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


Determining optimum gate size

Determining optimum gate size

Determining optimum gate size

My team is currently tasked with specifying dimensions for a twenty year old tool under reconstruction. We are only just beginning to put GMP in place where tribal knowlege had ruled. A 1980 tool print calls out a .035 diameter sub-gate with typical geometry. Original design personnel are history and this six cavity tool with two, 180 deg. opposed gates per cav. has a range of openings .053-.078. A co-relation has been shown between those cavities with the largest gates to be most prone to failure in a test mode designed to expose susceptability to linear cracking of the glass-filled nylon parts. Processing data for previously acceptable parts does not exist. We had been wingin' it. Any suggestions that would lessen our trial/test/repeat steps would be greatly appreciated. Thanks. May the Force be with you. :-)

RE: Determining optimum gate size

try changing gate location and enlarening vents at knit lines

RE: Determining optimum gate size

If you can give me some more specific info about your part I could give you a good estimate for gate size.  Also, always start small - this leaves you "steel safe" and most tool shops will resize the gate for no charge as part of typical mold trial/tuning.

What is the part material?, part volume?, length of runner?, part wall thickness? cavity surface area?

If I know this information I will estimate the gate and runner size for you.


Eric Fehrman
Fehrman Tool & Die, Inc.

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


White Paper – Data Security and Know-How Protection
Our data is constantly exposed to the danger of being intercepted or stolen as it wends its way over global data networks. Data security measures and measures for protecting intellectual property should not, however, first be implemented when data is exchanged – companies must lay the foundation for these measures within their own organization. Download Now
White Paper – Collaboration in the PLM Context
The influence exerted by the Internet of Things (IoT) means that there is a steadily growing need for collaboration in industry. Partners from new industries and areas of application need to be integrated in cross-company business processes to ensure that the lifecycle of smart, connected products can be managed from end to end. Download Now

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