Reporting Profile Tolerances on "Basically Located Surfaces"

[vizionary357]

i have a printt with a note that tells me "All untoleranced basically located surfaces must be..." with a surface profile tolerance of 3mm. The only untoleranced basic dimensions are distance dimensions. How specifically are these to be measured / reported in PC DMIS? So if I have a callout from one side of the part to the other for 2000mm, how do I dimension that? Do I do a distance dimension and set the tolerance to +/- 1.5mm? Do I take (2) points and report using profile? Little lost here. Any help at all with this would be greatly appreciated.

[Matthew D. Hoedeman]

you got a note on the print somewhere that says:

"ALL CAD DATA IS BASIC"

If so, then unless something is specifically called out, then all the un-called-out surfaces are prof/3

[vizionary357]

you got a note on the print somewhere that says:

"ALL CAD DATA IS BASIC"

If so, then unless something is specifically called out, then all the un-called-out surfaces are prof/3

I have no such note on this drawing. My thing is this: How to apply surface profile dimensioning to what would typically be a distance dimension.

[Darrollh]

I ran across something like this last week. I was told to take half the profile dimension and apply it to the distance. That's what I was told. I would speak with the engineer that drew the print.

[vizionary357]

Here's an example of what I mean. The circled dimension is a distance call out. Do I dimension it as such and split the tolerance (+/- 1.5mm) or is there a way to dimension it as a surface profile as the note specifies.

[Darrollh]

Yes. Take half of the profile dimension and apply it to the distance.

[marcc]

Here's an example of what I mean. The circled dimension is a distance call out. Do I dimension it as such and split the tolerance (+/- 1.5mm) or is there a way to dimension it as a surface profile as the note specifies.

I don't think your circled dimension has anything to do with profile, it is one of the basic dimensions for hole location. It is not surface basically located from the hole but hole from the datum B. Or does this hole does not have position callout?

[vizionary357]

I don't think your circled dimension has anything to do with profile, it is one of the basic dimensions for hole location. It is not surface basically located from the hole but hole from the datum B.

The circled dimension is just an example of what I'm dealing with. My whole drawing looks like that. There are FCFs for hole and datum locations, but there are dimensions like the one in the pic that span the whole part from one surface on one end to another surface on another end and I've been told that all basic "box" dimensions need to have the profile tolerance applied. It didn't make sense to me to apply profile to a distance, hence my question.

[Matthew D. Hoedeman]

basic dimensions have no tolerance.

[KIRBSTER269]

That basic dimension is for the position of that hole. I am curious what "B" is. One of those imaginary lines? or is actually related to something?

[KIRBSTER269]

Technically, What your note is saying is, Maybe you take any old random hit, maybe where I placed those arrows. That surface doesn't have a callout where I pointed, but that surface has to lie within that Tolerance zone stated in your notes

image_17156[1].jpg

[vizionary357]

That basic dimension is for the position of that hole. I am curious what "B" is. One of those imaginary lines? or is actually related to something?

The "B" datum is a hole.

[KIRBSTER269]

Thanks I was curious about that one.

[vizionary357]

This is a better example of what I'm asking. The distance along the circled dimension should be 2355.2. Do I dimension this as a distance (I'm thinking) or as a profile?

[Matthew D. Hoedeman]

BASIC DIMENSIONS show you the cad-perfect part. They have no tolerance. That basic dimension would NOT get that 'tolerance' even then, as EACH END would get that tolerance, and IF basic dimensions got tolerances (which they DON'T), it would be double since each end gets the full tolerance.

[Quality ish]

I have a customer that regularly indicates on their prints: "Unless otherwise specified, all tolerances are as shown".

This is on sheet 1 of 1. No hidden title blocks, no Note section.

And then there's no tolerance given on the print. Anywhere.

How do you justifiably tell someone that their part is out of tolerance with a print like that?

[marcc]

I have a customer that regularly indicates on their prints: "Unless otherwise specified, all tolerances are as shown".

This is on sheet 1 of 1. No hidden title blocks, no Note section.

And then there's no tolerance given on the print. Anywhere.

How do you justifiably tell someone that their part is out of tolerance with a print like that?

Is there a standard listed on the print anywhere? We have drawings with just a note: "Tolerances unless otherwise specified HES D0007-08" which is Honda standard or "Parts acc. to DIN 16742-TG6" which is another standard and we have to take tolerances from those standards.

[Quality ish]

Nothing. Nada.