multiple (four) parallel axis

More
25 Apr 2016 23:33 #73879 by andypugh

Anyway, we are kind of in a rush, as we have to submit the working machine next Friday


That's fairly short-notice. Would submitting a virtual machine suffice?

If you are prepared to write a custom kinematics file I think that might be simpler in the long term than doing everything in HAL.

Do you have any existing LinuxCNC experience?

Please Log in or Create an account to join the conversation.

More
28 Apr 2016 00:01 #73973 by andypugh
I created a sample config including a Vismach model of how I imagine the machine looks.

You will see that jogging X Y or Z moves a pair of axes, and jogging U V or W jogs only 1.

If you MDI G18 then a G2 or G3 move you will get mirrored arcs on two tools, and if you select G19 you get the arc on a different pair of tools.

Note that it is shift-drag to rotate the Vismach viewport, right-drag to zoom.

A real machine would need a homing config and some other details, but this seems to prove the concept.
Attachments:
The following user(s) said Thank You: pcsabi93

Please Log in or Create an account to join the conversation.

More
03 May 2016 15:09 #74175 by pcsabi93
Thank you Andy, and sorry for not replying for a longer time. We have been working on the project, and had several other problems to solve - and we still have loads to do. I finished working for today, and I don't have linux installed at home, but i will definitely check out your file tomorrow - once again, thank you very much for the vismach model.

As for homing, we will need a some sort of process, but it shouldn't be difficult, as we have absolute encoders (though we use incremental encoders for measuring, and the absolutes are only for the verification). This setup was already made, when we started upgrading the machine.

My LinuxCNC experience is definitely little, I only started working with it a few months ago. Could you tell me, what exactly custom kinematics files are?

Please Log in or Create an account to join the conversation.

More
03 May 2016 16:02 #74182 by andypugh

My LinuxCNC experience is definitely little, I only started working with it a few months ago. Could you tell me, what exactly custom kinematics files are?


Given that, I should perhaps say that you need to extract the archive into a folder in your linuxcnc/configs folder, and then you can pick the config from the config picker that is started from the CNC menu.

As for kinematics, it is what maps the XYZ etc commands in G-code to motor positions. In the case of a robot where the motors control all the elbows this involves non-trivial mathematics. For an XYZ cartesian milling machine it involves no maths at all.
linuxcnc.org/docs/2.7/html/motion/kinematics.html for more details.

Please Log in or Create an account to join the conversation.

Time to create page: 0.063 seconds
Powered by Kunena Forum