Re: [yeagerautomation] Next step for hobby CNC

Alan, you make some good points but the problem is that a 4 axis robot
arm doesnt behave the same way as a mill or lathe. A linear move requires a
complex set of geometric relationships (the sum of 4 simultaneous angular
moves). (in fact i'm not even sure if I can do it with only 4 axis)
By using this "recording" system that I am talking about you "trick" a
standard 4 axis control into manipulating a robot arm without having to work
out all the math.
In other words the control is only recording the motor motion, it has no Idea
what the actual welding head is doing. This is why a digitizer wouldn't
work. The system would have to record the actual motor motion. It would'nt
be able to reconstruct the path from a set of points.
So my system would be impossible to program without this learning
(recording) function, or writing your own software to convert the spherical
coordinate system to cartesian. Which is too much for me as I know squat
about software.
The alternative would be to build the robot as a cartesian machine and
use standard controlls. But I dont' think this would give me the degree of
freedom I am looking for.
Thanks for your feedback.

Alan Marconett KM6VV wrote:

> Hi Joe, (?)
>
> Can't think of any software now available. I'm waiting on a Renishaw to
> do a digitizer program, but that's not quite what you're asking for.
>
> I can see where "teaching" might be faster. But wouldn't a Gcode
> program be fairly simple anyway? So how about "commanding" (MDI) each
> position in sequence, and saving the Gcode commands? Something like
> that?
>
> OR
>
> With a DRO attached, you could disable the Gecko's, crank by hand
> (actually, I think I'd prefer to "jog" under power), and a simple
> program reading the DRO could generate a block of Gcode each time a
> "mark" key was pressed.
>
> Now if I just had a 3-axis DRO...
>
> Alan KM6VV
>
> jvicars@... wrote:
> >
> > What I would like to build is a home shop welding robot. The one
> > thing missing is the ability to run a program by "teaching".
> >
> > All the MIG robots I have seen work this way. You switch the machine
> > to "Teach Mode" and manually move the welding head around the work in
> > whatever path you need. While you are doing this the computer records
> > the motion and translates into G-code. You have simple record, pause,
> > rewind, etc.
> >
> > I pictured building this with steppers with encoder feedback. The
> > "recording" program and the control dont' even have to be related.
> > There's no reason CNCpro (or other hobby controller) couldn't run a 3
> > or 4 axis robot arm. The problem right now is on the software side.
> > The Gecko G201's already have the free spooling feature built in which
> > would make it very easy to switch back and fourth from teach to run
> > modes.
> >
> > Does anyone know of any software (free or cheap) that will perform
> > this "recording" function as I have described? Are there some details
> > that I am missing?
>
>
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