They may be known for being electrical engineers but on this episode, Parker and Stephen dig into the more mechanical aspects of their current projects
How low can the power consumption of the Cat Feeder Unreminder go? Parker and Stephen discuss leakage current on this episode of the podcast!
What lore have you discovered in component datasheets? On this episode, Parker talks about how he picks electrical components and risk management.
Rapid Fire Opinion
Parker is an Electrical Engineer with backgrounds in Embedded System Design and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. The following year he designed and produced an Atari 2600 video mod to allow the Atari to display a crisp, RF fuzz free picture on newer TVs. Over a thousand Atari video mods where produced by Parker from 2006 to 2011 and the mod is still made by other enthusiasts in the Atari community.
In 2006, Parker enrolled at The University of Texas at Austin as a Petroleum Engineer. After realizing electronics was his passion he switched majors in 2007 to Electrical and Computer Engineering. Following his previous background in making the Atari 2600 video mod, Parker decided to take more board layout classes and circuit design classes. Other areas of study include robotics, microcontroller theory and design, FPGA development with VHDL and Verilog, and image and signal processing with DSPs. In 2010, Parker won a Ti sponsored Launchpad programming and design contest that was held by the IEEE CS chapter at the University. Parker graduated with a BS in Electrical and Computer Engineering in the Spring of 2012.
In the Summer of 2012, Parker was hired on as an Electrical Engineer at Dynamic Perception to design and prototype new electronic products. Here, Parker learned about full product development cycles and honed his board layout skills. Seeing the difficulties in managing operations and FCC/CE compliance testing, Parker thought there had to be a better way for small electronic companies to get their product out in customer's hands.
Parker also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components.
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.
Special thanks to whixr over at Tymkrs for the intro and outro!
Welcome to the Mac fab engineering podcast. We're your hosts, Parker, Dolman and Steven Craig. This is episode 214. So between last podcast and this podcast, I actually was on vacation. So I didn't get to really kind of work on anything like my projects or anything other than getting sore. Yes, because I went skiing like five days in a row.
Did you ski or snowboard, snowboard?
But yeah, everything hurts. But one of the, in the Airbnb we were in. There was a whole, like DVD collection. And so you know, going through, see what videos they have. So we can watch. And they had, like all the James Bond movies on DVD. And so of course, we just are watching some of the old ones. And the topic I'm going to bring to the table today is bond gadgets. You know how we kind of do like Star Wars tech and stuff? Bond gadget episode would be really fun.
Just just slightly more believable than the Star Wars sci fi stuff.
Or not maybe or not
Because like we watched Goldfinger and like the giant laser was like,
it's Wait, isn't it? Aren't they on like an island, and he gets strapped to the table? And they're like, gonna cut him in half or something with the way
it's on an island. But yeah, he's strapped to a golden table. Lasers designed to cut gold.
Right, right. So it's a laser?
Yes, it's a laser. I guess you could probably tune the frequency of the laser to better cut, depending on the metal.
Yeah. You know, I don't I don't know enough about laser cutting. But I but my guess is you just more power. Just keeps adding more power. And it'll eventually do it. Right.
Yeah, that is true. I was looking into like building circuit boards a long time ago with lasers, and a normal co2 laser. Like, yeah, the pump hundreds of watts, like, vaporized copper, basically off the FR four. Whereas like a solid, I can't remember what frequency is. But they just call them solid state lasers. You can only you can do it with like 10 watts. If it's the right frequency, it's probably something to do with a metal liking to launch electrons off of them.
The oh gosh, I can't remember what the Greek symbol for it. But the work function, right? The word function is the amount of energy you someone's gonna get mad at me because I'm gonna say this wrong. But the the amount of energy you have to put on to eject an electron is the work function. That's probably wrong. But I don't know fact check me everyone and tell me how I'm wrong in our selection.
So yeah, I don't know if
you're right. Lauric function is the minimal thermodynamic work needed to remove an electron from a solid to a point in a vacuum.
