On Thursday 06 March 2014 22:56:56 Bill did opine: New first, we would rather not have to sort the order of reading a message, so we discourage top posting.
> Hi Gene > > I building a DIY desktop mill (moving table) 420x300mm bed 3 axis Nice size, could do, if its level enough, pcb etching nicely, or wood panel carving too. > I have minebea 17PM-M201-02 6wire HYbrid stepper motors driven by > ULN2003a 2 wire drivers unipolar. This seems a bit puny to me, or your are geared down pretty slow, and with the voltage limits imposed by those drivers, it is not going to be very fast. To move fast with steppers, you need high voltage at the driver, and the driver needs to enforce the currant limits via high speed choppers. The xylotex board can handle up to 2.5 amps of motor at 28 volts applied, and I have used them myself, but the A3977 IC that is the heart of those does have a tendency to fail with popping noises. That will drive a nema 23 motor at 250 oz/in, direct coupled to the screw, in can move a 20 tpi screw at 10 ipm while doing a reasonable cut. > I am using a HY-JK02-m breakout board Link? Not at all familiar with what you have in upside down country. I've got a pair of CNC4PC's C1G interface boards, nice, leds on all signals so you can see whats going on pretty easy. > My Computer is a HP thinkcentre Pentium iv Running Linux 10.04 only. If you have installed using the cdrom image from linuxcnc.org, Follow that instructions to run latency-test to see if that machine is a good candidate, quite a few motherboards do not have the required steadiness of Irq timing that it takes to run LinuxCNC well. This translates to losing top speeds because the uneven heartbeat leads to motor stalls. The usual for the man pages is man 9 latency-test for instance. Then post the "jitter" results. > The machine has been built for a year but I have been trying to sort out > the computer side ever since (Except for four months touring the > Murray and Murrumbidgee Rivers and cruising around New Zealand, I live > at Deception Bay in Australia.) I've had enough of Arduino. The Arduino's generally don't have the muscle, but sitting in the bull pen for linuxcnc is the BeagleBone Black, occasionally letting out a roar we hear about on this list. It has copious I/O facilities and some features that promise to run steppers even faster than we can on an Intel Atom motherboard, which I am using 2 of here. Interface capes/breakout boards, whatever they are called on the "bones" are in final development, sample boards at the board houses from several of this lists suppliers. So watch the list, when they are ready for sale, the announcements will probably be right here. > Thankyou for your quick reply As I said, welcome to the list, Bill. I hope you will find it useful, I sure have. And I could use some company in the old farts camp, I am halfway around my 80th trip around this star we call the sun myself. > Regards Bill [...] 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) Genes Web page <http://geneslinuxbox.net:6309/gene> NOTICE: Will pay 100 USD for an HP-4815A defective but complete probe assembly. ------------------------------------------------------------------------------ Subversion Kills Productivity. Get off Subversion & Make the Move to Perforce. With Perforce, you get hassle-free workflows. Merge that actually works. Faster operations. Version large binaries. Built-in WAN optimization and the freedom to use Git, Perforce or both. Make the move to Perforce. http://pubads.g.doubleclick.net/gampad/clk?id=122218951&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
