gene this is what jon offers and i am salivating over :) http://pico-systems.com/osc2.5/catalog/product_info.php?products_id=26
i figure if using rectified line voltage it would give about 3 hp out of my 2.5, with fan to cool it and would only need an isolation transformer for safety, once i am back in m o this and a mesa card will be my next upgrade On Tue, Apr 30, 2013 at 12:25 PM, Gene Heskett <[email protected]> wrote: > On Tuesday 30 April 2013 12:06:13 Cecil Thomas did opine: > > > Gene, > > You need to remember that the seemingly high hp ratings of these > > relatively small motors is due to the very high rpms at which the > > ratings are valid. > > These 1 1/2 to 2 hp motors develop that hp at 5000 to 6000 rpm. You > > will have to rethink your drive coupling system to reduce that speed > > down to something usable especially for threading. > > I am aware of that, the toothed belt pulleys stock on the 7x means its > turning about 8000 revs to get the 2500 rated in high back gear. I very > rarely use it as there isn't enough torque to even cut alu 1/2" in > diameter. > > > I am using a 2 1/2 hp treadmill motor with its original speed control > > on my converted jet 9 x 20. I had to use a 4.5 to 1 pulley reduction > > to get reasonable torque in the 200 rpm spindle range but still have > > about 1400 rpm available at top speed, which is good enough for > > me. > > That would also suit me just fine, low range is about 1200revs right now, > and this motors is in trouble at work diameters above one inch in steel. > > > I have plans for a shiftable double reduction setup which will > > be closer to 3:1 in hi and 12:1 in low. At that ratio the motor will > > cut anything that the toolpost will hold up to even at 150 rpm > > cutting a very coarse thread. > > That is part of my problems, the tool tip is often hanging out in front of > the way pads, and it has been known to tip and dig in, bringing everything > to a halt in 3 degrees of rotation. > > > I feed the speed controller through an optical isolator with PWM at > > 200 hz out of the parport with LCNC. Be sure to use an optical > > isolator. And DON'T try to compare the PWM into the isolator with > > the output with a dual trace scope.... Ask me how I know. > > Chuckle, I know too, blew a C41 and a JT250 all to hell. And it does > interesting things to scope probe ground leads too. And is the main reason > I bought me one of those pocket scopes. But ISTR I settled on a PWM at > about 1000/sec. Basically I went up till it started hunting because of > poor resolution, then backed off to well below the hunt point. Subject of > course to changes with gedit to the .hal file. :) > > But you say you are strobing the pot arm with an opto? That should give > faster response I would think, one of the major problems with the C41 > approach, that thing is ssssslllllllooooooooowwwwwwwwwwwwww as shipped. > > > I made my encoder wheel out of a CD which I painted black. It has 20 > > equally spaced notches with one twice as deep for the index. I used > > two optical interupters for the A and B quadrature and a third one > > set deeper into the index notch. I mounted all the interrupters on > > aluminum L brackets with supermagnets holding the brackets to the > > metal of the enclosure. I watched the Halscope while shifting the > > interupters around till I got the quadrature right and the index not > > coinciding with the A or B transitions. When all the signals looked > > right on the halscope I put a drop of superglue at the edge of the > > bracket...waited til it set then drilled the mounting screw holes > > through the bracket and into the sheet metal. Much more easily done > > than described. > > Yup, but my disc is brass, 50 slots + long index. All 3 opto's mounted on > a home made pcb, so the center one is the index. > > > > The 80 transitions per rev is plenty of resolution for anything I'll > > ever do and the pulse rate doesn't challenge the system. > > Not at 20 slots. I did some math and came to the conclusion that LCNC was > capable of tracking its 50 slots at nearly 6k revs. Absolutely NP at 1200. > :) > > > > Cecil > > ------------------------------------------------------------------------ > > ------ Introducing AppDynamics Lite, a free troubleshooting tool for > > Java/.NET Get 100% visibility into your production application - at no > > cost. Code-level diagnostics for performance bottlenecks with <2% > > overhead Download for free and get started troubleshooting in minutes. > > http://p.sf.net/sfu/appdyn_d2d_ap1 > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > 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> is up! > My views > <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> > You can't take damsel here now. > A pen in the hand of this president is far more > dangerous than 200 million guns in the hands of > law-abiding citizens. > > > ------------------------------------------------------------------------------ > Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET > Get 100% visibility into your production application - at no cost. > Code-level diagnostics for performance bottlenecks with <2% overhead > Download for free and get started troubleshooting in minutes. > http://p.sf.net/sfu/appdyn_d2d_ap1 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- jeremy youngs ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
