How do I convert a dimension parameter to a unit less value?

[Anonymous]

I have a Body in a Fusion 360 design that has a 1mm length. I want to scale this using a dimension parameter, but the scale feature requires a unitless value.

How can I convert a mm, cm, etc dimension parameter into something the scale feature can use?

For example, change 20cm into 200?

[hpekristiansen · Accepted solution]

Why would you scale by something that has a unit? -I do not think it makes sense to do such a thing.

If your parameter is:

length = 17 mm

and you want to scale by 17, you simply type this in scale factor field:

length/1 mm

[TheCADWhisperer]

I suspect that this question will be best answered by seeing the actual file.

File>Export and then Attach your *.f3d file here.

[Anonymous]

I want to do this because I’m using Insert Derive to create multiple instances of the same body but with each having a different length... it’s aluminium extrusion with a complicated profile that I don’t want to replicate multiple times in the main design.

My thinking is to create the profile as a separate design extruded to 1mm, Insert this into the main design, and use parameters to scale it to the correct length.

You’ve answered my question as I think this will work, so thanks! But is there an easier way to do this? I’ve noticed that the Insert Derive command has a parameter/ favourite checkbox in the dialog but can’t seem to work out how that work.

[ryderbrooks]

Pythagoras would disagree..

sqrt(7"^2 + 8"^2) would be a useful quantity, no?

[k.acker.mailautodesk7AY5V]

Very slightly more concise syntax:
myLength = 17mm

myLength/mm

returns a unitless 17

You can also convert to other measurements in the same action.
For example:

myLength/in 

returns a unitless 0.669291 (17mm=0.669291in)

[woodman.dana]

This is actually quite useful for scenarios like this:

Say you have a wall that is 11' long and you want to do a pattern to duplicate a wall stud ever 24" along the wall. You could have a formula like:

wall_length: 132"

stud_spacing: 24"

num_studs = floor(unitless(wall_length / stud_spacing))

Which would get you "5" that you could then use in a pattern.

Without something like unitless or making things like ceil/floor etc support units, you have to come up with much clunkier ways to do this afaik.

[alan.ferrell]

This is what I came to find out.  Thanks for that easy fix.

[etfrench]

You can directly change user parameters to any unit type as well as unitless.