i wish i could use Qcad CAm for my machines

Post to this forum to introduce yourself to this forum if you are new here. You might want to include some information about the work you are doing or planning to do with QCAD.

Moderator: andrew

Post Reply
User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

i wish i could use Qcad CAm for my machines

Post by Nube » Fri Dec 23, 2022 4:24 pm

I like very much Qcad CAM and i use it every day for drawing, i use also for nesting function-

Unfortunately I cannot use it for my machines, because they have 5 axes and Qcad cam  is designed only for 3 axes.

I found a solution for starting cuts from plain material, but no CAD CAM actually on the market can manage it.
I named this solution TECNICA NUBE

i link some video to show this:

https://youtu.be/r5racRgyzsg
https://youtube.com/shorts/UgiiQRWPG20?feature=share
https://youtu.be/FHnuuYqLYPw

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: i wish i could use Qcad CAm for my machines

Post by CVH » Sun Jan 01, 2023 2:38 pm

Hi,

Engravers use the technique to ramp down instead of plunging down for ages.
It all started with manual cutting tools and the same method was later used with machine cutting and later for CNC engraving.
Our conical engraving points are to delicate to dive fully into the base material in one spot.
I can kill the tip of a tungsten cutter in simple plastics like polyethylene or in MDF.
Ramping down is far better, a circular motion in Z is even better but rather complex to implement.

I also miss this ability in QCAD/CAM but I manage by fooling the G-code in direct.

In essence QCAD/CAM is not 3D, it is 2.5D because every pass of every contour is in 2D.

You could do the same for 5 axis.
I am quite sure that the diamond disk doesn't change its angle and orientation when it is cutting.
One can't really say that it behaves the same as a routing bit and this is also true for Drag Knives or Tangential Knifes for example.
So 2 axis stay steady and cutting straight can be done in 2.5D for that matter.

Another misconception is that the routing head of professional machines like yours can have several different tools mounted to it.
For example a saw, several drilling tools and some routing mills for woodworking.
In that case we don't speak of several axis but of several spindles.
Each spindle has a specific offset in XYZ, the head can rotate in A&B to align the saw but the action is simply done in 3 axis ... In 3 or 2.5D.

Regards,
CVH

User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

Re: i wish i could use Qcad CAm for my machines

Post by Nube » Sun Jan 01, 2023 3:59 pm

Thanks CVH,
as you mentioned, to realize the video I
had to modify the G-code otherwise I have no possibility to make the machine behaving this way. But this is just to show this technique I can't work by modifying the G-codes is too complicate for me and it take too much time.

I am sorry but I didn't know it was a technique already used, I never seen it before at least with diamond disk blade. I don't now anything about engravers, and
I am pretty new in the world of machines with g-code.

the CAD CAM software (Dcut is the name) supplied with my machine is a 2D CAD CAM but can manage 5 axis. I am not sure , but I think it can manage 4 axes together, because you can make an arch cut with peach. so this should involve 4 axes together.

I use Qcad/cam for drawing because the CAD part of Dcut is poor so for rectangles or other simple shape I use Dcut, but for more complicate shapes I use Qcad, and when I need some ideas to put many pieces in the same slab I use the nesting function of Qcad and when I find the solution I like I copy it manually on Dcut. I can't use the nesting solution of Qcad directly, because all pieces need an off set of the half of thickness of the diamond blade and with Dcut it easier to manage it, because it is designed for doing it.

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: i wish i could use Qcad CAm for my machines

Post by CVH » Sun Jan 01, 2023 4:33 pm

Nube wrote:
Sun Jan 01, 2023 3:59 pm
I can't use the nesting solution of Qcad directly, because all pieces need an off set of the half of thickness of the diamond blade
That is something that you can configure with QCAD nesting as far as I know.

Regards,
CVH

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: i wish i could use Qcad CAm for my machines

Post by CVH » Sun Jan 01, 2023 5:09 pm

Nube wrote:
Sun Jan 01, 2023 3:59 pm
I can't work by modifying the G-codes is too complicate for me and it take too much time.
It ain't easy but I do it kind of automated for several hundred of plunges when engraving text. :roll:
Nube wrote:
Sun Jan 01, 2023 3:59 pm
but I think it can manage 4 axes together, because you can make an arch cut with peach. so this should involve 4 axes together.
I understand, like rotating a piece of plywood around a centerpoint on a table saw but it removes far more material than the blade thickness.
Feasible for convex shapes but is there a solution for concave shapes? Maybe if the blade is tilted and still ... :?
Nube wrote:
Sun Jan 01, 2023 3:59 pm
I never seen it before at least with diamond disk blade.
Some professional controllers for woodworking machines do the same for saw blades.
It requires less horsepower and minimize stress on the blade and the workpiece, chip removal is better controlled.
But it is a forgotten art with the flood of cheap (Chinese) routers + controllers.
Most (DIY) machinist don't see a difference between a drill, a side-mill, a router bit or an engraving point. :roll:
They all spin around and remove material but there the resemblance ends. :wink:

