Stretch

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Rantanplan7
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Stretch

Post by Rantanplan7 » Mon Apr 09, 2018 4:01 pm

Today I was a bit struggling to find easy ways to stretch something.
I like the tool modify stretch but as far as I could find out by reading the book and playing a bit with it, it is not possible to stretch a block or a library item - only if I explode the symbols I can stretch them.
After that I played with the scale tool which is able to make a symbol larger with a factor proportional or only horizontal / vertical. Without a factor (by pressing the arrow button) it is not anymore possible to make a symbol larger only in one direction or is there a trick? I could only get it smaller or larger proportional.
To stretch a symbol only horizontal without knowing the factor is only possible after exploding it?
Best Regards

Sven

QCAD 3.21.2 / Windows 7 Professional SP1 64-bit / 8 GB RAM, i5 2520M@2.5GHz, SSD
(former Autosketch 10 user)

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andrew
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Re: Stretch

Post by andrew » Mon Apr 09, 2018 4:27 pm

Rantanplan7 wrote:it is not possible to stretch a block or a library item - only if I explode the symbols I can stretch them.
That's correct (note that a library item is also simply a block).

You can think of a block as a separate, named drawing that resides inside your drawing document (e.g. "MyBlock"). Such a block "MyBlock" can then be inserted multiple times into your main drawing, every time creating a block reference. All these inserted block references point to the same block "MyBlock", essentially saying: the block "MyBlock" is displayed at a certain position at a certain scale and rotated at a certain angle.

Therefore, you cannot stretch only one such inserted block reference since that would stretch all the other inserted block references as well, having very likely an unwanted effect.

You have two options:
- If you really want to stretch all block references, simply edit the block. You can do this using the block list (View > Block List) and double-clicking the block you want to edit.
- If you want to stretch only one block reference, you need to either explode it first or create a new, separate and different block.
After that I played with the scale tool which is able to make a symbol larger with a factor proportional or only horizontal / vertical. Without a factor (by pressing the arrow button) it is not anymore possible to make a symbol larger only in one direction or is there a trick? I could only get it smaller or larger proportional.
Scaling is in all but the simplest cases fundamentally different from stretching.. Perhaps you have a screenshot of your drawing to help me understand what you are actually trying to do?

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Husky
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Re: Stretch

Post by Husky » Mon Apr 09, 2018 5:21 pm

Rantanplan7 wrote:Without a factor (by pressing the arrow button) it is not anymore possible to make a symbol larger only in one direction or is there a trick? I could only get it smaller or larger proportional.
Nope - no hidden trick available. That tool is currently limited to work only proportional.
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Rantanplan7
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Posts: 46
Joined: Wed Dec 06, 2017 4:06 pm
Location: Germany - Heidelberg

Re: Stretch

Post by Rantanplan7 » Tue Apr 10, 2018 7:14 am

Scaling is in all but the simplest cases fundamentally different from stretching.. Perhaps you have a screenshot of your drawing to help me understand what you are actually trying to do?
Here is the screenshot:
RA4Slots.jpg
RA4Slots.jpg (188.79 KiB) Viewed 726 times
The two rectangles which are highlighted are a symbol. So first I would explode them and afterwards I would use modify-stretch and would stretch them with the command line, straight afterwards I would create a block from the modified symbol to get it back into one piece.
Modify-Scale would do the same without destroying the symbol but I have to give a factor and cannot say I would like to get -70 mm horiozontal.
Best Regards

Sven

QCAD 3.21.2 / Windows 7 Professional SP1 64-bit / 8 GB RAM, i5 2520M@2.5GHz, SSD
(former Autosketch 10 user)

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andrew
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Re: Stretch

Post by andrew » Tue Apr 10, 2018 3:55 pm

Note that scale would not only scale the rectangle but also the "hook" shape at the end which is probably unintended.
In any case, I'd create separate blocks (e.g. "gripper_20x100", "gripper_20x160", etc.).

Rantanplan7
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Posts: 46
Joined: Wed Dec 06, 2017 4:06 pm
Location: Germany - Heidelberg

Re: Stretch

Post by Rantanplan7 » Wed Apr 11, 2018 7:57 am

The hook isn't problematic as it is only a help to position the symbol on the machine. So I will explode symbols if I need to stretch them. I have done it that way yesterday with some complex drawings and if you get used to this procedure it is not the big deal. However my colleagues were asking for making this easier. They are all coming from Autosketch so they will all have the same things where they are used to and have to learn a different way. However maybe this is something useful for the future as a new function? Like in the picture below? With a mouse over function that the pointer changes to a circle for turning on the blue triangle, to a double arrow horizontal and vertical for stretching on the green triangles and to a double arrow 45° on the green squares for scaling?
RA4Autosketch.jpg
RA4Autosketch.jpg (14.48 KiB) Viewed 694 times
Best Regards

Sven

QCAD 3.21.2 / Windows 7 Professional SP1 64-bit / 8 GB RAM, i5 2520M@2.5GHz, SSD
(former Autosketch 10 user)

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Husky
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Re: Stretch

Post by Husky » Wed Apr 11, 2018 10:28 pm

Thinking about this .....

Note: Blocks are basically meant as a verified structure and the ability to customize them is natural limited.

However ...
Rantanplan7 wrote:The two rectangles which are highlighted are a symbol. So first I would explode them and afterwards I would use modify-stretch and would stretch them with the command line, straight afterwards I would create a block from the modified symbol to get it back into one piece.
Modify-Scale would do the same without destroying the symbol but I have to give a factor and cannot say I would like to get -70 mm horiozontal.
Question: How would you know that you need -70? I assume because you gathered that information with the dim/info tool or your source is based on a real world information. Correct?
If your block is meant to accomplish a "scale to fit task" then it is in your power to prepare those blocks accordingly. If we talk about a possible fence(?) you can prepare a fence block set which covers the lengths for e.g. 1000, 1500, 2000 blablabla mm. If that covers your needs - perfect - if not you are able to use expressions for those blocks during the insert task and QCAD will calculate the proper scale.

E.g. you need a fence with a 1430 length (regarding your -70 example) just use the block 1500 and fill in the proper scale values which shout be x [1430/1500], y [1] and the result would be a exactly 1430. I learned here distortion isn't a problem for you ...

Using the stretch tool: I would combine a block consisting out of multiple blocks. If I then use the explode tool twice only the stretchable part is totally apart and it is afterward much easier to collect the pieces to create the new modified block.

New tool: We have already a very powerful scale tool! The only disadvantage what I see is the lack of an option in combination with the "Scale with Mouse" task. Currently it is always proportional - I can't limit it only to x or y.
I would appreciate such an additional "Only X" / Only Y" option too.

Just my two cents ....
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