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  • #46
    Have you considered using a roll or taper pin instead of welding?

    lg
    no neat sig line
    near Salem OR

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    • #47
      Originally posted by larry_g View Post
      Have you considered using a roll or taper pin instead of welding?

      lg
      no neat sig line
      No, I have not thought of cross drilling and pinning because the arbor is hardened, how hard ?? I don't know. I don't have any tapered reamers that small anyway. Once the sleeve is on, its' on to stay.

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

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      • #48
        Originally posted by JoeLee View Post
        No, I have not thought of cross drilling and pinning because the arbor is hardened, how hard ?? I don't know. I don't have any tapered reamers that small anyway. Once the sleeve is on, its' on to stay.

        JL.............
        How about the green loctite? That stuff is effectively permanent.

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        • #49
          Originally posted by nickel-city-fab View Post

          How about the green loctite? That stuff is effectively permanent.
          I never used the green stuff before, just the red. But I don't see how loctite would would do any good on a press fit. There needs to be some space for it, like threads. The other thing is there is quite a bit of gap between the three flat surfaces of the arbor and the inside wall of the sleeve, I don't know if the stuff would cure properly with all that air space and it'll run out the bottom also.

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

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          • #50
            I just skimmed through this thread.

            Looks like the thread in question is a 1/2-16 4 start? Is that correct? By about 1/2" or 9/16" long?

            P.S. you can use a change gear to do multistarts by rotating the drivetrain by 1/4th if any gear is divisible by such.
            21" Royersford Excelsior CamelBack Drillpress Restoration
            1943 Sidney 16x54 Lathe Restoration

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            • #51
              Originally posted by The Metal Butcher View Post
              I just skimmed through this thread.

              Looks like the thread in question is a 1/2-16 4 start? Is that correct? By about 1/2" or 9/16" long?

              P.S. you can use a change gear to do multistarts by rotating the drivetrain by 1/4th if any gear is divisible by such.
              Yes, that's correct but I don't have the correct insert for that thread. Vardex doesn't make one that fits my tool holder. It's actually a 16 TPI but stretched out to 4 TPI. There's an issue with the helix angle.
              From what I understand I can't use the 16 TPI insert to do a 4 TPI thread. Not really sure on how that works.

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

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              • #52
                Originally posted by JoeLee View Post
                I never used the green stuff before, just the red. But I don't see how loctite would would do any good on a press fit. There needs to be some space for it, like threads. The other thing is there is quite a bit of gap between the three flat surfaces of the arbor and the inside wall of the sleeve, I don't know if the stuff would cure properly with all that air space and it'll run out the bottom also.

                JL.............
                There are versions of the green type that are made for bearing and press fits.... molecules are very small. It has been shown that it increases the force required to break the connection by quite a bit. They had an entire thread about it on PM where somebody actually tested it in a hydraulic press and got double-digit increases in strength.

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                • #53
                  Originally posted by JoeLee View Post
                  Yes, that's correct but I don't have the correct insert for that thread. Vardex doesn't make one that fits my tool holder. It's actually a 16 TPI but stretched out to 4 TPI. There's an issue with the helix angle.
                  From what I understand I can't use the 16 TPI insert to do a 4 TPI thread. Not really sure on how that works.

                  JL............
                  Right. They make tapered shims for the laydown tools for that reason.

                  HSS?
                  21" Royersford Excelsior CamelBack Drillpress Restoration
                  1943 Sidney 16x54 Lathe Restoration

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                  • #54
                    Post up some dimensions how you would build it. I want to try this weekend. Seems like a good challenge.
                    21" Royersford Excelsior CamelBack Drillpress Restoration
                    1943 Sidney 16x54 Lathe Restoration

                    Comment


                    • #55
                      Originally posted by The Metal Butcher View Post
                      Post up some dimensions how you would build it. I want to try this weekend. Seems like a good challenge.
                      If I were able to cut the 4 start thread I would make the entire arbor in one set up without removing it from the lathe to ensure concentricity. Only difference is I would make the shank 3/4" in dia. so I could mount it in an R8 vs the feeble 3 sided 3/8" shank.

                      Dimensions are: shank length 3/4" dia. your choice. Threaded end is 1/2" dia. x 9/16" long.

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

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                      • #56
                        The company sent me a new 1 3/4" hole saw. This one cuts 1.754. Perfect. That's what the problem was. They also sent me a new arbor. Now I can keep my original and make the sleeve for the new one.
                        In thinking up ways to ensure the sleeve is as concentric as possible with the threaded part I did a couple tests.
                        I indicated just behind the threads on the relief. Assuming that portion was cut in the same set up as the threads. I chucked up on the high points of the hex indexing around until I got the least amount of run out which is a bit less than .001. Good enough. I checked it with a saw mounted and got the same. I marked the spot in reference with the 0 mark on the chuck.
                        I'll press the sleeve on the shank and either turn it or maybe grind it to finish dimension.

                        A little less than .001 run out right there.

