Assembly Dimension - reference dimension with tolerance or dimension with tolerance
Assembly Dimension - reference dimension with tolerance or dimension with tolerance
(OP)
Hi - new here/first post.
I'm being asked to specify in an assembly drawing that two parts should be X distance away from each other within Y (±Y) tolerance. This is the overall dimension. This dimension is to be inspected (to ensure the assembly is assembled correctly). If it doesn't meet this dimension, it means the assembly is assembled wrong - and needs to be redone / reinstalled.
Is there a correct method for this? My company has strict ASME rules (y14.5 and y14.100).
My concern is this dimension might be considered a machined dimension ( there are other machined dimensions on the drawing already ).
Thank you!
I'm being asked to specify in an assembly drawing that two parts should be X distance away from each other within Y (±Y) tolerance. This is the overall dimension. This dimension is to be inspected (to ensure the assembly is assembled correctly). If it doesn't meet this dimension, it means the assembly is assembled wrong - and needs to be redone / reinstalled.
Is there a correct method for this? My company has strict ASME rules (y14.5 and y14.100).
My concern is this dimension might be considered a machined dimension ( there are other machined dimensions on the drawing already ).
Thank you!
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
ctopher, CSWP
SolidWorks '19
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RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
Don't tell your assembler how to do their job. Your dimension specifies a requirement that must be met, and that you will inspect for. They will machine it if they have to.
If you place functional dimensions on an assembly drawing, state your dimensioning and tolerancing standard (ASME Y14.5?), and then follow you standard. Reference dimensions should be in brackets. Any dimension that must be achieved by the assembler, must have a tolerance of some sort.
--
JHG
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
You may as well consider other Y14.5 means to control distance, such as profile of a surface.
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
As others have mentioned though I would consider why you need to control the assembler's process. If it's to protect performance, e.g. if strength could be negatively impacted by material removal, then maybe a note such as above is warranted. Otherwise you may be imposing controls that are not required.
RE: Assembly Dimension - reference dimension with tolerance or dimension with tolerance
As ctopher indicated, show the assy on the dwg with a distance dimension with tolerance. Add parallel/flatness/profile etc as required.
I assume one part is fixed, and the other part is floating within a range (clearance between fasteners and holes).
What happens if you can't achieve the distance you want in the assembly? It does not sound like you have a mechanism to control this distance.
Best regards,
Alex