On Monday 04 April 2016 09:37:08 Nicklas Karlsson wrote: > > Maybe. OTOH, I can probably knock up something in eagle or geda/pcb, > > and carve it on my machine by the time UPS could make a drop here. > > Those pictured boards Farnell shows me are quite simple, and adding > > another thru-hole for the supply bypassing those chips ought to have > > would be easy enough. If I have a problem I might consider it, but > > this VFD is RS-232, if that option is plugged in. I didn't find it > > when I had it apart OTOH, somebody, Mesa or Pico, maybe PMDX really > > ought to knock up something like that so we'd have a ready-made > > plug-n-play solution we could buy at a reasonable price. > > > > Potential product suggestion guys. > > You need VFD? > Potentially. I am considering buying a Sable for PCB work, and I am NOT impressed with the optional belt driven spindle they can supply. The rest of the machine looks as if it can do .001" accuracy as the Sable gantry is part of the machine frame and does not move except the spindle carrier sideways for what I'd call Y. The table moves under the stationary gantry instead, on what for its size are quite substantial 25mm rods & bearings. If the gantry can support this motor, then its 24k revs should allow a huge improvement in production speed.
But I have some other things I need to get out of the way to make room for the Sable. Now, I am contemplating, because the Z is so much slower than the XY on this G0704/BF20, replaceing the3.5 amp 1600 oz/in motor and ma860 driver with its matching 60 volt switching psu, with this: <http://www.ebay.com/itm/US-Ship-1-Axis-CNC-Kit-1841oz-in-Nema-34-Stepper-Motor-Driver-CNC-Mill-Router-/331600637974?_trksid=p2141725.m3641.l6368> which it seems ought to triple the Z speed, but the 110 volt max dc supply, which I'd expect I'd better hold to about 100 volts, or if a stepdown tranny in the AC, 70 volts, and I have nothing to do that with at that power level. In AC that would be a 57 volt buck at nominally 8 amps=a 500 watt rated buck transformer. Hens teeth category in that fleabay hasn't such a critter that I can find. And switchers seem to top out at about 72 volts & not quite enough amps. In other words, I haven't anything that could power it correctly. And ebay's search engine has no damned concept of what the word "volt" means. No association with the 100 in front of it. The only tranny I have in that power category or above, is a toroid, 250/125 volt autoformer with at least a 5kw rating, a foot in diameter and 6" thick that I can't move it without a 2 wheeler, at least 90 lbs bare. I had visions of a better load balance on my house by running the mill off a 252 volt two pole breaker. But to be NEC legal I'd need a steel houseing box but haven't stumbled over one of them critters of a suitable size used yet. Sad, but its the story of my life it seems. What we need, is the MA860H in a MA8130H so it could be powered with a straight 127 volt line connection. We may get it eventually, but not on my watch I suspect. Ideally, 2 of the Pico pwm servo amps with special quadrature drivers could do it, but the driver would need to be pretty special, doing the pwm and dir with the pwm duration mapped to the microstepping needed. They can do 20 amps on a 160 volt supply. But here we go again, the beggar is still looking for the free horse to ride, so the money doesn't get spent. :( Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
