On Saturday 14 October 2017 04:38:57 John Dammeyer wrote: > As I recall, there was a specific comment that lathes were not yet > supported. For now I think I'll leave it alone because even if it > were supported there are so many things on my plate that I wouldn't be > able to test it anyway. Unfair to put pressure on Charles or anyone > to get something working and then not use it. > > Going way back 10 years to when I first started the E-Leadscrew > project, cost was a factor to adding electronic gearing. One of the > costs was a decent quadrature encoder with 250 lines to fit the > spindle. Turns out the encoder disk wasn't that expensive for the > size spindle of the SB 10L. Only about $70. But I'd have to buy 100. > That put it out of reach.
John, who buys this stuff?, Make it, that IS what we do. I found some code in our wiki.linuxcnc.org for an optical interrupter style of encoder that I used for a model to make wheels for TLM, then added a slot because there was room for it, to the G0704's encoder wheel. I had put ball screws in the xy of my expanded micromill quite some time ago, so I had fair accuracy there, and I made the wheels for both TLM and the G0704 on the micromill. Bought a sheet of brass intended for door kick plates, and experimented with mill sizes, and slot spacings until the output was usable. IIRC the slots are actually wedge shaped. I put the index slot inside the circle of outside slots so the opto's could all be in a row on the board, even made the dbl sided pcb's on the micromill using eagle to generate the gcode. That way the center opto is the index. One of the later versions of that code for a smaller wheel is here: <http://geneslinuxbox.net:6309/gene/Genes-os9-stf/LCNC/genes-encoder.ngc> And thank Lester of course. Then for the Sheldon, I just put some (mumble)667's on an alu carving that matched the OD curve of the big 60 tooth bull gear, so I have 240 edges per rev to drive the rest of LCNC with. I gooped a screw to the side of the gear for an index pulse generator and put a 3rd 667 offset sideways to make that pulse. I'm retired, on SS and can't afford to buy that stuff, and 99% of the time I'd have to make adapters anyway, so why not just make the whole thing? Time is the one thing I usually have enough of as I've got till whenever I miss morning roll call for good. Thats my only deadline. > An alternative was an encoder driven by a toothed belt and pulleys > from the SB spindle. Again, cost of all the bits and pieces for that > came close to the target price for the ELS which back then was only > $150. This was all before Beagles and Pi modules. I think I have less than $200 for raw material in all 3 encoders that I've made so far. > At this point if I did add a Beagle to do CNC on the lathe I'd want to > include the 4.3" touch screen cape and use a similar interface that I > have for the ELS. I just don't have a need for a CNC lathe. CNC on the lathes, both of them, has been a net time saver for me once the code is written. It took about a week to write the code, and 10 lbs of scrap steel carved up for test fits, and a day to fine tune the cutting tool, to swap the about shot out and pitted 30-06 Ackley Improved barrel in old meat in the pot out for a fresh SS barrel in 6.5mm tight twist and chambered for a 6.5 Creedmoor. Hornady's new 143 gr ELD-X bullet works well, in bad windy weather, the first group will put venison in the freezer on any day of the week, from any range I can guess accurately enough. And its a heck of a lot easier on an 83 yo shoulder than the Ackley-06 was. Old meat in the pot is a P-17 Enfield, with square 10 tpi threads. You can't buy a tool to carve that. And you don't want to write code thats carving up a $500 barrel, without being sure it fits by carving scrap shafting first. That was harder stuff than the barrel itself was. > And to be truthful, for the amount I use the lathe and the number of > metric threads I cut the ELS is the perfect solution. Perhaps one day > I'll find a project that requires both Z and X to be powered and has > to do more than what my ELS does. But for now, the biggest issue with > turning is pulling out the spiral bits of metal as the lathe cuts. > > Thank you for the suggestion. I know it's something that should be > followed up. > > John > > > -----Original Message----- > > From: Jon Elson [mailto:[email protected]] > > Sent: October-13-17 10:01 PM > > To: Enhanced Machine Controller (EMC) > > Subject: Re: [Emc-users] MachineKit on the BeagleBone Black > > > > On 10/13/2017 05:13 PM, John Dammeyer wrote: > > > The desire for the Beagle with me was originally that with > > > LinuxCNC and > > a > > > quadrature encoder on the spindle along with the hardware QEP > > handled by > > the > > > PRU we'd have an awesome little lathe controller. Alas, that's the > > one > > thing in > > > MachineKit that hasn't been addressed yet. > > The PRU code by Charles Steinkuehler definitely supports > > encoders, if you tell it to instantiate one or more. > > I don't know the particulars, but they are in the PRU code. > > You might send Charles a message, he is VERY helpful. > > Once the encoder is instantiated, it is just a matter of > > hooking the right hal pins to the pins exported by the PRU > > driver. > > > > Jon > > ---------------------------------------------------------------------- >------ -- > > > 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
