Parameters of model not calculating correctly ??

[Anonymous]

I am trying to create a parametric spherical tile.

I know the length & widths of my tiles, but to create the revolved sketch of the arc I wanted to use parameters  to calculate the revolved angle.

So I can input the width as a length of arc, say 120mm and it will revolve the sketch to the correct angle.

However when trying to transpose the formula for length of arc, L= 2*pi*Radius * (angle / 360)

to

angle = (Length of arc / (2*pi*Radius)) * 360

It is not calculating even close to the 4.2° I am expecting.

plus the formula is coming out red and it is confusing the units...

I have previously done calculations this way in 2017 without problems.

So I broke it down in stages:

A1= PI * Rad_Sphere

A2 = A1 * 2

A3 = Width / A2

Width here being the width of tile, or length of arc = 120mm

and it is coming out as 0.119366

where as this should be 0.0119 - so it is out by a factor of 10

What is going on here ?

Have I missed some simple tick box/ check ?

Thanks, I would paste a snip but it won't let me...

I think I have been able to attach.

Thanks, Neil

[Sergio.D.Suárez]

Hi, make sure to place the correct units, see the image that I attached. Observe the correctly placed angular units and the parentheses for the equation. The reddish color would indicate in your case a unit problem
I hope this helps. regards

[Anonymous]

Thanks

I thought I had that covered.  when I set to degrees it wouldn't accept.

I will try again and check the brackets.

Neil

[johnsonshiue · Accepted solution]

Hi Neil,

A3 is a length parameter with a unit of mm. But, the equation actually returns a unitless value (Width/A2). I think you can add *1mm to the equation to convert the unitless value to a length value again.

Many thanks!

[NileshV.Khairnar]

i faced same issue earlier then i found this unit issue  

[Anonymous]

Thanks, definitely a unit issue, thanks