- Brewery Update
- Pump mount design completed
- 3D printed brackets
- Bending tubing this week!
- Need to finish the last bit of wiring in the electrical box
- Python PDF Creation
- Why do they all suck?
- Currently using fpdf
- CNC Update
- Still need to get the X-axis moving
- Sprockets to weld on
- Will try rotational tig welding
- Midi to G-Code
- Motor Cable
- Igus 16/4 plus braided shield
- Best way to attach the shield?
- Rack Mount Amplifier
- Replaced the transformer last week to boost the votlage
- Went from a 12:230 to a 10:230 ratio for a 20% increase
- Output changed exactly by 20%….go figure!
Rapid Fire Opinion
Special thanks to whixr over at Tymkrs for the intro and outro!
About The Hosts
Parker Dillmann is MacroFab's Co-Founder, and Lead ECE with backgrounds in Embedded System Design, and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. He also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components. Parker graduated with a BS in Electrical and Computer Engineering from the University of Texas.
Stephen Kraig began his electronics career by building musical oriented circuits in 2003. Stephen is an avid guitar player and, in his down time, manufactures audio electronics including guitar amplifiers, pedals, and pro audio gear. Stephen graduated with a BS in Electrical Engineering from Texas A&M University.
Host 3 00:10
Welcome to the macro fab engineering podcast. We are your host, Stephen Craig and Parker Dolman. This is episode 215.
Host 2 00:18
Whoo. Okay. So I think tomorrow when this podcast comes out, comes out, like I have a webinar. So come bug me. Oh, this
Host 3 00:28
Is your, your first webinar, right? Yeah, be my first webinar. So I'm bound to mess it up. It's a swarm like everyone join up.
Host 2 00:38
Yeah. So I was gonna, I was gonna post it in our Slack channel, and see how many people I can get the show up because I got to beat everyone else that's been doing these webinars. I think Chris church did one. His was the first one. And then I think Chris Mullins did the second one.
Host 3 00:52
Chris church is the CEO and Chris Mullins is he does sales something. Something like that did like in sales engineer or something like that? I don't know. I've never actually met him. He was he was post my time.
Host 1 01:08
He does a lot of of everything, I think. But I'm actually looking at our About Us page. Like see what his official title is.
Host 3 01:18
Yeah. Because everyone has like a really swanky title at Mecca. Yes. Senior Vice President of Sales. Yeah. Okay. So yeah, new sales was in there somewhere with him. Yeah. But he's a but he's a trained engineer, right? No, no. I thought he had that he was a degreed engineer. No. Oh, okay.
Host 1 01:35
I don't think Mullins. I might be incorrect, but I'm pretty sure he does not have a degree in engineering.
Host 3 01:41
Well, if you're listening Molad Sorry. Yeah.
Host 2 01:44
Well, he also listens to this podcast like, right when it comes out. So
Host 1 01:47
Does he Okay, pardon me, you're running to my desk tomorrow. When he when he listens. He's like, I
Host 3 01:52
Have a PhD in engineering. See, I've actually I'm looking at the Bell this page, I actually had the longest title. Oh, God, really not any more and more stuff to it. Because like co founder, lead application engineer, and in podcast co host, so I need to keep adding more and more stuff on there. Yeah, yeah, you need you need more projects to get more more titles or titles. And so the webinar that you're doing is, I think we talked about it last week, but it's just in general, it's kind of like people can join up and hang out and ask their questions. How does the platform work? What does it do for you? That kind of stuff? Exactly. Yeah. Cool. But there's no like set agenda. I guess.
Host 2 02:40
I think the agenda is to go there is like bullet points at the hit. Like you're showing how the platform works for like, like salespeople, or how it works for purchasing managers, or how do how does an engineer use it?
Host 3 02:52
But but it's, but what I'm getting at with no set agenda is not like, people log in and watch you just walk through a PowerPoint. Correct? Yeah, it's not like it's not because you'd have like zero people.
Host 2 03:03
Yeah. So. Okay, so I've been working on the brewery finally, it's inching closer and closer and closer to brew dates, right?
Host 1 03:16
Yeah. brew day 2021. optimistic. Hey, it was supposed to be done on the at the end of 19. A, ya know,
Host 3 03:27
So I got the pumps mounted. Oh, cool. I ended up using that aluminum on a because I said it had some like quarter inch aluminum leftover from a previous product project, finding out that you had the same thing and you use your leftover aluminum for mounting the spindle on your CNC. Well, I ended up using it for different projects. So why would you would you make your brackets out of or did you go buy new material? I 3d printed it. Oh, okay. Yeah, so I'll share the model and stuff. I'm going to start I'm gonna print one tonight. So I modeled it out of a, I guess at a bits right, you model it out of bits on the computer screen right. I'm going to print it up polycarbonate. It should be plenty plenty strong enough. And I've did like captive bolts. So that way like when I mount the bracket I can just mount I can take the pump on and off easily without having to you know, get a wrench on the backside.
