Re: [CAD_CAM_EDM_DRO] Re: Open (i think) design for a parallel robot (reprap may be interested)

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Mike Pogue <mpogue@...> wrote:
>
>> I am guaranteed to always be as close to the circle in stepper motor
>>coordinates as it is possible to be with steppers. It's not a PID
>>algorithm, so I don't have overshoot to deal with.
>>
>>Note that the quantization introduced by the steppers is way smaller
>>than the backlash in the mechanical stuff.
>
>
> I'm just saying that the quantization exists, you said it didn't
> because the number of decimal places in the control program matched
> that of the steppers. There will always be some difference between
> where the tool should be and where it is if the position of the tool
> is discretized by steps.
>
> I'm not saying its a problem.
>
> The other point was simply one about numerical accuracy, its academic
> but when defining a circle say in a PC even at 64 bits there is some
> quantization error. Its academic because the error is smaller than
> the machine resolution.
>
> Graham
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