Like most of you, I'm constructing my first CNC (an OX variant). However, I've run up against a number of issues relating to the NEMA 23 steppers which I can't make head nor tail of. My electronics & software fit out is: - Arduino Uno with Protoneer CNC shield & A4988s (DRV 8825s on order) - 12V PSU but have a 24V available if necessary - 2x 12V opto coupled mains relays - NEMA 23 steppers (23HS8430) - grbl 1.1 - Universal G-Code Sender Everything seems to run & function but I can't get the stepper motors to do what I expect them to do. I've dismounted a stepper for test purposes but when jogging an axis (I'm using Y) via UGS the stepper: - moves in large increments (8 steps per 360 degree rotation) - turns in the same direction regardless of direction it is commanded - swapping the polarity of the wiring connections at the CNC shield causes it to rotate in the opposite direction regardless of direction it is commanded The coil pairs are Black/Green & Red/Blue. I worked this out by shorting wiring pairs out and testing for shaft resistance. My tests also tally with the documentation that I've been able to locate so far. I've read through everything that I can get my hands on and I can't find anything that would assist in determining what is going on. Any help that anyone could give me would be greatly appreciated Rodney
12V is too low for NEMA 23s and StepSticks aren't gonna work either. Dump the CNC shield, get real stepper drivers. You probably could drive unloaded NEMA 23s with DRV8825s, but it's honestly just not worth trying. StepSticks are for NEMA 17 3D printers and not much else, realistically. Something like this should run them well: https://smile.amazon.com/STEPPERONLINE-1-0-4-2A-20-50VDC-Micro-step-Resolutions/dp/B06Y5VPSFN I know there's a... Bit of a price difference, but that's just the name of the game, unfortunately.
I am aware of the Blackbox Controller and in fact have been keeping it as a backup option. But I do have some issues with it - its designed to be a standalone unit whereas I've constructed a control box - it appears to run grbl, does this need to be loaded? How about 3rd party apps such as UGS? - there are no buttons for hold, resume or abort or more importantly E-stop - pendant support is somewhat mickey mouse However, none of these things are a deal-killer. The fact that its a tested & reliable turn-key solution has a lot going for it.
I was kinda aware that this might be the case. The entire build so far has been more chaotic than a plate of spaghetti. However, I'm pretty much at the end now. I've just got to sort out the electronics, complete a little wiring and build a spoilboard. The question for me now is proper drivers or a Blackbox. There's a lot to be said for a proven turnkey solution. However I do have some reservations about it.
Since you need 4 of those drivers, plus IO for running spindle, switches, vacuum, whatever else, it's basically a question of whether you want to spend $200 in one shot or spread it out over time. Personally I'm not a fan of integrated solutions, I like to limit failures to single replaceable components. It's the TV/DVD/VCR syndrome. Which isn't that bad here, since grbl is well-documented and characterised, and it's pretty easy to hit it in distinct steps: 1) steppers, 2) spindle, 3) limits, 4) everything else. An Uno terminal block shield is definitely your friend here. On the flip side, BlackBox isn't just a conveniently packaged Arduino+drivers+relay, it also uses OpenBuilds' new connector-based Xtension system so wiring everything up takes, like, an hour or two. Plug'n'play. And if anything breaks, they replace the whole thing after Peter has you run some tests. So the net result is effectively the same, though keeping entire BlackBoxes spare on the shelf is a little different to keeping an extra DM542 or two to minimize downtime. Of course you may consider "having" to buy OB limit switches a negative, which I would understand. "Ecosystems" in open source systems make me suspicious. But it's not like they also don't give you enough info- directly or indirectly- to be able to do your own thing in the future if you want to. "3.81mm pluggable terminal block" isn't hard to Google, and it's right there in the product description. Up to you!
