Announcement

Collapse
No announcement yet.

Is it possible to machine a Oval Shaft

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Is it possible to machine a Oval Shaft

    As title says was wondering if it’s possible to machine a Oval shaft out of a round material on a Manual Lathe?

  • #2
    Originally posted by Tundra Twin Track View Post
    possible to machine a Oval shaft?
    After measuring the diameter at half a dozen places around a supposedly round shaft, yes it is more than possible to turn an oval.
    The question you probably should ask, "Is it possible to turn an eliptical shaft with controlled major and minor dimensions"

    Comment


    • #3
      I can imagine rigging up something like a (possibly hydraulic) follower to move the cross slide back and forth with each revolution of the work.
      "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

      Comment


      • #4
        Depending on the exact geometry you're looking for, you might be able to turn it on 2 centers, each offset from the center of the bar an equal amount. You would do 1 side at a time, then sand down the tangent points to blend.

        You could also use the lathe carriage like a shaper and make lengthwise cuts, indexing the part a few degrees between cuts, and adjusting the cross slide in or out appropriately. You would probably need to make a chart to go by for that.
        Last edited by Toolguy; 04-08-2021, 04:02 PM.
        Kansas City area

        Comment


        • #5
          Originally posted by Tundra Twin Track View Post
          As title says was wondering if it’s possible to machine a Oval shaft out of a round material on a Manual Lathe?
          I guess the first question would be; accidentally, or intentionally? Never tried it intentionally.

          Might be a little off into the weeds here, but maybe a creative adaptation combining this with a lathe and tool-post grinder would give the desired results:

          https://www.mandalaroseworks.com/product/rose_engine

          Comment


          • #6
            Originally posted by Toolguy View Post
            Depending on the exact geometry you're looking for, you might be able to turn it on 2 centers, each offset from the center of the bar an equal amount. You would do 1 side at a time, then sand down the tangent points to blend.
            I have done this before with the addition of the tail stock offset to turn it on a taper.

            It worked out well for what it was but this wasn’t a high precision project and I don’t think you are turning a true “oval” at that point.

            I’ll try and get a pic of it later.

            Comment


            • #7
              A better question would be.
              Is it possible to machine a round shaft on a lathe?

              Comment


              • #8
                I've not tried it on a metal lathe, however I have turned hammer handles on my wood lathe. Turn between centers, and offset your holes in the ends of your shaft in the same direction. It's an interrupted cut.

                Comment


                • #9
                  Originally posted by Bented View Post
                  A better question would be.
                  Is it possible to machine a round shaft on a lathe?
                  I should have asked can a round shaft be machined into oval shape.It’s for a handle on my Avalanche Shovel,the portion that swedged down to fit in blade. Click image for larger version

Name:	99636B6F-94B8-4B08-93E6-12C19A325D90.jpeg
Views:	556
Size:	3.18 MB
ID:	1937854 Click image for larger version

Name:	BB1DA86E-7838-4148-9C02-D9FFA9858931.jpeg
Views:	546
Size:	2.92 MB
ID:	1937855

                  Comment


                  • #10
                    Originally posted by Tundra Twin Track View Post

                    I should have asked can a round shaft be machined into oval shape.It’s for a handle on my Avalanche Shovel,the portion that swedged down to fit in blade.
                    Are you making an entirely new handle? I'd try simply crushing a round tube to shape first, this is how the handle areas of composite kayak paddle shafts are ovaled. You're not going to "machine" it to that shape, the wall is too thin. You could do a solid piece with some kind of cam follower rig, but boy would that be a mess to set up. The only other great idea I have it to cast a section in a glass composite after pulling a mold off the piece with the D handle.

                    My 22 yo climber son just took up back country skiing and asked for an avalanche kit for his birthday last month. Like rock and ice climbing were not dangerous enough...
                    Last edited by gellfex; 04-08-2021, 10:32 PM.
                    Location: Jersey City NJ USA

                    Comment


                    • #11
                      Well, there's a way to turn a cam profile, so the answer is yes. Between centers you can turn an offset, like a crankshaft, but those are still round. You want to do a profile on a wooden handle- chances are you don't want to come up with an elaborate setup for one or two handles. Perhaps it would be easier to mill it- mark out the profile on the end of the 'stick', set up in the mill and rotate the handle bit by bit, raising or lowering the quill to suit for each cut. You'll be left with a bit of a sanding job, but for what you're doing you can achieve a close enough fit without a lot of pain.
                      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

                      Comment


                      • #12
                        Originally posted by gellfex View Post

                        Are you making an entirely new handle? I'd try simply crushing a round tube to shape first, this is how the handle areas of composite kayak paddle shafts are ovaled. You're not going to "machine" it to that shape, the wall is too thin. You could do a solid piece with some kind of cam follower rig, but boy would that be a mess to set up. The only other great idea I have it to cast a section in a glass composite after pulling a mold off the piece with the D handle.


                        The swedged down area can fail with extreme use,my thought was to have a machined piece to match the smaller&larger Oval ID then slide in from long end.
                        My 22 yo climber son just took up back country skiing and asked for an avalanche kit for his birthday last month. Like rock and ice climbing were not dangerous enough...
                        This shovel is carried on my Mountain Sled,I built the custom mount real easy to release&attach.I would recommend your son takes a Avalanche Course,this was my 36th year riding in the back country.Have seen many Avalanches and was caught in one in 2008, a ABS back pack Click image for larger version

Name:	EACC66C9-836A-43A8-BFDB-0F5849E86B2D.jpeg
Views:	493
Size:	2.95 MB
ID:	1937882 saved my butt🙂

                        Comment


                        • #13
                          Originally posted by Tundra Twin Track View Post

                          .I would recommend your son takes a Avalanche Course,
                          He has. In addition to being an Eagle Scout, he is an AMGA single-pitch climbing instructor, a wilderness first responder, and is completing an EMT course this, his final semester. He is leaving school 2 weeks before he actually graduates and finishing the semester remotely because he has to report for his third season of guiding ice climbs on a glacier in Alaska! He takes safety seriously, he's about to become a full time professional.
                          Location: Jersey City NJ USA

                          Comment


                          • #14
                            The word "oval" is not a precise term.

                            https://en.wikipedia.org/wiki/Oval

                            From the looks of your shovel, the OEM handle is what you say it is, swedged down from a round tube. The out-or-round fit is probably to prevent the shovel head from rotating on the handle. But heaven only knows what the actual shape really is.

                            I think I would sort-of repeat the OEM's method by getting or making a size of tubing that will work out properly and just squeezing it in a vise until it fits.
                            Paul A.
                            SE Texas

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

                            Comment


                            • #15
                              It looks like you already have a handle for that shovel. Do you want to extend it or is this just a thought problem?
                              Tom - Spotsylvania, VA

                              Comment

                              Working...
                              X