Host 1 04:28
Yeah, it should be it should be plenty strong enough. Yeah, probably sharpen it. So
Host 3 04:34
Well, but but you do have these pumps hanging upside down. So you're fighting gravity all the time. Yeah. Yeah,
Host 2 04:40
I mean, as long as gravity doesn't decide to be stronger,
Host 3 04:44
Right. So so but the biggest the biggest thing is like the weight of the pump. It vibrates a lot when it's running and it gets moderately warm. That's the but your bracket simply fine. Yeah, that'd be fine. If not, then I'll just make him out something else. Oh, Ha, if he's not working, I can send it off to xometry and get him machined. Or you can machine them for me. I couldn't machine them for you. Yeah. So let's try that polycarbonate because I bet you it's gonna be, it's probably just fine. And if it's not, then we'll machine some out of aluminum. Your printbed is big enough to make like a monster bracket for these things. I mean, these fonts are not that big. They're like, What? The? Yeah, they're like I six inches like Yeah, four by six and then about an inch tall. Yeah. Well, about half inch tall. And then they weigh maybe two pounds. Two to four. Commerce.
Host 2 05:36
Yeah. Yeah, around that, that weight. They're pretty beefy, though. Have you ever taken the head off of the pump? Head off of one of those?
Host 3 05:45
Yeah, I do. I when I was brewing once a month, I would take it off. And I would go heavily clean inside because it's a magnetic head.
Host 2 05:56
Yeah, it's, it's interesting, because like, there's no shaft for the motor to go through. It's a magnetic rotational
Host 3 06:05
Thing. That's why they have to be primed. Because if it doesn't have the load of a liquid to push against, then the motor can just burn out. So be careful about that. Yeah, it'll just free wheel spin with no load.
Host 2 06:20
Yeah, that's why I'm mounting my pumps underneath the pots. Yeah. So it should be pretty easy to make sure that's the thing. You know,
Host 3 06:27
I've read a handful of things online before I bought my, my pump where people were like, don't even let it run for one second, without without liquid in it. And I've accidentally, you know, not had liquid or I was at the end of the pump. And it it finished the last little bit. And it ran for an extra, I don't know, 20 seconds or so it was fine. But like people were like, it only takes one second for it to blow up and it'll explode and you'll die. And I don't know, like, so be careful. But I don't think you have to be. I don't know, the internet's full of alarm. Yeah, well, I mean, even the manufacturer warns about it. So Right. Right. Because I mean, it could happen for sure it could happen. Yeah, it's just yeah, don't do a continuous. Yeah. So then that once I get these brackets printed, I'm gonna try printing on the night, I'll probably get that will be done by the end of this week. I want to get the, the pumps mounted and then start bending up tubing. Like I got that whole roll. I ordered 25 feet of rolled stainless half inch tubing and proceeded to unroll it straight and eight foot sections because trying to manage a 25 foot half inch diameter tube is a little unbearable. So I cut it up into eight foot sections and that's been like lying on the floor of my garage for like three months taunting me. So I need to get in there and get the pumps mounted and then all the tubing bends. And then once all the tubing has been just like finished that electrical box and mount that nice and then take it all apart so I can paint it and put it all back together. But that's like the homestretch. Like, the moment I get to that part, I'm like I'm not going to stop. I read like four o'clock in the morning, like spray painting stuff. Yeah. Oh, for sure. And then and then you go right into the brew, right? Yes, right. Right. Like it's like 72 hours of straight work
Host 1 08:28
Yeah, that's getting really close to being done. I can't wait. I'm hoping it's March now isn't it? Two to two hours two and a half months through 2020 Already Don't remind me
Host 3 08:44
Wow, the so we I asked this question before and I don't think you had like a specific answer. Maybe you've put some more thought into it. What's your first brew gonna be? Oh, so the I'm actually I got my my brew book here. Oh, yeah. He's black book, my black book of all my brews. I've. The best thing about this is actually I recorded my first brew day. I started brewing in April 2013. Oh, nice. So I want to brew if I can brew, April 6 2020. With my new rig, that'd be seven year anniversary. Oh, that's cool. So Well, then. Yeah, you should. Yeah, you got plenty of time for that. You say that. In reality, there is not a lot of work left on it. It's just like, fuck, like, I'm getting to roadblocks. Like, you know, when you're designing something, and you're kind of like, like, like you like my original like drawing for this was just like, on like an appliance schematic, right. At best. Like yeah, like, like, you draw it and you're like, yeah, that's should be doable, right? You get like 90% of the way done built and you're like, oh, Ah crap. There's something in here that like, is really hard to manufacture or make, like throws a whole monkey wrench and like, the whole idea with this system I wanted to build was making it really easy to clean. And then like I got it all built and I'm like, Oh crap, how do I get the grain out?
Host 1 10:17
It's like okay, crap. I gotta figure it out. I gotta design a crane now to pick the great the crane green. Pick it out.
Host 3 10:27
That's how you that's what you should call it the crane grade, not the crane crane. The crane crane, the crane crane? Yeah. Okay, that that needs to be like on a plate on the side. I'm gonna get a vinyl sticker on it. Oh, yeah, that works. Yeah. Oh, I should I should engrave a plate and send that to you. I will totally do that. Yeah. The brewery two years in the making, right. Oh, yeah. brew day 2021. Okay, yeah. So So yeah, we got off track. What's What's the brew? You're gonna do? Are you gonna do? Are you gonna do
Host 1 11:04
This? I just saw some. Wait, these are brewed security cards in here. Did you lose it seven years ago? No, no. I haven't been looking for it. And I just like,
Host 1 11:19
Well, now you know, now you can put it somewhere else and lose it. Why was it in my blue book? I have no idea. Or I brew notebook I should say. Okay. So my first brew I ever did was a.