Holy shit, I remembered something from college. Yeah, it's
probably related to that. And also just like, reflectivity of metal, because you're hitting it, you know, with photons. So
actually, you know, you know what's funny? In, I'm gonna pull this to vacuum tubes, like I always do. But in in the high powered Big Bottle vacuum tubes that are pen toads. There's five elements that you connect in there. There's, there's the high voltage anode, and that's the one that basically it Okay, well, you have the cathode that boils off electrons. And you create this sea of electrons that flow in in a vacuum, but they don't move anywhere, unless you apply a potential to another plate that's some distance away. And as soon as you apply a plate, then you just have free floating electrons in a vacuum, they they get attracted to that plate. But since they're in a vacuum, and you have such high potential in there, they end up going pretty damn fast. And then when they actually strike into the plate, they have enough energy that a lot of them produce secondary emissions. So they hit the plate and then boil off more electrons backward. So Pinto does have an extra element inside that you actually tie to a low, low voltage, either the whatever the cathode is sitting at, or a lot of times you can just ground it and that actually repels those secondary emissions back. So like an entire like have metal apparatus inside the tube is just there to make sure that it doesn't. Those electrons don't flow around and strike other things and produce weird artifacts. So that's that's what you're looking for, I guess I guess so. But I can't see an application where that would actually be good.
Guitars like crunchy noises Yeah, crackles and all kinds of weird shit. So, back to James Bond bond. Um, so, Steven. Yeah. If you could have a James Bond style gadget, what would you build?
Oh, it was, like, so So here's the thing. I'm typically not a very aggressive human being just in general, like, it takes a lot to get me mad. It takes me a lot to get me going. Except for on the road. Like if I'm, if I'm in a car, it takes nothing to get me mad. So I can think of probably like 50 devices that would be great to have on my truck. Like, the whole oil slick thing in the back would be awesome. You know, like, just like this. This guy's hugging my ass here. Just I'll press a button. And he's been like, that kind of crap. But I've always thought it would be. This is ridiculous. But I would always be fun to have some method to identify crappy drivers where you could like shoot like a paintball thing and it would hit their car and like, if you see a car going down the road where people have all marked them with a bunch of okay, they're an awful it's like, it's like Yelp for drivers. You know? If you drive bad, your car's gonna get all marked up. I hit
him with like a UV pin that'd be like, like, you know, when you're a kid writing secret messages that that lemon juice would expose on paper?
Oh, yeah, yeah, yeah share with your friends at school so
is UV pink ball that you hit some asshole driver?
Or Okay, so I think it was a I can't remember exact maybe it was it was one of the Pierce Brosnan bonds where he's he's in his car and he's driving it remote control in the backseat and he's like laying down as he's getting shot and his his tires get shot out and then he just was that good night. Okay, yeah, he presses a button and his tires reinflate. That would be a legit, like that's super practical. Like
I don't know that one. That one's good. I'm of the age that Goldeneye was my bond. I mean, Pierce Brosnan was my bond. Like when when someone says bond? That's what comes to mind? Because that's, gosh, when did Goldeneye come out? That was 98
My bad. It's actually it was Tomorrow Never Dies. The one with the car. Was it? Okay. I GoldenEyes on with a tank if I recall.
Yeah. GoldenEyes Yes.
Where he's driving around and tank. Tank scene. Yep.
And also Pierce Brosnan is my bond. It's 1997 is what it looks like. But he's he's my bond because of the Nintendo 64 game because I dumped unbelievable amounts of hours into that.
So I'm, I'm scrolling through this tomorrow. Tomorrow Never Dies. Movie, I guess on YouTube, well seen on YouTube. And it's like, the controller is supposed to look like a cell phone. It but it like opens up like this because it's, you know, was it late? 90s.
Oh, wait, wait, I'm sorry. The video game was 97 The movie was 95.
But it's supposed to look like a brick cell phone. Right, right. And then you open it up and then it's got a trackpad like you would have on a laptop and then a screen where the car is going right? And a couple of buttons. The funny thing is nowadays, if you were doing this, you would just use a smartphone. And you would just have your finger on the on the touchscreen, right? I was really hoping it would be like a smartphone, but it's kind of weird. It's like a brick phone. That's not really a brick phone.
So you would do car gadgets,
car gadgets for sure. Well, okay. Also, the laser in the wristwatch is pretty legit.
That's pretty cool. Yeah, yeah. I always wondered if you could actually that's like the lightsaber and Star Wars, right? Yeah.
