If they fit function on assembly, yes - its one of those catch all statements for people who do not interpret GD&T or dont have a CMM on hand so cant measure the parts. at least its a 'close enough' reference to thow a pair of calipers across the part.
for these parts, which are sheet...
The Profile tolerance takes precedence. But i have QA at companies who do not interperate the GD&T correctly... at least the +/-0.2 linear is as close as you can get right?
Additional question:
Would it be acceptable to add a note to allow measurement of |PROFILE|0.2|A|B|C| with a +/-0,2 linear measurement on 'simple' features, for those companies who do not interpert GD&T / GPS.
Thanks John-Paul,
Understood, but if the note were to say form and location?
Yes the idea is the hole size is important, its location less so. and to avoid basic dimensioning all the holes, to use the standard surface profile note to cover it?
thanks!
Hi all,
I have a standard drawing note stating: 'Unspecified form to be within 0.2 surface profile of supplied CAD data.'
On a drawing of a sheet metal part, I have callouts for size control of holes, i.e. Dia. 5.3 +/- 0.05 mm
Is it correct to control the position on the sheet metal of the...
Thanks Greenimi,
Thanks for pointing out the requirement of collection planes! I thought it was somewhat implied from the view, but I see it must be defined.
And on second thoughts I think the Line Pofile may be a sufficient call out for my application.
Is there a way to define at which hieght...
Dear all,
I am trying to control the main outside profile of this part but hold the end feature to a tighter tolerance.
See attached: https://files.engineering.com/getfile.aspx?folder=5c5a3e36-e738-49ba-9716-020dfa4d601b&file=gdt1.png
Is this an acceptable use of the surface profile call out...
After some more looking I came across these two documents that have some data on measurement methods... and I just realised 3Ddave had linked to simillar documents also! sorry!
https://iigdt.com/1/1035/
https://elsmar.com/Cove_Premium/Measuring%20Threaded_Holes.pdf
I am maybe more confused about threaded holes than to begin with... [dazed]
From what i understand, if i specify a True Pos. tol on a threaded hole callout:
I am specifying the true position of the centreline of the Pitch Diameter. This is effectively an immearsurable feature. But flexible...
Hi all,
Thanks for you comments, definitely a bit out of my depth now, but its good to learn.
Just replying to some points in order:
DMPF doesn't apply to our design intent. We require the face to act a sealing face.
I haven't used projected tolerance zones before. I sort of understand the...
Thickness is 20 +-0.1.
And isn't flatness independent of thickness.
I.e. you can have sheet metal of 3mm +- 0.1 thickness and then roll it to a radius of 100mm, It would not longer be flat but thickness is still 3+-0.1
Hi Dave, thanks for the feedback!
I will add the all around symbol!
We use a standard tolerance table dependant on decimals, hence why no tolerance on some dims. But yes point taken.
Hi all,
I was hoping if someone could review my use of Datums and FCFs in this example sketch. I am creating a production drawing for a part, and will be applying a GD&T scheme similar to this. But this is one of my first formal uses of GD&T,
To understand design intent: The 15mm hole aligns...
