[solved] Moving the ZERO

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CVH
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Re: [solved] Moving the ZERO

Post by CVH » Sat May 16, 2020 10:09 am

Very correct Husky.
It did resurface in odd topics.

The discussion is not about UCS vs WCS or a 'Move/Rotate/Scale All' tool.
Here, initially this topic was about that Qcad did not save a certain ZERO.
Remark that the file with such a ZERO is still out.
I doubt that it will be UCSORG and UCSXDIR as they are AC system vars.

A good functional USC has its use and may even solve things we can't do upright.
Like moving and slanting the piece of paper you write on.

Regards,
CVH

TreestumpExhaustpipe
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Re: [solved] Moving the ZERO

Post by TreestumpExhaustpipe » Tue Jan 05, 2021 5:58 pm

It is a Royal PITA not to be able to move the zero fast and consistently in CAD. And I got bitten lately again by this lack of functionality in Qcad, Especially during a rework of an existing piece. When the Zero is set in CAD I have no problem. CAM software generally is good but you have the looming trouble that with every small CAD change, the zero needs to be set again in CAM. Using CAM the problem is introduced that the zero is slightly different every time a CAD edit is made to the design, completely destroying high value rework parts. If it was set once in Cad, future changes to the design will ensure an accurate rework. I proved this to myself over and over again. I have no trouble if the Zero is set in CAD. Reworks are accurate this way.

It is absolutely preferred to have the zero set in the drawing and not just some Random zero as currently is the method most use due to the difficulty of establishing an accurate moveable zero and then the CAM has to deal with all the offsets. Whether you use CAM to do it or Not. Consistency prevents expensive CNC errors. At the moment the Zero issues breaks consistency. The Zero is the most important information for a CNC, therefore being the most important, a CNC aware CAD needs to be able to manipulate the zero elegantly fast and repeatably.

Having this done in CAM creates errors, frustration and huge loss of time for no reason.
Having the zero accurately set in CAD saves so much interference with the Gcode.

Maybe there is a different way around this.
I will post another suggestion to at least bring the mountain to the man easily using handles.
This might be an easier workaround, to let the zero be and rather focus on a Blocked design with an easily movable handle.

I will draw up an example and I am sure someone might have a solution.

I worked through the examples given as workarounds, but they dont always work. Ideally the zero should be moved.
QCAD is the greatest software in a long time. This is not a rant or a put down. Dont take it like that and dont get demoralized. This is not critisism either. It is all about doing the right thing that is needed in order to be able to work repeatably and consistently with a design. It will only make QCAD more CNC aware.

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andrew
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Re: [solved] Moving the ZERO

Post by andrew » Tue Jan 05, 2021 6:47 pm

You can absolutely move the zero point in QCAD. Make sure all layers are visible, then Select > Select all, Edit > Cut with Reference, click where in your drawing you want the zero to be, Edit > Paste to 0/0. 0/0 should most definitely not just be at any random point.

CVH
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Re: [solved] Moving the ZERO

Post by CVH » Tue Jan 05, 2021 7:22 pm

Well, ...
A dxf is always generated in world coordinates.
(World Coordinate System - User Coordinate System)
And I/we are pretty sure that most/all CAM Apps take the drawing origin as the world zero.
(0,0,0) is the mathematical origin. (0,0) in 2D.

QCAD doesn't support a UCS in saving (yet) but it loads 3dparty dxf files in the active UCS.
From that point on this becomes the WCS.
Probably your CAM tries to read a UCS table, and falls back on the WCS.
And we wouldn't know without the drawing and output I asked for.

We also think you refer to 'setting' the QCAD relative zero.
The little red crossed circle that follows your moves. (Without color customization)
This reference is dynamically set with huge benefits in drawing.
We can set and lock that but this is not part of the dxf standard.
After loading a drawing that is set to the WSC origin to start with.

Most CAM software provide in offsetting to the world zero.
Meaning that it doesn't care where the drawing origin is set.
For that you should refer to your CAM manual.

So, I see 3 options ...
- Move all entities so the absolute drawing zero is where you need it as CAM origin.
- Provide your CAM the proper offset in relation to the dxf WSC.
- Generate your Gcode 'as is' and use a simple 3dparty tool to move the Gcode.

