Thu, 30 Sep 2010

Updated Cams Page | Cam followers page

Cams are used to convert rotary motion into reciprocating motion. The motion created can be simple and regular or complex and irregular. As the cam turns, driven by the circular motion, the cam follower traces the surface of the cam transmitting its motion to the required mechanism.

Cam follower design is important in the way the profile of the cam is followed. A fine pointed follower will more accurately trace the outline of the cam. This more accurate movement is at the expense of the strength of the cam follower.

As the cam turns it has a tendency to push the cam follower to one side. To overcome this a separate cam follower and push rod can be used as in this mechanism. Here the cam follower drags over the cam surface, accurately tracing the surface of the cam. Any movement of the cam follower is transferred directly to the push rod


Find out more about cams by making your own cam model. Download and make the interchangeable cam kit; use it try out the movement created with the different cam profiles included in the kit. You can also experiment with your own profiles using the blank cams provided. Members can download the kit for free.

Download and make the Agreeable Sheep for free and find out how cams work first hand!

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Comments (25)

  • Anonymous November 18, 2010 at 5:14 am

    Hey Rob,
    I downloaded the

    Hey Rob,

    I downloaded the agreeable sheep for trial. Why are the back pieces slightly bigger than the front? I am not sure if I am missing something here.




    • robives November 18, 2010 at 6:05 am

      Hi Mukti, the back pieces are

      Hi Mukti, the back pieces are larger than the front to allow for printer error. When you flip you card over and return it to the printer it is difficult to get the alignment 100% accurate so I make the back pieces slightly larger  and the overlap stops any white edges appearing on the parts. Rob

      • Anonymous November 30, 2010 at 10:45 am

        hEYYYY rob…!!

        hEYYYY rob…!!

      • Anonymous November 30, 2010 at 5:06 pm

        Hey Rob,
        Thanks for the

        Hey Rob,

        Thanks for the prompt reply. I got the front and back printed on separate papers and thought they needed to be stuck together or something 🙁



  • Anonymous November 30, 2010 at 9:51 am

    Hey rob great work


    Hey rob great work mate.

    From Derek xxxxxxxx

  • Anonymous December 5, 2010 at 2:13 pm

    Hi Rob, found the site this

    Hi Rob, found the site this week and really like it, nicely done!

    I was trying to envision a cam that could be used to make the cam follower appear to pause at both and upper end and lower end (in your animation it pauses at the lower end). 

    To do that, would you just draw two circles of different dimensions, connect their outer edges, and spin along the center of the bigger circle?  I added to picture to show what I was talking about:

    I realize that the pause and the top and bottom will be of different lengths of time, but that seems necessary to get the cam follower to roll along nicely.

    Thanks and keep up the great drawings!



    • robives December 5, 2010 at 5:06 pm

      I hope you don’t mind, I

      I hope you don't mind, I answered this question in the blog.

      • Anonymous July 13, 2011 at 10:38 am

        hi rob, my home school child

        hi rob, my home school child realy enjoyed this web site thanks for evreything

        your sincery ,

        paul gibbins from middlesex

      • Anonymous January 14, 2012 at 12:12 pm

        hiya robives. i have an

        hiya robives. i have an urgent question. So , you know them biro pens with the clicky thing at the top which when you press it the pen at the bottom comes out? Well, its about that. Here is the question:

        Is the spring in that pen a mechanism?

        plllllllllllzzzzzzzzzzzzzzzzzzzz reply quickly this is for a school oroject

        The spring is part of the mechanism. I don't know if I would count a spring as a mechanism, rather a component of a mechanism – RI

  • Anonymous June 23, 2011 at 2:42 am

    This is great for children

    This is great for children and learning. Thank you rob for helping us.


  • Anonymous August 17, 2011 at 10:23 pm

    Hey Rob.
    Just letting you

    Hey Rob.

    Just letting you know that you are a really cool guy – you make my life so happy. I am doing a graphics assignment at school where I have to create a moving toy and boy oh boy you're cams inspire me. So thank you, you technologically-savvy young man. Love always, your biggest fan, Shaniqua =)

    • Anonymous November 19, 2011 at 4:44 am

      You can find great cam

      You can find great cam follower research here.



  • Anonymous January 19, 2012 at 10:39 am

    luv u rob

    luv u rob

  • Anonymous February 15, 2012 at 11:04 am

    this is the most totally

    this is the most totally awesome website ive been on alllll day, i mean WOAAAAH this is soooooo totlally cool!

  • Anonymous March 22, 2012 at 9:45 pm

    hey this website is

    hey this website is so cool!! My friend and i were wondering weather you could give us any ideas on a project we could do for school. It has to be an endangered animal in New Zealand. it also has to move up and down like its flying or jumping. If you could help us that would be great.



    thanks, champion and mouse 🙂

  • Anonymous April 4, 2012 at 3:36 pm

    hey rob ,
    please! explain

    hey rob ,

    please! explain cylinder cam

    Cams come in a variety of forms where the cam profile is parts of some sort of rotating surface. A cylinder cam would simply be a cam that is part of a cylinder with the profile either on the side of the cylinder or on the end of the cylinder – RI

  • Freya May 7, 2012 at 5:36 pm

    Hey Rob, great website btw! I

    Hey Rob, great website btw! I have a school technology project coming up, it has to be an endangered animal that tells children about why it is endangered and how they can help. The only problem is, I can't decide what animal to do? Which animals sell best?

    Thanks, Freya 🙂

    Cats and dogs sell best but they’re not endangered. Elephants or Pandas would be my choice. – RI

  • Anonymous January 11, 2014 at 6:24 pm

    Great site, thank you!

    Great site, thank you! Can you tell me if the word CAM is an acronym for something? As CAM toys frequently appear as all capital letters. I was just wondering what they stood for. many thanks,
    Sarah UK

    Hi Sarah, no cam doesn’t stand for anything, not in mechanisms at least. It should be spelt with lower case letters – RI

  • jackz October 10, 2014 at 8:29 pm

    Is “cam” short for “camera”

    Is "cam" short for "camera" or something?  Why are they called "cams?"

    • Smelter October 12, 2014 at 8:55 am

      “Cam” is a word in it’s own

      "Cam" is a word in it's own right.

      No internal combustion engine could work without them.


      "cam" is a curruption/shortened version of camera, as in "webcam".

      Sadly the English language suffers badly from people who don't have the time to spell full words.

  • Anonymous May 14, 2015 at 10:34 am

    Hi Robinator,

    Hi Robinator,


    Good Job, This website is soooo helpful, Im going to pop in everyday!!!!

  • maxabbas55 September 6, 2015 at 8:29 pm

    Hey rob please reply, how

    Hey rob please reply, how could this mechanism be used in an iwatch thanks!

  • AryAru October 1, 2015 at 11:15 am

           Found a great


           Found a great model on cool4cats website,'The Artist'. Cost is only 48 yen. But I cannot transact there. So I decided to make my own. It is a cam powered project. When finished, I will post it.

    I look forward to seeing what you come up with Ary – RI

  • robives xxxx May 16, 2016 at 10:41 am

    thanks for the info babes

    thanks for the info babes xxx

    but it annoys me the site is slow

    lots of love
    Rauiri xxx

  • Collin April 10, 2019 at 6:10 pm

    This is very useful for me and my class!!!

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