Soft e-stop is a horrible idea What is an emergency? The PSU could be on fire, The router could have fallen out of the mount, a hand could be stuck in machine. A button that pauses the controller is a bad Idea, E-Stops MUST CUT ALL POWER (inline before power strip is the best spot)
You know, now that I read it I have to agree with you. BUT...of course there is a BUT , I like the way the e-stop just pauses the program from running. I used it many times when I saw a problem during the cutting (not going the pass I expected, bit broke and so on). I would like to keep that option and maybe add to that the option that the spindle stops too. But I do see the merit of an all encompassing stop and I think I'll add some main disconnect, re switches, on the front of the machine to facilitate the general stop. I have now two e-stops. I may add an off switch next to each of them.
I hear where you're coming from. Being able to drill down to faults in a single component means that its only necessary to replace the faulty part. Where I run into issues with the individual component aspect is that changing to 24 volts means that I need to step the voltage down for the Arduino & the opto-coupled relays. On the other hand, if I get the Blackbox, its all taken care of in one hit. In honesty, its been a long haul and I'm just keen to get the good bits... especially since I'm so close now. I sort of regret not going down the X-carve or Shaepoko route as I would have been long up & running by now. They probably would have shipped to NZ but I would've gotten killed on the postage & handling which I objected to. BTW I wasn't sure what an OB limit switch is. I've got the standard microswitches with lever arms, two per axis. Also I was under the impression that those Driver boards were capable of driving 2 motors simultaneously for single axis, dual motor operation.
You should be running a minimum of 24V for NEMA 23s anyway. Makes all the difference in the world on my NEMA 17s, I'd personally go 36V for 23s. The Arduino gets power over USB, don't need to worry about that, just the other components. I have a second dedicated little 12V 2.1A power supply for the laser, but it's wired in parallel to the mains with the 24V unit. Not a big deal, it's like $10 and I don't have to worry about it. It will likely also run a relay once I get the air assist line plumbed in and nozzle made. My laser machine, parts acquired in early 2016 and started building in late 2017, is only recently "usable" and slowly moving towards "finished". So I definitely get that! The advantage of this system is all the learning you get to do along the way, though. I feel like off-the-shelf kits hold your hand a bit too much and when something goes wrong, your diagnostic toolset is a little limited. Same. BlackBox has Xtension plugs for limits (Xtension Limit Switch Kit) - and everything else, for that matter. Wouldn't be a huge issue getting some plugs and wiring up your existing limits though, just gotta make sure there's good inline filtration. Theoretically they probably can, current-wise, but it's not a good idea. They're designed to monitor the feedback from a single inductor per phase, and would calculate wrong if there were two inductors interfering with each other. One motor per driver keeps things cool, smooth and quiet. BlackBox has 4 drivers for grbl's three-axis limit use too.
True but I found it to be impractical. If I'm monitoring the machine, but not standing by the computer, and I see a problem by the time I get to the computer, grab the mouse, move the mouse to the pause/stop software button and press it the problem is way beyond a small problem or even, with some luck, no problem. It will be a disaster.
grbl has a feed hold input on pin... A4, maybe? Somewhere around there. Technically that would be a better use of resources, but I tend to agree, I think in terms of "soft emergencies" and "hard emergencies". No reason there couldn't be a button for each, though a reasonably reachable lever switch would probably accomplish the same task- that's how it's done on big-boy machines, at least. If something's on fire, you have the extra 3 seconds to get to the switch vs the 0.2 seconds to stop the machine from killing itself.
Well, obviously I'm the nubie here so I can't really speak with any authority on the subject of E-stops. My woodworking gear uses E-stops to prevent you cutting your fingers (or worse) off so I understand what you're saying. However I'd expect that there's still an argument for something that temporarily pauses cutting operations. The gold standard for any milling job is that it starts at the beginning and carries out all necessary operations all the way through to the end without issues... in the ideal world. That probably happens most times but there's got to be once or twice when that doesn't happen. I don't see a hard E-stop & a soft E-stop being mutually exclusive. Why couldn't you have both? In my field of expertise (office telecommunication systems) there are usually multiple ways to achieve the same thing. There are usually nuances to the different methods which determine which best suits a particular situation. For example Call Forward & Follow Me do the same thing but one sends calls and one brings calls. Again, nuances.
