• Welcome to engineeringclicks.com
  • Designing a Parallel Scissor Mechanism for a Project

    Discussion in 'The main mechanical design forum' started by Quan, Jan 21, 2014.

    1. Quan

      Quan New Member

      Joined:
      Jan 2014
      Posts:
      3
      Likes Received:
      0
      Hello all, I'm new here and thought to see if I can ask for some help here on a project. Basically we're working on suspension trucks on a skateboard. I know nothing about skateboards when I first joined the group, but I'll be reading more on it soon.

      I'm trying to design a parallel scissor mechanism so the truck will only have one degree of freedom, which would be vertically. The mechanism would be mounted between the trucks and the bottom of the board. Shocks will be added to this mechanism later.

      I've looked on some bearings on mcmaster carr and we've decided to use the 5/16" outer and 5/32" inner size double-shielded steel ball bearings due to the limited space we have, but these could change depending on the load applications and testings we'll do later. This is one of the main problems I'm having. Must be silly questions, but what would be the best way to implement the bearings into the mechanism? If they were to go into the slots in the pics below, what parts/ways would be best?

      Are there any good websites that show how the joints and bearings work? Can't seem to find any sites that show detailed drawings of the bearings in slots.


      Thanks, I'm totally new to this. Will be modeling this in Solidworks and later machining at the shop.
       
    2.  
    3. Lochnagar

      Lochnagar Well-Known Member

      Joined:
      Feb 2011
      Posts:
      157
      Likes Received:
      0
      Firstly, I wonder if there is a "mistake" with the words you have used - since a "truck" - normally means a lorry - and a "skateboard" is normally used by people to get around quickly on a pavement - so I am struggling to understand the "application"?

      Secondly, you mention you have posted some pictures - but there are none to be seen in your posting?

      Below is a quick illustration of how a scissor mechanism works

      https://www.youtube.com/watch?v=PSy7_hNmDic
       
    4. Quan

      Quan New Member

      Joined:
      Jan 2014
      Posts:
      3
      Likes Received:
      0
      Sorry, was in hurry and couldn't edit the original box. Also had to wait for approval of thread before I could add picture.

      I meant skateboard trucks, and we're just doing this project to see if we can implement this into the trucks of the skateboard.

      Here are the pics:
      [​IMG]

      [​IMG]
       
    5. Lochnagar

      Lochnagar Well-Known Member

      Joined:
      Feb 2011
      Posts:
      157
      Likes Received:
      0
      It is good to see the pictures - so that we can see what the question is about. However, I still haven't got a feel for the physical size of the scissor lift - which will obviously influence the exact size of the bearings you use - so I am still unsure whether you are planning on lifting lorries (trucks) with this scissor lift. I still think there is still a need for some clarification on what you mean by trucks - since the word trucks - mean lorries to me.

      However, I would use what is sometimes called a "cam follower bearing" - or "stud type track roller bearing" - see the first link below. These bearings run in channel sections (C sections).

      Depending on how large this scissor lift is - you can also use what are called "Jumbo Sections" - with the associated bearings. These Jumbo Sections are either C Sections or I Sections. The bearings are detailed opposite the section - see second link below.

      http://www.schaeffler.de/content.sc...ne_tool_-_product_range/stk_1/nstk_1/nstk.jsp

      http://www.euro-bearings.com/crjumbo.htm

      Hope this helps.
       
    6. Quan

      Quan New Member

      Joined:
      Jan 2014
      Posts:
      3
      Likes Received:
      0
      Yes it helps, actually just talked to a professor at school and he's helped a lot too. Thanks again
       

    Share This Page