Scale and dimensions in Acad 2004

[Mr Ron]

When I want to scale an image up by a factor (say 2), the image doubles in size, but the dimension associated with the image also doubles.
As an example: If I want to scale up a small screw that is dimensioned, by a factor of 6, but I want the actual dimensions of the screw to remain the same. How do I scale and keep the dimension from changing? I did it once, but I can't duplicate it again. I know the dimensions and image need to be on different layers.

[tedg]

When I want to scale an image up by a factor (say 2), the image doubles in size, but the dimension associated with the image also doubles.
As an example: If I want to scale up a small screw that is dimensioned, by a factor of 6, but I want the actual dimensions of the screw to remain the same. How do I scale and keep the dimension from changing? I did it once, but I can't duplicate it again. I know the dimensions and image need to be on different layers.
Hmmm, I guess I don't quite understand your process. If you scale something up by two, it will be twice as big.... and so when an associative dimension is fixed to it, it will change and give you the correct size (which in this case is twice as big as it was before).

What do you want it to do?

Are you working in model space with everything drawn 1:1?


Are you using viewports and dimension styles with scales?

Please explain :(

Just to clarify why I'm asking, it sounds like AutoCAD is doing what it is designed to do, and you want to over-ride it or trick it into doing somehing else, is that the case?

[jaberwok]

You might be looking for DIMLFAC (see Help).

[dzatto]

When I want to scale an image up by a factor (say 2), the image doubles in size, but the dimension associated with the image also doubles.
As an example: If I want to scale up a small screw that is dimensioned, by a factor of 6, but I want the actual dimensions of the screw to remain the same. How do I scale and keep the dimension from changing? I did it once, but I can't duplicate it again. I know the dimensions and image need to be on different layers.
Go to the format dimensions dialogue box. Modify the dimension. Under the primary units tab, change the measurement scale from 1 to .166667. That works for a 6:1 ratio. You will need to figure out the scale factor for anything else by dividing 1 by however big you scaled the drawing up.

Just realized it's the same thing John mentioned above. I just always did it through the dialogue box.

[irneb]

What you're doing is how we used to work without paper space (in the old days). With paper space you don't need to scale the actual entities, but you do need to change the viewport's zoom factor to the scale you want it displayed in. This way you draw everything in model space at 1:1 and adjust the viewport's zoom factor to suit ... you can thus show the same piece of linework at 2 (or more) different scales (including the dimension without affecting its value). For keeping the dim's text & arrows the same size as well, look into placing the dim on Paper Space or alternatively use Annotative Scaling.

Another workaround (if you're for some reason forced into doing this) is to make a block of the screw & its dimension. Then scale the block insert, which would scale the dimension without affecting its value. Unfortunately however, the dim's text size would also scale accordingly (as would its arrows / ticks).

If you go the route described by jabberwok & dzatto you need to create a new / override the DimStyle to suit the "bastardized" scale. Then assign the relevant dims to the new style or override.

[Mr Ron]

Hmmm, I guess I don't quite understand your process. If you scale something up by two, it will be twice as big.... and so when an associative dimension is fixed to it, it will change and give you the correct size (which in this case is twice as big as it was before).

What do you want it to do?

Are you working in model space with everything drawn 1:1?


Are you using viewports and dimension styles with scales?

Please explain :(

Just to clarify why I'm asking, it sounds like AutoCAD is doing what it is designed to do, and you want to over-ride it or trick it into doing somehing else, is that the case?
I'm in model space, drawing is 1:1. Some details due to their small size, are larger than the text size of the dimensions. I want to blow up the detail without changing the value of the dimension. In other words, if I blow up a detail of a 1" square, I want the dimension to read 1" regardless of scale used.

[jaberwok]

As irneb says, that's a very old-style way of working.
The best answer is to use paperspace viewports.
The second best is to create additional dimstyles in which DIMLFAC is adjusted to give the result you want - if you've scaled the geometry up by 2, DIMLFAC should be set to 0.5 and so on. You will need at least one dimstyle for each scaling in the drawing.

