This Has Always Driven Me Nuts Re: Dimensioning 45 Degree Angles


Steve-C
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It seems that every time I have a plan that contains a 45 degree angle I run across this issue. Maybe it's a setting I'm unaware of, I don't know. When I dimension from 2 different sides I often get dimensions that are off by an inch (keep in mind that I always round to the nearest inch for plan appearance). When I adjust corners slightly in order to try and match these dimensions I rarely have success and usually I have to create a dimension line (from a CAD line) in order to make it work out. What really drives me nuts is when I try and adjust these walls I notice that more often that not, the number is not rounded to the nearest inch. For example; I'm working on one now where I had to shorten one side but keep the other side the same and one side had an even 2'-2". When I reduced that dimension by 1/8" the displayed dimension dropped to 2'-1". Why is that? Shouldn't the dimension round to the nearest inch?

 

I'm sure I'll get a lot of "you should never round off" comments but this is how I learned and it (usually) saves a lot of time (except when 45 degree angle are involved). It's been my experience as a build that the plans with excessive fractions will confuse a framing crew in a hurry.

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Steve:

 

I agree with the fractions just causing confusion

 

I measure to 1/16 for as-builts - per my Disto Plus

I model to 1/16 for as-builts

I'll allow up to a 2" discrepancy - but keep notes as to the measured dim

 

when doing new build - I try to get rid of fractions by tweaking the plans

I'll accept a few fractions if the tweaks won't eliminate them

 

at time of printing I round/display to 1/2" or 1"

depending on the project needs

 

at time of printing I round/display to 1/2" or 1"

depending on the project needs

 

if you do the rounding too early it can lead to discrepancies

maybe even "errors"

 

Lew

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....... When I reduced that dimension by 1/8" the displayed dimension dropped to 2'-1". Why is that? Shouldn't the dimension round to the nearest inch?......

 

Just tried it,  could not repeat your issue,  it worked for me.......  using 1/8".....  but I did  notice anything less than 20/32" rounded down,  and we all know 19/32" should be rounded up.  Anything 1/2" or more should round up.

 

I think you found a bit of a bug,  I think you should report it.

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You may have it on it P. Not grid rounding but distance rounding.

But... from the help file:

Rounding Method - Specify how the sections of dimension lines that locate more than two objects are rounded.
• Grid Rounding ensures that the sum of the parts of a dimension line add up to the whole distance. To produce this result, some sections may not be rounded accurately. This is the recommended rounding method and is selected by default.
• Distance Rounding addresses each section of a dimension line individually, which could result in the sum of these sections not being equal to the whole. This option is selected by default for files created in Version 8 or prior but is not recommended for newer files. See Compatibility With Previous Versions.
 
I could easily be misunderstanding the issue presented by the OP, but I don't think the rounding method in the dimensions dbx applies to the issue...
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Chief doesn't allow you to violate physics with the dimensioning tools.

 

We do however allow you to fudge a bit by providing a non traditional grid based rounding system rather than the more problematic traditional mathematical rounding. Both are options.

 

I'm thinking that I should change the rounding options to 8 lb hammer, 4 lb hammer, 24 ounce hammer, and fist.

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Chief doesn't allow you to violate physics with the dimensioning tools.

 

We do however allow you to fudge a bit by providing a non traditional grid based rounding system rather than the more problematic traditional mathematical rounding. Both are options.

 

I'm thinking that I should change the rounding options to 8 lb hammer, 4 lb hammer, 24 ounce hammer, and fist.

Problem with a post like this is it does  not answer the OP's question.  I think several of us offered explanations or solutions the best we could based on our knowledge,  but Doug,  if you knew there is a minor bug or Perry provided the solution,  it would of been appreciated if you had acknowledge the answer.

 

After your response I still do not know the answer.

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First, There is not a bug in Chief.

 

Second, you can't create a 45 degree triangle where the sides are exactly to 1 inch. The Pythagorean theorem tells us how to calculate this very simply. Let's take a simple example of a triangle 20' on two sides and then calculate the length of the hypotenuse (long side). The length is sqrt(20*20 + 20*20) which comes out to approximately 28' 3 7/16". Actually it is slightly under that number, but our tape measures don't give us that much accuracy.

 

Chief provides 2 methods of rounding.

 

Historically Chief provided only the traditional method of rounding that states that a value of .5 or greater rounds up and everything else rounds down.

 

But, we had a lot of customers who ended up with dimension runs that didn't add up because while the length of a particular dimension was properly rounded the precision of the model made it so that things appeared wrong. The customers that had this problem were the ones that insisted on not building a model that was accurate.

 

So we added a new method of rounding to a grid that basically shifted what we measure to the nearest grid value. This works great for many cases and reduced the number of complaints, but you can still create a model that won't round to the dimensions you want if you are sloppy enough.

 

Bottom line, always draw your model such that things are positioned exactly to the rounding that you prefer.

 

When your dimensions aren't doing what you want you need to look at the model because it is where the problem is.

 

In some cases you may need to use some fractions to get things to work.

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Historically Chief provided only the traditional method of rounding that states that a value of .5 or greater rounds up and everything else rounds down.

 

I GET THAT,  BUT I JUST DID ONE WHERE THE 47.5" ROUNDED DOWN TO 47" AND 47.51"  ROUNDED UP TO 48",  CLOSE ENOUGH FOR ME BUT NOT EXACTLY WHAT YOU SAID. (and I had it set to using ROUND TO DIMENSION as opposed to ROUNDING TO DIMENSION.

 

But, we had a lot of customers who ended up with dimension runs that didn't add up because while the length of a particular dimension was properly rounded the precision of the model made it so that things appeared wrong. The customers that had this problem were the ones that insisted on not building a model that was accurate.

 

So we added a new method of rounding to a grid that basically shifted what we measure to the nearest grid value. This works great for many cases and reduced the number of complaints, but you can still create a model that won't round to the dimensions you want if you are sloppy enough.

 

Bottom line, always draw your model such that things are positioned exactly to the rounding that you prefer.

 

When your dimensions aren't doing what you want you need to look at the model because it is where the problem is.

 

In some cases you may need to use some fractions to get things to work.

I know  Doug,  we are being anal,  bottom line,  I think Perry hit on it.  It was my mistake to use the rounding to THE GRID,  once I changed to rounding to the dimensions,  it was close enough for government  work.

 

I hope this info helps out Steve N.

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