2 Replies Latest reply on Jul 8, 2018 9:42 PM by Nelson Lopes

    Draw an arc of unknown angle and extrude?

    Nelson Lopes

      Hoping someone might please be able to assist me with a part I'm having to design.  Short story - I have an old "model" pirate pistol (got it from Disney when I was a kid many years ago) & was showing it to my son who accidentally dropped it and broke the hammer that gets cocked back.  I can't repair what broke as it appears to be cast iron and the parts were press fitted   Anyhow, I took the mechanism apart and have measured the part the best I can with my calipers and am redesigning it in SolidWorks so I can 3D printer a new plastic part which I believe will work fine.


      I'm new to Solidworks and have no formal training yet so please excuse my drawing that I'm attaching.  I have the entire shaft created and the only thing I need to do is create what appears to be a "CAM" like feature on it.  I have no idea how to do this?  I have measurements, but no angles, etc. to somehow create this arc.  I'm also including some pictures of the part with hopes that it helps to understand what I've created and what I need assistance with.


      If someone would kindly add this to my drawing and explain how they did it or provide detailed instructions on how to do that, I'd greatly appreciate the help!  Thank you very much.


      Kind Regards,


        • Re: Draw an arc of unknown angle and extrude?
          Rob Edwards

          Hi Nelson

          That looks like a worthwhile project to do with your son

          I hope this gives you some ideas!

          I used a centerpoint arc slot..  I've never actually used one before, but it's pretty straight forward.


          I didn't know how to dimension it, but thought maybe you could take the measurement across the width as shown by the tangent construction lines.

          You can just delete any dimensions you don't like and recreate them.


          I took the assumption that the radial lines DO point directly to the central axis.

          Again you will have to mess about with it to get it right.


          A couple of extra things I did you might like to look into are

          adding a sketch picture

          using a revolve


          Good Luck.


          Any questions, do not hesitate to ask.



            • Re: Draw an arc of unknown angle and extrude?
              Nelson Lopes

              @Rob - Thank you very much!  I was able to modify the part and get the arc to match as close I could to the original part.  I had to make about 6 iterations of it (half a mm makes a difference on this thing), but finally the new printed part works great!  Only bad thing is it's made from plastic and not metal, but at least I know I can keep working on improvements if needed..  Thank you again for your time and assistance!


              Kind Regards,