Sent from my iPhone
>> On 23/07/2018, at 10:32 AM, Gene Heskett <[email protected]> wrote: >> >> On Sunday 22 July 2018 17:42:48 James Boulton wrote: >> >> Replace your 4 photodiodes with a webcam without a lens. Put a tube in >> the lens place to reduce ambient light. This will give you a cheaper >> detector with higher resolution. Use a laser collimated to 3 to 5 mm. >> Then put a lens on the tool post. This lens will make a ‘light lever’ >> which will accentuate the laser deflection on the ccd. >> > And the lens on the toolpost is all that moves? Or does the cameras ccd > stay at a fixed location vis-a-vis the lens, moving as a unit? The ccd is on the fixed to the end of the bed. Use a lens with a long focal length focused on the ccd with the tool post closest to the chuck ( I’m assuming a lathe). As the lens moves closer to the ccd on the carriage the spot will get bigger ( giving you z displacement) and deviation will be proportional to carriage deviation. > > That sounds doable although thats a bigger beam than most diodes, which > are about 1.5mm's, and likely will be felt in the divergence as the > carriage is moved. I'll see if I can round up the goodies. How long a > f.l. for the lens? Cameras I have several of, of not bragging > resolutions or fps's, some with focusing lenses but all with exposed > ccd's if the lens is removed. > > Then I wonder if the pi has enough iron in its butt to run camview. That > is yet to be determined. FWIW, the new camview fails in almost exactly > the same manner as the previous version on an amd64 wheezy box. Python > bug methinks. But if the pi can do it, that would give me target rings > that cheese in a separate window can't. Ignore the grinding noises from > my brain. > > Thanks. > >> Sent from my iPhone >> >>> On 23/07/2018, at 6:21 AM, Gene Heskett <[email protected]> >>> wrote: >>> >>> Greetings all; >>> >>> In trying to come up with a means of measuring and compensating for >>> bed wear, it strikes me that a laser diode with a very small beam, >>> well under a 1mm diameter with minimal beam divergence would serve >>> as a light source. >>> >>> Then a 4 pixel ccd, with the pixels in a square pattern could serve >>> as a detector. If mounted at a 45 degree angle, one should be able >>> to separate the up-down error from the in-out error >>> >>> Mount the laser in the chuck, on center, and point it toward the >>> tailstock and diddle the aim until it hits whereever on a center, >>> but with as little wobble as it can be adjusted for, then move the >>> center until its hitting the tip of a dead center nounted in the >>> tailstock. >>> >>> bring the ccd into the beams path and adjust its position for equal >>> output from all 4 cells whi ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
