HWC - static tool, moving block

Started by petebooth, April 23, 2015, 05:11:13 AM

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Hi All,

I'm new the the forum, as here at UTAS we are just starting out in the world of KUKA|prc.
For our first project, my students have built a custom vacuum hold effector for our KR120 that is to be used in conjunction with a static table mounted hot wire cutter.
We understand how to define the vacuum holder as a custom tool on the KUKA, but we are struggling to understand how to define the table mounted HWC (horizontal) as the cutting element in KUKA|PRC.

ideally we would like to undertake something like RMIT did a few years back - https://vimeo.com/71018219.

any suggestions would be great.


Johannes @ Robots in Architecture

Hello Pete,

Great to hear about UTAS!
There are ways on the KUKA controller to deal with static tools, however we just did the transformation within Grasshopper. The core part of this operation is the Orient component in Grasshopper where you flip from one coordinate system into another.
I've attached part of an exercise that we did at ACADIA 2014. It contains some additional functionality within the cluster, but the transformation should be clear.
Hope that helps, if not just let me know and I'll see if I have a nicer example around somewhere!

Johannes @ Robots in Architecture

P.S.: I also just enabled your member access so that you can access the member section. The new PRC version there is quite much improved and you can install it alongside the "old" version that you are probably using. Just note that you will have to adapt any existing examples such as the attached ZIP files as the versions of the components are not compatible (e.g. replace any LIN move component from the old PRC with LIN move from the new PRC).


I am Kentaroh from school of Architecture in UTAS. Thank you for your Grasshopper Kuka definition. It was a great help.
However, we think that we are currently having an issue with it. When we use it with our robot, the definition causes a large rotation in axis A4, A5 and A6 . As a result, even if  the prc simulation is OK, in reality cables of our Kuka robot arm wrap around the arm, and make the operation impossible. Is  there any definitions to control or limit these axis in the Kuka Grasshopper definitions? So, ideally we would like our robot to cut without unnecessary rotations which causes a lot of troubles to the robot.
If we get help from you, it will be fantastic.

Here is a video and our Kuka prc definition and rhino file. 

Kind regards


Johannes @ Robots in Architecture

Hello Ken,

The new PRC quite accurately tracks the axis values so you should be able to detect such issues much more quickly. You can adjust the initial posture of the robot by either adjusting the status value (three binary values, e.g. 010) either in the menu or by adding a PTP position with a status value at the beginning of the job. This often helps with reorientations as well.
The new PRC works alongside the old one, however you must not "mix" components, i.e. only use the new LINear movements for the new PRC. Also, there was a change in regards to the custom tool, where you now have to place your mesh as if it were on the robot's flange, i.e. the X axis facing "downwards".

I've also unlocked your account so that you can access the member section with the new KUKA|prc.

Johannes @ Robots in Architecu