does your title block have basic tolerances such as .xxx= .005, .xx=.01 etc. if so what are your default tolerances
This is what we have, but in reality it should say...... "Fudge This"
LMAO... Fudge this.
We stuick to our tols and actually at times gd&t requirements of .xxxxx
S. Casale wrote: actually at times gd&t requirements of .xxxxx
S. Casale wrote:
actually at times gd&t requirements of .xxxxx
What do you do if there is a temperature change of 20 degrees, surely the parts have to be made in an environment controlled area...
We test to very extreme temperatures at various levels of build and prior to application.
.X = +/- .1
.XX = +/- .05
.XXX = +/- .003
Dimensions in mm
Scott, that's a tough question you have there ...
Honestly, we have tolerances that are all over the map. When it comes right down to it tolerances cost money and the customers deliverables dictate the tolerances applied.
We'll run anything from "Carpentry" (Fractional) type tolerances to High Precision Machine Shop (Grinding/Wire EDM Machines) tolerances that range in the microns.
Over and above that, as S. Casale eluded to we also have the pleasure (I'm trying to be facetious here) of dealing with the latest standard of "Limited Dimension" drawings where the tolerances applied are all based off of GD&T Profile call-outs.
Sorry for the open ended answer but in all honesty if we can get our customer to sign off on a tolerance of ± "a country mile" why wouldn't we ...
I'm not much of a fan of decimal place title block tolerancing. I prefer something along the lines of ISO 2768, where the allowance automatically varies based on feature size, and also includes some flatness/squareness tolerances. Somebody smarter than me came up with these (as I understand) to get a good balance between always being guaranteed to work vs. cost to machine. Usually works pretty well for machine building etc, and you can even specify fine, medium, coarse, or very coarse.
General ISO Geometrical Tolerances Per. ISO 2768 | GD&T Tolerances | ISO G&T Tolerances - Engineers Edge
What are you designing? Weldments, aluminum/steel machined parts, tool & die, carpentry/woodworking, Plastic injection molded parts?
Each of the above ~ have different tolerances because there are different machines utilized to cut the parts. Some more precision than others. Or they could be different ways to assemble parts, so the hole spacings and diameters may need to be tighter... lots of variables...
The size of parts also have a lot to do with tolerances... bigger part require bigger tolerances (usually)...
Help us, help you,
As Said Josh Brady maybe need to includes something else like those ones too.
Tolerances for Holes (ISO 286-2)
Limit and fit | ISO hole chart | Tolerance
ISO Tolerances for Shafts (ISO 286-2)
ISO shafts chart | Shafts tolerance chart |
Here are ours:
Totally agree with Josh. However just calling the standard could be challenging for everybody - from designer to machine shop to QC.
On our title block we added a table referencing the standard- works great for us:
"f" is only for T1 though, we should really put an H in there too for T2 i.e. ISO 2768-fH.
We set the title block tolerances in Property Tab Builder. The default tolerance values are all 0, so we have to go in and decide what is appropriate for the particular part.
Dwight Livingston wrote: We set the title block tolerances in Property Tab Builder. The default tolerance values are all 0, so we have to go in and decide what is appropriate for the particular part. Dwight
Dwight Livingston wrote:
<sigh> all the extra work...
We use ISO 2768 with options set in property tab builder including an option to use our old decimal place based tolerance
Agree Josh Brady, my general tolerancing is as simple as this.
DIMENSIONS WITHOUT TOLERANCES
AS PER ISO 2768 - m K
m - medium class for linear, radius, chamfer, and angular
K - class for straightness, flatness, symmetry, run out and perpendicularity
Saves sheet space!
We also use ISO2768 -m as DEFAULT.
But we work with many different processes, each having different tolerance standard. Eg. EN755-9 for aluminum extrusions.
So we have a custom property on the part named "Tolerance standard" in which we select the appropriate standard.
But we are considering to switch to: ISO 2768-mK
Ok so this is a chance to find out if we are weird?
When we make the model we assign the basic tolerances there as seen int this screen shot.
We do everything from the model or assembly.(Dimensions, Weld Symbols, Tolerance, Ect)
Then when you open a drawing the tolerance block is blank.
Then when you insert the model it populates the fields.
Retrieving data ...