> I have been given a quote for electrochemical machining of an encoder > for my project. > http://www.photofab.co.uk/index.php/services/chemical-etch-photo-etch/ > There is a £95 setup charge, then another £100 for a sheet of parts. I > get 25 of my design (75mm dia) on a sheet, but only need 6 or so. > The material I want to use is 0.3mm 304 stainless. I can add different > designs to the sheet for no extra charge. > Does anyone have anything intricate that they need making from > stainless shim like this?
What resolution can they produce? How do you read the encoder, transmission/reflection of IR-LED or ? Would the pattern produce a square wave-signal, or a sine-wave (which can be 'interpolated' to yield higher resolution) a dream project of mine would be a telescope mount. To minimize tracking error one should measure the rotation directly on the geared axis (not the motor) and one wants maybe 4 million pulses (22 bits) per rev for that. >From what I've understood it's done by A/D converting a sine-wave encoder, so if you get e.g. 8 to 10-bits of reliable interpolated data then you want an encoder with 12 to 14 bits of sine-shaped counts, i.e. up to 16k-counts/rev. How big a circle would that require? Anders ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users