Host 3 11:36
Let's see, what was it an American rye ale? That's a first brew. Yeah, maybe I should just read through this and see if it's was good. I don't have tasting notes. I just have like notes I took while I was brewing. Yeah. I'm just gonna go out on a limb and say it probably wasn't that good. Probably not. Just because it was your first one. And I've never met a single person who had a good first brew. Like I've had some 75% efficiency. Apparently. That's not terrible. What your first brew was all grain? Yeah. Oh, that's impressive. Most people do syrup. That's the Irish Red Ale was my next one that I remembered that beer was not good. I brewed a Guinness as my first one and it tasted like vinegar. Honestly, this beer was good. This this beer I called the Red Coat rebellion. IPA. Okay, it was a it was like a mixture between a English IPA and an American style IPA. So I had a nugget Erica pops with the grain bill of British grains. And this was my British friend was getting married. And so I threw this beer for it. That's cool. That was a really good beer. Like, a whole bunch of Norwegians were at the wedding. And they were like, oh, yeah, this is good beer. And they got like, completely shit faced hammer.
Host 2 13:06
It was hilarious. Like learning. I don't think they were used to beer being 6.72% ABV.
Host 3 13:13
Apparently. That's kind of hefty. For just, you know, like walking around a wedding. Yeah, yeah. I can do that. Um, do the right seven years in the making. Yeah, just brew brew that rye beer. Exactly. Like how I brewed it. Yeah, liberty and cascade. Is the liberties weird. Okay. Those are those are both hops. Yeah, no, but Liberty hops. Okay. For the listeners. Yeah, Liberty hops. I don't think I've ever burned anything with Liberty ever again. Maybe that's a sign that you shouldn't do. Yeah, maybe I shouldn't do that. Because I don't think I've ever breathed that one again. Yeah. There's that. Fat Elvis. Elvis is good. My mock Tober fest beer. I'll brew that. I liked that beer a lot. Yeah, and it's still kind of cool and quotes here in Houston. So what temperature is it right now? Is it in the 80s 7777
Host 1 14:18
It's actually really nice for 7070 it's like kind of cool. So I'll take you out for it. Gotta get that brewery done. So I got three weeks and that's my new target is the brew.
Host 2 14:30
Sounds like April 4. When is that? happens to be a Saturday?
Host 3 14:37
It's like destiny. stretch goals is get it done in two weeks. Yeah, stretch. So I can test it. Yeah, yeah. Get your efficiency up before. Oh, you don't want to have to figure out all the valves on brew day.
Host 2 14:55
I actually I wrote a, a diagram of valve map, a valve map. up. And I got I'm gonna 3d print little like arrows that I can put on the gate on the valves. Because all of them are like those three way valves, right? So I'm like, Okay, I need an arrow to point like where flow is going?
Host 3 15:14
Yeah, because if it's three way and you like, it matters, the sequence
Host 2 15:18
Oh yeah, cuz and because the handles are spin 360. Right. So. And then for work, I've been working a lot with Python scripting. I think I talked about this a couple weeks ago. And I've been doing a lot of like report generation and building PDFs, because apparently people still like PDFs, whatever.
Host 3 15:44
Why PDFs feel professional? I guess. So. They look nice. Is that what's that professional document format? PDF?
Host 3 15:58
Every single python module I've used for PDF creation absolutely is garbage. Why is that? It's just none of them makes sense. Like how you craft a, a PDF, I think it's it might be because a lot of them are like wrappers for other things. Like there's one PDF module that you basically build HTML in your, like, you build an HTML document. And then it converts that HTML document to a PDF. The one that I'm using right now is called F PDF, and it uses like tables to build PDFs. That makes sense. Kind of like an Excel spreadsheet.
Host 2 16:45
Okay, it's the best in quotes. One, I think, maybe was the first one because I or first one, I was able to wrap my head around how it worked. But yeah, they all kind of are not very good.
Host 3 17:01
So if anyone out there in Twitter or slack land has been using Python, the beat do PDFs. Let me know what you're using. Because all of them kind of suck.
Host 2 17:14
I'd like that. Make sense? Yeah. Write my own. Yes. Anyone wants a hardware engineers python module?
Host 3 17:24
Cool. What are the what all? What are you actually trying to accomplish with that?
Host 2 17:30
So building reports, like when we're sending out stuff for quoting or stuff like that, like right now?
Host 3 17:37
What used to be, you know, like gathering all the information that we need to send out to quotes and stuff, this just straight up automates it. So you're like, Okay, I want to quote this thing. I press one button, and it generates a report with all the information when it was time stamped version control all that stuff. Trying to automate that process. So we, you know, less mess ups and screw ups. And
Host 2 18:03
The big thing is revision control. Sure. So like, when was this dock? When did we collect all this information for quoting?
Host 3 18:10
I'm not actually asking this question. But like, sounds like there's a reason you guys need like, like a screw up or something like that. We're like, Okay, well, it's not really a screw up made this it was, I came on board to work with, with sales and logistics on like making their stuff more efficient. And that was one of the big things was like, they had everything everywhere of how they were storing information. And I'm like, Okay, we're going to fix this make one place where everything lives. And we'll make scripts to run reports. So you click a button, get a report, and then everything has been groovy. Nice. So the problem right now is like, if I needed to make a new report, I kind of like built a template in Python that I can like, copy paste around. Yeah. It would be nicer to have proper templates, though. But I might basically, I want to think you know, I need to do is make a module that uses FPDF.
