Escape from (VFD) noise?

That's no good. That just means we're both making the same mistakes.

That's curious... you're seeing up/downward deflection on the Z actuator itself? What sort of machine are you running?

It's definitely a step up from the xPro, and it'll handle bigger steppers too - so if the stepper is the problem, it's more likely to cooperate (although I don't know the details on that 425oz you mentioned). If the problem is something else, then the BlackBox would still be an upgrade, but might not be a solution. Mathing out the economics of that equation is going to be up to you.

Tell me about it

Y'hear that, Rob? He thinks I've actually got a clue!

Sounds like good news to me - at least in one regard. That means that whatever you're dealing with is not an EMI issue (or at least not a VFD EMI issue - and unless you've got a microwave running on the workbench there probably isn't anything noisier in the area). While I understand the appeal of discovering other people with your same problem, an infestation of RF gremlins really isn't the problem you want to discover. My system's been offline for a month now (well, it's been pretty much offline since before Christmas - but a month due to the noise issue), and, while I've almost got the enclosure & filter ready to try again, I have absolutely no assurance that the problem won't come back the a day, week, or month later anyhow.

In other good news, that test also (assuming I'm reading things right & you removed the whole spindle & ran it with the bare axis) means that the problem isn't the weight of the spindle either.

That's two big "maybe"s cleared up in one quick test.

Of course, now that we know what your problem isn't, the next step is figuring out what it is.

I think my first guess (err... my first next guess? next first guess?) would be to look at Rob's suggestion that the stepper is too big for the driver. Any chance you could swap in your original stepper (keeping the spindle detached for the time being, to simplify the situation as much as possible) & see whether there's any difference in behavior there? Or, alternately, swap with the gantry stepper & see whether the problem stays in the same place or moves.

The limit switches were specific to Semper's situation. Unless you're seeing messages saying the switches have been triggered when you know they're not being triggered, it most likely has absolutely nothing to do with yours. The blinky switches are a neat upgrade in their own right, but, again, they aren't likely to address the problems you're seeing.


-Bats
(if, on the other hand, your biggest problem is insufficient blinkyness, the switches are a huge step in the right direction... and the BlackBox has some even nicer blinkers on it.)

 

I know the xPro is solidly on the weak side - especially for lifting a monster spindle - but weren't the v3 & then v4 pretty much Openbuilds' go-to controllers for everything (including NEMA 23 builds) up until recently, when they launched the BlackBox?

Then again, that could explain why my v3 is struggling so much to drive the toy lathe's steppers. I'd assumed it was because they were some weird 90s industrial surplus score & just weren't suited to the controller - or the task - it in the first place.

Maybe he does have one of my problems after all!


-Bats
(now to determine which "weird one")

 

Oops! Looks like I completely missed the word "shield" there, and assumed the Arduino was acting as a sender for the V3 xPro.

So, yeah. That driver's going to be feeling a trifle inadequate when it looks up at those big steppers (especially that horse-like 425oz) - probably no wonder it's having trouble getting it up.

After getting that clarification and innuendo out of the way, I'm going to defer to your earlier analysis and say that the BlackBox is probably the best way to kick things off, regardless of spindle size. Might as well throw in those blinky switches, too. They're still not related - or strictly necessary - but it'll save worrying about false trips from the VFD somewhere down the line.

And they blink.

It's probably for the best, since I was starting to run short on guesses... although it also occurred to me that, depending on settings, GRBL likes to shut off the power to idle steppers, and it might be letting the spindle drop between passes. If, of course, it were a weight issue. Which we probably already eliminated. And if it were idling between passes. Which it probably wasn't.

So, yeah. It's time for der Blinkenboxen.

The fact that it is a lathe - and a tiny lathe at that - means I can get by with rapids approximating a turtle whacked out on valium and still do things like this:

(my test pieces are ever so imaginative and inspiring, ain't they?)

...so it's not a showstopper, but it definitely wouldn't fly on a CNC mill, never mind a router or 3D printer.