Regards,
CVH

User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

Re: i wish i could use Qcad CAm for my machines

Post by Nube » Mon Jan 02, 2023 6:56 pm

CVH wrote:
Sun Jan 01, 2023 4:33 pm
That is something that you can configure with QCAD nesting as far as I know.

Regards,
CVH
Probably yes, but I don't know how to do it. The only thing I know is that you can set the number of pieces.



CVH wrote:
Sun Jan 01, 2023 5:09 pm
I understand, like rotating a piece of plywood around a centerpoint on a table saw but it removes far more material than the blade thickness.
Feasible for convex shapes but is there a solution for concave shapes? Maybe if the blade is tilted and still ... :?
To make curve cut off course you make a cut larger than the blade thickness. The more is small the radius the more the cut is larger.

If the good part is the inside (for example a round table) the blade will work vertical (90°).

Instead if the good part of the cut is the outside (for example a round hole of 60 cm in the middle of a tile 120x120cm) the blade is tilted and the cut will result more larger than with the blade vertical but the important part of the cut will result 90°.

For both kind of cuts you can't make just one cut, but you need several cuts that go deep few mm each time.

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: i wish i could use Qcad CAm for my machines

Post by CVH » Tue Jan 03, 2023 8:14 am

Nube wrote:
Sun Jan 01, 2023 3:59 pm
I can't use the nesting solution of Qcad directly, because all pieces need an off set of the half of thickness of the diamond blade
CVH wrote:
Sun Jan 01, 2023 4:33 pm
That is something that you can configure with QCAD nesting as far as I know.
You can indeed set individual quantities by a different tool.
What that does is adding a custom property to your entity(-ies) called QCAD/NestingQuantity and the number of copies.
This parameter is taken into account for individual shapes when nesting.

But with Nesting itself there is an Option Toolbar like with most tools in QCAD, usually left high.
If not visible then make it visible in the menu View .. Toolbars and Widgets .. Toolbars >> Options
This is a key functionality in QCAD and one should not hide the Options Toolbar at all ... :roll:

There are 2 nesting options that handle inter-spacing, Sheet Margin & Margin.
Sheet Margin is what it says, like a paper margin, and Margin is the minimal space between parts, e.g. your diamond disk thickness. :wink:

Regards,
CVH

User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

Re: i wish i could use Qcad CAm for my machines

Post by Nube » Thu Jan 05, 2023 7:15 pm

CVH wrote:
Tue Jan 03, 2023 8:14 am
There are 2 nesting options that handle inter-spacing, Sheet Margin & Margin.
Sheet Margin is what it says, like a paper margin, and Margin is the minimal space between parts, e.g. your diamond disk thickness. :wink:
Thanks CVH,
I didn't note this function, I tried to follow your instructions and it is very easy, this will help me to check exactly the pieces I can put in a slab with more precision. But is still not what I need.

Dcut (the Cad Cam software I use) doesn't manage pieces, but lines and arch that you can put together like a block. You can select together all the lines of the same piece, move them and align them, but still remain lines and arch. The line (or arch) is the center of the cut.

For example to cut a rectangle 1000x300mm with a blade of 3,4mm thickness you need a rectangle 1003,4x303,4.

Dcut make this very simple, because when you draw it you put the actual measure and automatically ask you if you want to offset the drawing with the thickness of the blade.

Same thing when you load a DXF, it ask you if you want to offset the drawing.

In the case of Nesting I should have all the pieces offsetted with the right thickness of the blade. As I wrote this specific offset is quicker to do with Dcut than with Qcad. And also the risk of making mistache is less, because with Qcad you need to offset with half of the thickness of the blade, then you need to erase the original drawing, finally you have to explode the poliline.

Also if Qcad Nesting find me a solution close to what I like, but not exactly the way I want it, then it is complicate to select the single line that compose a piece to move them.

