2011/11/1 Jon Elson <[email protected]>
> On 11/01/2011 5:50 AM, Andrew wrote:
> > Hi,
> > Anyone can share the source of inexpensive linear scales/encoders? I'm
> > looking for 5-10um resolution, quadrature is better as I plan to
> > connect them to MESA 7i39. BTW, how can I connect encoders with
> > differential output to 7i39?
> >
> 10 um = ~ .0004" which is pretty low resolution. Some people have tried
> this, it does not give great performance. You generally want 10 X the
> displayed
> resolution for smooth servo control.
Thanks, John,
I'll think about 1-2um resolution, if not too expensive. I suppose that the
finer resolution requires closer and more accurate distance between tape
and encoder, like 0.35mm instead of 1-2mm.
> Also, you MUST have minimal backlash
> between the motor and the linear slide, so unless you have zero-backlash
> ballscrews, you will have very annoying servo hunting.
>
With small linear motors and medium preload guideways, I hope for minimum
backlash.
2011/11/1 Javier Ros <[email protected]>
> I used renishaw magnetic each axis was about 300€-400€ for 1 meter,
> magnetic guide is no the mos expensive part so using longermaganetic tape
> should not be a problem.
>
> Maximum resolution, was 1um, but I think using lower resolutions was an
> option but changes in price where not really important.
>
> Renishaw is a top brand so, it is possible that you can find something
> cheaper. If other conditions don limit your design, the bigger the
> resolution the best, specially
> if you are using a derivative part in your PID.
>
> I'm sorry I don't have more information on this.
>
Thanks Javier. I already found encoders for 300-400€, but still looking for
something cheaper. The stroke is near 200mm, so the expensive part is only
encoder module.
Andrew
------------------------------------------------------------------------------
RSA® Conference 2012
Save $700 by Nov 18
Register now!
http://p.sf.net/sfu/rsa-sfdev2dev1
_______________________________________________
Emc-developers mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-developers
