×
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

TP callout for two bearing counter bores

TP callout for two bearing counter bores

TP callout for two bearing counter bores

(OP)
Hi there,
I need your opinion on the case below:
Problem: A buterfly valve with a shaft goes thru both side of the wall. Each side has a bearing bore callout.
1. The hole for the shaft is a thru hole with diameter A +/- tol with a datum A callout.
2. The bearing bore on the right states 2 X diameter +/- tol (for two bearings bores) with a TP of .002" to datum A.
3. They call out a datum C on the bearing bore on the left of the body with a TP of .003" to datum B-C.
Question:
a. Is the callout in item 3 above valid? and good control?
b. Does the 2X diameter +/- tol with a TP of .002" to datum A in item 2 above apply to both bearing bores, regardless the callout in item 3 above? In other word, the callout in item 3 above is NOT REQUIRED.
Your earliest help is appeciated.
Uptick.

RE: TP callout for two bearing counter bores

(OP)
Sorry. The datum B callout is missing in the bearing bore on the right (item 2.
Hope to hear from you soon. Thanks
Uptick

RE: TP callout for two bearing counter bores

Hi uptick

Please post a sketch its far easier to see and follow rather than your description.

desertfox

RE: TP callout for two bearing counter bores

Please do not cross-post, as it is against site policies.
The GD&T forum is the correct location for this question.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

RE: TP callout for two bearing counter bores

Primary datum should be the butterfly bore.
The shaft bores are tertiary at best.

 

Mike Halloran
Pembroke Pines, FL, USA

RE: TP callout for two bearing counter bores

(OP)
Hi all,
Sorry. I posted in the wrong place before I posted this here.

Mike: The datum A (the shaft thru hole) is already tight to the butterfly bore which I did not present here. Now the issue is the bearing bores are controlled the A. I wont to know if the callout is correct (valid). I know the total runout for C to B is the best, but does this one (TP callout) work?
Thanks,
Where is KENAT?
Uptick.

RE: TP callout for two bearing counter bores

Functionally, the shaft bore doesn't come into play until the bearings are worn out.  Why include it in the stackup?

 

Mike Halloran
Pembroke Pines, FL, USA

RE: TP callout for two bearing counter bores

(OP)
Sorry ewh. I did post overthere after finding out the correct location.

RE: TP callout for two bearing counter bores

Quote:

Where is KENAT?

Working the job that pays my bills.  I'm not overly familiar with valves and didn't follow your description well enough to comment.

forum1103: Drafting Standards, GD&T & Tolerance Analysis thread1103-279665: True position callout

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: TP callout for two bearing counter bores

Hi uptick

I think you can't reference B&C to themselves which is what you appear to have done.
What I would do is have B&C as your datum and then use runout of the bore datum A (thru hole) to the datum B&C.

desertfox

RE: TP callout for two bearing counter bores

Hi uptick

Further to my last post your tolerance figures should actually be derived from the clearance between bearing internal diameters and shaft diameters, ie when the bearing housing holes are misaligned and the bearings and shaft have minimum float, you should still be able to assemble all the components.

desertfox

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