×
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

Designer seeking Mfg. input

Designer seeking Mfg. input

Designer seeking Mfg. input

(OP)
Gentlemen,

Can an EDM process be used for producing a sharp inside corner (.002 max R) within a blid hole?

The hole is about 3.5" diameter and 3.5" deep.

Thanks for the help!
djk

RE: Designer seeking Mfg. input

It has been years since I did anythimg with EDM, but that seems like too tight of a radius. You might get it with a second electorde burn, but the elctrode burns fastest on the sharp corner.

"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
CAD/CAM System Analyst
Ingersoll-Rand

RE: Designer seeking Mfg. input

Just curious.
Why do you need a .002 max radius in a blind hole?

RE: Designer seeking Mfg. input

(OP)
Cast pump design(simplified) is currently 3 piece design.  I.E., a housing with a through hole and a seal w/ endcover at both ends.  

I'd like to be able to eliminate a leak path and save money by making the pump a two piece design.  I.E. one housing with blind hole and one end cover.  A sharp corner is required to help prevent an inefficient pump.



RE: Designer seeking Mfg. input

It can be done using conventional EDM's. However it would be very difficult, expensive and time consuming to produce. From a manufacturing engineering standpoint I would not recommend it. The 0.002 max radius is difficult to maintain regardless of what process you use. Might be worth looking into for a few pieces, but not for mass production.

RE: Designer seeking Mfg. input


Are you planning on using a graphite or copper electrode?

RE: Designer seeking Mfg. input

(OP)
I don't know about the electrode material.  

I was really just wondering about process capability.  I googled all over for edm references but found nothing concerning sharp corners within blind holes.

RE: Designer seeking Mfg. input

What about making the hole oversize and pressing in a pre-sized cylindrical liner?  The OD of the liner could be chamfered to accomodate whatever corner radius you produce on the receiving bore.  The inside corner of the liner, where it meets the bottom of the receiving bore, would be sharp or slightly undercut.

 

RE: Designer seeking Mfg. input

(OP)
That would work, but adds another part.  But that solution does eleminate a leak path...  A cost analysis would need to be done.  Hmmmm...

thanks all.

RE: Designer seeking Mfg. input

Add an operation to the Boring/Turning machining process, to put a minimum undercut into either the sidewall or bottom face of the bore. There is plenty of room to get a tool into corner and it would be cheap to do.

RE: Designer seeking Mfg. input

What is stopping you from machining it?

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