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$26 Skyhook

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  • $26 Skyhook

    This is a little skyhook that dad and I built. I thought I would show it off, it works well. Other than the winch which we got new, everything else was on hand, so I'm not factoring in the cost. But maybe another $75 if you didn't have anything.

    Click image for larger version

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    This version goes in place of the toolpost instead of using a dovetail. That's a bit simpler and a lot more rigid.

    This is the base:

    Click image for larger version

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    To build your own:
    1. Figure out the appropriate dimensions for your size lathe. I basically copied the commercial skyhook as it's a good size. I'm not sure of the dimensions or angles I went with at the present moment, but I can measure and edit this post. I used 2" pipe.
    2. Measure your toolpost nut. The ID of the lower tube needs to be greater than this.
    3. The post mount should be the height of the toolpost. We'll get to that in a minute.
    4. If your lower tube is not smooth and round on the inside (using pipe or whatever) bore it out until it is round. Dimension is not important
    5. Weld the tubes together.
    6. Weld the plate on for the winch. Just a rectangular plate, the size of the winch.
    7. Drill and tap or through bolt for the winch.
    8. Weld a plate on the end with a roller. We used C channel. The roller is just a bushing on a bolt. A crowned roller may track the strap better. Twin rollers or a hoop to capture the strap is not a bad idea.
    9. Now, onto the base. Pick out a suitable piece of round or rectangular plate that is thick enough to not bend. Ours was about 3/8" when finished. Start with something thicker than your finish dimension. The largest size that can fit on the compound is the best.
    10. Find a piece of round stock slightly larger than the bore on the pipe.
    11. Drill a hole in the thin plate roughly 1/2" smaller than the finish OD of the round (aka the bore of the pipe).
    12. Machine a shoulder on the round to fit in that step. Machine the shoulder back only some of the thickness of the plate to where there is 1/16-1/4, whatever, your choice of a step. This will make machining easier.
    13. Insert the round into the thin plate and weld. I opted for Tig welding as it is easier to machine.
    14. Gripping by the tall round, turn the bottom of the plate. If it's round, a good time to do the OD as well. This is what is clamped by the toolpost clamp bolt. The quality of the weld is of low importance as the compression from the stud keeps it together.
    15. Flip the piece around and machine both the top side of the plate and the round. Use a center if needed. The round should be turned to be a sliding fit inside the pipe. No need to be a hero on accuracy here.
    16. Pop a hole through the center of the round. This can be done in step 14 or 15 depending on if you need a tail center or not.
    17. Deburr and finished!
    Click image for larger version

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    To use: simply remove the toolpost, install the base, slide the hoist over and lift! The added friction from not having bearings or the like keeps chucks from swinging around.

    Here is a video of it in action. If lifts our heaviest chuck (150 lbs) and holds body weight just fine.



    One thing that was weird in building it, is that I managed to pick out unwelded pipe for the lower section. It was like normal pipe but where their welder broke or something. I dunno. Clearly visible seam both inside and out. I should have tossed it, but I didn't want to waste my effort in it so I ran an autogenous tig weld down the seam. Low penetration but enough for what is is. When I do V3.0 for my lathe at home I'll do a better job and maybe build some plans if there is enough interest. The winch is a bit of a letdown (heh) as there is no brake on the down side. If you take your hand off or the handle flys off it drops. So keep your feet clear eh.

    Lastly, for any comment about breaking a compound: save it. Not concerned in the slightest. This isn't used on a 10" Atlas.
    21" Royersford Excelsior CamelBack Drillpress Restoration
    1943 Sidney 16x54 Lathe Restoration

  • #2
    Have you got a landing zone mapped out for the chucks?

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    • #3
      Originally posted by old mart View Post
      Have you got a landing zone mapped out for the chucks?
      We have a cart with a lip and open top with 4 caster wheels. We had to take some chucks off so we could fit the most used ones. Issue is that it gets so heavy that it doesn't like to move and then bangs into everything when you finally overcome friction. For the Sidney I'll probably just stick it's chucks on the floor or on the ways behind the tailstock.
      21" Royersford Excelsior CamelBack Drillpress Restoration
      1943 Sidney 16x54 Lathe Restoration

      Comment


      • #4
        very cool! Given that the size and weight of chucks scales with the size of the lathe, if you made one for a 10" Atlas it would be lifting a 30-40lb chuck, so the compound would be perfectly fine with that weight.

        Looks like it would be handy for loading long/ awkward/ heavy stock too.

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        • #5
          Originally posted by mattthemuppet View Post
          very cool! Given that the size and weight of chucks scales with the size of the lathe, if you made one for a 10" Atlas it would be lifting a 30-40lb chuck, so the compound would be perfectly fine with that weight.

          Looks like it would be handy for loading long/ awkward/ heavy stock too.
          Thanks! Hopefully no more than about 20 lbs for an Atlas! I just made that comment in preparation for comment's I've seen on Video's like Adam Booth's on his skyhook where everyone freaked out.

          Yes, heavy stock was the idea as well. You don't even need a strap since it's built in!
          21" Royersford Excelsior CamelBack Drillpress Restoration
          1943 Sidney 16x54 Lathe Restoration

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          • #6
            That looks superb! And for what they want for the brand name one I think you did great.

