Feedback: Can we please allow the value "0" in dimensions, extrude commands, etc?

[FusionFan3000]

Wanted to share some feedback because not being able to enter "0" as a dimension is a problem that I have found frustrating on multiple occasions.

At first I believed I may have found a workaround, but it only seems to work for creating "dimensions" in a sketch. However, it does not work for the "extrude" command, and likely other commands as well.

I have attached an image which details the problem.

Problem Description: The ability to use the value "0" as a dimension (even if it is just the value of a user created parameter) is very helpful for testing and iterating designs when you're not sure what the distance between two objects will be and you want to test them (for example, I want to test if the distance between two mating objects should be 0.5mm, 0.25mm, or 0mm). Additionally, other formulas may rely on calculating the distance between two objects, so if I have to delete a dimension and make it a "colinear" constraint each time I am going to change it to be "0", that would break some formulas.

A possible workaround (not thoroughly tested), is to create a parameter and make its value nonzero. Then, create a dimension and make its value the parameter you just created. Now if you need to make that dimension "0", change the value of the parameter to "0".  

That workaround works only for a sketch dimension, which I am fine with. However, I just ran into an issue where I have an object that is extruded a certain distance, based on a parameter that controls several things in my parametric design. Well if I change that parameter to "0", rather than the extrude command not extruding anything, it simply gives me a warning and proceeds to extrude the object at whatever value the system remembers it to be prior to me changing the parameter. While all my other design elements correctly changed when I set the parameter to "0", the extrude command is still stuck trying to use the previous value, and so I have to go in and manually find the extrude command and suppress it. That can be time consuming for complex, parametric designs.

I hope this helps the Autodesk team understand the value of allowing "0" as a valid dimension measurement (even if it's only honored when used as the value of a parameter).

[stiller.design]

you could use 0.00001 instead, you wouldn't see the difference. could that be helpful?

[FusionFan3000]

Thanks for your reply and for bringing up that point! I did that a few times and the only reason I have hesitation is because it “seems” unclean. 

By that, I mean there are a few areas where the non zero value will show up and may be a bit confusing:

• when measuring an object, or viewing the properties of a body or component, the bounding box dimensions won’t be exactly what you intended, they’ll show the trailing 0.00001 at the end.
• when extruding with the “to object” command and using the reference point as a dimension that is “.00001” will cause other the extrude feature to extrude by “.00001” less, so that object will also have an “imperfect” dimension than intended. This may be redundant to the point above.
• when sending the design to a factory for manufacturing, my concern is that the “.00001” dimension will show up in drawings, which may cause confusion. I’m not experienced in this, so I’m guessing that this might be an issue, but maybe it actually isn’t.

Ultimately since the goal is to convert a CAD design into a physical object, I’m all for doing whatever is practical, as long as it’s the correct thing to do. So if you’re pretty sure that “0.00001” is practically identical to “0”  for all intents and purposes including when sharing the design for manufacturing, I think that could be fine.

[laughingcreek]

I would agree that using a really small value (.0001) is not a good workaround for this. When looking at a design I would assume an insignificant value like .0001 was a mistake (and start wondering where else mistakes are). numbers like that don't convey design intent, so should not be used imho.

it's interesting that your workaround works as long as your not starting with a value of zero. 

you can get your work around to work with extrude if you use the "extrude to" option, and select a sketch article to extrude to. (which is pretty much all I ever do anymore. easier to change things with dims in a sketch than finding the right extrude and editing that)

I doubt this would ever get implemented by AD. I can see all kinds of pit falls on the sketch solver side in allowing this. I personally have never thought about doing things this way TBH, I wonder if others do?

[stiller.design]

@laughingcreek  its possible to get it down up to : 0.000001mm BTW

which is a millionth of a mm. go figure

[FusionFan3000]

Thank you both for your input! The 0.0001 (or better yet 0.0000001) workaround seems like it could be fine, though I think my initial concern resonated with laughingcreek which is about design intent, communicating the design to others, and confusion when measuring objects and seeing a measurement that looks like 400.00001mm .

So in a way, my post is partially a feature request but alternatively a question about design best practices.. is anyone else experiencing these dilemmas and what are you doing in these situations?