Host 1 19:14
And it's back in, that's a template module. I got to figure out how to do Python modules. It's kind of
Host 2 19:24
Confusing how those work, I guess is a good way to explain it. I haven't been able to figure out how to make modules yet in Python. Like, because in C, you just like, you make a new C, you make a header file with all your definitions and stuff. And then you can just call you can just call your header file at the top of your other file. And then you kind of get everything right. You get what you use. You get what you use, where's Python. It has similar things like that, but I don't know how to make like a call function. Another Python file
Host 3 20:02
Yet, cleanly at least. What I found a dirty way to do? Well, yeah, this
Host 2 20:07
Is like you can just like, yeah, yeah, it's kind of a weird way, there's got to be a legit way to do it. Well, mainly because there's, uh, I mean, people make modules all the time, right?
Host 1 20:22
Yeah. Yeah. Python has to be able to do that pretty easily. Oh, does it just I haven't figured out how to do it yet. Yeah. So that's what I'm lap next at in my learning. Python is building modules now.
Host 3 20:33
Men. Okay, so, so a little bit of a side tangent, just what you were saying there kind of sparked in my mind the what you're saying about, you went into the department and notice that everyone was kind of doing disparate things, and they were jumbled all over the place. I think that's one of the most fun aspects of being an engineer and manufacturing is like going in seeing how everything is kind of just like, barfed all over the place. And then figuring out how to make the process such that at all, like congealed into something that makes more sense. Like I don't know, like making the process more efficient, and figuring out all of those little aspects. And especially figuring out what, what is being done that doesn't need to be done, or what needs to be done. That isn't those that's just really fun. I really geek out on that stuff. Oh, yeah, that's, that's, I mean, that's pretty much what I've always done at macro fab. So yeah. That this is my next next big task is like, solving this problem? Streamlining? Sure. Yeah. Like at at at WMD, when we got our new mill, and we purchased the mill with the intent of completely doing our own panel manufacturing our own, like front panel manufacturing. And we bought that mill and none of those processes were there. So I mean, I've spent a good portion of the last year, going from nothing to building the entire like, here's how we do manufacturing for panels. And, and what's been really fun is going from like figuring out how to just do it to figuring out like, how do we standardize around it? How do we do all of our file creation? How do we make it such that it's
Host 1 22:18
Bulletproof. And then now my like, I've word like, crank in production all the time. My main goal right now is to press the fewest amount of buttons on that machine as possible. Like, I want it. So I walk in, in the morning, I take what was cut off the machine, put new material down, press a few buttons, and then leave and repeat that the next morning. I don't want to do anything throughout the day on it. And I'm getting close to that. I mean, it's almost doing that every day now, like 24 hour runs on the mill. And I just don't even want to look at it, you can load that much material in there. Yeah, yeah. And our stuff takes a good bit of time to cut. We do have some programs that are over 30 hours of cutting. Just mainly, it's actually not I shouldn't even say cutting, we do so much engraving, because we integrated take a long text that takes so long, but it looks really good. And it's got a really clean look. And you can't scratch off something that isn't there. So it's, you know, it holds up better. Because with Eurorack synthesizers, the whole purpose is to like plug things in. And there's there's a phrase called rack rash, where you know, like, you're trying to plug things in in your head hitting all your panels with Jack's and things your brain is hitting stuff. Yeah, silkscreen is great, but it'll eventually chip and ink printing will chip chip and stuff. So we figured engraving is impossible. Like even if you scratch your panel, you can still read it. Yeah, you know, so. But the but the whole thing of like working with my vendors to provide material in like specific sizes that are perfect for what we need, and then working through the process to get it. So the programs are just like plug and play, man, like, even though it's diminishing returns, I love the hunt for that. Like, how can I save a little bit more time on this? You know,
Host 3 24:09
I think you should start diving into Python man, it really that's like, yeah, it I would say that scripting language saves me so much time. That's that's the next step for me in terms of this process building, because right now, I'm still doing a handful of manual code adjustments to make our programs right, but so at the at the time of generation, I have to do a little bit of copying, pasting. It's just a few characters. But I still have to do it. I would love to be able to have a Python script. Just do that for me such that I press go and it's there. You know, well, we could do a like a screenshare sometime in and I can show you how to do that because I know how to do that part. That'd be awesome. Yeah, let's do it. Okay, cool. Yeah, it's been a while. It's been a while since we've done one of those. The last one we did I think was a debounce code circuit. Yeah, we did. Yeah, exactly. Yeah. Actually, that was over a year ago, because I was. That was for the my micro tracer, the tube tester.
Host 1 25:14
That's right. Yeah. Yeah. So yeah. Well, we'll have to set that up that that would be a bunch of fun. Yep. Because we could probably knock that out in an hour or two. Oh, easily. Just because the thing that's, that's nice about it is like, I know, I know everything. I know, the inputs, and I know what the outputs need to be. I just need to connect the dots.
