Question : 5axis simultaneous setup in LCNC
21 Jan 2019 15:08 #124551
by andypugh
No.
TCP does not have the rotation centre at the part origin or the machine origin, TCP has the rotation centre at the tip of the tool.
If you jog a TCP machine in one of the angular axes then just about every axis will move at the same time to leave the centre of the tool tip perfectly stationary in space as the tool tilts around that point.
TCP G-code uses XYZ ABC to control the position and orientation of the tool. So it doesn't matter what the machine geometry is.
Then with a TCP-kinematics machine the G-code of tool positions is interpreted by the kinematics module into the linear and rotary joint positions required to achieve that tool position and orientation in the workpiece coordinate system.
Imagine machining a pyramid, with the tool perpendicular to the triangular faces. This would be a number of combined XYZ moves for each face at 4 different tool orientations ( (A60m B0) , (A-60m B0), (A0, B60), (A0, B-60))
It doesn't matter if the machine tool is a robot arm moving a tool around a fixed block of material or a fixed-spindle machine with the pyramid rotating in complex ways underneath it.
Also note that in the latter case the XYZ moves would be complicated in G-code space, but simple when converted to joint positions, basically working at constant machine Z but moving all 3 axes in the workpiece coordinate system)
Replied by andypugh on topic Question : 5axis simultaneous setup in LCNC
ahhhh
I think I grabbed the concept.
Cam-output from an imaginary setup having rotational axis at zero will produce the Gcode and that gcode will work with tcp kinematic machine each having their own offset settings, is this correct?
No.
TCP does not have the rotation centre at the part origin or the machine origin, TCP has the rotation centre at the tip of the tool.
If you jog a TCP machine in one of the angular axes then just about every axis will move at the same time to leave the centre of the tool tip perfectly stationary in space as the tool tilts around that point.
TCP G-code uses XYZ ABC to control the position and orientation of the tool. So it doesn't matter what the machine geometry is.
Then with a TCP-kinematics machine the G-code of tool positions is interpreted by the kinematics module into the linear and rotary joint positions required to achieve that tool position and orientation in the workpiece coordinate system.
Imagine machining a pyramid, with the tool perpendicular to the triangular faces. This would be a number of combined XYZ moves for each face at 4 different tool orientations ( (A60m B0) , (A-60m B0), (A0, B60), (A0, B-60))
It doesn't matter if the machine tool is a robot arm moving a tool around a fixed block of material or a fixed-spindle machine with the pyramid rotating in complex ways underneath it.
Also note that in the latter case the XYZ moves would be complicated in G-code space, but simple when converted to joint positions, basically working at constant machine Z but moving all 3 axes in the workpiece coordinate system)
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21 Jan 2019 15:16 #124552
by KevKim
Replied by KevKim on topic Question : 5axis simultaneous setup in LCNC
I just built a virtual machine, tested it and failed as you described.
Okay, then how will I be able to program a g-code having rotational point at tooltip?
Is that even possible in general cam software?
I am really curious about how this approach can be done
regards,
Kev
Okay, then how will I be able to program a g-code having rotational point at tooltip?
Is that even possible in general cam software?
I am really curious about how this approach can be done
regards,
Kev
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21 Jan 2019 15:47 #124553
by andypugh
Replied by andypugh on topic Question : 5axis simultaneous setup in LCNC
I think that Fusion360 can produce 5-axis TCP G-code (I have done some Google searches and found complaints that it is difficult to turn it off)
Unfortunately the (free) version of Fusion that I have does not have 5-axis capability (or didn't last time I looked) and I don't have a 5-axis TCP machine, so I can't test it.
Unfortunately the (free) version of Fusion that I have does not have 5-axis capability (or didn't last time I looked) and I don't have a 5-axis TCP machine, so I can't test it.
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21 Jan 2019 22:09 #124570
by Hakan
Replied by Hakan on topic Question : 5axis simultaneous setup in
Many postprocessors, and certainly the linuxcnc postprocessor, in Fusion360 are prepared for 5-axis tcp output.
One has to go in to the postprocessor code and in the onOpen function around line 190 there is a false that should be changed to true. That is basically it. There are better descriptions in the autodesk forum/knowledge base on how to do this. It seems to me that it is much easier for the post processor to create tcp g code than the alternative.
Fusion 360 supports quite a few multi-axis tool paths. There are three methods for true multiaxis (5axis) and then there are some for four axis tool paths, with and without tilting of the tool.
One has to go in to the postprocessor code and in the onOpen function around line 190 there is a false that should be changed to true. That is basically it. There are better descriptions in the autodesk forum/knowledge base on how to do this. It seems to me that it is much easier for the post processor to create tcp g code than the alternative.
Fusion 360 supports quite a few multi-axis tool paths. There are three methods for true multiaxis (5axis) and then there are some for four axis tool paths, with and without tilting of the tool.
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25 Jan 2019 22:36 #124864
by JDS
Replied by JDS on topic Question : 5axis simultaneous setup in
The Linuxcnc post on fusion does indeed support 5 axis control. At line 192 you have to change if (false) to if (true). Below that you have to set up the axis for your machine. Below that there is a line that says optimizeMachineAngles2(0); // TCP mode, the (0) tells the post to use TCP, (1) turns it off.
I just figured this out on fusions forums, there is a page describing how to do this for most posts. I have yet to figure out how to set up my specific machine on the post yet though.
I just figured this out on fusions forums, there is a page describing how to do this for most posts. I have yet to figure out how to set up my specific machine on the post yet though.
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05 Oct 2020 18:00 #184989
by Profed81
Replied by Profed81 on topic Question : 5axis simultaneous setup in LCNC
Where can I find more information on this topic? I mean, about the 5-axis post processing, I mean, about this whole topic you mentioned
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05 Oct 2020 18:13 #184990
by Profed81
Replied by Profed81 on topic Question : 5axis simultaneous setup in LCNC
Where can I find more information on this topic? I mean, about the 5-axis post processing, I mean, about this whole topic you mentioned?
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05 Oct 2020 18:58 #184993
by andypugh
Have you read the rest of this thread?
How about: linuxcnc.org/docs/2.8/html/motion/5-axis-kinematics.html
Do you have any specific questions?
Replied by andypugh on topic Question : 5axis simultaneous setup in LCNC
Where can I find more information on this topic? I mean, about the 5-axis post processing, I mean, about this whole topic you mentioned?
Have you read the rest of this thread?
How about: linuxcnc.org/docs/2.8/html/motion/5-axis-kinematics.html
Do you have any specific questions?
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05 Oct 2020 23:52 #185020
by Profed81
Replied by Profed81 on topic Question : 5axis simultaneous setup in LCNC
Where can I learn more about this topic, that is, how is it to configure the kinematic in the cam software or in linuxcnc?
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