revise the part to use an aluminum extrusion WITH a through hole for an insert next time.
            Darn good idea.... extrusion dies are (or were) cheap as of the last time I had to get one.

            Except it they actually need that shape in the middle and the end.... that is pretty anti-extrusion.
            1601

            Keep eye on ball.
            Hashim Khan

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            • #21
              Originally posted by J Tiers View Post
              Ow..... You got yourself a pup there........

              The thin area is shorter than I thought, though. That's a good thing. Gives you a better chance.

              I'd have suggested a smaller dia drill, but they are worse on chip removal, and I do not know of solid gun drills under 1/8".



              Darn good idea.... extrusion dies are (or were) cheap as of the last time I had to get one.

              Except it they actually need that shape in the middle and the end.... that is pretty anti-extrusion.
              After looking at it more, I'm pretty sure that aluminum part is actually an extrusion now. Not sure I understand what anti extrusion shapes you're talking about. I'm not saying make the whole part from an extrusion just the insert, and with a hole next time.

              Either way, sounds like an entire life cycle of parts is run off, and modification of what's there is the game plan. Just the way she goes.

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              • #22
                "I'll also try with a centre drill to try getting the start of the hole as straight as possible."

                Whatever you do, don't use a center drill. Use the correct tool, a spotting drill.

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                • #23
                  Originally posted by Dan Dubeau View Post
                  After looking at it more, I'm pretty sure that aluminum part is actually an extrusion now. Not sure I understand what anti extrusion shapes you're talking about. I'm not saying make the whole part from an extrusion just the insert, and with a hole next time.

                  Either way, sounds like an entire life cycle of parts is run off, and modification of what's there is the game plan. Just the way she goes.
                  Ah, I get it... you are thinking there is an extrusion pressed or even cast into the end parts. Yes, they could do that with the hole in it, maybe. There are some issues with how big (or small) the hole can be, and the change of cross section across the die that can foul up flow of the aluminum, but if anything, it looks as if a hole could improve the flow now, depending on what size it can be.
                  1601

                  Keep eye on ball.
                  Hashim Khan

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                  • #24
                    The plastic ends don't look good enough (to me) to rely on as a locating surface.
                    If it was me I'd rig up mill vise jaws to clamp on the aluminum center section. It's hard to see if the aluminum is symetrical, if not you'd need two different sets of vise jaws. Drill from each end. If your mill doesn't have a quick change tool system, do the spot drilling on all parts first.

                    This job is going to be a nightmare. You want to be sure to peck drill withdrawing it frequently to clear chips. Somebody said you only have .025" wall thickness....OUCH.....be sure to keep hole clear of chips and cool, otherwise with that thin or thinner (when the drill wanders) the wall may bulge from the drilling. Having the aluminum clamped in special vise jaws would help prevent side bulge.

                    Buy a few extra drills. good ones, Titex and Emuge are a couple good brands. Check with the drill manufacturer for recommendations of flute type, etc. You may have to buy in package quantitie$.

                    Honestly...you might consider giving the job back, tell the customer it isn't practical to do with any degree of accuracy and success rate.
                    Last edited by DR; 12-12-2017, 04:15 PM.

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                    • #25
                      3" into that gummy extrusion is NOT going to be fun.

                      Can you try rigging one up in your drill press? I'm thinking first off that you can then run the drill bit a lot faster than you can in your lathe. That should help a lot with chip clearing and it SHOULD help with reducing wandering. You'll also want a lighter sort of touch on the drill to aid with allowing the drill to cut without wandering. And doing this in the drill SHOULD aid you by allow you to clear the chips often during the deeper portion... which is anything deeper than around 1/2" in this case. So that's a LOT of clearing operations.

                      The mill would be good too if you can put the quill into "drill press" mode and use the handle to allow for feel of the pressure and frequent chip clearing. But be it the mill or a drill press if the higher speed works out then spend a bit of time to rig up a way to hold the parts accurately and consistently. The one really consistent thing is the extrusion through the middle. Perhaps rig up some V block sort of thing on an angle plate to reach in and clamp against that section of exposed extrusion?

                      For coolant try straight mineral spirits. If it works the upside is that you don't need to do any cleanup. It'll evaporate away on its own. Might take a while if the shop is cool but in a couple of days it'll mostly be gone and within a couple of more days even the bottoms of the holes should be dry. But if that does not work for keeping the metal from gluing itself to the cutting edges then use whatever you have to use to ensure that it does not stick. For MOST things you should be able to clean it away with a good swishing around in a big bucket of detergent and water.
                      Last edited by BCRider; 12-12-2017, 04:19 PM.
                      Chilliwack BC, Canada

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                      • #26
                        Originally posted by DR View Post
                        "I'll also try with a centre drill to try getting the start of the hole as straight as possible."

                        Whatever you do, don't use a center drill. Use the correct tool, a spotting drill.
                        Is the benefit of a spotting drill that they have a sharper tip angle? I can get 90 degree ones, overall length is a mere 1-1/4"

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                        • #27
                          Originally posted by DR View Post
                          Honestly...you might consider giving the job back, tell the customer it isn't practical to do with any degree of accuracy and success rate.
                          Drill wander is probably close to practical limits with conventional twist drills but not a problem for gun drilling.

                          THE problem is needed time: Lets say 1500 rpm on a hobby lathe and .0001" feed per rev with gun drill is mere 0.15" per minute. Gun drilling at 1500rpm the total 4000 inches of hole would take 444 hours.. about 3 months daily job.

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                          • #28
                            And to give some (false) hope Dormer A940 deep hole twist drill run at 5000 rpm and drilled from both ends would manage the task in 10 seconds of actual cutting time (not accounting for pecking)

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                            • #29
                              Originally posted by MattiJ View Post
                              Drill wander is probably close to practical limits with conventional twist drills but not a problem for gun drilling.

                              THE problem is needed time: Lets say 1500 rpm on a hobby lathe and .0001" feed per rev with gun drill is mere 0.15" per minute. Gun drilling at 1500rpm the total 4000 inches of hole would take 444 hours.. about 3 months daily job.
                              In aluminum, the feed would be faster, and I've never had to do that even in steel. Even adding in the time to clear chips, it has to be lots faster. If he did 0.001" instead of 0.0001" (per your numbers) that would be 44 hours.... better anyway.
                              1601

                              Keep eye on ball.
                              Hashim Khan

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                              • #30
                                Who care how long it takes within reason.. it could pay for 1/2 the price of a Turret used mill, or a fairly decent lathe..
                                Or a car seat covered in tooling that you cant afford to order right now... or..?

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