Re: Digitizing arm?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Don C" <tekno62@...> wrote:

>
>
> True the error is cumulative but if the error is low enough then its
> ok or you could have a program look at the date and if something is
> radically different then its disregarded.
>

When I say the error I mean the difference between measured and actual
position due to encoder resolution. Avoid the maths completely and
draw a simple 3D sketch, then move each limb by your 360/5000
resolution and see how much the end moves. The error will vary
depending on how the arm is positioned but you can get a good idea
about how good it needs to be.

Personally I'd look very carefully at those 16 bit absolute encoders,
16 bit is over 65000 pulses per rev and its not even pulses, it uses
serial comms to tell you the absolute position, that means you also
don't need to have home switches etc.

Graham