Scaling Finished Size

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taholmes160
Newbie Member
Posts: 7
Joined: Mon Jan 14, 2019 1:31 am

Scaling Finished Size

Post by taholmes160 » Mon Sep 08, 2025 6:24 pm

HI folks:

Im a hobby user, so im not as familiar with the software as those of you who do this all day every day, so Im sorry if this is something I should know --

When I download cad blocks from online, a lot of times there are either VERY large or VERY small (the window I just downloaded was something like 120' long!!)

What I would like to do is to be able to select the item (window in this case) and tell qcad -- I want it to end up as 4' long -- and have qcad scale it for me

Is this possible???? --- is there another way?

Thanks
TIM

CVH
Premier Member
Posts: 5123
Joined: Wed Sep 27, 2017 4:17 pm

Re: Scaling Finished Size

Post by CVH » Mon Sep 08, 2025 7:00 pm

Hi,

Depending the origin one can indeed see large differences.
One reason would be the intended scale.
Another is the unit, for example inches, feet or mm, cm, meters.
Fine if that would be the drawing unit because QCAD converts between them.
But a large number of professional designers use unit 'none' by default.

One can insert a Block as Block Reference at any scale.
Vector data is loss-less scalable.
See Scale X(Y) option on the Option Toolbar when inserting.

If already inserted as a Block Reference, adapt the scale in the Property editor when selected.
Required for each Block Reference based on a certain Block or as a group selected with the Selection Filter.

Or one could edit every Block its content and scale the content itself.
That change will be reflected in all Block References based on that Block.

If the Block is created from a Library Item then I would edit the item its DXF in direct before importing.

To scale a selection of entities see SZ or even AE.

Telling that a Block content should be 4' long is not possible without knowing the original size.
We always have to come up with a scale factor.

Then make the Block 10' long or 1' long and include that in the name.
For a 4' window the scale is then simply 40% (0.4) or 400% (4.0)

Regards,
CVH

taholmes160
Newbie Member
Posts: 7
Joined: Mon Jan 14, 2019 1:31 am

Re: Scaling Finished Size

Post by taholmes160 » Mon Sep 08, 2025 7:11 pm

Thanks -- ive been cheating and measuring out the original and telling google how long it is and asking for the scaling factor as a decimal and doing it that way

TIM

CVH
Premier Member
Posts: 5123
Joined: Wed Sep 27, 2017 4:17 pm

Re: Scaling Finished Size

Post by CVH » Tue Sep 09, 2025 2:39 am

Hi,

Strange method. :wink:
Things can be measured up without creating a Dimension with the info tools, not inserting the measurement.
For example: Distance Point to Point (IP).
Hold down the Alt key for indicating the second point in orthogonal sense.
The info tools typically report in the Command Line history where you can select and copy a part of the text.

Remind that properties, Dimensions and even info measurements display rounded numbers.
Linear measurements can be in full floating point notation with a tweak.

Most input fields can do simple to complex equations.
A scale factor would then be: [Required size] / [actual size]

Or for your window example: 4/120
Without unit symbols!
All values in CAD are typically unit-less and expressed in the drawing unit.
QCAD will then evaluate the division and use factor: 0.0333...

If things are not squared up you could exploit menu Misc .. Draw .. Draw Bounding Box
The length of the sides is then the overall size in XY.
Delete the box afterwards.

Regards,
CVH

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