I stuck a camera underneath to grab some snaps of the nameplates, but (not entirely surprisingly) couldn't track down any datasheets.

I don't remember much of my stepper math, but the combination of that 6V rating and the six wires hinting at unipolar motors makes me suspect the motors are more of a problem than the xPro. Then again, I think I'm still running with half or quarter-stepping right now, so moving to full-stepping would likely squeeze a bit more speed & power out of 'em.

Or I could always just replace the steppers...but somehow that feels like cheating. And I'm already cheating by not using the old driver system.


-Bats
(...and I learned from my ex-girlfriend that two cheatings don't equal a not-cheating)

 

I've always made a point of staying far away from Bobcad (the company, more than the software), so I can't say first-hand, but if it has a generic GRBL postprocessor (and even if they don't have one included, I have to imagine someone on the world wide innertubes has put one together), then you should be able to use the output from that with CONTROL without any trouble.

I know there are some more heavily-modified Openbuilds-specific posts out there for various software - and I ended up making a lot of tweaks to the posts for Aspire & Fusion 360 for myself (mostly because I'm picky about my gcode readability) - but unless Bobcad does something really wacky, the generics should give you a solid functional base to start from.


-Bats
(an better question might be "is Openbuilds compatible with high-pressure sales and Scientology?")

 

Canned cycles are another other big area that's missing. I don't know about Bobcad, but I know Fusion sometimes likes to use canned cycles when you set up identical pieces with different origins, so that might trip up someone using a linuxCNC post.

I seem to remember CV mode also being unavailable too, but that's easier to live without.

It also skips out on all the variables, loops, math, and anything else that might let you mistake G-code for a programming language... but if you make much use of those features you're probably better equipped to write or modify your own post than I am.


-Bats
(of course, those are exactly the things I never had any use for, but suddenly find myself missing lately)

 

A brief on-topic interruption...

The enclosure has been languishing on hold half-finished for a week or so until I could get the ribbon cable and a 13/16" (step) drill delivered.

The ribbon cable showed up today. Delivered along with... an empty envelope.

Thanks, Amazon.

So... any great tips for making holes in .085 steel without the right bit (or boring head)? It looks like the biggest thing I've got is a 3/4", which won't fit the fittings I have on hand, and I'm really not looking forward to making up the difference with an old, dull, mistreated, and thoroughly inappropriate file.


-Bats
(I guess this is what happens when all the Amazon workers go on strike and Jeff Bezos has to figure out how to seal envelopes himself)

 

Hey, @Peter Van Der Walt - think you could drop me a line? I've got something I need to ask you about, but I'm having some trouble messaging you.


-Bats
(that, unfortunately, is very low on the list of "things I'm having some trouble with" today. most of the others are closer to on-topic... but not in a good way)

 

*sigh*

I don't know if Governor's still reading (and this post doesn't actually have anything to do with his problem), but remember how I said that this RF noise issue is not a problem you want? There's a reason for that.

It's back. And I don't know why.

It'd previously cropped up when I first started putting together the enclosure, but went away as soon as I ran the 120V line through the EMI filter, so I'd stopped worrying about it... but then, last night, after getting everything together, it was back.

Naturally it waited to crop up until I had everything nicely boxed up in the enclosure.

After unplugging everything else possible (only leaving the USB cable from PC to the Blackbox), I eventually narrowed it down to the LED ring being plugged into the Blackbox's PSU - something I'd never even thought to look at before, because it didn't even plug into the Blackbox. If it was plugged in, noise showed up in the logs whenever the VFD was turned on. If it was unplugged, no noise. Interestingly, the noise would get even worse if I also unplugged the power cord from the PSU - presumably the ground wire was helping to limit things.

As it turns out, the LED ring had a lot of extra wire coiled up (because I still wasn't sure where the PSU was going to end up mounted), and cutting that off seemed to make all the difference in the world - no more noise.

...until I boxed everything up again. Then, like the cat in the song, the noise came back. Again.

