On Tuesday 07 February 2017 10:32:39 Greg Bernard wrote: > I believe that distribution is for GRBL, not LinuxCNC.Probably the > Protoneer BOB would be most > appropriate. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >++++++++++++++++++++++ "Anyone who believes exponential growth can go > on forever in a finite world is either a madman or an economist." > -Kenneth Boulding, economist > Corporations are NOT people and money is NOT speech!
That is LinuxCNC that I am running on an R-pi 3b, with a $60 Mesa 7i90HD "bob", but the pi doesn't have a "parport" per sei. The 7i90 can be driven via a full epp parport, but the spi bus is faster, so the pi's best interface to talk to the 7i90 is rpspi.so, designed to drive the 7i90 with any spi based firmware loaded into it. This interface runs at 32 megabits when its exchanging data, but the linux spi module is not functional at that speed. Mr Martinjak (sp?) has that driver. I have some steppers driving an 11x36 Sheldon lathe, and I'll still have about 45 pins of uncommitted i/o left by the time I get the rest of the home & limit switches installed. Whats not to love? $35 for the pi, $60 for the 7i90, and less than a $20 for a SpinX1 to run the VFD if you have one. If you want to thread, then you'll have to make and hook up, a spindle encoder. With a ferrous metal bull gear on the spindle, thats a bit of alu made in a curve that matches the gear diameter to hold 3ea, ATS667 hall effect devices about 2mm from the gear teeth, with some means to vary the sideways separation of one of them for the best quadrature signal on a dual trace scope, or even on the halscope thats part of the LCNC install. That gives you the ability to thread at any pitch your threading tool can handle. Metric, USS, SAE, Whitworth,,... Its all math in the gcode, the machine doesn't care if its in snickerdoodles as long as it can translate it to mm's, inches or furlongs. 2 of them generate the quadrature timed s/b signals as the gear teeth go by, and you glue a piece of a steel screw whose tip is in line with a tooth on the gear and that ATS667 is mounted off the edge of the gears teeth so it only trips on the passing screw, and thats used as the once per turn index signal Your time to make it is way more than the cost of the ATS667's. In my case, the gear has 60 teeth, and every edge is a time reference, so thats 240 known places, or a pulse every 1.5 degrees the gear turns. Thats more than accurate enough to cut some very precise threads, at any tpi you want. My small mill has some round insert nuts that I use to take up the end play in the ball nut holders of the xy table, no flanges, just bare ball nuts. With a conical section on each end of the cage I made to put some squeeze on a felt wiper, and no means of locking the adjuster, so I made them with 50 tpi threads. Except for taking them up once as the felt crushed into shape, they've stayed put. And what was once a $400 hf toy mill now does .001" tolerance carving if the tool is fresh. > From: Abdul Rahman Riza <[email protected]> > To: Enhanced Machine Controller (EMC) > <[email protected]> Sent: Tuesday, February 7, 2017 6:46 > AM > Subject: [Emc-users] linuxcnc on raspberry pi 3 > > Dear All, > > I have successfully installed linuxcnc on raspberry pi 3 using image > from here > http://wiki.protoneer.co.nz/Raspberry_Pi_CNC_User_Interface_SD_Card_Im >age_V3.00 > > I want to build 3 axis vertical milling cnc for wood using gantry, my > question before wrongly purchased component is: > > 1. What is the best compatible breakout board using raspberry pi3 ? Mesa 7i90HD > 2. Is there any list of stepper motor compatible with raspberry pi > 3 using linuxcnc? You can use any motor and suitable driver for that motor, that is big enough to get the job done. Don't use too big a motor as the max speed goes down with the size of the motor going up. For a gantry, I'd drift toward one of the newer Nema 24 offerings. I just bought an 8 wire that is about the size of a 235oz nema 23, but its a nearly 400oz motor. You didn't mention the size but the mass of what you are moving will have some effect on the ACCEL settings in the .ini file. > 3. what is the best touchscreen for linuxcnc using > raspberry pi3? Most touch screens I have come in contact with have a slow (9600 baud) rs-232 interface, so you'll need a db-9 to usb to make use of a touch screen. I have 2 such monitors but am not using then on a machine so I'll not comment further. > 4. Is there any basic algorithm flowchart to build > cnc? Just install it from the repo with apt, no need to build it. Put this line in your /etc/apt/sources.list: deb http://buildbot.linuxcnc.org/ jessie master-sim Then sudo apt install linuxcnc done, start configuring it for your machine. > 5. is there any cheap and compatible tool changer for raspberry > running linuxcnc? Generally those are shop made to fit the machine. Theres lots of pix on the web to steal ideas from. > Many thanks for you guys help > > regards, > > Riza > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
