Contact US

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!

*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

Threaded Connection

Threaded Connection

Threaded Connection

Hello all, I don't know if this falls exactly under gears and pulleys, but I figured some Machine Design professionals would find this an easy problem.

I have a general threading question which I will attempt to describe as accurately as I can.

I need a device that will allow small adjustments in a table's orientation. This strut will allow for a one time adjustment of a large magnet. To this end a threaded shaft inserted into sockets, one socket is attached to a fixed support, the other is . As the shaft is rotated small movement in the shaft allows for fine tuning pitch,rotation, etc.

^^^^^^^^                                  ^^^^^^^^
vvvvvvvvvvvv                                  vvvvvvvvvvvvv

This is a quick representation of the shaft with two threaded ends. My questions are: what combination of handing will allow for the greatest accuracy of adjustment (RH-RH,RH-LH, etc.), Secondly is there a formula for calculating the amount of torque required to turn a shaft such as this one through one rotation. And finally is there a way to determine (once the handing is determined) how much distance will be covered by one rotation of the shaft.

I hope that I have been clear enough but feel free to request additional information.

RE: Threaded Connection


The smalles adjustment I think will be obtained useing RH-LH threads. The threads must be of a different pitch, for example.

RH - 2mm pitch
LH - 1mm pitch

One rotation will result in the RH screw going out 2mm and the LH screw going in 1mm resulting in a total movement of 1mm. By selecting pitches that are closer together the resultant movement is decreased.

The distance can be determined as shown above by subtracting the thread pitches (single start threads) for RH-LH threads.

To determine the torque apply 'power screw' theory. It is normally in any mechanical design book.


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! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close