I wonder why that thing must have a hell of a battery pack. That has the bad guy. What's his name? He played a bore on the air in in it Lord of the Rings Sean John been right. That's his name. I love that actor.
Well, maybe we'll you'll have a because you know we do once a year we do a Star Wars Episode maybe we should do a bob bond episode, like during the summer or something,
you know I can't remember where it is but there's a there's a museum of like spy gadgets and stuff we should go visit that and then get inspiration for a bunch of stuff. Yeah, that'd be cool. So wait, so you asked me what is your your gadget
that you would do? The gadget I would do is I really like the like all the weird gadgets from like back in the Sean Connery days I can't remember what was the one from I can't remember. I can't I came up with this this topic like three days ago and I'm like, Oh, yes, it'd be this one. Oh, it would be there's a it's in diamond is a diamonds are forever. And there's a really Yeah, diamonds are forever and there's a really goofy scene where Sean Connery is like escaping from the like, evil lair facility. In like a rover. He finds like a like a, like a moon rover. Like there's like a moon set underground that he could like crashes into Okay, and so the the rover is really goofy looking. I think I would want to build all the goofy like vehicles and stuff in
Sorry, I just saw a picture I forgot. I forgot he has a crocodile in Octopussy. Yes. So good
though, all the vehicles, the goofy vehicles that he that he always finds himself using? Oh, they have a Honda three wheelers in that movie as well. Really? Yeah. They'll happen to explode on contact as well. As
does everything in a Bond movie. I'm just looking at like random bond gadgets now. You got me the same thing? Yeah. What's What kind of stuff is it? Yeah, there's the the boombox that has like a shotgun in it.
Yeah. I think earlier in diamonds are forever two. I can't remember what it was but Bond has like, it's like a mousetrap where he would normally put his gun you know, in his jacket. Yeah. And so someone go goes to like, get his gun from his jacket reaches in and it's like it gets slapped with a mousetrap on his fingers. That sounds like something from Naked Gun. Yeah. Or our awesome powers.
Oh, yeah, for sure. Yeah.
Oh, man. There's a Wikipedia page for list of bond gadgets by era.
So like a whole bond gadget website.
Oh, it's just the Wikipedia page. Oh, that's right. Thunderball has jetpacks.
Yep. Yep. My, my roommate in college got all of the Bond movies. One, I don't know one time and he spent like three weeks just watching everything James Bond. Like, oh my God, dude. He also got all of Johnny Cash is his entire discography, which is over like, 1500 songs. And he listened to them sequentially. It was insane. It was like days and days of Johnny Cash.
They just call it the pocket. snap trap apparently is a gadget. Interesting. Yeah. Kind of low, low, low. No electronics needed on that one. Yeah. Little
low tech. Right. Yep. Okay, cool. Good. So yeah, let's let's plan that. That would be that would be really fun to do a We should get a guest on to talk spy gadgets with us? Yes. Yeah. So if anyone knows an interesting spy gadget guest, or actually, if anyone knows anyone who's actually designed legit spy gadgets, that
would be really cool. That would be cool. And they can actually talk about it. Yeah. And we can make up goofy stuff. Cool. So we've been up to Steven.
