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

"Heavy" Fabrication Processes , Techniques, Design for Mfg.

"Heavy" Fabrication Processes , Techniques, Design for Mfg.

"Heavy" Fabrication Processes , Techniques, Design for Mfg.

I have been involved in many metalworking plants, and structural steel fabrication, along with miscellaneous steel, but would like insights in so called "heavy fabrication" material handling, fixturing protocols, special welding tecniques, and machining (boring) large items.
How would I go about developing process designs and design for manufacturing for these huge products? How much does the HAZ in welding affect large plates?  Should plates be horizontal or vertical for work?
Think rail car bodies, agricultural equipment weldments, etc. Thank you very much!

RE: "Heavy" Fabrication Processes , Techniques, Design for Mfg.

The question you have asked would easily fill several textbooks to answer. Fortunately, said textbooks are already written and readily available through a number of sources.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: "Heavy" Fabrication Processes , Techniques, Design for Mfg.

I've been involved with what you called a heavy fabrications. I worked at a 4-wheel drive articulating Ag tractor plant. I would not call those fabrication a heavy application. The main side plates of the frame were .500" thick for the large model. The front and rear frames weighed about 4000 pounds. For a heavy fabrication think of a submarine fabricated out of 2" thick or thicker 80k yield steel with full penetration welds welded into a single hull 400 feet in length. That is a large fabrication but of course the ship yard I am familiar with alse built Nimitz class aircraft carriers over 1000 feet long.

I have also worked at a large(heavy) job shop with one specialty was tire molds for 8-10 feet in diameter tires. The tire mold castings were cast at the company into the outer case and the inner tread ring. The outer case was machined in the inside and the inner tread ring was machined on the outside and then these pieces were pressed to together with an interference fit.

The machining process and the parts are massive but the biggest problem was material handling. When handling a part which weighs 4 to 20 tons a single mistake will kill you.

Lot sizes were very small. Cycle times were sometimes very long. Think of a high speed steel gear hob 12-14" OD cutting an 96" OD gear with a 10" length of the tooth. First roughing pass starts and the next day you check the progress of the first pass. Cycle time measured in days.

If you want to designate the processes for these parts start talking with the old timers and become very good friends and they will help.

RE: "Heavy" Fabrication Processes , Techniques, Design for Mfg.

I worked in a plant that had the capability to roll 12" plate - quite the sight.  One vessel we manufactured spanned 11 rail flat cars when it shipped.  The rail car bodies we manufactured were the light fill-in work.


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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. 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