Dimensioning a single-ended slot

[2JL]

Hello Everyone

I know that the topic of slot dimensioning has been discussed a lot around here. However I didn't find much about single-ended slot. I always struggle with this particular case. Most of time, profile tolerance is the trick but not in this one.

Attached is a sketch of what I am thinking of doing. Does it make sense for you?

Thanks
2JL

 

[greenimi]

If you would just profile the 4X R will looks much better
13 basic--maybe revised to the center of the slot
profile the radius for size / location/ orientation and form

 

[2JL]

Thanks!
"13 basic--maybe revised to the center of the slot
profile the radius for size / location/ orientation and form"
Do you suggest to add a profile tolerance for the round?

 

[greenimi]

Yes, I do. (profile callout for the round)
Also if the basic dim goes to the center of the round....probably is better.

 

[KENAT]

Actually, I think what you have is reasonable 2JL and is probably how I'd do it - depending on function. I don't think boundary comes into play on an open end slot like this so won't open that debate.

Making 13 basic only works if you go to surface profile for the feature - it's an option but not necessarily my first choice.

Dimensioning to the ends of slots arguably normally better reflects function and in one place in Y14.5 is stated as the preferred way for dimensioning ob-rounds, then somewhere else they give 2 other options.

(Don't think it makes a difference by I work to ASME not ISO.)

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[2JL]

Thanks Kenat
My main concern is the 13±0.25 dimension. I was not sure wheter it was correct per 2009 ASME standard. As for the function, it has to clear a pin.

Greenimi
Profile tolerance between the two points (left and right) on the open end was my first guess. But since people here don't like profile very much, I always try something else first.

 

[KENAT]

Your "13" dimension is defining the size of the feature, like the diameter of a hole etc.

I'm not sure anyone doesn't like profile, but some think it should be used almost universally instead of +- (except perhaps holes) while others tend to stick with +- dims unless they won't do the job adequately.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[2JL]

Well, the reason lies somewhere between the endlesss support we have to give to suppliers on how to interpret and inspect the profile callout and old dimensioning habits.

 

[greenimi]

Quote #1:"But since people here don't like profile very much"
Quote #2: "the endlesss support we have to give to suppliers on how to interpret and inspect the profile callout"

2JL,
Are we working for the same company? Are we using the same suppliers?

What is going on?

 

[2JL]

I hear you Greenimi. I don't quite understand why myself. For some small shops we use for simple parts, it's Ok since they don't have CNC or CMM.