Lines in different Units 1

[davidgutnik]

What i'm trying to do is Very Simple.

With out scaling the whole drawing, i am trying to draw a line that is 10mm then draw another line that is 10 inches.
I've searched through forum after forum, i can't find a way of switching between units.
I've tried :
format--> unit system. set to inches
line --> select start point --> move mouse in a direction --> type 10 --> enter.
then
format--> unit system. set to mm
line --> select start point --> move mouse in a direction --> type 10 --> enter.
Both lines show up the same length.

 

[tr1ntx]

I don't think you can switch drawing units after you've set them for the file.

If you are working in inches (have your dim's set to inches), draw a line at 10. This will be 10 "drawing units" and the drawing units are set to inches.

Then draw another one or copy & paste (or offset) the first line. Then scale it.

25.4 mm = 1 inch. So you need to scale it down by 1/25.4

However, you can't enter a fraction with a non-whole number denominator. Thus you need to express that ratio with a whole number denominator.

Anyone?

Anyone?

Anyone?

Bueller?

The scale factor will be 5/127.

Then if you dimension it (with alternate units enabled), it will show 0.394 inches [10 mm]. Of if you're using fractional or engineering units it will show 3/8 [10].

If you start in mm and draw your first line, then you copy it (or offset) and then scale it up with a scale factor of 25.4. Then you'll have a 10 mm line and one which will dimension as 254 mm [10 in].

 

[davidgutnik]

Wow that seems so backwards.
I'm sort of new and have always been working in solid works.
Solid works was VERY easy to pick up and relativly straight forward.
Autocad is Such a pain to use, i can't believe anyone still uses it.
I thought since the makers of solid works made draft sight, it would be just as simple as solid works.
but...

 

[MikeHalloran]

In AutoCAD, you probably wouldn't scale the line you just drew.
Instead, you would bring up the inline calculator to compute the scaled length while entering the length number, as:
'cal 10/25.4 <enter>

I have no idea if it works in DraftSight.


Mike Halloran
Pembroke Pines, FL, USA

 

[tr1ntx]

Mike,
Yes, that is a better way to do it. I was self-taught (figure it out as you go) on AutoCAD and learned the Scale command before the 'cal function. Plus, I worked with adapting metric based components to English unit based assemblies, so often had metric parts models to insert into inch models. I used Scale a lot.

David,
I wouldn't call it backwards, it's simply that AutoCAD and SolidWorks are set up to operate differently. In AutoCAD, a line for instance is known to be from coordinates 4,10,0 to 104, 10,0. That is 100 of what AutoCAD knows as "drawing units". It is a mathematical, spatial coordinate based system. That's what it tracks. Dimensions are simply added-on notations to the model. A dimension can be mm, inches, Angstrom units, miles, or whatever. If a user wishes to mix/change the unit basis of what he is modeling, he has to be sure the relative sizes of the objects are correct.

 

[MikeHalloran]

I just tried something similar in Draftsight. The 'cal command brings up a graphic calculator in the u/l corner of the screen. The calculator is straightforward enough, but it seems that you have to ctrl-C then ctrl-V to transfer the results back to the command line at the l/l corner of the screen. You also have to mouse over and click 'clear' to zero it out to start entering the calculation. There's nothing specifically wrong with it, but it breaks up your workflow, whereas AutoCAD's "tick-cal" function does not.



Mike Halloran
Pembroke Pines, FL, USA

 

[davidgutnik]

I work mostly in solid works with inches.

One thing i really like is sometimes when i have to mix metric. i can do things like ...
Draw line : 60" + 25mm + 3"
Assuming ad 60" frame a 25mm spacer to space a THK rail, then 3" space above for a block.

One feature i REALLY like in solid works is i can change a dimension easily and my whole part changes (dependent on fixed points or relations)
Can i do this in draft sight?

 

[MikeHalloran]

I too find much to like in Solidworks. ... with the notable exception of its sometimes (logically) Gallic logic.

Like AutoCAD, Draftsight's associative dimensions seem to be one-way associative. I.e., draw a rectangle, grab and move the corners, and any associated dimension changes to suit. ... but editing the dimension itself does not move the corner.
... unless AutoCAD has changed since I last used it.



Mike Halloran
Pembroke Pines, FL, USA