×
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

"Closed" dimensions

"Closed" dimensions

"Closed" dimensions

(OP)
Guys,

I'm suffering memory loss and need some help and possibly a reference [standard] to verify but I've always known "closed" dimensioning to be wrong.

This is where you have:

|<----- 1 ----->|<--------- 2 --------->|

as opposed to this:

|<-----------------3 ------------------>|
|<----- 1 ----->|

Help me out - is this a will/shall type thing or a best practice and more a result of getting more out of your tolerances? I'm struggling to remember and I browsed through an old engineering drafting textbook and couldn't find anything on it.

Thanks,

Jack Lapham, CSWP
Engr Sys Admin
Dell M6400 Covet (24 Season 8, Ep 22)
Intel Core 2 Duo T9800, 2.93GHz, 1066MHZ 6M L2 Cache
8.0GB, DDR3-1066 SDRAM, 2 DIMM
1Gb nVIDIA Quadro FX 3700M (8.17.12.5896)
W7x64 | sw-01: 55.92
SolidWorks 2011 x64 & EPDM both sp2.0

RE: "Closed" dimensions

Do you have access to Y14.5 standard ('94 or '09 edition)? Fig. 2-4 plus para. 2.6 might help you.
Figs. 1-19 & 1-20 in '09 or 1-17 & 1-18 in '94 may be also helpful.

RE: "Closed" dimensions

Depends on which dimensions are important and which aren't.
Say you had +-.005 on all the dimensions in your examples.

it could be:

<----1.005--->|<--------2.005------>|
for a total of 3.010 max dimension.

while for the other method
3.005 would be the max dimension.
but this could happen:

<-----------------3.005-------->|
<-----.995---->|
implying:|<-----2.010----->|
Just depends on the type of control you need.

RE: "Closed" dimensions

Either are fine to use, no requirement for one to be used over the other. As thebuc1010 stated though, beware the tolerance stack-up when chain dimensioning.

RE: "Closed" dimensions

(OP)
Thanks guys - you cleared it up perfectly!

Jack Lapham, CSWP
Engr Sys Admin
Dell M6400 Covet (24 Season 8, Ep 22)
Intel Core 2 Duo T9800, 2.93GHz, 1066MHZ 6M L2 Cache
8.0GB, DDR3-1066 SDRAM, 2 DIMM
1Gb nVIDIA Quadro FX 3700M (8.17.12.5896)
W7x64 | sw-01: 55.92
SolidWorks 2012 sp3 x64 & EPDM sp2

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