Use the Door interlock terminal as intended to provide a pause/resume (refer notes in Grbl eource code) The original question was about e-stop specifically. And for that the argument stands.
Thanks for that, it cleared up a number of other uncertainties that I had. What would your recommendation be for powering the 2x 12v optocoupled relays that I have? I've done some experimentation with buck converters but they've proven to be less than useless. For me, this coming November will make 24 months in the building phase. I originally started with a basic OX kit that I've been heavily modifying loosely in the OX Metal style... but there were many aspects of that build that I didn't like so I went my own direction. I was also slowed down by being unable to find anyone that would 3D print the required parts that I needed. After no-one returned my calls, I ended up constructing my own 3D printer. This turned out for the best as I wouldn't have been able to do what I've done without it. That said, I have no intention of still working on this when the 24 month anniversary rolls around. Unfortunately, Covid-19 coupled with the fact that NZ is far away from anywhere makes trying to get specialist parts somewhat painful at the moment.
Easiest option? They're like $5, just get 24V ones. Save the 12V ones for a 12V automation project or machine. There's a lot of this in this hobby/industry. It's also why you can't be too hard on yourself for occasionally slow progress.
Thanks for that. I guess I'll have to go away and boil my head for a while and decide what path I want to to take. The problem with doing something that no-one around you is doing is that when you hit a bump in the road, there's no-one to turn to to provide you with informed commentary. Literally, no-one I know has their own 3D printer... and their own personal CNC?... not a chance. Once I get this bit sorted and working, I've got some other upgrades that I'd like to action. Top of the list is upgrading the Z-axis with a C-beam gantry cart so that I won't be limited to really thin pieces of stock. I published my Dust Shoe design onto Thingiverse today so that's no longer on my To Do list.
Hello everyone, I'm getting problems jogging the Nema 23 stepper motors in my new Yuyong Queen Ant using Blackbox X32 and OB Interface. The situation is this: When I try to jog the stepper motors using the Interface, they make a sound like "Tumb" and turn like 1 or 2 mm to one side and nothing more. Touch again the Interface bottom, and the same thing happens. If I let the finger on the Interface for long, after the initial "tumb" doesn't move anymore. The read out in the Interface changes the distance, but no move in the axes. Can you help me please, I have no idea what to do to fix this issue Thanks
Check your wiring and verify your coils are wired to the BB correctly, use a meter (resistance) or the short method to find the coil pairs, using color isn't reliable on many brands. Also some of your settings are not correct, such as $4=7 should be a 0 or a 1 and with BB $4=0 is correct and change $1=255 not 25 Cheers Gary
The wiring is correct, I've followed the documentation instructions and check for continuity with the multimeter. I'm going to try with the correct settings. Thank you so much Gary
Just another question, please When I power on the BB X32 the Interface lights up. Comes the logo (new design, bluish..) and start some lines until says connecting. After that restarts again and goes through the all checking until stabilizes in the normal display. Is that normal restart 2 times? Before the last update, it didn't do that.
Did you follow all the setup steps on docs.openbuilds.com/interface - for example if its a V1.4-1.6 Interface, did you remember the Retrofit Jumper?
Hello Peter The Interface is V1.7, so I followed the documentation accordingly but I had some difficulties with the Wi-Fi. Is it possible to restart everything from the begining or better leave it like that? Thanks
There are ways to start over, but that would not make a difference. V1.7 with firmware V1.57 should be pretty solid. Double reboot means something is not 100% normal but also not an issue - just means the power rails weren't settled yet.
Ok Peter, thanks, the less I mess with electronics the better it is. Anyway, I'm sending a video about what's happening, Thank you so much