                        Click image for larger version

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                        Indicating between the gullet and the ridge I get the same amount of run out. The other size saws check out about the same. There is a slight variation depending of which one of the four threads the cutter starts on. I marked those as well for future reference.

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

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                        • #57
                          Like so?

                          Click image for larger version

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                          I'll admit. It wasn't easy. My first attempt I had my gear dividing wrong and scrapped it. I was naïve and cocky enough to think I'd get it first try. The second try wasn't without casualties either. I had chipped the corner off my HSS tool the first time by doing a no relief groove style and for some reason I decided to go with carbide this time. A lay down tool, which I increased the clearance angle to 15 degrees to account for the 10° helix angle of the thread. Well, I chipped one of those too. Then I had a chip curl and jam between the toolholder and part, casing the half nut to get tight and I was late on my disengagement (20 thou clearance), which moved my toolpost. So I picked back up the thread and kept going. I ended up chipping my second grind on the laydown as well. Oh and lastly I screwed up on my very first index by 1 tooth, so that thread is wider than all the rest by about 1/8th of 1/16th of an inch (theoretically). I really should have used a relief groove like the factory one, and I should have stuck with HSS. My hand ground tool got much closer to the shoulder than the laydown tool anyway.

                          So yeah, here is the high mag to make it look like ****:

                          Click image for larger version

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                          You can see the wide thread right in the middle. I did cut it to the wire specification (after recalculating the value using the Bureau of Standards formula for over the wires measurement, as I thought the high helix might be problematic (truth is, it only changes it by 1 thou)), but for all I know the wires were hitting on the wide root of the thread due to the chipped tool. After wirewheeling and buffing on a scotch bright pad to remove the burrs, the OD is 15 thou below nominal dimension which seems like a lot. So it's possible it is overcut and the thread wires are hitting the root. I could have ground yet a 3rd insert and recut the root, but I was kinda done with it by that point.

                          So yeah, as said, it was really more of a selfish skill gaining experiment, and I wasn't 100% going for a usable piece or I would have made yet another, correctly. That said, it's worthless to me, so my my goal the whole while was to send it your way if it works. I'm not sure that it will, but if you want it, send me a shipping address and I'll send it your way JoeLee.

                          So lastly, thanks for the challenge JoeLee! It was a lot of fun and a seriously good skill building exercise. I used the indexing technique showed by Find Hansen linked in a thread by JTiers. Thanks both for that. That way I could still use ordinary compound infeed and the cross-slide stop on my Sidney lathe. I took some video of making it. If the sound isn't completely clipped I'll try to throw together a "How-to" thread and video, even though I feel like far from an expert with all the tribulations in making it.
                          21" Royersford Excelsior CamelBack Drillpress Restoration
                          1943 Sidney 16x54 Lathe Restoration

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                          • #58
                            Not reading all the posts and seeing the material is pretty thin. My first thought is to forget the holesaw and use a step drill if the hole size is right.

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                            • #59
                              Originally posted by The Metal Butcher View Post
                              Like so?

                              Click image for larger version

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                              I'll admit. It wasn't easy. My first attempt I had my gear dividing wrong and scrapped it. I was naïve and cocky enough to think I'd get it first try. The second try wasn't without casualties either. I had chipped the corner off my HSS tool the first time by doing a no relief groove style and for some reason I decided to go with carbide this time. A lay down tool, which I increased the clearance angle to 15 degrees to account for the 10° helix angle of the thread. Well, I chipped one of those too. Then I had a chip curl and jam between the toolholder and part, casing the half nut to get tight and I was late on my disengagement (20 thou clearance), which moved my toolpost. So I picked back up the thread and kept going. I ended up chipping my second grind on the laydown as well. Oh and lastly I screwed up on my very first index by 1 tooth, so that thread is wider than all the rest by about 1/8th of 1/16th of an inch (theoretically). I really should have used a relief groove like the factory one, and I should have stuck with HSS. My hand ground tool got much closer to the shoulder than the laydown tool anyway.

                              So yeah, here is the high mag to make it look like ****:

                              Click image for larger version

Name:	IMG_8242ECS.jpg
Views:	63
Size:	92.8 KB
ID:	1941279

                              You can see the wide thread right in the middle. I did cut it to the wire specification (after recalculating the value using the Bureau of Standards formula for over the wires measurement, as I thought the high helix might be problematic (truth is, it only changes it by 1 thou)), but for all I know the wires were hitting on the wide root of the thread due to the chipped tool. After wirewheeling and buffing on a scotch bright pad to remove the burrs, the OD is 15 thou below nominal dimension which seems like a lot. So it's possible it is overcut and the thread wires are hitting the root. I could have ground yet a 3rd insert and recut the root, but I was kinda done with it by that point.

                              So yeah, as said, it was really more of a selfish skill gaining experiment, and I wasn't 100% going for a usable piece or I would have made yet another, correctly. That said, it's worthless to me, so my my goal the whole while was to send it your way if it works. I'm not sure that it will, but if you want it, send me a shipping address and I'll send it your way JoeLee.