All I can guess at this point (and it really is down to guessing) is that there's a loose connection somewhere that didn't like where it gets wiggled when I cram everything into the enclosure.


-Bats
(worst of all, "the noise came back" doesn't even rhyme. maybe "the noise annoys"?)

 

I know neither of the two, but I have to imagine that in a corner-cutting design any components dedicated to noise-reduction will be the first to get dropped as superfluous - especially in a country that has little need for UL approval and even less to fear from the FCC.

Possible, yes... Pleasant? Oh no.

Not only do the two setups need very different settings - and, being utterly different makes & models, it'd take some work to even sort out just what the right settings are likely to be. That's the easy part, though. The two being tightly wired into mounted enclosures is what makes the whole idea so utterly unpalatable.

Also, though, there might be a c) to add to that list (although no easier to eliminate or A/B test). It hadn't occurred to me before (or had occurred, but the idea of testing it was so frustrating I blacked out the memory of it) , and that's the spindle. My suspicion is still the VFD - since it always seemed a whole lot noisier when I went poking around with a radio - but I don't have any easy way to conclusively rule out the spindle. Sure, the noise isn't present when the spindle's unplugged... but there also isn't any load on the VFD.

I'd tried moving it & the BlackBox as far from each other as I could, but without buying a longer VFD cable that wasn't much more than 10 feet, and with no useful obstructions in reach.

My understanding of such things has always been a little cursory, but somehow that sounds to me more like trying to manufacture a ground loop. Granted, I read at least one source recently suggesting that problematic ground loops are so rare as to be nigh mythical... but it sounds more like the counterexample of what star grounds aren't supposed to be.

Incidentally, I did discover another "cause" the other night (I say "cause" because there've been so many that I thought were causes, only to have the problems still persist)... It seemed that when I unplugged the spindle's LED ring from the Blackbox's PSU, the noise all went away. Plug it back in, the noise came back.

My assumption was that the coil of excess cable (waiting for me to decide on the PSU's final resting place and/or the machine's final dimensions) was acting as an antenna, so, reluctantly, I cut it short, hooked it back up, and... voila! No noise!

Well, no noise for a couple hours of testing (it occurred to me yesterday, the spindle has probably logged more hours testing than it has cutting), at least. So, being (marginally) satisfied I'd solved it (again) and generally sick to death of the whole process, I boxed everything up (without re-triggering the noise this time) and hurridly (holding that thing one-handed at head level is hard) mounted it to the loft (stripping the head of at least one screw along the way... should've picked up some of your fancy pants special screws, but, did I mention being sick of this ? ).

Naturally as soon as I had it mounted, the noise came back (and, worst of all, I already used the line about the cat).

Unplugging the LED ring (with the now-truncated wire that'll no doubt give birth to a few new obscenities when it comes time to move/enlarge things) again made the noise disappear... again. Or at least enough to make it through an hour of testing and a ~20min test cut without interruption.

Peter seemed to back up my antenna thoughts, with the added observation that, forget the wire, the ring itself was a loop antenna around the noisebeast spindle itself... so for now I'm running in the dark and hoping things don't start getting noisy again anyhow.

He also reminded me that ferrites had somehow fallen off my shopping list, so I've got a few handfuls on order.


-Bats
(I'm hoping I can melt them down and forge them into a magickal amulet of warding against evil spirits)

 

Unfortunately I'm so far out of my depth here that I think I saw an angler fish swim by... I think I'll leave that sort of speculation to @Peter Van Der Walt.

Can I get by with a good rubber-booted president?


Right now the fourth wire in the VFD cable is tied to the spindle case at one end, and then to the enclosure & VFD at the other - and of course the shielding is also grounded. Are you thinking of something more?

An old friend of mine played (plays?) keyboard in a Magnetic Fields spinoff band. Given the rate they generated spinoff acts, I'm sure he would agree.

I feel like I'm getting lost... Are we talking about LED rings, ring grounds, or ring-shaped ferrites? Or insufficient caffeination?