[irneb]

To explain the difference, attached is a drawing showing all 5 methods of dimensioning showing @ 2 different sclaes (1:10 & 1:5):

The OLD tab indicates how to do this the way you're describing (as if you're only using model Space). This method only requires one viewport (or you plot directly from MS), since you're making copies of the linework & scaling them physically in Model space to accomodate. Note you require 2 Dim Styles here, one of which's DIMLFAC=0.5. All other methods don't require a copy of the linework, simply a new view thereof.
MS+Layers+Styles show how to dimension in Model Space using layers to show only the relevant dims in the correct viewports. Also here you're using 2 dim scales with each DIMSCALE variable set according to the scale you want it displayed at. Scale of 1:10 --> DIMSCALE=10.0; Scale 1:5 --> DIMSCALE=5.0
MS+Layers+PS Scaling is similar to 2, but uses a DimStyle with DIMSCALE=0.0 to adjust per viewport's zoom factor when created. The Dims are made through the viewport so they use the vp's zoom factor for their DIMSCALES
PS (the easiest method IMO) the dims are all placed on Paper Space using the same DimStyle as in 3 (i.e. DIMSCALE=0.0 --> effective 1.0 and DIMLFAC=1.0). They're al placed on the same layer, the Model Space doesn't contain any dims.
MS+Annotative is a new method since 2008 (in which this DWG is drawn). A single Dim set to being Annotatively scaled (i.e. DIMANNO=1) is drawn in Model Space and assigned the scales at which it should be shown. Then only the automatic version thereof is shown according to the scale of the viewport.The order of preference runs basically worst to best. Except mabe for 4 & 5, which depends on your feeling. 4 doesn't have dims in model space, so you need to have DIMASSOC=2 (not 1) otherwise a modification to the linework won't update the dim. Method 5 works by placing the dims in model space, but requires some extra effort to get them to show correctly.

I've been using either method 2 or 3 since AC R14 (mid 90's somewhere), although 3 could have been used by then as well. Since last year I've been using method 5, just because we tend to draw our dims in model space to be able to xref them into other DWGs.

Method 1 was only used (by myself) in late 80's & early 90's in R9 & R10. To give you an indication of how far ahead we are: 2000=R15.0 ... 2006=R16.2 ... 2007=R17.0 ... 2008=R17.1 ... 2009-R17.2 ... 2010=R18.0

But by all means, if you want to you could still use the 15+ year old method #1 :mrgreen:

[oliveoil182411]

Since we are retrograding, why not get really caveman about it. Ronaldseto should go ahead and explode the dimensions. You could also just edit the dimension value with the DDEDIT command just like you would text. This way you could revert back to a good dimension using the Express Tools\Dimensions menu. I know that this is sacrilege, but it sounds like the dimension on the image is probably not going to change or be used by anybody else, ever... I know, I'm probably banished from Augi for life now.

[irneb]

You're correct! It does seem you need to be wrapped over the finger that clicked that button :lol:

But this would basically do the same as per my previous example of creating a block of the linework together with the dimensions & then scaling it. You'll still scale the text & tick sizes together, as if you simply used a photostat machine's scale function.

You could go and manually adjust after the fact, but why so much work?

[oliveoil182411]

You're correct! It does seem you need to be wrapped over the finger that clicked that button :lol:

But this would basically do the same as per my previous example of creating a block of the linework together with the dimensions & then scaling it. You'll still scale the text & tick sizes together, as if you simply used a photostat machine's scale function.

You could go and manually adjust after the fact, but why so much work?

Great minds think alike. However, I think I would make it a one shot deal. Create the junk piece of geometry and run. And, if you hear a co-worker screaming down the hall about not being able to adjust this dimension, just make a comment about how incompentent "these newbies" are. That should cover your $%#.