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How to make 1 object from a drawn object

Posted: Sun Jun 07, 2020 5:47 pm
by bmhor333
Sorry if the title is unclear but hopefully this explanation will help....

I'm new to CAD so please excuse me if I get the termanology wrong.. e_surprised

I've drawn the object in the attached file but when I feed it to SheetCam it will not cut as one...

How can I make it one object as opposed to a bunch of lines and curves??

Bob

Re: How to make 1 object from a drawn object

Posted: Sun Jun 07, 2020 6:27 pm
by Husky
bmhor333 wrote:
Sun Jun 07, 2020 5:47 pm
I've drawn the object in the attached file but when I feed it to SheetCam it will not cut as one...
Without knowing SheetCam - every CAM is looking to follow a clean paths in a drawing. Clean path means no overlapping lines or transitions, only entities which are accepted by the CAM software etc etc.

Looks like your example drawing isn't clean enough for your CAM software. There are points along the predicted path, overlapping entities and "bad" transitions like this one.

Husky-2020.06.07-01.png
Husky-2020.06.07-01.png (11.58 KiB) Viewed 1276 times

Solution: Try to produce a more precise drawing before you feed your CAM with it ... :wink:

Re: How to make 1 object from a drawn object

Posted: Mon Jun 08, 2020 8:19 am
by CVH
As Husky said : Bad transitions.
Most CAM will tolerate this up to some point. Unknown.

What most CAM won't accept are null-entities.
And surely if it sits outside your curve.
Beside that, there are Points on your curve too.

Point dump:
Point,51.5059,103.92,0,
Point,57.6697,99.3992,0,
Line Based dump:
Line,139.8869,206.8368,0,139.8869,206.8368,0, isNull,

Regards,
CVH

Re: How to make 1 object from a drawn object

Posted: Mon Jun 08, 2020 8:56 am
by CVH
Pictures say more then words.

Re: How to make 1 object from a drawn object

Posted: Mon Jun 08, 2020 10:03 am
by bmhor333
Gents, Thanks for the reply's.

SheetCAm accepts the drawing ok but won't cut it as one, it does part, jumps elsewhere then comes back and carries on.

What I can't figure out is how to remove the "points" and join the whole shape into one "line" as opposed to lots of bits "stuck" together.

Bob

Re: How to make 1 object from a drawn object

Posted: Mon Jun 08, 2020 11:44 am
by CVH
Your drawing is pretty simple.
For the sake of using fairly rounded numbers lets say that:
- the main shape has a radius of 92.5 @ 150,105
- the notches have a diameter of 6 an lay on an radius of 98.5
- the top notch is rotated 2.4° from straight up
- the left notch is spaced 90°
- the right notch is spaced 104°
- the roundings need to be with r=5

See attached file: test plate_Construct.dxf
test plate_Construct.dxf
(108.6 KiB) Downloaded 77 times

On layer 1... I drew the construction lines.
Remark that I drew the spokes straight up and then copy-rotated them 2.4°
On layer 2... I drew the circles.
Thaw layer 2...
The double construction spokes help me with opening the circles.
For the sake of visualising this I made a copy of the circles on 3...
Freeze layer 2... and thaw layer 3...
The circles are openend with 'Break out Segment' (D2) with option Remove Segment active.

Hide the construction lines: Freeze layer 1...
Activate 'Round' (RN) with option Trim active, radius 5.
Visualized on 4...(a copy of 3...)
Freeze layer 3... and thaw layer 4...
The places you point at matters for the preview and the result.
I already did 3 roundings of the 6.

Finaly you end up with 12 loose entities. (12 Arcs in this case)
Freeze layer 4... and thaw layer 5...

It is a good practice to convert them to a single closed contour.
'Select All' (TA) >> 'Polyline from Selection' (OC).
Select the created Poly, visual check if its simplex and complete.
Check if the closed nature in the Specific Properties is indeed 'Yes'.
If not the error would be where the poly ends.

Even if your CAM doesn't support polys it serves to use OC to check.
The explosion of a proper contour as poly is also flawless as single entities.

Regards,
CVH

Re: How to make 1 object from a drawn object

Posted: Mon Jun 08, 2020 12:52 pm
by CVH
BTW
bmhor333 wrote:
Mon Jun 08, 2020 10:03 am
how to remove the "points"
That should be easy while selected them and hit 'Delete'. :wink:

eg. Box-select the area in question (left2right).
Deselect curves you might have included with Shift+Select.
Look at the Property Editor 'Selection' and verify that you got 2 Point entities in selection.

eg. Selection Filter (type GF if not vissible)
Type: Point
And hit the left icon (Replace the current selection)

Regards,
CVH

Re: How to make 1 object from a drawn object

Posted: Wed Jun 10, 2020 12:25 pm
by bmhor333
CVH you're a star, thanks for the help.

Creating a Polyline from selection is where I'm at now BUT
when I enter OC at the command line I get the following error:

Unknown command or invalid coordinate or value: "oc"

and I can't find that in any of the menu's....
I'm using Version: 3.24.3.0 (3.24.3) on a PC if that makes any difference.

Bob

Re: How to make 1 object from a drawn object

Posted: Wed Jun 10, 2020 12:29 pm
by bmhor333
Just a thought,
I'm running the Community edition of QCAD, is the OC command Pro and above?

Re: How to make 1 object from a drawn object

Posted: Wed Jun 10, 2020 12:39 pm
by andrew
bmhor333 wrote:
Wed Jun 10, 2020 12:29 pm
I'm running the Community edition of QCAD, is the OC command Pro and above?
Yes. I've also moved this thread into the appropriate forum "QCAD Community Edition".

Re: How to make 1 object from a drawn object

Posted: Wed Jun 10, 2020 1:32 pm
by CVH
bmhor333 wrote:
Wed Jun 10, 2020 12:25 pm
Creating a Polyline from selection is where I'm at.
That's nice, the point is that a good geometrical model will
give you a proper closed path. A poly is by default a singular path.
With OC you could test yourself. :wink:

It can be done without the advanced polyline functionalities.
Most CAM's will find nearly closed paths themselves.
But not as presented in your first drawing.

Regards,
CVH

Re: How to make 1 object from a drawn object

Posted: Wed Jun 10, 2020 2:59 pm
by bmhor333
That was part of the problem, I couldn't get the lines to join properly....
I ran your layer 5 through sheetcam and it can handle polylines :lol:

Guess its time to buy Pro...

Bob

Re: How to make 1 object from a drawn object

Posted: Wed Jun 10, 2020 3:21 pm
by CVH
bmhor333 wrote:
Wed Jun 10, 2020 2:59 pm
Guess its time to buy Pro...
Sure it is! :)
I know you don't gonna regret that.
bmhor333 wrote:
Wed Jun 10, 2020 2:59 pm
I ran your layer 5 through sheetcam and it can handle polylines
Layer '5 Loose entities'. It is all in the name. No poly, still successfull simply by a sound geometric design. e_geek
SheetCAM has detected the valid closed path.

Regards,
CVH