Coordinating Motion with an External Axis

[Johannes @ Robots in Architecture]

Hello Mark,

The Custom Turntable component allows you to define a custom turntable geometry and the associated rotary axis position and speed. It won't change anything directly relating to your code generation.
What problems are you tackling at the moment?

Best,
Johannes

[MkMrA2]

Hi Johannes,

Here are some samples of what I'm making.

https://www.instagram.com/p/DQm1ecvjxNJ/
https://www.instagram.com/p/DPSH1gZjw4w/

Generally, it is working well, or well enough. However I'd like to dial it in further to get it more refined. And the way I'm having to generate rotary motion is a challenge.

The rotary on this setup is E1. It isn't part of the kinematic model with A1-A6. I compute the rotation, normal vector, and speed for every point. When both E1 and A1-A6 are in motion together, it works well. However when A1-A6 move very little, but E1 moves a lot, LIN moves are problematic. An example is printing a ring of clay at the top and bottom of a circular form. A1-A6 don't move. Only E1 moves. When this happens, if I use a LIN move, E1 spins very fast. Because A1-A6 aren't moving at all, it 'thinks' it just needs to instantly put E1 there. So it spins way too fast. Earlier in this thread, you helpfully suggested using PTP moves instead. So, I detect and special case when E1 is very dominant in the motion, and then I switch to using PTP moves. These can be specified as a percentage, and thus I can better control the speed. But I think it's only an integer percentage, so it's not that great of control :)

This also happens at moments in printing in general, where the moves to print are nearly E1 only. It's too fast relative to the other motion, and the clay bead winds up being too thin, or torn, because the rotation was too fast.

I think I was hoping the Custom Turntable component would magically solve my problems by building E1 into the kinematic model along with A1-A6. But it sounds more like a visualization tool. I fight on...

Mark

[Johannes @ Robots in Architecture]

They are beautiful!!

Have you tried lowering the $VEL_AXIS_MA[n] value where n is the number of your axis?
You can set it in the R1\Mada\$machine.dat file.
That value cannot be changed in the program, but using $VEL_AXIS_EXT[...] you can set a percentage value (0-100 of $VEL_AXIS_MA[n]) as a Custom KRL command in the program.

Best,
Johannes

[MkMrA2]

Thanks, Johannes.

I haven't tried that but I will tomorrow afternoon. It makes sense how I could make that work. Thanks again.

Mark