Host 3 25:34
Yep. Especially if you're like injecting like the same code. And you know, where it needs to go in the file. Like, let's say it's line like eight, it needs to go in line eight, or it needs to go like after a certain key? Yeah, you basically would, what you do is you would load in your file into into the python module into RAM, basically. And then you would look line by line until you find what you want. And then put it in your starters in Yeah, yeah. And then you would out output RAM. That's exactly what I need. So the specific line will be different for every program. But there are some key words that always show up in the same places like that, like every program starts with the word absolute. And then immediately after the word absolute, I add three or four lines of code. And so an absolute doesn't exist before that in the code. So I just need to find the first instance, instance of absolute and then dump some code in basically,
Host 1 26:44
We can do that. Cool. Let's set it up. And speaking of seeing, see, even your CNC is moving now, mostly, mostly moving,
Host 3 26:55
I say mostly because two of the axes are moving the third axis. So the x axis, which is the gantry axis, the main longest axis. I wanted to purchase new Sprockets for it, because it is a chain drive, and the old Sprockets I had were rusted and kind of gross because they were out in the Houston humidity. Yeah, I mean, they were outside. Yeah, effectively outside for years. Right, right. And frankly, I probably could have used them, they weren't in like awful shape, or anything like that, but whatever, I'll just buy new sprockets. So those actually just arrived yesterday. So tonight, I'm going to weld on the, those sprockets and get the x axis moving. But the other to the Y in the, in the Z axis I have moving, which is awesome. It was funny, because I can remember what we were talking about earlier. Oh, yeah, your your rubric. And like, you know, you have all the drawings and everything like that. And you're like, Oh, this is easy. And you get like 90% of the way through and it was easy. I ran into that, like, I've been working on this CNC now for a few months. And everything has been super smooth sailing until last weekend. And it was just like, I kept running into all kinds of like, just stupid things. Like always is to something you should have thought about. And you might not have the right partner anymore. Or I've ran into where like, I had to order parts and I went to go order like I had an ordered like three new like, like 90 degree bend, like stainless quarter inch NPT fittings, right? Yeah, go to the place where I normally buy them. They're all sold out. And I'm like, well,
Host 1 28:36
The EPS Yeah, well, like I built, I built this entire base for the thing went beautifully. I cut and built my torsion box. Not a single cup was bad. Everything just went together flawlessly. I made I ran to 20 in my basement and then made a sub panel and then ran all the electronics for the CNC and like never didn't do any double work on anything. Like it was all just like super easy sailing and then and then on the weekend I find that the plate that is the Gosh, what is it the z y axis plate. So the plate that holds the, the vertical Z axis that slides across the gantry in the y direction that plate was it could have been better. So I ended up just re fabricating it. And in re fabricating it. I drilled some of the holes, kinda crappy.
Host 3 29:36
Well, like it was one of those things where it's like a drill. I use a center punch in and drill them and it was like hey, this is great. And then I put a bolt through it and the bolt was cocked.
Host 1 29:47
Damnit, because I don't have a drill press that you would think that's something I would have but I do not. So I did that one by hand. Luckily like the actual, the holes don't. They just need to be generally in this in the right spot because they get tension So I just bought him open a little bit. That worked out, but the drill
Host 3 30:04
Bit in there and wait a little bit. And yep, that's exactly why.
Host 1 30:10
But then like, so I get all of that installed and everything's great. And I'm like, Oh, I've had my CNC computer for years. And I go to turn it on. Well actually, let me back up, I go to plug it all in and realize that it's, the motherboard is super old on it, because it was the last motherboard I could buy that had a parallel port on it. And I realized it only has VGA connections. So I go scouring my whole house, I can't find a VGA cable anywhere, because why would I have a VGA cable? You got rid of everything when you move? Exactly. Well, yeah. But also like, even then why would I have a VGA cable, so I gotta go get a VGA cable, and then I go to turn it all on. And it computer doesn't turn on.
Host 3 30:53
So, so eventually, like, I'm looking at the at the motherboard, and I remember that it has a CR 2032 battery for the BIOS backup. And I just replace that and everything fires up. So like, it was just crapping on the CMOS initialization. So it's just like, you know, it's one of those things where it's like, everything went smoothly until one day where everything didn't. But regardless of you know, overcame all of that, and I've been doing access calibrations on stuff just because I mean, all the numbers I had should be generally the same, but I wanted to redo it, because the last time I, I really spent time on it, I didn't have the same measurement tools I have now. And I was calibrating my Z axis just the other day, and actually using a micrometer for it, a dial mic, and I got it to go an inch, which is about as far as I can go with, with my with my mic. And it's within a 1,000th of an inch across an inch. Which, you know, that's if you're calibrating between two points on a CNC, you can make those two points flawless. So that doesn't define the actual accuracy of the machine. That means that between those two points, it's perfect, right? Yeah, but it's only perfect at those two points. So I made it perfect across an entire image. And then I did steps of a 10th of an inch in between there to check you know, what's its linearity in between those two points? And it's okay, it's not amazing. It's a few foul up and down throughout that. But that's, I mean, a lot of that could be due to the way on measuring it and things and who knows if I had my mic, you know, perfectly
Host 1 32:41
Perpendicular to it. Yeah, right. Right. Right. But But regardless, the fact that I can get an inch and I'm pretty close, the the, the thing that I was really shooting for was repeatability is like can I go an inch and then back an inch and then forward an inch and do that 10 times and it always lands in the same spot and it does do that so that's nice. So one of the things I'm actually excited about. So the the main shaft that runs through the gantry on this, this this CNC has the x axis stepper motors in the middle of the gantry and it drives a shaft on both sides. So a lot of a lot of CNC is now have the X stepper motor somewhere outside the actual gantry in fact a lot of times you see two of them that drive it forward and backwards this one's in the middle and so I have two shafts that that meat at the stepper motor and previously the CNC had couplers that just couple the shaft to the thing I ended up just welding them right to the to the stepper motor just because like Why use a coupler I don't care like I'm just gonna straight up weld it so I tack welded those on there. But what I'm going to try to do tonight because I've been wanting to do this for a while is have the stepper motor, just spin at a slow rate and then TIG weld a rotating shaft on to you know, like like a rotating table. Yeah, but but I was thinking about it like where do you connect your ground clamp if you have a rotating shaft and the shaft is through the bearings. Like I don't want to just connect it to like I don't know the mounting bolts of the stepper motor.