I imagine a pair (or a pair of pairs) of LED strips could do the job just as effectively while abandoning/breaking up the ringyness of it... although I think the only options I have lying around are some 12V RGB strips (which would probably be more trouble than just picking up some new strips) or a bunch of loose LEDs (ditto) or some CCFL bulbs (because how better to fight an inverter than with MORE INVERTERS?) - although it's still an interesting question.

My bigger worry is that the LED ring/antenna still isn't the source of the problems, and that it'll just pop up again as soon as this particular facet is dealt with. I don't really know, either - I think the ring was plugged in throughout all (or at least most) of the troubleshooting, so it's entirely possible that it is the main pathway for the noise into the BlackBox...

But my luck doesn't tend to be running that way.

As can be seen from the fact that I'm heading out to the driveway to figure out the horrific screeching noises my car is making.

If the ferrite doesn't do the job, I'm thinking the whole issue can just be sidestepped with a 24V wall wart. If that still lets the noise in (through a transformer and over the mains) then I may think about caps. Or I'll just give up on the ring and build a fire on the spoilboard for light.


-Bats
(wait... that's not an angler fish - it's a batfish!)

 

But you're able to speculate.

I, however, can only flail around blindly in an uninformed attempt to guess.

I'd loan you my old VFD, but you'd need a spindle and a magic smoke refill before you could scope it.


Some day I need to dust off my scope, get some probes, and try learning to actually use it.

Any idea where I can find a copy of 1940s Naval Oscilloscopes for Dummies?


-Bats
(and that's assuming the tubes are all good, of course...)

 

There actually was a fair bit wrong with this analog scope - not least that the tube of the CRT had been ripped out of the (boot? plug? fitting? thingy? whatever you'd call a thing that holds the glass part of a CRT, has all the contacts, and gets plugged into a socket), leaving nothing but a bunch of bent wires (pins?) sticking out.

I think the biggest problem, though, was just the lack of probes & lack of a clue where to stick said probes.

Err... where else to stick said probes. Sicko.

So would this be approximately what I'm looking for? https://www.amazon.com/dp/B07MBN1PS6/

If you've got it connected to the right place, at least... I think the other problem was just a general lack of confidence in blindly connecting this big untested 120V antique to random bits of dainty little 5V electronics without any spare replacement smoke . At the time, I believe the plan was to buy or breadboard some sort of simple wave-generating circuit so I'd at least know what I was supposed to see, and then go looking for it.... but bats are easily distracted animals. And from what I remember, at that point in time a few bucks worth of components & the breadboard to put them on may well have been out of reach (the then-broken scope itself having been an "I'll pay you to take it" sort of fleamarket score from my brother).

The financial constraints no longer exist (or at least aren't that constraining), but the distraction? Well... that may still be a struggle.

Still, at least now I've got a reason to get it running....

I've looked into picking up one or another of the cheap little digital scopes at least a dozen times over the years... but somehow the research always gets out of hand, the decision never gets made, and the scope never gets bought. I'll keep that one in mind, though. Maybe if that "please buy stuff so the US economy doesn't self-destruct" check ever shows up I can celebrate by sending some of it off to China.


-Bats
(aka the "please spend me on a used Bridgeport" check)

 

Ahh... right. The $8 50 ohm probes that are neither $8 nor 50 ohms. Ordered.

(or, well, actually I grabbed a 2-pack that was $5 less and had a few more reviews... but they looked to be the same specs - and probably came from the same factory in Guangzhou)

Don't mind the dust *cough* but here's the front panel (which I think I mostly understand):



...and the top panel:



...and the surprisingly pristine back panel too, just for good measure:



Feel free to point it out... or to point out anything else of interest, really - I'm kinda in the dark here.

Oh, right... divisions... that's the other thing it doesn't seem to have. No reference grid or anything of the sort - just a green line (or dot, depending on which knobs have been twiddled where). I suspect there was originally some sort of overlay, but it was gone before I got my grubby little hands on it.


-Bats
(...which were considerably grubbier after they'd been on it)