Not skiing. That's, that's one thing I've been doing. So I've got a handful of stuff. So I got back into doing simulation. So I got another simulation of the week. This one is actually kind of fun, because the past couple simulations I've done have been sort of like utilities or like chunks of circuits. And this one is like a legit circuit that you can simulate and find it. The Behringer Model D is a copy of a Moke synthesizer out there. And I was just cruising through the internet a few weeks ago and found the actual schematic for the Behringer Model D available and so I was like oh that's super cool. cuz the Model D is like a really classic synthesizer out there that has some really kind of unique characteristics about it. And it's like, it's like analog man's analog like the, it's like the like, the deepest level of analog, you can go kind of stuff. And so it was like, this is perfect. I want to see if LT spice will actually do it. Because there's some really, really unique stuff in there. There's, there's op amps, there's exponentiation in terms of like a voltage to exponential current converter. There's constant current capacitors in it. There's discrete transistor op amps in it, there's discrete transistor comparators in it, and it all has to function together to get your correct output. So I plugged it all in and sure as hell it actually crashed it. No. Okay, here's the thing. LTE spice I was, I was always kind of against LT spice, because I think that the use, the user interface is just unbelievably clunky. And I just can't stand the user interface. So I've always used other spice programs. But then finally, one day when I was like, I'm gonna get over the crappy user interface. lt spice has crashed on me once. And crashes in like said, like, oh, I can't do this simulation, this is too much for me to think about. Whereas PSPACE it's been my experience that the user interface is a lot nicer, but you have to like really, really ask it nicely to do simulations, because it'll constantly just be like, Oh, I didn't converge. I don't know what to do. Tell me how to live my life. And it gets really annoying, but lt spice is super, like, I guarantee you that just plugging in values, and dropping transistors into peace vice, that this oscillator would not have simulated in peace bytes without a lot of extra work. The very first time I click run in LTE spice, it just worked. And I got something that is pretty much exactly what I would expect the output of this circuit to be. So if you if you want to learn some really cool analog stuff, stuff that will make you scratch your head as in like, Why the hell is this transistor here? Or why are they doing this and like, Oh, my God, what's going on, like, visit my GitHub. And check out the LT SPICE simulation section, I've put both the simulation but also the schematic, the PDF version of the Behringer Model D schematic up there, so you can kind of follow along with it. There's a couple of things like if you want to look at different waveforms, you have to there's not a way that I can connect it for you. So like if you want to look at a triangle output, just look at the schematic and see where the switches, connect wires and then do that in the schematic. And if you want to look at a pulse, do that. And workout. I wish I could have like a legitimate switch and Lt spice but it's not going to work out too well. But yeah, it's super cool to have it do all of all of those really unique characteristics where you're kind of playing with the edge cases of transistors, especially doing like differential pairs, and the voltage the current conversion. So like one of the main aspects of a sawtooth core oscillator is the fact that you have a constant current, that you plug into a capacitor, or you're pulling from a capacitor. And the general equation for a capacitor current is is equal to C times dV dt, where dv dt is a voltage gradient, you know change in voltage over change in time. So it's in this equation, there's sort of three elements, current capacitance, and then a change in voltage divided by the change in time. So your capacitance is caused constant, because that's just the capacitance value. If you pull a constant current from it, then you have is equal to C dV dt where i and c are both constants. Therefore, dV dt is a constant, right? So the change in voltage over a change in time is constant, therefore you can get a linear slope. And as long as you can handle that linear slope and reset it, then that's how you get a sawtooth core. So it's kind of cool to see the simulation handle that so well. Without without really going off the rails and not converging and things like that, especially at the point when with a sawtooth wave, you know you have a linear slope, and then eventually at some point, it has to transition from that linear slope very, very quickly to some other voltage. That's usually the point at which simulation software goes, Hey, I'm fine with everything going nice and slow and linear. But as soon as you want me to, you know jump and go into like really fast traveling signals, it starts to freak out.
But yeah, it's in theory. It's A you know, infinite change, right?
In theory. Yeah. But actually, if you zoom in on it like it's, it can't be, of course. So no. How does the simulation handle? It? Can't be, you know? Yeah. So yeah, that's, that's really fun. And the thing that's really kind of weird about it. So the model the I don't remember what year it was designed, but it was a long time ago. So the, the entire output of it is just a network of transistors doing op MP things. So it looks like if you go to the datasheet of an op amp, and you know how sometimes they have the internal diagram, and you see all those transistors there and you like, you could sit there and analyze it, or you could just buy an op amp and use it. Yeah, this is like implementing the, the internals of an op amp in a discreet way. So so if you want to really, really kind of dive into that analog stuff, go check this out, it's really kind of cool. The first time I saw it, which was a handful of years ago, I was like, What the hell are they trying to do there? And then I started taking it one transistor at a time and saying, like, what is this one doing? And what is this one doing? And the funny thing is, you could accomplish all of it with just op amps. You don't like it doesn't need to be discreet. But this is like, classic. So they, you know, for was that was done that way for a reason? I don't know why.
Well, yeah. Well, was it designed an era with op amps? Or could they just not get the op amps they needed at the cost they needed?