Personally my designs are all over the drawing, on different layers, similar or optional designs side by side.
Preparing to CAM I take a snippet dxf with only the things that matter, usually only neat closed pockets.
Then I move the design in the snippet so my drawing zero is at the preferred CAM origin.
All in relation to the stock I will use. Round things centered and squared out thing usually left low.
With the gcode prepared I have to zero my setup at the intended zero on my stock.
Exceptions still occur. I went with the first option that shortcuts dragging numbers around.

Regards,
CVH

TreestumpExhaustpipe
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Re: [solved] Moving the ZERO

Post by TreestumpExhaustpipe » Wed Jan 06, 2021 5:34 am

andrew wrote:
Tue Jan 05, 2021 6:47 pm
You can absolutely move the zero point in QCAD. Make sure all layers are visible, then Select > Select all, Edit > Cut with Reference, click where in your drawing you want the zero to be, Edit > Paste to 0/0. 0/0 should most definitely not just be at any random point.
Thanks a lot for this Andrew. It makes it way easier not to have to Select ALL then grab a handle which might place the selected object out of view and you never can drag it onto the zero.
This makes it way way easier.

My current workaround is to create a "handle layer", then create a small circle around where I want the zero to be on the drawing, saved in the "Handle Layer". I then Select All and Drag on the handle of the circle created and that is fine enough and the handle is basically at the point I want to drag to zero at high resolution. . It works well for me, but it is great to have a built in method that works.


Thanks to all for responding.
This thread should have enough info, for any Qcad user with the same issue.
I think it is finally solved by several different methods including my own workaround.

CVH
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Re: [solved] Moving the ZERO

Post by CVH » Wed Jan 06, 2021 6:55 am

So,
the info was there all the time to begin with :!:

Still even Andrew's answer is the same so called 'boondoggle'.
Or 'bringing the mountain to the man'.

You find it is idiotic to move the entire design relative to Qcad origin.
But that is exactly what you do with Cut with reference and Paste on drawing origin.

Correct, for that you need a reference to cut from.
- a 'small circle around' will do, a round stock size too.
- any corner of a stock will do too.
- a known reference on your piece too. (e.g. adding a text line on a former engraved piece)

Regards,
CVH
Husky wrote:
Tue Apr 07, 2020 7:23 am
You have to move the drawing in relation to absolute zero to suit your needs.
CVH wrote:
Tue Apr 07, 2020 9:33 am
Pretty sure my CAM takes the drawing origin on file load.
CVH wrote:
Tue Apr 14, 2020 7:51 am
A) Draw in relation with the origin
B) Cut, Paste, Copy, Move have all methods that let you decide where the source and where the target point is.
Nothing to do with can or can not move into view.
Panning and zooming is always allowed.

TreestumpExhaustpipe
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Re: [solved] Moving the ZERO

Post by TreestumpExhaustpipe » Wed Jan 06, 2021 7:35 am

It really is "Bringing the Mountain" aka the design to the "man" aka Zero.
It is obvious and a huge fuss compared to simply being able to place the zero in your design (which functionality doesnt exist currently)

This doesnt solve the fundamental question and problem in a way that you could rather efficiently and rightfully preferable, bring the "man to the mountain". It is still absent,
BUT...... this thread gives several options of how to bring the "Mountain" in the "least inefficient" way to the man and it is the workaround that is important.

Not ideal at all, but it is a workaround, and I appreciate all the help, and makes dragging the entire design to the zero a bit more bearable and workable.

For my CNC work placing the Zero accurately solves so many problems.

I think this thread could be very useful as every noob will run into this eventually. I have been using Qcad for almost a decade (I think) , and I am still a noob.
Thanks.

ljbuller
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Re: [solved] Moving the ZERO

Post by ljbuller » Sun Oct 16, 2022 9:33 pm

I am in agreement with treestumpexhaustpipe.
My procedure is to make all layers visible
select all
move/copy from the point I want to be the new 0,0 to 0,0 (delete original option)

certainly not the end of the world, but a one button "place origin here" to accomplish the same functionality would be great!

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