Announcement

Collapse
No announcement yet.

Cutting a V-Grove Pulley

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

  • Cutting a V-Grove Pulley

    I am trying something new. I need a smaller crank pulley for an vintage SCCA car I am trying to get going. I have a boxford CUD lathe so I figured I would try and make one out of aluminum. I saw a video on youtube where they used a parting tool at a 19 degree angle to cut the V groove. Is that the best tool to use? It worked in the video but seemed odd. I am thinking it may take a few attempts but I always learn from projects.
    You may only view thumbnails in this gallery. This gallery has 1 photos.

  • #2
    Anything that will cut the correct angle, and is not too dangerous to do is fine.

    IIRC, I used a tool that was actually ground to cut acme threads. The benefit of that was that it "shaved" the surface, so the surface was smooth. Parting tools tend to leave a "phonograph" surface, but would work and can leave a good surface with care..
    4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

    Keep eye on ball.
    Hashim Khan

    Everything not impossible is compulsory

    "There's no pleasing these serpents"......Lewis Carroll

    Comment


    • #3
      Have at it.

      V-Groove cut with a parting tool, after rouging.

      After the parting tool did the finish pass I had to add a sharp V at the very bottom with a form tool because that is how the part is on the drawing.

      Comment


      • #4
        Thank you for the replys! I ended up ordering a svvcn 3/8 holder to try. Its another Youtube recomendation by someone cutting a pulley. I will try it and see it the helps the process.

        Comment


        • #5
          Parting tool works great for cutting V grooves. Rough it out as seen in post #3. Do the finish pass using the compound set at that 19*. It means breaking into the setup to change sides, but it's easy enough to do. Don't think you will need a form tool for the bottom of the groove. A flat bottom the width of the parting tool should work, as long as that width is narrower than the flat on the inside of the

          Comment


          • #6
            Originally posted by tom_d View Post
            Parting tool works great for cutting V grooves. Rough it out as seen in post #3. Do the finish pass using the compound set at that 19*. It means breaking into the setup to change sides, but it's easy enough to do. Don't think you will need a form tool for the bottom of the groove. A flat bottom the width of the parting tool should work, as long as that width is narrower than the flat on the inside of the
            This was not a V-Sheave but a groove for a quick clamp liquid coupling, this would also not require a sharp V but that is how it is on the customer drawing (-:
            All angles done with a parting tool.
            Last edited by Bented; 07-01-2021, 06:24 PM.

            Comment


            • #7
              If you've got a lathe with enough ass you can just grind a double sided form too to finish it in after roughing (finishing one side at a time). If it was a production job on a manual lathe, I'd absolutely do it that way. But for a one-off, I'd just cut the angles with a compound and a radius grooving tool.
              21" Royersford Excelsior CamelBack Drillpress Restoration
              1943 Sidney 16x54 Lathe Restoration

              Comment


              • #8
                Originally posted by The Metal Butcher View Post
                If you've got a lathe with enough ass you can just grind a double sided form too to finish it in after roughing (finishing one side at a time). If it was a production job on a manual lathe, I'd absolutely do it that way. But for a one-off, I'd just cut the angles with a compound and a radius grooving tool.
                No compound on this machine.

                Comment


                • #9
                  I found that a form tool is best on Aluminium Pulleys, the photo shows one that I made earlier this week. It is 100mm diameter, 38 degree groove to suit an M section belt. I now have to machine the inside to accept a Taper Lock Bush.

                  Click image for larger version

Name:	Pulley.jpg
Views:	887
Size:	88.9 KB
ID:	1949636

                  Comment


                  • #10
                    Originally posted by Bented View Post
                    After the parting tool did the finish pass I had to add a sharp V at the very bottom with a form tool because that is how the part is on the drawing.
                    Nice lookin' job when it's all done.

                    Rule number xxx; the customer is always right. Even if it makes things unnecessarily more expensive, or obviously compromises the structural integrity of the design.

                    When doing parts to a MIL. spec drawing we sometimes referred to these as a "TFP41" print. Don't dare question (potentially insult) the designers expertise,
                    it's an MIL. TFP41, so you simply "Make It Like The Friggin' Print For Once!"



                    Comment


                    • #11
                      Originally posted by Bented View Post

                      No compound on this machine.
                      That was directed at OP. Obviously I would do it differently on a CNC lathe.
                      21" Royersford Excelsior CamelBack Drillpress Restoration
                      1943 Sidney 16x54 Lathe Restoration

                      Comment


                      • #12
                        Thank you for the replies, I always learn new things when I post here.

                        Comment


                        • #13
                          Technique may vary depending on the machine. Some high powered machines can get a really good finish, when the same tooling on a lower power machine that must run that tooling slower, gets a far worse surface.

                          It's good to remember the source, and the target, when evaluating advice.

                          4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

                          Keep eye on ball.
                          Hashim Khan

                          Everything not impossible is compulsory

                          "There's no pleasing these serpents"......Lewis Carroll

                          Comment


                          • #14
                            Originally posted by J Tiers View Post
                            Technique may vary depending on the machine. Some high powered machines can get a really good finish, when the same tooling on a lower power machine that must run that tooling slower, gets a far worse surface.

                            It's good to remember the source, and the target, when evaluating advice.
                            Yes I have a pretty small and only 3/4hp Boxford CUD lathe. Its not cnc, not even a power cross feed, but I am learning how to make the most of it. I looked for a nicer lathe, but all I keep finding are absolutely worn out USA stuff or import stuff that you cant get parts for it somthing breaks. So the Boxford stays in the shop and I really think the lack of skill on my part is a bigger factor in making parts. Thank you for the advice. I will experiment and see if I cant knock out a v belt pulley. The materials are not a lot of $ so if I mess up its not the end of the world.

                            Comment


                            • #15
                              You don't need a sharp V at the bottom of the V-groove. (Look at a V-belt)
                              12" x 35" Logan 2557V lathe
                              Index "Super 55" mill
                              18" Vectrax vertical bandsaw
                              7" x 10" Vectrax mitering bandsaw
                              24" State disc sander

                              Comment

                              Working...
                              X