I'm sure there was a lot of reasons behind it. Probably what it ended up boiling down to is offense were probably more expensive than transistors. And this is there's a lot of really novel solutions with the transistors in this situation. So I bet you it was cheaper to do the transistor implementation, especially knowing Bob Mogae was the guy who designed this circuit. And one of his I'm butchering this, and this is a huge paraphrase here, but one of his sayings was, you know, an engineer can design something, but a good engineer can do it for pennies. And, and I think that was one of his things like, yeah, you can coerce a bunch of op amps to accomplish something. But can you make two transistors do the same thing that you would normally take five op amps to do? You know, if you exploit their capabilities? So
yeah, I guess if you're only using a op amp in one mode, or one way, you might not need all the circuitry that's in there.
Yeah, absolutely. And a lot of times a single transistor will just do multiple things, you know, you can you can you depending on how you bias them, you can set them up to do more than what you just think they're not just switches or just amplifiers. And you know, another thing that's that it's not reflected in this schematic, but it's pretty interesting. This Behringer, Model D uses a specific IC that has seven transistors inside of it. It's like an SOC 14 that has seven drains. Now it's probably bigger than I can't remember how many pins but it has seven transistors in it. And they use those in really unique positions. And the reason why is because they're all on the same silicon die. And they're all really, really close to each other. So they all vary in temperature in the same way. So you don't get huge variation from using discrete transistors. While I mean, they are discrete, but just their proximity in their construction is their next door neighbors.
Yeah, when and when they got made in the on the masks. They're right next to each other as well.
Right. Right. So their variation is very, very close. Yes. In fact, I had a, I didn't realize the importance of this, but I had a lab back in college, where we actually one of the steps in the lab book was like, place your fingers on the transistors, and, you know, monitor its output or monitor the effects to the circuit while your hand is warming it up. And like we had our circuit working, and then we put our hands on the transistors and it just obliterated our circuit, like stop working entirely. And it was like, Oh, God, this is awful. But I guess I didn't really realize the impact of it. Back in college, I was like, Yeah, okay, he makes it do things.
Yeah. In my experience, like with product design, there's like, there's a handful of phases you go through the first phase is like, get it working. And then And that's usually more of the faster phase and then the phases after that is like get it always working. And that's the one that takes forever, especially when you get to temperature testing, because it's just like, oh god it takes so long
One of my testing is I'll take take the board and I'll throw it onto the passenger seat in the jeep and let it ride there for about a week or two. And then I'll power it up like is it still working? Yeah, it's probably good then.
In Houston, yeah. Because it probably cooks at 140. All that
heat cycles it ESD. You know, just living in the jeep.
Yeah. Yeah. Holt testing in the jeep. Yeah. Well, and vibration going down the roads, right? Yep. Yeah. That's a good test. Yeah, I worked at a place. I may have mentioned this before, maybe I don't know, I worked at a place once where the engineering manager had something he called the newspaper test. And they had a problem. I don't remember what it was. But they had a problem in one of their devices a long time ago, with tantalum capacitors, catching on fire. And one of his solutions was to put the boards down on a table and put a newspaper on top of it, and run the boards through like a huge variety of tests. And if the newspaper doesn't catch on fire, then it's probably safe. And he actually did this test in front of the CEO of the company. It's like this is my newspaper does and the CEO was like, Cool. We're good to ship.
It's probably safe. It's probably
safe. Yeah. Yeah. If the newspaper doesn't catch on fire.
