Relative Coordinates Check Box not working.

[wayne]

Hi,

On page 75 in the e-book "An Intro to CAD" I have no problem entering the Cartesian coordinates and the first relative coordinates, but when I try to enter the second relative coordinates, I am unable to get the enter fields for relative values. I click the check boxes for relative coordinates, but system still wants me to enter x,y coordinates. I'm using release3.2 on an ubuntu system.
Wayne

[clive]

Hi,

On page 75 in the e-book "An Intro to CAD" I have no problem entering the Cartesian coordinates and the first relative coordinates, but when I try to enter the second relative coordinates, I am unable to get the enter fields for relative values. I click the check boxes for relative coordinates, but system still wants me to enter x,y coordinates. I'm using release3.2 on an ubuntu system.
Wayne

Hi Wayne and welcome to the forum

Personally I find it a lot easier just to use the command line for entering either absolute or relative coordinates.

To view the command line (if you haven`t already) go to view > toolbars > command line (you can also dock this elsewhere if you need to!).
Press space bar to put the focus in the command line then enter your input:

e.g. To draw a line either use mouse and select the line tool you want or press the space bar and enter the keycode li (line from 2 points)You will need to press enter after typing in li.

1. For absolute co-ordinates just enter e.g. 100,100 (first point) then e.g. 250,250, (next point) this will place your line points absolutely relative form the 0,0 origin point!

2. For relative co-ordinates use the @ symbol e.g.
First point e.g. 100,100 (absolute)
Next point e.g. @250,250 -this will place your next point "relative" to your last point, in this case 100,100 (not 0,0).

So the @ symbol used for inputting co-ordinates will make points relative to the last point placed.

You can also use negative co-ordinate input as well.

e.g.

First point 100,100.
Next point @-50,-50

Hope this makes sense

[clive]

wayne

Ive just had a look at that exercise in the book and if you are using that method - using the input fields, then you need to select the Polar coordinate (so), this will change the input fields to what you want!

[wayne]

Hi Clive,

Thanks for replying.
In reference to your second post, I do choose the relative button, by clicking
on it, but after the first use of the button, it goes back to a Cartesian coordinate system and I also notice that my scale values gose from 1:4
2 < 12. I will try the command line. I been playing with that example for
about 2 days now - I have to move on and will come back to it later.
Again, thanks for your time.
Wayne

[clive]

Hi Clive,

Thanks for replying.
In reference to your second post, I do choose the relative button, by clicking
on it, but after the first use of the button, it goes back to a Cartesian coordinate system and I also notice that my scale values gose from 1:4
2 < 12. I will try the command line. I been playing with that example for
about 2 days now - I have to move on and will come back to it later.
Again, thanks for your time.
Wayne

Wayne, Just to clarify are you selecting the "Polar coordinate" (so) option in the snap options to perform the next stage of the example (@20<0) in the book or are you clicking on the "Relative" check box still in the "coordinate" (sx) option?

No problems for me in Windows at work but I`ll check this out later in Ubuntu and report back!

[clive]

Hi Clive,

Thanks for replying.
In reference to your second post, I do choose the relative button, by clicking
on it, but after the first use of the button, it goes back to a Cartesian coordinate system and I also notice that my scale values gose from 1:4
2 < 12. I will try the command line. I been playing with that example for
about 2 days now - I have to move on and will come back to it later.
Again, thanks for your time.
Wayne

Wayne, Just to clarify are you selecting the "Polar coordinate" (so) option in the snap options to perform the next stage of the example (@20<0) in the book or are you clicking on the "Relative" check box still in the "coordinate" (sx) option?

No problems for me in Windows at work but I`ll check this out later in Ubuntu and report back!

OK Wayne

Ive tested this in Ubuntu and I can report that all is working as it should be.

If you check/un-check the relative option in either the coordinate (sx) or the polar coordinate (so) tool bar this will indeed change the input to either absolute or relative input.

Both the coordinate and the polar coordinate options have their own separate input fields and both have an option to make your input relative or absolute.

The Cartesian coordinate system used in CAD in general and in QCAD uses all absolute/relative and all polar absolute/relative input.Cartesian is the name given to the system used not one particular method of input.

again I hope this makes sense to you. Good luck with the rest of the book and don`t hesitate to ask questions on this forum there are many experienced people here!

[wayne]

Clive,

After entering the Cartesian coordinates,10,10, I then click the polar
coordinate icon. I then enter the polar coordinates, @20<0, this works ok. But, when I go to enter the second polar coordinates,@20<60, the scale values changes to 2 < 12 and I lose the able to enter another polar coordinate value.
Wayne

[wayne]

Hi Clive,
I finally got the rhombus.
Thanks for your help!
Wayne