×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Compression spring design

Compression spring design

Compression spring design

(OP)
Hello,

I am designing a tool that will hold parellels against the inside faces of a vise. I am having problem selecting the right compression spring. I do not know how to calculate the required load (a machinist should be able to fully compress it with one hand) in order to deternime the number of coils or materials to use or even wire diameter. My guess is that it should be resistant to typical CNC mill coolant. What I do know is that is should fit over 3/8 inch diameter tubing, a free lenght of 8.500 inch or more and a minimum working lentgh between .750 - 1.000 inch.

Thank you.

RE: Compression spring design

Any decent machine design text will go into spring design in detail.  It sounds like you want the forum to design the thing for you.

Tunalover

RE: Compression spring design

woodrunner
Why don't you take this to forum 693 spring engineering?
B.E.

RE: Compression spring design

If you can get a copy of "Machinists Handbook" of recent vintage, their spring design chapter is one of the best IMO.

RE: Compression spring design

(OP)
Thank you for the help. I'll look into it.

RE: Compression spring design

You need to figure out the loads for yourself.  From the loads, you can determine the characterstics of the spring you need.  What you probably will need to start with is the force the spring needs to exert at one or two given lengths.  With forces at two lengths, you have determined the spring k-factor and preload.  then you can try to find a spring that delivers your forces that fits in the space you have available.

Try this calculator:
http://www.engineersedge.com/spring_menu.shtml
 

RE: Compression spring design

WoodRunner,

   I keep a spring scale at my desk.  If I want to figure out how much force to exert on something, one option is to pull on the spring scale.  I can exert a force I feel comfortable with, then I can put a number on it.  

               JHG

RE: Compression spring design

While it wont solve all your problems, you might want to look at a spring catalog from someone like Lee Springs and try and pick an off the shelf spring, at least for a prototype or one off if that's the case.

Selecting how strong a spring you want can be surprisingly tricky.  A colleague and I got it fairly wrong once and ended up with a tool that once closed was almost impossible to open.  Not my finest hour, and this was done with a bunch of calcs to try and find the required load, I'm guessing we made a mistake in our assumptions somewhere.
 

KENAT,

Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Compression spring design

There is a free compression and extension spring design calculator at the following link that may be helpful to you...

http://wwweng.uwyo.edu/commend/

 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources