NickJ Posted July 16, 2022 Author Share Posted July 16, 2022 11 hours ago, ajg193 said: Take a look at clough42's videos on youtube, he has some decent stuff that is relevant Oh, there is a stack of content there, cheers! Do I spy your lathe mods inspiration? Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 17, 2022 Share Posted July 17, 2022 On 04/07/2022 at 22:26, NickJ said: Fricken mail day! 7i77 6ch servo control board and 7i92 Ethernet board. 8ch relay output module, I expect many more of these to end up in the system, this should be enough to get started..... On lesser (But way more important issues) Loading Linux onto the computer has been a ballache of learning about stuff I care little for. It turns out Debian(OS) and linuxcnc are not friends which I lost a few evenings trying to figure out, that lead to a copy of Linux Mint being wired my way "Just hit load" Yeah right Kept getting a "Grub2" error, who? what? eh? So i've now learnt more acronyms that still mean little but the gist is; -Enable legacy boot (in BIOS) -Custom install partition table -reserved BIOS, swap and main partitions With the OS loaded to the hard drive, a healthy reward was the latency dropping from well in the no go range to well inside the preferred range, stoked. Another weird issues was the cheap VGA adapter, for some bizarre reason boot screens don't pass through meaning I had to borrow the girlfriend's office monitor to fiddle in the BIOS, this had me thinking I had bricked the computer until sanity suggested the logical problem solving technique of trying a different monitor.... Slow progress, but moving forward and closer to hardware movement! Good morning friend. Why didn't you install that pre-compiled (I think thats the word) version of linux that has linuxcnc pre-installed? That's what I set up on mine and it works great (jitter is a bit shit but within acceptable ranges) Does that pendant interface with the mesa card? Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 18, 2022 Author Share Posted July 18, 2022 11 hours ago, flyingbrick said: Good morning friend. Why didn't you install that pre-compiled (I think thats the word) version of linux that has linuxcnc pre-installed? That's what I set up on mine and it works great (jitter is a bit shit but within acceptable ranges) Does that pendant interface with the mesa card? Yeah so i tried the latest LinuxCNC version but it just didn't want to fly with my computer, I had some potential causes rattled off but my inexperience could not comprehend what i was being told. In the end, the good man who is helping me gave his custom Mint setup which in comparison loaded happily, as I have no idea exactly whats going on, working = good and i'll just keep running with this option (until is doesn't). Yip, the MPG will wire to the Mesa 7i77, i'm not 100% the exact pinouts just yet, but i'll get to that in time. 1 1 Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 18, 2022 Author Share Posted July 18, 2022 Successful weekend with getting all axes to move via Linux, unsuccessful due to hopes and dreams wiring. The old controller used a 4 wire feedback loop, what appears to be each phase of the encoder ChA,Chb,Ch0 + gnd, I took a massive assumption and just hooked each phase up to the 3 positive inputs on the Mesa card. Nope Nope and Nope, although open loop shifts things (I obviously got the AO signal and enable in the right place) into closed loop just ends up in runaway, or as i term it, a good test of the E-Stop circuit.... Thankfully in the folder of schematics there is also the servo drive tech sheets Digging through the wording, the drive bounces the raw encoder signal out pin 19,20,33,34,35 and 36, it is these that I should have used. Today I picked up 12m of CAT6 which should do the trick, now for a spare day to open up the fiddly little connectors solder and route to the Mesa.... While I had everything powered up I messed about with the air controls a bit more, using clippy leads I went through the control solenoids one by one to see what actually worked, surprisingly I managed to get the spindle to release and grab a tool holder, will need much more work to get tool changes running but its a slice of motivation I needed after the wiring woes. 6 1 Quote Link to comment Share on other sites More sharing options...
ThePog Posted July 18, 2022 Share Posted July 18, 2022 Piece of piss, told ya. 1 Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 18, 2022 Author Share Posted July 18, 2022 10 minutes ago, ThePog said: Piece of piss, told ya. Everything is such a bloody battle until I screw up, then its obvious that at the 50/50 chance of getting it right I chose wrong. 1 Quote Link to comment Share on other sites More sharing options...
ThePog Posted July 18, 2022 Share Posted July 18, 2022 There will probably be a kind of a watershed moment when things click together in your head, however banging about in confusion is required for an unspecified amount of time. 5 Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 18, 2022 Author Share Posted July 18, 2022 You understand how much i'm banking on this then! So getting the axes to work is pretty good as once one runs, its pretty much copy/paste but..... The X is 3.5m long and currently half buried under usual shed stuff so its out for testing on. The Y is 1.5m but if running away would smash the side of the Datsun. Which leave the 250mm of Z as the obvious to test on, except it has a brake which if released too soon dumps down to full negative, tripping the overtravel alarms and because I never noticed, then spend an hour trying to find why the servodrive enable contactor wouldn't pull in.... So the only way to test each axis is to drag the Datsun out into the carport, clear the table (just in case) and test on the Y axis. I'm reasonably confident that once running the VFD will be straight forward then a full dive into classic ladder to enable all the required pneumatics, my hope here is that there is pretty basic feedback so at least trial and error has a better chance of success compared with the software oddities currently plaguing me. Oh, and then a G-Code refresher Followed by hasty CAM refresher And likely forking out for Fusion360 to get all the toolpaths 2 Quote Link to comment Share on other sites More sharing options...
ThePog Posted July 18, 2022 Share Posted July 18, 2022 I can flick you some linuxcnc pathways for testing initially...? 2 Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 18, 2022 Author Share Posted July 18, 2022 Oooh, like calibration cuts, circles/shapes etc? Have had a thought in my head about how to verify certain things, if that is such a thing? 2 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 18, 2022 Share Posted July 18, 2022 39 minutes ago, NickJ said: You understand how much i'm banking on this then! So getting the axes to work is pretty good as once one runs, its pretty much copy/paste but..... The X is 3.5m long and currently half buried under usual shed stuff so its out for testing on. The Y is 1.5m but if running away would smash the side of the Datsun. Which leave the 250mm of Z as the obvious to test on, except it has a brake which if released too soon dumps down to full negative, tripping the overtravel alarms and because I never noticed, then spend an hour trying to find why the servodrive enable contactor wouldn't pull in.... So the only way to test each axis is to drag the Datsun out into the carport, clear the table (just in case) and test on the Y axis. I'm reasonably confident that once running the VFD will be straight forward then a full dive into classic ladder to enable all the required pneumatics, my hope here is that there is pretty basic feedback so at least trial and error has a better chance of success compared with the software oddities currently plaguing me. Oh, and then a G-Code refresher Followed by hasty CAM refresher And likely forking out for Fusion360 to get all the toolpaths It's f360 cam not free? Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 18, 2022 Author Share Posted July 18, 2022 Just now, flyingbrick said: It's f360 cam not free? yes, but they've locked some features away behind paywall, i'm not up to date on the details, but thats the way regular users have informed me. Also been told of loopholes via free internet courses which may be worth exploring. 1 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 18, 2022 Share Posted July 18, 2022 Yeah I had to pay to get the simulation features. Bloody expensive at near $100 a month Quote Link to comment Share on other sites More sharing options...
ThePog Posted July 18, 2022 Share Posted July 18, 2022 Yea I can easy do some setup paths. I get a pretty full version of hsm works with a f360 sub.... 1 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 19, 2022 Share Posted July 19, 2022 Test dick and balls Quote Link to comment Share on other sites More sharing options...
ajg193 Posted July 19, 2022 Share Posted July 19, 2022 Freecad Path works quite well these days, I use it for all my machining Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 29, 2022 Author Share Posted July 29, 2022 Last weekend I wired up the CAT6 cable to much better results. All axes return sensible values with movement until they're stationary, then the input starts creeping, it would appear I have a pretty large noise source somewhere. In chatting with men of greater knowledge it sounds like input noise, likely my 5V supply rail not appropriately earthed. So in the usual weekend mode i'll push all the toys outside, liven up the machine and have a poke around with the multimeter/scope. 5 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted July 29, 2022 Share Posted July 29, 2022 How do you earth a 5v supply rail... Damn that's got me confused. Do you mean the 5v power supply itself? 1 Quote Link to comment Share on other sites More sharing options...
NickJ Posted July 29, 2022 Author Share Posted July 29, 2022 5 minutes ago, flyingbrick said: How do you earth a 5v supply rail... Damn that's got me confused. Do you mean the 5v power supply itself? Just twist the 5V wire to earth........ Haha, yeah thats terribly written, I think the 5V supply isn't grounded correctly which has left the 5V floating, well at least thats the simplest answer to what is observed. 1 Quote Link to comment Share on other sites More sharing options...
Popular Post NickJ Posted July 31, 2022 Author Popular Post Share Posted July 31, 2022 WTF was I smoking and where did I leave it? Fired up the machine today and sure enough, same issue with axis creeping on the encoders, with multimeter in hand I started checking the obvious... 5V ground to system ground....30mV - Nope, not there. Utterly disappointed at this hypothesis being wrong I clutched at easy straws, 24VDC ground to system ground........ 30mV Control board ground to system ground....... 30mV OK, lets see how you like oscilloscope! Hmm, thats a pretty good square wave coming back from the encoder, for noise..... Almost as if the axis was moving............ The good old tape around the screw trick soon showed that yes, the axis is actually creeping, not just one, but all 3, last session I was sure to confirm nothing was moving, I have no idea how I missed this, but there you go, sane conclusion to that issue and even better, I have working encoder feedback! Next question then, why does the machine error out as soon as I try start it? first guess was the lack of limit switches, getting these wired up was quick and easy but gave a new error, active axis vibration, aha! I've seen this before, what PID values are in? It would seem that default PID values are P=50 I=0 & D=0, not sure I can do the best to explain here, these fancy values are what allow it to get to where it wants to be, in short with P set too high, the system will vibrate obnoxiously, dropping this to P=0.1 will have terrible response (more on tuning to come) but with stability. So dial in the change, hit the enable switch and everything behaved! Scrubbing up on g-code from many years ago I gave the machine a quick jog around and confirmed travel scaling is within tape measure precision, later on i'll dial this in better, the current plan is to just get things going. With movement in all three directions, I moved to the VFD, again, wiring had to be converted from sinking to sourcing but soon had the output reading correctly (to my understanding) Switching on power to the VFD I hit go at 1000rpm only to be greeted by the sound of a jet engine taking off! It would appear the go command gets through but the speed reference is not quite doing anything except shooting to the moon. I'm unsure if this is wiring based or VFD based but leaves the next move as going over the VFD wiring (again) and comparing that with the manual (again) which will then be confirmed with the VFD internal settings. 14 1 Quote Link to comment Share on other sites More sharing options...
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