In conclusion I am happy just with the suggestions I receive from Qcad Nesting, then nesting in Dcut manually by coping what Qcad has created is very quick. At least is quicker than trying to find a nesting solution without and idea of where to start to put pieces together

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: i wish i could use Qcad CAm for my machines

Post by CVH » Thu Jan 05, 2023 7:36 pm

Nube wrote:
Thu Jan 05, 2023 7:15 pm
Also if Qcad Nesting find me a solution close to what I like, but not exactly the way I want it, then it is complicate to select the single line that compose a piece to move them.
Ever tried double clicking near an entity that is part of a contour ... :roll:
Double clicking selects all connected entities.

No need to group them in a polyline and that is also not required for Nesting.
They remain individual entities and thus no need to explode the polyline afterwards. :wink:

Half cutter offset works very well ... Even for a laser beam.

Regards,
CVH

User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

Re: i wish i could use Qcad CAm for my machines

Post by Nube » Wed Jan 18, 2023 11:09 am

Hi CVH,
i want to show you how the machine make the cut with diamond disk blade

I realized a small arch piece.

In the video you can see the initial part of the cut. The machine tilt the head and does several arc cut starting from the top of the piece and going deeper every cut.

In this case for each cut use only 3 axes together X Y and B (rotation) and between a cut and an other X Y Z to reach the starting point of next cut.

https://youtu.be/cCut238KZJU

In the pictures below you can see the final result of the internal cut of the arc


Taglio1.jpg
Taglio1.jpg (165.01 KiB) Viewed 12272 times
Taglio2.jpg
Taglio2.jpg (133.97 KiB) Viewed 12272 times


Then I took the entire piece and I polished with manual grinder the inside of the arc and putted back to make the cuts for the joint and the outside part of the cut. I was in a hurry so I didn't make the video, only took some pictures.


Taglio3.jpg
Taglio3.jpg (110.39 KiB) Viewed 12272 times
Taglio4.jpg
Taglio4.jpg (69.1 KiB) Viewed 12272 times
Taglio5.jpg
Taglio5.jpg (107.56 KiB) Viewed 12272 times


Best Regards,
NUBE

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: i wish i could use Qcad CAm for my machines

Post by CVH » Wed Jan 18, 2023 6:33 pm

Hi again,

Fully understood the method used from your descriptions but seeing it in action is even better. :P

Still, while cutting it is just acting in 2.5D + the vertical axis ... Tilting the blade only sets a certain offset in XYZ. :wink:
The vertical axis is always tangentially to the working direction.

This also means that a bridge between QCAM and COMMADULLI should be feasible.
I know from my controller that I can configure this for using Tangential Knifes or Rolling Blades.
Axis A is then controlled automatically regarding motions in X&Y.

Nice example of a 'hanging' gantry setup.

I saw 'Tecnica Nube arc' on Youtube ... Ever tried a concave approach?

Regards,
CVH

User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

Re: i wish i could use Qcad CAm for my machines

Post by Nube » Wed Jan 18, 2023 8:29 pm

CVH wrote:
Wed Jan 18, 2023 6:33 pm
....
This also means that a bridge between QCAM and COMMADULLI should be feasible.
----
I believe it is true, but I am not able to do it
CVH wrote:
Wed Jan 18, 2023 6:33 pm
----
I saw 'Tecnica Nube arc' on Youtube ... Ever tried a concave approach?
....
The arc motion is just an hypothesis, I never tried because I am not able to create G-code for it.

The reason of the arc is because in that way the back part of the blade remain always in the start point of the cut. It is important in “blind cut” to not pass the start point. (for example a cut for a fitting a stove in a counter top for kitchen)

I never thought about a concave approach, in theory it goes deep quickly when there is less resistance and slows down the penetration when there is more resistance, this means that it could be better.

You gave me an idea, I will work on it and I will let you know. Maibe I can use another Cad Cam specific for profile (Dprofile is the name) to do this testings. I have got to check if there is this possibility.

User avatar
Nube
Junior Member
Posts: 11
Joined: Wed Nov 04, 2020 6:51 pm
Location: Modena, Italy

Re: i wish i could use Qcad CAm for my machines

Post by Nube » Thu Jan 19, 2023 3:32 pm

I tried but I can't make the arc movement also with Dprofile.

I tried to figure the concave approach but I didn't find how it could be done without damaging the starting point of the cut.

Here is the drawing I use to calculate roughly the line to follow for “Tecnica NUBE”, there is also the arc.
Quote Affondo.dxf
(116.47 KiB) Downloaded 253 times
I saved DXF R12 single lines, because is the only format that Dcut reads.

P.s. Maybe we should continue Qcad CAM forum area? I don't know, just asking

Post Reply

Return to “Introduce Yourself”