Sketch offset dimension value

[roman_Sholiak]

Hi All , 

Just get strange behavior during sketch offset .

Create empty sketch , draw rectangle and offset lines for 1mm ( default value inserted by SW - no input from me ).

After this when try to modify it - offset shows strange value of 1.0000000149 mm .

If offset value inserted by me - then everything works fine .

Tested on 2 different PC`s and accounts ( Subscription )  . Version - 2.0.14337 . 

[TheCADWhisperer]

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@roman_Sholiak wrote:

Hi All , 

Just get strange behavior during sketch offset .

no input from me ).

…strange value of 1.0000000149 mm .

If offset value inserted by me - then everything works fine .

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This isn’t strange.

This is expected logical behavior.

[roman_Sholiak]

What you mean expected ? 

It propose 1mm offset ( in data value it shows 1.00 - not 1.0000000149 mm ) - but in fact it use this strange value.

If proposed value is 1.00 - then in fact must be 1.00. This few digits can create additional misalignment later on . 

[TheCADWhisperer]

I must not understand the problem description.  I thought you were sketching by eye rather than by explicit user defined dimensions.

Can you File>Export your *.f3d file that exhibits this behavior  to your local drive and then Attach it here to a Reply?

[roman_Sholiak]

No file needed - try to draw rectangle on any sketch and offset his line ( but not enter any value in data box - use what Fusion propose and press Enter ) . After when you see this offset on a sketch - double click on it for modification and check what value you will see .

[TheCADWhisperer]

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@roman_Sholiak wrote:

… ( but not enter any value in data box -

...double click on it for modification and check what value you will see .

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Why, oh why would I not enter the explicit value that I want?

I will, of course, enter the value I want and if I edit the value I will see exactly what I expect to see.  The logic makes sense to me.

[roman_Sholiak]

Current example that Fusion propose me offset 1mm which OK for me in many cases when I use this function.
In case proposed value is the same as I need ( currently it`s 1mm ) - so I need enter this value again to get proper result ?
This was the main purpose of this post - if SW propose some default value , it must be correct one .

[TheCADWhisperer]

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@roman_Sholiak wrote:
…if SW propose some default value , it must be correct one .

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Is Fusion really really proposing a dimension out to 10 decimal places?

I don’t have Fusion on this device to check - but I doubt Fusion is initially showing 10 decimal places if I follow your instructions.  Can you create a screencast showing that Fusion is proposing 1.0000000000 and then changing it to some other value when you hit Enter.

In my case, if I recall correctly, I have my Properties set to only show 2 or 3 decimal places.

I can start up my PC and check all of this if necessary.

[TheCADWhisperer]

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@roman_Sholiak wrote:

Hi All , 

Just get strange behavior…

Create empty sketch , draw rectangle and offset lines for 1mm ( default value inserted by SW - no input from me ).

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That’s it? Zero decimal places? In that case 1.0000000999 = 1.

[TheCADWhisperer · Accepted solution]

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@roman_Sholiak wrote:

 ( in data value it shows 1.00 - not 1.0000000149 mm ) - but in fact it use this strange 

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1.00 = 1.0000000149 

[roman_Sholiak]

Sketch offset dimension value
https://knowledge.autodesk.com/community/screencast/d3e8cbf0-c5c0-43ea-95c0-258e878e510c

[TheCADWhisperer]

It is only showing 2 (or 3) decimal places in your video - how do you know what is beyond the 2nd decimal place in your offset?

https://www.google.com/search?q=dictionary+sketch&rlz=1C1GGGE_enUS487US509&oq=dictionary+sketch&aqs=...

I recommend increasing your General precision AND explicitly defining exactly the value that you want.

[roman_Sholiak]

I found this when I made body from that offset and measure it with all decimal point`s turned on.
It`s good to know that this value must be entered - but it`s looks like a bug in the SW .
If SW propose 1mm - that must be 1mm .

[TheCADWhisperer]

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@roman_Sholiak wrote:
If SW propose 1mm - that must be 1mm .

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I edited my last response with screenshot from my screen.

It shows that Fusion isn't actually proposing 1.00 - only to that number of decimal places.

If you increase the General precision you should see the more precise proposed value.

[roman_Sholiak]

Why it propose not round value ? What is the purpose of this ?
Most likely it`s not as must be ...

[TheCADWhisperer]

Why? I don't know.  It seems like it should propose integer values.  I was wrong - it isn't logical if your work is more precise than mere sketching.  Good catch!

All I know is Design Differently.

[jeff_strater]

Fusion is a tool for designing things that are manufactured.  Do you realize how small a value 0.0000000149 mm is?  Certainly below the tolerance of any manufacturing process that is likely to be used.  Fusion's sketch solver uses a tolerance in its calculations.  I think the tolerance value is 1.0E-06, which is bigger than this value.  Yes, I understand that you expect it to be exact to any arbitrary number of decimal places.  But, can you point to any way in which this difference is affecting your design?

[roman_Sholiak]

Easy - very often I found this strange dimension deviation during manufacturing process .
As an example - Bore operation not working properly if hole is not on the same axis as Z axis . This can be when I build this components using this offset (in my case 1mm offset I used mostly - this will give nice fit for different plastic covers ). In this case operation 'selecting same size' not working as hole axis is misalignment.
Also this kind of deviation looks like create strange angles when you start playing with assemblies and joints .

[Stuart-H]

What is the accuracy of your machine , ie what is the design tolerance that your machine can work to 

I would think a Kern Micro Vario. would be oush to work at 10 decimal places 

[roman_Sholiak]

Who was talking about the machine at all ?
Problem can be in Manufacture environment of Fusion .
When this strange not round values gives some strange 0.000003 degree misalignment and I can`t use drilling operation .

In any case this is strange that SW propose not round value .