Host 3 34:28
So I guess I could try to get the ground clamp to spin around with the shaft.
Host 1 34:34
I think if you put it on the shaft Yeah. You I don't know how much power you will be pumping through but it just riding on it should be fine.
Host 1 34:43
For the show the shaft is quarter inch and then the actual shaft on the stepper motor is half inch. So I'm doing a quarter a quarter inch into a half inch and when I just tack welded it I used 100 amps and that, that worked out pretty well. So I don't want to send 100 amps through the stick.
Host 3 35:06
Oh, yeah, cuz, well, if you put it on the mounting bolt, it will go through the bearing. Yeah, yeah, I know. I don't want to do that. And, Nick, I want to connect earrings to Michael currents are you know, only point contact? There's there's technically an ideal case there's only one molecule of of that iron in that bearing not after 100 amps goes through? Yeah, going through that one one atom there. Right? Right.
Host 1 35:32
So I don't know, like, the thing is I have tax tack welds on it that are plenty strong enough, I could just leave it as is, instead of putting up full, fill it around the whole thing, but it would be nice, you know, fill it would look cool, it would look cool, and I haven't. So I've been TIG welding now for about a year. And I say TIG welding in quotes, because it takes a long time and a lot of practice to get good at TIG welding, I can make things stick together. That's about as much as I can do. And I've I've wanted to do something rotational for a while, so I don't have to worry about moving the torch. I can focus more on the fillit. And so I was kind of excited about this one. Because I was thinking a while back about just busting one of these steppers out before I was building the CNC and just using it as a rotation table. But I don't know, maybe I'll get my chance tonight.
Host 1 36:25
Well, there was a YouTube channel. I think you watch it to this old Tony DeSoto. Yeah, yeah, he made a rotational table. I would see how he grounds that table. And that
Host 3 36:35
That build? Oh, that's a good point. Yeah. Because it rotates to I wonder if he grounded it through the shaft of the of the stepper? No, because he uses a motor? I don't think he's a stepper. Yeah, but I mean, it's still a shaft and bearing. Yeah, yeah. I would see how how he did that. Yeah, that's a good point. I'll check that out. I mean, regardless, I'll have the x axis moving tonight, because all I have to do is tack the two sprockets on the end, and then grind them flat,
Host 1 37:07
I got it. Take a piece of aluminum foil, folded a couple times and then drape it over the shaft. So you kind of like making like a sleeve? I think clamp onto that.
Host 3 37:20
Yeah, I wonder how it's like a really inexpensive bushing or a, like a bushing. For electric motor. I wonder how long a few folds of aluminum foil would last against 100 amps of
Host 1 37:32
Welding? I mean, they used to wire houses with aluminum, not aluminum foil. Yeah, but if you know, enough contact area would be fine. Yeah.
Host 1 37:44
So So I found something cool that I think I'm gonna have to christen the CNC with, I found a website that will put the link up there. It's ultimate solver.com. But they have a G code creator on this website that is called MIDI to G code, where you can enter in a MIDI file, or just upload a MIDI file to this to this link. And then it has a handful of configuration.
Host 3 38:16
Information like how many steps per revolution, your steppers go and how many axes you have, and how many, it actually reads how many channels are in
Host 1 38:26
The MIDI file, so you could export just a guitar or just a piano or whatnot. But it will take a MIDI audio file, and it will convert it to G code and have your stepper motors play the music. So I found meatloaves bad.
Host 3 38:45
And I'm gonna try to have my CNC play meatloaves bat out of hell, it's actually cool too. Because on this, this G code creator they have you can have it set limits. So your machine just doesn't drive itself into oblivion as the wall Yeah, you can do good to have a go, I don't know three inches forward, and then three inches backwards and things like that. So but I mean, my machines huge. So the cut envelope is I'm not worried about driving it to insanity. I backed out of hell as an eight minute song. So well, I did. But what I'm saying is like I could make each axis a foot and it would be fine. You know? Yeah, actually, I don't have a full foot of travel in my Z axis. I think I have eight inches. So but I mean most of the stuff I'm planning on using this CNC to cut mainly flat, flat objects, and I don't need a ton of Z axis. In fact, the thickest thing I'm planning on cutting is guitar work and and that doesn't really get over two and a half inches.
