Dealing with Mixed Units

[EatingSteak]

I have some US components - in feet & inches - that I need to put onto mounting plates and cabinets that are all metric.

 

Comparatively, the components are very complicated and the cabinets rather simple. My drawing is staying in feet & inches.

 

However, for the plates, I need to move lines by a metric amount - like 25mm. Obviously, if I hit [M][Enter][25][

 

If I do an arithmetic conversion, it's going to be 0.9842519685... inches, but that will introduce rounding error. Is there any way to get an exact value here?

[dbroada]

the simple answer is no. Drawings are done in "units" where 1 unit is whatever you want it to be but you can only have one unit system within the drawing.

 

As the cabinet is the simpler item I would scale it by 25.4 and then continue in only metric.

[ReMark]

Why not use decimal inches instead of feet and inches? Wouldn't that be more accurate?

[SLW210]

I do it way too often. Just did a few drawings today like that.

 

I set up the drawing with -DWGUNITS and select yes to insert items at the drawing scale. There are a few options for other system variables for insertion units, that sets everything up for you.

 

You can set up a second dimstyle for the metric or use alternate dimensions or adjust the dimensions individually through Properties.

[Dadgad]

Why not use decimal inches instead of feet and inches? Wouldn't that be more accurate?

 

I typically work in mms, our fabrication is done in China, but when working on projects stateside, if the fabrication will be done there, I am forced to use inches, which I hate.

Decimal inches makes everything easier, compared to converting them to metric, but rarely does one see a tape measure with decimal inches.

No doubt, Starrett and other high end companies sell them, but not too many people have them handy.

In such cases I just do an Inch based drawing (or use -dwgunits if need be), and create and use an Imperial dimstyle, rather than using the alternate dim display.

[ReMark]

It seems like a recipe for disaster whenever you starting mixing units (ex. - imperial template and metric blocks). Why not stick with one unit and dimension using alternative units (i.e. - show both metric and imperial dimensions)?

[mdbdesign]

Found it on "TheSwamp" and it work great for both templates.

Instead of typing (inch template example):

 

 

[M][Enter][25][

 

 

type:

 

 

[M][Enter]['mm][25][

 

 

and done.

 

 

PS: sorry for not wrapping, tags not working.

Inch2mm-imm.lsp

mm2inch-mmi.lsp

[nestly]

Can your "components" be blocks? If so, when inserted they should automatically scale to match the host drawing. OSnaps should solve the rounding issues.

[EatingSteak]

Thanks mdbdesign, this is awesome - didn't expect any solution that simple.