[R2D3]

Hello. Need more use cases.Especially for cuctom what data needs to change 45 degree axis Worked like 90 degree? Can it also be used with these
rotating axles?

[servtech]

Hello. Need more use cases.Especially for cuctom what data needs to change 45 degree axis Worked like 90 degree? Can it also be used with these
rotating axles?

I would have thought using the "rotate" function for the axis plane angle would work for you.

[R2D3]

No, I'm more like asking how to use it

[R2D3]

I'm interested in the mathematical meaning of the matrix. Rotation also changes the matrix. i know how rotation works, but how to change matrix without rotation (by just writing numbers in matrix)

[PlanetCNC]

"Matrix" is 4x4 affine transformation matrix.
https://en.wikipedia.org/wiki/Affine_transformation

[servtech]

No, I'm more like asking how to use it

kinematics begins by describing the geometry of the system and declaring the initial conditions of any known values of position. A machine tool manufacturer may machine a kinematics test piece after proving the machine geometry to known specification. Or, develop a setting process to find and plot the kinematic data. Both using dial test indicators at the known axis swivel point length, ie tool tip/ ball end test bar.

The idea being, in 5 axis and 3D machining, all inaccuracies are taken into account during machining. The data table you show is to enable you to "dial in the machine geometry" so when machining a 3D workpieces all points are know by the post and machine system, so the component is produced with smooth blends and without steps or misalignments during rotation of the workpiece.

To fill in the table you show, you need a proven procedure to input the axis offsets. Usually by the manufacturer or post software developer. LinuxCNC for example. Below shows example, tip of the tool stays in a fixed kinematic position.

https://youtube.com/shorts/6z6fucQHDDE?feature=share

[R2D3]

I understand that these matrices are independent along 3 axes. I'm right? I have a question, is it possible to create a dependency. Like in the video

https://youtube.com/shorts/6z6fucQHDDE?feature=share

I think the program is that of the machine G00 X0 Y0 Z0 C0
G00 X0 Y0 Z0 C-90
G00 X0 Y0 Z0 C90
When manually rotating the C-axis, the Y(X)-axis and Z-axis change values(the end of the tool changes position in the room).

[servtech]

I understand that these matrices are independent along 3 axes. I'm right? I have a question, is it possible to create a dependency. Like in the video

I think the program is that of the machine G00 X0 Y0 Z0 C0
G00 X0 Y0 Z0 C-90
G00 X0 Y0 Z0 C90
When manually rotating the C-axis, the Y(X)-axis and Z-axis change values(the end of the tool changes position in the room).

The machine in the video has a setting piece machined after the final machine inspection. The idea is that following a service, repair or collision, the setting piece can be mounted on the table, Renishaw probe mounted in the spindle set to an exact tool length.

A program named "kinematic" is run, all features of the setting piece are probed and the new kinematic data is read in, over writing the old data ie; +/- zero offset data of X,Y,Z and A,B axis.

This ensures 3D machining accuracy is restored.

[PlanetCNC]

"Custom" kinematics is used only for X, Y and Z axes. This feature was named "Metamorphosis" in old versions and it was experimental.
It uses same math as "Transformation" feature. I use it a lot for testing but I 'm not sure if I would use it on actual machine for 45 degree rotation.

I asked ChatGPT to "create 3d affine transformation matrix for 45deg rotation on xy plane" and here is its response:

Yes, I can create a 3D affine transformation matrix for a 45 degree rotation on the xy plane.


The affine transformation matrix for a 3D rotation about the z-axis by an angle theta is given by:


|cos(theta) -sin(theta) 0 0|
|sin(theta) cos(theta) 0 0|
| 0 0 1 0|
| 0 0 0 1|


To perform a rotation on the xy plane, we need to set the z-axis rotation angle to 0.