Host 1 39:46
But the company some play fields for pinball machines, I could totally do that four foot at work actually know this thing. So the cut envelope was designed to be four by four but in reality it's about four and a half. by five,
Host 3 40:02
That's plenty big. Yeah. playfields three and a half feet by two feet. Oh, yeah, I could get that easy. Reset vector? Sure. I'm actually working on another one. So Oh, you're like a personal one or with a crew? I can't really say, Okay, well, that means with a crew. Cool. So yeah, as soon as I have, as soon as I have my machine welded up and playing meatloaf, I will post that up on our Slack channel. So another thing actually with that, so I bought one of those Chinese spindles that you can get on Amazon, the 2.2 kilowatt spindles, which are water cooled. Yeah, it's a water cooled guy, which is super cool. And so far, it's been, it's been awesome to work with. But one of the things that I was reading, and I
Host 1 40:58
Now have to figure out or I've been figuring out, I guess, since it's a VFD, a three phase VFD, that runs on 220 volt, it has some pretty nasty chopped up spikes that go from the VFD to the the spindle itself. And first of all, just as like a good steward of the environment, you don't necessarily want to just be chopping to 20 and spitting that out everywhere. But second of all, it's right next to, you know, switches and your control signals that go to your steppers and things. You really don't want to just wire your spindle in, you want to actually put something decent there. So I did a bit of research and I found a company called, I don't know how to, if you pronounce it this way, but I guess I gos, I guess, I guess. Yeah, so they do motor control cable. And they actually have a a line of control cable, it's called Chain flex, and I needed 16 slash four. So four conductors, 16 gauge wire, plus a shield on that in order to run everything. So 2.2 kilowatts results in 10 amps of current, if it was running max torque max speed. So that would be yes, 16 gauge on that. So the reason I ended up buying this is mainly because you can buy it by the foot with these guys, which is convenient, because 16 It's surprising 16 Four with a shield is not easy to find. That's not something that's readily available. 18 four with a shield is everywhere. And I didn't want to undersize my cable. But what's nice about this stuff, and we'll post a link up to it. This specific material is or cable is meant for motor applications that move. So it's tested for a lot of flexing, in fact, you know, depending on the radius that you actually flex the stuff it, they rate it up to 10 million moves. So I'm never going to break that for sure. But, you know, like if you went over to Home Depot and just bought 16 For non shielded SW cable, you know, the rubber stuff that's nice for like extension cords. It's like tool. Extension tool you are Yeah, yeah. But in that stuff nice and all but it's not necessarily intended for this application. So the biggest thing that I'm kind of confused about maybe confused isn't the right word, but that I'm working on is the shielding. When when shielding something of this kind of power. So it's four conductor, right four conductor plus a shield, this cable. So I've got u, v and w which are the actual power phases. And then there's a ground wire, but then there's also a shield. So what I've been reading online is everyone says connect your ground and your shield on both ends of the cable. So that means you have ground current that would flow through your ground wire but also through your shield. And that seems really counterproductive to me.
Host 3 44:09
Yeah, I've never I don't know how it isn't seeing sees but for data cables and, and other motor applications. I've worked with you ground on one side. Yeah, right. Well, usually it's on your controller side. Exactly. Exactly. So my thought was you ground the shield on one side and that would be at the VFW. And then sorry, VFW VFD VFD, the vamtam the VFD and then and then the ground wire. I would connect on both sides. So the shields are acts purely as a shield like a drain. Yeah, but they're to absorb the EMF. Exactly. And and what but everywhere I've read online, I mean obviously this is like CNC hobby, whatever. But everyone say no connect on both. And that just doesn't make sense. If you connect it
Host 1 45:01
On both ends, basically, it becomes a secondary ground wire, and it would have the same, like, it would have the same potential swings as the ground exactly half.
Host 3 45:12
Exactly. So like this. That's where it's just kind of blowing my mind. And it doesn't make much sense. So we could test this, though. You could hook it up the on one end, and then take your take like an antenna on your like, on your oscilloscope. Oh, yeah, that's just like an am radio actually just hold up my scope probe in the air. Yeah. And see,
Host 1 45:34
If you what you pick up and just see what the background is. Compared to both of them. That's yeah,
Host 3 45:40
That's a good idea. In fact, you know, would be would be cool, too, is to see which one is better. Like, if if you connect one ground at at the drive side, or one side, at at the spindle side? Which one prevents the most? Or both? Or yeah, yeah, all three conditions. And it may be that the people who are staying connected on both ends don't also have a ground wire, they might have three conductors in a shield. But I have four conductors in a shield. So I don't know, it's, and on top of that, it's kind of weird. I need to crack open my spindle, because some people say that the ground wire doesn't actually connect to anything in the spindle, it's just a fourth wire. So and with this Chinese stuff, like you don't really get instructions, you just get a box with it in it. But I mean, I've actually already spun it up, and and had the drive work and but it did like, you know, I was just doing that with some random cable I had lying around just to make sure it spun. So yeah, Chicka chicka, I just were I guess, however you pronounce it. And they got a bunch of really cool stuff on there. And if you ever have like, any kind of motion based electronics, these guys have a ton of cable, and you can buy it by the foot, which is cool.
Host 1 46:59
So one last thing. Last week, I talked about replacing a transformer and that rackmount amp, because I was getting about 250 volts off of my weird transformer configuration. And last week, I had mentioned that the transformer that was in the amp was a 12 to 230 ratio, or 12 volt to 230. Step up. And I'm replacing it with a 10 to 230, which is about a 20% increase or decrease depending on how you look at it. So I was expecting my output voltage in the power supply to change by 20%. And I measured it and it changed by exactly 20%. It went from 250 volts to 303 100 is what I was originally hoping for. So it was like hey, go figure it worked. Yay. And and it was funny, because last week I mentioned that I had already done this with a regulated power supply. And I didn't notice any change in the sound of the amplifier. And I did it this time. And I still have not noticed a change in this out but it was it was the principal the original design. I wanted 300 volts. I didn't get it. So now I have it like literally it's 300 on my on my meter. So I'm happy now. Okay, yeah. Cool. That's, that's what matters. Yeah, exactly. Yeah, yeah. So onto the RFO, rapid fire portfolios. So I put two articles up this week from Hackaday. And they're both kind of related in a way. Because I was just kind of cruising through Hackaday, I noticed that there was two separate articles that were talking about using 3d printing, and forming sheetmetal, either with a press and some forums, or one of the other articles was talking about using 3d printing to make dyes for press brakes, which I was like, Hey, that's pretty cool that we're starting to see that and the fact that there was multiple articles about his like, people are actually trying to do things on this. So in this first article, the person doing it here was trying to make a sheet metal forming jig both like I press and while both sides of the dye and then putting it in a I think it's a 10 ton press and cranking on it. And it came out with mixed results on it. I mean, it's worth it's honestly worth watching the entire video the video is kind of fun, especially to see like the design revision changes as it started off with like, yeah, we can do this and then like the forms just die, just crack and explode. And and the fact that the person doing it was like having to go through all these changes. I don't know it's super cool to see 3d printing being used in in this kind of way as opposed to like printing little boats and things like that.
