Downloaded file in metric. Can dimensions be converted?

[Kevin45]

I recently downloaded a 2D dwg file that was drawn in Metric format. When I add dimensions to the drawing the dimensions are in Metric. Is there a way to automatically convert the dimensions to Standard dimensions instead of physically having to use a calculator to figure and edit the dimensions? The reason I ask is tht this is for a tool design I am doing and I would rather save time by not having to convert and edit by hand.

TIF
Kevin

[i44troll]

Kevin,
You can't 'automatically' change the dimensions because the drawing has been scaled to be dimensioned using metric units.
You will have to select the full drawing again and re-scale it so that your dimensions will accurately describe your drawing using imperial measuring units.
Since the print is intended for reproduction in a machine shop I assume we are dealing with mm and not cm, otherwise the following instruction will be incorrect.

1. First erase all dimensions that are in metric (existing numbers do not change during scaling)
2. choose the 'select' tab, select everything in your drawing (from the menu: edit / select all)
3. choose the 'SC' (the scale button) located in the select tab
4. either type in 1/25.4 or .03937 at the prompt and press enter (they both equal the same value)
5. select the 'view' tab, then 'ALL' (view all). Your line weight will likely be very heavy.
6. go to the 'options' menu and choose 'drawing scale'
7. enter the value "1", press enter (for very large objects skip this step)
8. go to the 'view' tab, click 'ALL' once more. Your line weight should now be normal and you can replace your dimension lines so that they read in imperial units.
   

Chris 'i44troll'

[Kevin45]

I'm on vacation now. As soon as I get back to work I will try that. I didn't think of trying to Scale it.

What is odd though is that when I add in one of my lines (say for instance a parallel line with a distance of 1.000) the line barely moves off of the line that I am trying to duplicate if that makes sense. But if I put in a dimension of 25.400 the line moves the correct distance in the drawing. It sort of seems that the drawing was originally drawn at a 10x scale in metric.

[i44troll]

Kevin,
That makes perfect sense, here is why.....

The scale of a metric drawing in DeltaCad IS 25.4! Therefore "1" unit of measurement becomes equivalent to "1mm", and since there is 25.4mm in one inch your line was offset by 1/25.4, or .03937 of an inch, making it a very short offset.

The scale that DeltaCad uses is based on imperial units and not metric units. We know this because, by default, your drawing units are "one inch drawn = one inch seen", or 1:1 scale. Had Deltacad chosen to use metric units as the default scale then 1:1 would have either been equal to "one millimeter drawn = one millimeter seen" or "one centimeter drawn = one centimeter seen", making us have to scale the drawing by MULTIPLYING the "scale factor" by 25.4 for mm, or 2.54 for cm, to draw and dimension that same drawing in imperial (inch) units.

What we have to realize is that no one system of measurement is proprietary. All systems have a scale of 1:1, but if two systems use the same XY grid, as does DeltaCad, then one system must dominate to set the scale and the other must be subordinate to adjust to it.

Had DeltaCad been produced anywhere else where the metric system is dominant, the default scale would have most likely still been equal to "1" (1:1), but it would have been based on metric units making your drawing "one millimeter drawn = one millimeter seen" -or- "one centimeter drawn = one centimeter seen" and we who live in the US would have had to adjust our viewing scale accordingly to be able to draw and dimension our drawings in imperial units.

[Admin 1]

Wow, that's a great explanation. I would like to add that, for original drawings, you can set your "scale/dimension" defaults as you see fit in DeltaCad by clicking on the "Options" tab and selecting the "Drawing Scale..." option. Within that pop-up there are a number of pre-defined 'scale' buttons which include centimeter & millimeter scaling.

Keep in mind that changing that setting WILL NOT change the displayed dimension values of an existing drawing. The value shown on a dimension line are DRAWN as part of the graphics of a drawing and you can ONLY modify that 'drawn' text in EDIT mode on an existing drawing.

We have a few drawings available on our site that were created using the MM/CM scale and we also have others that were created in the INCH/FOOT scale. To convert them to your common unit of measurement will take some effort. However, if no lines are moved or modified, the end result will be exactly as drawn regardless of whether it was originally designed/drawn using metric or imperial units.

The most important thing to know, in either case, is how truly accurate do those measurements really need to be. -- In engineering, a fraction of a MM may be very important so that Part A meshes properly with Part B ... were as, in home or furniture construction, a sixteenth to an eighth inch (about 1.5 MM to 3 MM) is an acceptable -accurate enough- measurement to maintain the designed structural integrity of it.

[i44troll]

Think of how easy it would be if we had all changed to the metric system 25 years ago when we were all told that "we had to". Even in applications of woodworking just as in the above post, Chris ("the Boss") makes the statement that ".....in home or furniture construction, a sixteenth to an eighth inch (about 1.5 MM to 3 MM) is an acceptable -accurate enough- measurement to maintain the designed structural integrity of it", and yet many people couldn't identify a sixteenth of an inch on a tape measure! Matter of fact, I can prove to you that the average American doesn't understand fractions.......
McDonalds, America's most popular fast-food chain does NOT sell a 1/2lb burger, instead they sell a "double" 1/4 pounder, but they won't use the fraction "1/4", they will spell it out "double quarter pounder" instead! Why? Because people don't know their fractions and think 1/4lb is bigger than 1/2lb because "4" is greater than "2". Think about it, if your sales suffer because people don't know their fractions you better change something so that your customers understand what it is they are buying. (I actually learned this from a McDonalds employee)
Think they are the only ones?........
Try to get a 1/2lb burger at Brahms. You can't! It's 1/3lb or 2/3lb only. Apparently the people at Brahms also realize the average Americans deficiencies and have chosen to use fractions that cannot be reduced. Pretty smart really!

Chris "i44troll"

[jw48]

At the risk of causing 'thread drift', this happened to me the other day...

Went in the local general shop to buy some milk and other bits and pieces. The sum was

[i44troll]

[quote]....she took the