                              So lastly, thanks for the challenge JoeLee! It was a lot of fun and a seriously good skill building exercise. I used the indexing technique showed by Find Hansen linked in a thread by JTiers. Thanks both for that. That way I could still use ordinary compound infeed and the cross-slide stop on my Sidney lathe. I took some video of making it. If the sound isn't completely clipped I'll try to throw together a "How-to" thread and video, even though I feel like far from an expert with all the tribulations in making it.
                              That's outstanding............. It would have taken me way more try's than that and I probably still wouldn't have gotten it right. You can see the importance of the relief cut. You can't just stop in the middle of a thread cut as the tool will stick an the tip will break. It's even worse with carbide.
                              Difficult to stop and back out at the same time when your right against a shoulder. With the carriage moving at 4 TPI (acme thread rate) it's next to impossible on a manual machine no matter how slow your turning. I was going to put my hand crank on my lathe and turn it by hand. I bagged the idea of trying to cut the thread because I can't find the proper insert. Vardex doesn't make one and even with a combination of anvils under the insert I couldn't get the helix right. So........... this morning I made the sleeve and pressed it over the shank.

                              After pressing it on I indicated it and it was within .0015 with the relief cut. I flipped it around in the chuck and gave the sleeve a light pass. I flipped it around again and indicated the relief and
                              I got zero dial deflection. So I guess my method will work. Tomorrow I'll weld the hole to the top of the shank and turn it down to .750. I hope the heat doesn't mess anything up.

                              Click image for larger version

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                              I'm not sure how long the threads are on the one you made. There is a hex nut that goes between the saw and the arbor. It's about 3/16" thick. It's not threaded, just a straight through hole.
                              that's how you crack the saw loose. I can't believe how these saws repeat when put on the arbor. There is no register surface or seat, it just butts flat against the nut.
                              If I do have any run out when I'm finished I can always index the saw to a different thread start. I've found that some starts and some saws have a "sweet spot" I'll indicate each one and mark them. I have two 3/4" R8's. My new Lyndex has .0015 run out and I have an old SPI collet, surprisingly the SPI has about .0002 run out. Both were checked with a gage pin.

                              I'll give your arbor a try and see how it works out. thanks for the help.

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

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                              • #60
                                Originally posted by JoeLee View Post
                                That's outstanding............. It would have taken me way more try's than that and I probably still wouldn't have gotten it right. You can see the importance of the relief cut. You can't just stop in the middle of a thread cut as the tool will stick an the tip will break. It's even worse with carbide.
                                Difficult to stop and back out at the same time when your right against a shoulder. With the carriage moving at 4 TPI (acme thread rate) it's next to impossible on a manual machine no matter how slow your turning. I was going to put my hand crank on my lathe and turn it by hand. I bagged the idea of trying to cut the thread because I can't find the proper insert. Vardex doesn't make one and even with a combination of anvils under the insert I couldn't get the helix right. So........... this morning I made the sleeve and pressed it over the shank.

                                After pressing it on I indicated it and it was within .0015 with the relief cut. I flipped it around in the chuck and gave the sleeve a light pass. I flipped it around again and indicated the relief and
                                I got zero dial deflection. So I guess my method will work. Tomorrow I'll weld the hole to the top of the shank and turn it down to .750. I hope the heat doesn't mess anything up.

                                I'm not sure how long the threads are on the one you made. There is a hex nut that goes between the saw and the arbor. It's about 3/16" thick. It's not threaded, just a straight through hole.
                                that's how you crack the saw loose. I can't believe how these saws repeat when put on the arbor. There is no register surface or seat, it just butts flat against the nut.
                                If I do have any run out when I'm finished I can always index the saw to a different thread start. I've found that some starts and some saws have a "sweet spot" I'll indicate each one and mark them. I have two 3/4" R8's. My new Lyndex has .0015 run out and I have an old SPI collet, surprisingly the SPI has about .0002 run out. Both were checked with a gage pin.

                                I'll give your arbor a try and see how it works out. thanks for the help.

                                JL..................
                                Thanks!

                                Yeah, I do not like relief cuts but sometimes they are necessary. I find them ugly, weak, and often unnecessary. No relief groove is generally more elegant (not this time!).

                                I was running at 20 RPM. Normally I'm great at the retract and disengage, but not at such a slow speed. It just made for a wall basically, and if I went a few thou too far... snap!

                                I say don't worry about the right insert. If you have a toolgrinder, just add some relief until you see all the yellow go away. Or use HSS. That's really the right tool for the job.

                                How tight was your press fit? There is a decent chance you will need no welding at all.

                                I made it to your dimensions specified. The thread is 9/16" long. The shank is 3/4" x whatever the max length grippable in an R8 collet is. 1.25" I think.

                                The flange is 1.25x0.25. I figured you'd just hold the brake to spin it off. Mill a hex on it if needed. Cut a thread relief groove too. Modify it in any way you want. Just send me a PM with your address and I'll send it along.

                                PS the saw register the same way as a screw on chuck. Via the inherent centering effect of a thread.
                                21" Royersford Excelsior CamelBack Drillpress Restoration
                                1943 Sidney 16x54 Lathe Restoration

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