Dimensions not adding up

Dave wrote:

Wrathchild wrote:
I don't really think my model could be the problem. I almost always (if not always) type in exact units when laying out my plans.

Even though accurate model building is the "always" the goal, one missed snap either in building or dimensioning and there it is. And sometimes if you're building with real material dimensions it can happen. As a final check I put it in 1/64" and adjust the model to get the right dimensions. That way the dimensional creep visits less often.

Dave

I can't imagine not using real material dimensions. That seems like asking for trouble.

Wrathchild wrote:
I can't imagine not using real material dimensions. That seems like asking for trouble.

I agree, but the point is, let say you have 15/32" actual sheathing and inadvertantly snap to it rather than framing line (either in dimensioning or placing) then depending on your offset you can come up with dimensions that are off by some small amount which show up as a 1/64" when dimensioned at that setting or give the strings that do not add up at a higher setting.

Ahhhhhh the old "it just doesn't add up" thing comes up again - and again. Many moons ago in the Frenc days, this was a serious problem - once costing me a lot of money to have the foundation forms for a large residence to be re-set. All because of my own negligence in creating extremely accurate modeling. As a result of this error, I adopted the procedure of only creating in 1/64ths, including dimensioning, and making all of the graphics as correct as humanly possible - then at the end or at significant milestones re-setting the dims to 1/4. This was the best way at the time to assure that the strings would at least somewhat agree. Another method I used was to set a walls only layer set that had those elements that required best dimensioning practices and dimensioned that set. The slabs, ceilings and other elements then had to be the same as the walls. The whole thing was exacerbated when trying to use composite walls - my way around that one was to only draw studs -- not great but kept the plans simple and readable.

Now days with the structure display the process is much simpler, but I still draw with 64ths as the default and change to a more appropriate fraction at required times.

BTW the Frenc explanation at the time was to recognize the difference between 6 decimal places of the computer and the resolution of the screen and brain. Forcing the use of absolute input elements.