How do I change units on an existing drawing with appropriate scaling

Rhino Rhino for Mac
1

I could swear I’ve done this in the past (6+ months ago). I have a drawing I did in centimeters. I want to convert it to inches and export as a DXF so I can take it into my CAM to app to mill the part on my CNC mill. My CAM workflow is all in inches. What is the appropriate way to do this? I’m on the latest 5A713

2

Hmm, it seems that there used to be a “Model” and a “Layouts” tab in preferences. The Layouts tab is not there now.

3

In Mac Rhino the units would be in file SETTINGS, not Rhino PREFERENCES.
There are no Layouts in Mac Rhino yet so you won’t find that.

4

Thanks, I meant File Settings!

So is there a way to do what I want to do?

5

Hi Michael -That should work- File > Settings > Units - change to the units you like and answer Yes to the question about scaling, to keep the object the same size. Any luck, or am I missing the question?

-Pascal

6

Thanks. That’s what I thought I did in the past but when I do that I don’t see any change at all. Let’s say that I draw a circle 45mm in diameter. Then I change units to inches and check Yes to scale all. I then select the circle and look at its properties - it is still 45mm diameter. If I also select the object and export selected to a DXF file, it imports at the other end (CAM) as 45 inches diameter.

7

Hmm - assuming you started using an mm file, and you made your circle at 45mm diameter, then changed the units, measuring the diameter should report 1.77 inches (~ 45mm) … is that what you get?

-Pascal

8

I agree, that is what I expected. But no, I see 45"

In fact, I learned a technique. First I drew a line as the diameter of the circle - 45mm long. The I used the _Length command with nothing selected. This allows you to 1) select the object to measure and 2) select what units to display the length. I select inches-decimal and get 45".

9

It looks like a bug to me.
The actual scaling is not happening.
You’ll need to do that manually now.
Going from mm to Inches, I entered 1/25.4 as the scale factor.

I’ll get it on the pile
Thanks

10

Thanks John. At least I wasn’t having an elderly moment!

11

Weird… it did the right thing here. Build 5A 716

-Pascal

12

Pascal 5A 713 is the most recent version on the web, perhaps you have an internal version that does not have this problem?

13

Works OK here (5A713). Changed it from mm to inches and back and checked the same line length every time, scaling is fine. I did not dare to tick the “apply to all?” box, I don’t want all of my designs to be scaled by mistake. Did you tick it?
The thing you notice when scaling is the grid size increasing by a factor 25.4, it looks like your design is shrinking but it isn’t.

Max.

14

Thanks Max. I did it both ways on 2 different Macs both running 10.10.2 and the results were the same - no apparent change. I know this worked at some point in the past - maybe 4 months or more ago.

15

Michael, just to be clear, this is where I changed the units form mm to inch:

And I confirmed with Yes here:

Max.

16

http://mcneel.myjetbrains.com/youtrack/issue/MR-1556

17

John, this is strange. I followed your bug description to the letter, and this is the before/after scaling result:

The scaling is OK, the dimension object does not play ball though…

Max.

18

Right- it is still the same dimension style - you’ll need to pick a new one that is scaled correctly, or edit the style.

-Pascal

19

On Tue, Mar 3, 2015 at 8:18 AM, maxz steve@mcneel.com wrote:

20

Pascal, the point is that Michael and John are having scaling issues when changing units, and I don’t. The dimension style is secondary to that I think.

Max.