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


One mold or a few more molds

One mold or a few more molds

One mold or a few more molds


I want to know if I can only need one mold will do what I need. For example, I'm going to make a plastic ball using glass filled composite. So, I make a mold for it. Then later I need a bigger ball, can I change the size on the mold? Then later, I need a smaller size of ball, can I change the mold size?

Or I need a few mold for different size of ball?

I need a cheap solution. thanks

RE: One mold or a few more molds

If you start with the smallest size but use a big enough bloc of material to make the biggest ball, you can do it by increasing the size, however it will cost almost as much as for a new mould as most of the cost is labour, not materials.

Decreasing the size is much more difficult.

See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
for site rules

RE: One mold or a few more molds

Like Pat said.

But, balls are a special case.  
You can hand lay up an ugly epoxy/glass sorta- ball over a balloon, which can be adjusted for size until the resin kicks.
Tooling doesn't get cheaper than that...


Mike Halloran
Pembroke Pines, FL, USA

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!


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