The affine transformation matrix for a 3D rotation on the xy plane by 45 degrees is therefore:


|cos(pi/4) -sin(pi/4) 0 0|
|sin(pi/4) cos(pi/4) 0 0|
| 0 0 1 0|
| 0 0 0 1|


Simplifying this matrix using the values of cos(pi/4) and sin(pi/4), we get:


|sqrt(2)/2 -sqrt(2)/2 0 0|
|sqrt(2)/2 sqrt(2)/2 0 0|
| 0 0 1 0|
| 0 0 0 1|


Therefore, the affine transformation matrix for a 45 degree rotation on the xy plane is:


|sqrt(2)/2 -sqrt(2)/2 0 0|
|sqrt(2)/2 sqrt(2)/2 0 0|
| 0 0 1 0|
| 0 0 0 1|

[deadlykitten]

I'm interested in the mathematical meaning of the matrix. Rotation also changes the matrix. i know how rotation works, but how to change matrix without rotation (by just writing numbers in matrix)

hy r2d3 do you know attached ?

if you need some help with 3d geometrical changes, i can help you. Just share more details on what you want

as for matrices, they are a general method of implementation, but for some tasks, not all matrices fields are needed. thus a general matrice may bee too much for, let's say, only 1 rotary axis / kindly

[R2D3]

Yes, we need sineand cosine (I also watched thelessons). I don't understand how to insert them into the matrix. I also need a variable into which you can write a value from any axis (for changing coordinates dynamically). I want this variable to be inserted directly into the matrix field along with the formula I need (sin, cos...)

[R2D3]

if you need some help with 3d geometrical changes, i can help you. Just share more details on what you want

I don't want to confuse anyone. Therefore, we stop before the proposed video https://www.youtube.com/shorts/6z6fucQHDDE
This movement can be specified in two ways.
1 using the program:1 using the program with G2 or G3 and rotating axis (if kinematics is disabled)
2 Rotate only the rotating axis without affecting the linear axes.(Movement along linear axes is controlled by kinematics).


Unfortunately, I don’t have time to write math and two programs and also attach a picture with coordinates, but on the weekend I will try to do it

[PlanetCNC]

Feature in video is called RTCP.
"Custom" kinematics can not handle rotary axes. It is meant for different things.
All kinematics support TPC, rotary kinematics support RTCP (R means rotary).

For example, is you have "Custom" kinematics defined so that space is rotated 45deg around Z axis (XY plane) then G01 X100 will move horizontally with Program/Kinematics unchecked and at 45 angle if Program/Kinematics is checked. Program/Kinematics turns TCP on/off and can also be controlled with M58 g-code.

[R2D3]

Will an improved system ever be introduced? It would be cool to create something useful: https://www.youtube.com/watch?v=HxPjH4v5iEg Of course I like the new 'kinematics' feature. I think it's very helpful. It's just that I always want more...

[PlanetCNC]

This is possible but it is no as useful as it looks.
I'll explain in more detail and create some examples when I get little more time.

[deadlykitten]

hy planet if you will have time to put it out, i will really like to hear your opinion on ' tool center control ' / kindly

[PlanetCNC]

I don't have 5th axis installed on my machine. But I can show this in simulation.

[adidoro]

I'm interested in this topic too, it would be cool to have TCPC and even cooler RTCP.

[Ed3]

Is there any documentation for using the kinematics feature? I would like to use PlanetCNC with a 5 axis milling machine where the C axis is attached to the Z axis, and then the A axis is on that axis, like this picture https://www.researchgate.net/figure/...fig1_262516425

[panamafighter]

Is there any documentation for using the kinematics feature? I would like to use PlanetCNC with a 5 axis milling machine where the C axis is attached to the Z axis, and then the A axis is on that axis, like this picture https://www.researchgate.net/figure/...fig1_262516425

hey, i was planning to switch from mach3 to linuxcnc when i found planetcnc. looks very promising so far and i would really like to avoid messing around with linux at all. Though, for a far future project i would also like to be able to operate a 5 axis machine configered in the way Ed3 discribed and showed in the picture (actually i will be using a c-axis and aggregate like this https://www.youtube.com/watch?v=mlKwpiPMrkE). As far as i understand the current kinematics options, this would not be possible at the moment, right? is there any chance of implementing such c-axis and angle head aggregate in planetcnc in the future?
thanks a lot, great work and software!