Re: NAMES 2000 PICS

Jon Elson wrote:

>
>Bert Eding wrote:
>
>> Very interresting!
>>
>> Do you have a special version of EMC,
>> how do You control 6 axes,
>> I am very interested.
>>
>> Is there a 6 axis trajectory planner in this EMC version,
>> if so I woul like to have it.
>
>The hexapod version of EMC offers very limited 6-axis
>control. There is no way to tilt the platform by way of the
>RS-274 commands. In other words, it accomplishes only
>3 degrees of freedom in the commands, and that is the
>cartesian coordinates. The guys at NIST are working on
>generalizing the interpreter to accomodate up to 6 degrees
>of freedom. When this is done, it will not only generalize
>movement of a Stewart platform (hexapod) but also allow
>fully general movement of 4-6 axis machines, I am told.
>I am looking forward to this eagerly, as I have wanted to put
>a dividing head on my mill.

Jon is right on here. I have a copy of the next NIST interpreter and it
can be compiled into 3 to 6 axis of cartesian motion. But the motion stuff
that has to listen to it and run the coordinated motors is going to take
some time.

My quick names review.
- Awesome working models of all kinds of things.
- Hats off to those guys.
- Nearly everything moved, spun, fired up...
- World's supply of vallium isn't enough for me to model like that!
- Fantastic cooperative spirit all round.
- CNC's in one place great for the crowd.
- CNC's in one place great for most CNC folk.
- A lot of interest in each of the different CNC systems.
- Dave Anderson did yeoman's service to get babyhex working.
- Babyhex was a definite attention grabber.
- CNC presentation was standing room only.
- Q and A after above was a quick mini CAD_CAM... digest.
- Nice to put NAMES to some faces.

My quick hex review.
- Hexapod, robot, and cartesian kinematics all exist in EMC now. Each can
be connected into a working controller by the way that you set up your ini
file. If you're using steppers, you'll need to get a bug free
steppermot/freqmot file and make sure that your parallel port can pull
up/down the appropriate pins.

- Babyhex is a device for proof of concept/software/math. It's ability to
do work is limited by it's weight and location within the work envelope.
My understanding of it is that it did some milling of light plastic at NIST.

- Hexapods (Stewart platforms) would not be limited to the geometric
relationships that are used in babyhex. The angles between struts at both
ends are configurable.

- Hexapods have limited x,y,z and roll, pitch, yaw. They will not work on
the underside of a piece unless you turn the piece over. (common NAMES
question)

- Grown up working hexapods, as opposed to babyhex, would need more rigid
links or some extra down force. Since the EMC software to drive it is
available to the experimenter, I'd think that it would be worth looking at
the Kirk screws with integral slideways for a light material, large Z,
router/carver.

- It was suggested that we could make a long cable babyhex with a camera on
board for next years NAMES show. The new motion planning stuff should be
ready by then but there is a lot of engineering left. Anyone up for this.

- Since I have exposed joists on the ceiling in my basement and spare
steppers...

If you respond to parts of this shotgun blast it would be a good idea to snip.

Ray