On Friday, February 17, 2012 11:02:33 PM andy pugh did opine: > On 17 February 2012 20:30, gene heskett <[email protected]> wrote: > > Am I in the ballpark at 60-65% blockage?, > > It depends, to an extent, on the triggering point of the detectors. > If you have adjustable comparators in the circuit then you can adjust > the duty cycle, but I am not sure it matters that much anyway, as long > as you have a phase difference.
Well, I'm trying to maximize the amount of time that LinuxCNC has to grab a valid sample when this thing is turning 1000+ rpms. It can go 2500 but I have no clue what for other than maybe polishing something. The only thing adjustable in this 9 part circuit, is the mounting holes for the opto's ears are over sized, so I can if I have to, slide them a few thou sideways and equalize the times for better quadrature. At 2500 revs, it would have 0.000133333333333 seconds to grab a valid sample while it has turned 2 degrees, or 0.133333333333 millisecs, or 133.333333333 microsecs, so theoretically at a base_thread of 20 u-secs, about 6 good cycles per state of the wheel as it turns. I guess that will be ok if the D525MW can keep up. :) But I just did a dumb-assed thing. I cleaned out my pallet & filed the edges of a board so it would lay nice & flat in the pallet, without any play & ran the etch, drill and text files on the top, looked perfect except for one mounting hole I need to move to the right about .2". Usable, but hey. So thinking I had a good board going so far, I turned it over and started the bottom etch file, but it seemed to be running deep, so I checked the depth offset in my autoz function, looked to match what I used to carve the top of the board. I'm sitting there contemplating my sins when it hit me that I had not de-burred the work on the top of the board, and those burrs were busy holding some parts of the board about 1.5 to 2 thou high. I'd forgotten to scrub it on a sheet of 600 w-r-d laying on my surface plate before remounting it. Yeah, dumb-assed. Darned good thing I am not trying to do this for income from this item, but I wouldn't mind making a few bucks with the lathe once the cnc conversion is working. Too late to fix tonight, my heaters are losing ground as it is down in the mid 20's out now & that shed isn't at all well insulated so despite 3kw worth of heaters, it was down to 64 at eyeball height & the fifty's around my feet. That is quitting time. Tomorrow I'll restart that box and write me a clearance routine that will take the center of the board pocket down about 15 thou, leaving a .025" wide ledge around the edge to hold the board so if I forget to de-burr it, I can do it when both sides have been done. A board that small should support itself in the middle I'd think, at least till the etch point is so dull its pushing it down. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> Linus? Whose that? -- clueless newbie on #Linux ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
