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abfa9358
12-04-2011, 06:57 PM
Hi All,
Does anyone know of a source of encoders suitable for spindle rpm / direction measurement. It'll be interfaced with a MESA 7i43 card and EMC 2
Regards
Andy

djc
12-04-2011, 10:03 PM
Does anyone know of a source of encoders suitable for spindle rpm / direction measurement?

Your question is somewhat vague. How much do you want to spend? What kind of output is suitable as an input to EMC? How fast will the spindle go? What precision do you require?

If you want speed only, a simple reflective opto-switch will do. If you want speed and direction, you will need something that outputs in quadrature. This can be as simple as two photo-interruptor switches spaced around a slotted disk. If there are metal parts involved (i.e. a gear), Hall effect switches are good.

Search for 'incremental encoder' to see a wide variety of what is available as a package deal. Apart from the expense, the hard part with these is mounting them properly concentric with your rotating shaft as well as finding something that won't obstruct whatever hole you require through the spindle.