×
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

Drawing a gear and a rack
3

Drawing a gear and a rack

Drawing a gear and a rack

(OP)
I have a gear and rack (these are physical units that I have in my hand) that I need to create a model and drawing for in SolidWorks. For this, I first need to make the relevant measurements on the gear and rack and then figure out how to reproduce in SW. My question is: what measurements do I need to take, how do I take them (i.e. what instruments do I use) and how do I draw them in SW. I have an older version of SW, so I might have to make these from scratch. I think there is a feature "Gear" in newer SW. Your comments will be greatly appreciated.

RE: Drawing a gear and a rack

Newer versions of Solidworks have a mate option called gear mates.  This allows you to mate two discs and assign a ratio.  When you rotate one, the other rotates per the defined ratio.

As far as doing a drawing of a gear, it is not critical to actually draw the teeth (unless you want a pretty picture).  The critical areas are typically tabulated on the face of the drawing.  These areas are:
1. Diametral Pitch
2. Number of Teeth
3. Pressure Angle

As far as measuring the gears you have, you can count the teeth, and there are formulas that relate the diameter of the gear and the number of teeth to find the dimetral pitch.  As far as the pressure angle goes, that deals with the shape of the tooth.  I am not sure how you will be able to find that.  Somewhat standard for pressure angle is 14.5 degrees

You may be able to check out www.engineersedge.com for more info.

RE: Drawing a gear and a rack

Mkmech, my question to you is what purpose will the gear and rack models serve?  Their end-purpose will determine how accurate your models need to be, what you will use to measure them and how they are constructed in SW.

"I think there is a world market for maybe five computers."
Thomas Watson, chairman of IBM, 1943.
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: Drawing a gear and a rack

mkmech,

   The standard way to do accurate measurements of gears is to use three pins.  The pins engage opposite teeth, and you measure across the pins.  A textbook on gears should explain this all.  This will help you confirm the pitch.

   Dudley's Gear Handbook (McGraw Hill) has instructions on how to draw a gear involute.  It works.

                            JHG

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