Host 3 49:56
So the funny thing though, is In that first video, the guy who did it was printing all of these forms. But then like, didn't get what he wanted. So he went to his mill and milled like a block of steel, and replaced one half of the 3d print with like a really nicely milled piece of steel just to get what you want. Just in the first part, exactly. So I don't know, the whole point was like, could 3d printing do it. And in the end, he got a piece. In fact, it was a blade guard for a saza. Ya know, and it's like, it's the $10 saws, all that you get at Harbor Freight. Right? Yeah, oh, in the amount of probably the amount of money he spent milling and doing all this work as well, more than that. So the other article that was talking about this was actually about making dyes for
Host 1 50:54
Press brakes. And they actually ended up making some dyes that were able to withstand five tons of pressure, which I'm, I don't know how, like, that seems unbelievable with 3d printing. I mean, it's 100% infill, right. So that makes a huge difference in both print time and strength, right, especially when you're just talking about compression forces on the thing, so. But I would love to see this kind of grow into something more, maybe there's a way that people could start designing around understanding that, hey, I'm gonna press or form something with 3d printing, therefore, I need to change what the actual sheet metal piece looks like. Because you know, you're not going to, there's no way you're going to get like a box out of it, you know, you're not going to get like nice 90 bends out of this, you're going to destroy your 3d printed piece. So maybe if you make designs that have less steep angles, and press nicer, then you can actually get away with it. And it's really cheap. I think one of the cool things though, was with the person that did the the, the brake dyes, they were talking about, hey, maybe, maybe we can do this 3d printed, and then eventually get the tool steal one made it because we can go through design iterations and make all of our mistakes with the 3d printed stuff, and then spend the big bucks on the tool seal because if you make one mistake on those things, it gets pricey.
Host 3 52:26
So while I've been looking at doing molds for this, I'm not doing it with 3d printing, but doing molds and make my own lenses for automotive applications. What like lens lenses that cover like, like turn signals and stuff? Oh, okay. Yeah, because a lot of these old cars, there's not a lot of manufacturers out there, they're still made, unless you have a really popular car. No one's making these parts anymore, right. And I'm a big fan of clear turn signal lenses. I don't like the amber. So I will usually I'll go in and replace them with a clear one and put an orange Amber bulb in it. And no one makes those for my wagon or my checker. And so I was looking around online was a couple of weeks ago, and I stumbled I just I can't remember what I was actually searching for. But I stumbled upon a Google image search image of someone making Corvair Chevy Corvair lenses for their turn signals for clear. And you make a mold out of silicone out of out of it, you have to get a good turn signal first lens first. Fortunately, oh minor and are intact. So you basically have to polish it and get rid of all the scratches and stuff because any scratches will be just transfer. Yeah. And then the new use a two part. Pouring epoxy. That's for making clear molds and
Host 2 53:53
Then you you'd actually do it under pressure. Because I always thought you would like do it under vacuum. Like you'd try to pull the bubbles out. But apparently you just put a bunch of pressure on it. Bubbles, pushes the bubbles, like I guess gets rid of them. I don't know. I don't know how that would work. But apparently that's the way to do it. You don't pull a vacuum you pressurize it.
Host 3 54:16
Is it like is that just for silicone? Because I swear you're supposed to pull a vacuum on mold making and it's just how they were doing is under pressure. Okay, cool. They use a pressure vessel to do it. Well, gotta try that eventually. Yeah, that's way down the road, though. That sounds like that's another one of those like, I need to build eight tools to do this thing. You know, it's funny. My father actually asked me about doing exactly that. Because he was restoring an old dirt bike. And and the he's able to buy every part for this bike except for one and it's the rear red brake light. lens cover. on that and his bike, he has one but it's cracked. And to buy a brand new, it's just a piece of plastic. It's like $180 from somebody who makes reproduction ones. And he was like, he has actually a good one. But he has two Hastert bikes. So, he was like, yeah, if he had the good one would, he was asking about milling a mold, actually. And I was like, you could do that could do that. But you'd have to digitize it first. And that would be a pain in Yeah, I think doing a silicone mold is the best way because then it's, it's, it looks like a lot faster and easier. And it does work really well. Right. Well, if I ever get that working in year 2023 I'll let your dad know brewery first? Yes, brewery first. Oh, man three weeks away. Guess that's going to end this podcast. Yeah. Cool. So that was the Mac fab engineering podcast. We're your hosts Parker, Dolman. And Steven Greg. Later everyone take it easy.
Transcribed by https://otter.ai