            One teeny niggle if I may? I'd want the plate on the bottom of the pivot pin that clamps to the compound to be square and the same size as the upper contact area just to spread the load on the T slot lips out a little more. Even the slight extra will do a lot towards reducing the force on the T slot lips if I recall the mathematical relationship. And it's actually a little worse with the smaller diameter spacer ring I see.
            Last edited by BCRider; 05-07-2021, 05:06 PM.
            Chilliwack BC, Canada

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            • #7
              Originally posted by BCRider View Post
              That looks superb! And for what they want for the brand name one I think you did great.

              One teeny niggle if I may? I'd want the plate on the bottom of the pivot pin that clamps to the compound to be square and the same size as the upper contact area just to spread the load on the T slot lips out a little more. Even the slight extra will do a lot towards reducing the force on the T slot lips if I recall the mathematical relationship. And it's actually a little worse with the smaller diameter spacer ring I see.
              100% agreed on all points. I think it would be a lot less force as well.

              However, it was sized for the smaller of the two lathes i will be used on, dad's 1440 Lagun. I couldn't make the post mount taller either as then it wouldn't fix the CXA size for the Lagun so I had to make it CXA sized for the Sidney as well. Either way, if one is going to brake it would be the Lagun. The Tee slots on it are maybe 1/2" thick? The Sidney's is almost an inch I believe. Multiple square inches of cast would have to be sheared.

              I could take the spacer ring off the bottom and place a small one on the top, but again, I'm not worried about it.
              Last edited by The Metal Butcher; 05-07-2021, 05:23 PM.
              21" Royersford Excelsior CamelBack Drillpress Restoration
              1943 Sidney 16x54 Lathe Restoration

              Comment


              • #8
                Originally posted by The Metal Butcher View Post

                We have a cart with a lip and open top with 4 caster wheels. We had to take some chucks off so we could fit the most used ones. Issue is that it gets so heavy that it doesn't like to move and then bangs into everything when you finally overcome friction. For the Sidney I'll probably just stick it's chucks on the floor or on the ways behind the tailstock.
                I've been on the look out for a Skyhook, maybe I should just make one. Kicking around ideas for a rolling chuck cart. Right now all the chucks are on a pair of Harbor Freight hardwood dollys I had laying around.
                Mike
                Central Ohio, USA

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                • #9
                  Took about 8-12 hours I'd say, though it was span out over a lot of days. Probably worth the time unless you can finda used one cheap.
                  21" Royersford Excelsior CamelBack Drillpress Restoration
                  1943 Sidney 16x54 Lathe Restoration

                  Comment


                  • #10
                    I had the same problem (Harrison M400, D1-8 camlock chucks).

                    I'm lucky in that I have a strong concrete ceiling above teh workshop, 3m floor to ceiling. I rawlbolted 2 4" channel sections back to back above the lathe running from past teh tailstock to well past the headstock - about 3 1/2m long. These formed an H beam. Why not use an H beam? Heavier to lift into position, that's all.

                    Small chinese trolley and 250Kg chain block, shortened the chains and it works fine.

                    Ian
                    All of the gear, no idea...

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                    • #11
                      Nice, simple and low cost
                      in Toronto Ontario - where are you?

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                      • #12
                        Perhaps it is just me, but I would worry about using the compound as a mount. The compound primarily needs to resist the cutting forces which are mostly in a downward direction. The forces and torques in it's other five degrees of freedom are small compared to that downward, vertical force. This skyhook is going to add a torque about a horizontal axis to that downward force and the torque will be of a fairly large magnitude. And that horizontal axis changes direction as you swing the skyhook around it's vertical axis. So the compound is stressed by a torque that changes as this rotation takes place. I would fear what that may be doing to the jaws of the compound as well as to whatever it's mount consists of. I am sure that the designers of that lathe did not take any of this into account in that process.

                        I would find another way to mount it. Frankly, I would not attach it to any point on the lathe itself.
                        Paul A.
                        SE Texas

                        And if you look REAL close at an analog signal,
                        You will find that it has discrete steps.

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                        • #13
                          I agree with all who think it's not a good idea to mount on a lathe compound, or a mill table. Lots of options, but space restrictions factor into design. Cranes are simple devices and easy to build to suit your circumstances. I wouldn't spend 3 grand on one if I were a billionaire.
                          “I know lots of people who are educated far beyond their intelligence”

                          Lewis Grizzard

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                          • #14
                            Originally posted by Paul Alciatore View Post
                            Perhaps it is just me, but I would worry about using the compound as a mount. The compound primarily needs to resist the cutting forces which are mostly in a downward direction. The forces and torques in it's other five degrees of freedom are small compared to that downward, vertical force. This skyhook is going to add a torque about a horizontal axis to that downward force and the torque will be of a fairly large magnitude. And that horizontal axis changes direction as you swing the skyhook around it's vertical axis. So the compound is stressed by a torque that changes as this rotation takes place. I would fear what that may be doing to the jaws of the compound as well as to whatever it's mount consists of. I am sure that the designers of that lathe did not take any of this into account in that process.

                            I would find another way to mount it. Frankly, I would not attach it to any point on the lathe itself.
                            It would be very interesting to see some tests to destruction on some of the smaller compounds just to see what they will take.
                            Location: Saskatoon, Saskatchewan, Canada

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                            • #15
                              It would be very interesting to see some tests to destruction on some of the smaller compounds just to see what they will take.
                              Got one you're volunteering?

                              Seriously, even several of the the same make and model would not behave identically, so you'd have to kill several dozen to get a statistically valid breakage point. Then of course you'd want to de-rate that by some amount. Might well be quicker and cheaper for someone (more competent than me) to do the engineering calculations.
                              "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

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