Cool. Okay. So yeah, check out that simulation on my GitHub. So I've also been putting a bit more work into my CNC, which it Yeah, quite a bit, actually. I've been sending Parker pictures of stuff. So
I got the entire base of the of the table made, which is all made with four by fours. And then over the last weekend, I built that portion box, which I discussed in the last episode, which is all three quarter MDF construction. And the torsion box is basically it's a bottom skin of flat MDF, and then a matrix of interlocking vertically cut MDF boards and then a second skin on top of that of three quarter MDF. So the this top portion box probably weighs 200 pounds. And, but it's all glued and screwed together. And in basically the way I built it is such that or I chose the torsion box because it resists warping, and it resists movement due to like changes in temperature and humidity. And it's just an MDF in general is pretty damn flat. So it makes like for a perfect top of the CNC. So we'll post some pictures of this up in the in the show notes that you can check out later. So I've I've got my gantry on the on the table now. And last night I was actually playing with the z axis carriage. I don't know what is that? It's what's the name of that, like Gan chairs the big thing that moves forward and backwards. It's yeah, carriage carriage or head or I don't know, I don't know what the you could call it ahead to Yeah, so the one I have is not in fantastic shape. I so I'm thinking about how to make some changes to it. I in fact, I was kind of like,
you got to build a CNC machine to cut parts to make this CNC. You
know, I trust me, I've been thinking about that. So the whole 3d printer thing, I did buy a new spindle for my CNC, which is an 80 millimeter 2.2 kilowatt spindle like one of the big beefy guys. And it came with I'm holding this up so Parker can see it. We'll put some pictures of it. But I've got this big beefy aluminum mount for it. And it's great. However, the holes, the mounting holes for it are actually not. They don't really interface very well with my carriage, my Z kits, they sort of interfere with a bunch of things. And the bolts that go into this thing are some I don't even know maybe 10 millimeter metric bolts. And I don't know how exactly I'm going to work that out. But I did find in my basement, a chunk of 5.5 millimeter thick aluminum plate that was actually used for a previous project for the fab. That is, oh yeah, just about right size for everything to fit
5.5 millimeters, just quarter inch.
That's 6.35 You bet you're about a millimeter off. I could just say a quarter of an inch. I think I was actually shooting for a quarter of an inch but just to get this thing flat. I had to go down first because it was a little bit warped, but it's great because this has already been flattened. So all I need to do is punch some holes in this. So I think I'm going to use Use this piece of aluminum and make a like a secondary plate that the that the actual spindle mount will connect to and then this will get connected to my carriage adapter plate. Yeah, like so. Yeah. And it's just big enough that I can do that pretty easily. So I think that's my next kind of step. One of the things, my gantry has never really been treated fantastic until recently, like it was always just like a beater CNC. I got
Oh, yeah, it was living in a somewhat in overhang enclosed environment.
Yeah, yeah, it's a it's a abusive temperature.
It'd be in one year, it would be 120 or 100 100. I had to be actually 120 that building at one time, I was surprised. And then, you know, below freezing. Yeah. So yeah,
right. And and I never really maintained it because it was never meant to be an accurate CNC. Like if it was within an eighth of an inch, I was happy. And that was fine for what it needed to do was it made cabinets, right, but I'm actually going for a bit more accuracy now. And it's in a temperature controlled basement. And I'm trying to make it nice. The one thing that sucks is one of the legs of the gantry is just ever so slightly warped. So I know that if I were to cut a square right now, I will get a trapezoid. So I've got to figure out a way to kind of get that warp out of it. And
don't you have a CNC at work?
Yeah, I do. I do. And in fact, that's why I'm totally fine with cutting this plate aluminum. In fact, where do you think that I leveled this plate. And like the thing that's beautiful about the CNC, I have it work, I can design and have this this plate cut. I'm not even joking here probably 15 minutes, I can I can come up with the solution for this. In fact, I had, there was a guy at work, who he, he came up to me this morning. And he was like, Hey, I've had this idea that I need to knock out a new panel for one of our products. But it needs to be a different form factor, it needs to fit horizontally as opposed to vertically, the logo needs to move on it. And a handful of whole patterns needs to change. I hand it to him in like 20 minutes. Just because like the way that machine works is just like a handful of button presses. And I've got everything modeled up in Fusion 360. So if I need to change anything, it's just, it's no work whatsoever. So I'm really, really spoiled with that machine. Although get this, I ran into an issue that's super annoying, like super freaking annoying. And I, I don't I don't really know a good solution to it. I mean, I have a solution to it. But I don't like this solution. We do a lot of Engraving and chamfering on our products. In fact, every product gets both engraving and chamfering. And the engraving bit that we use is a point one millimeter tip engraver, which is four thousandths of an inch, so it's really sharp. And every time the machine goes to pick up the bid, or anytime it goes to put the bid away into the tool magazine, it does a measurement of that. I've been noticing recently that the engraving looks fine, but it looks slightly different than it has in the past. And so I started putting them under the microscope and noticing that it's engraving deeper than I'm asking you for. So this machine auto compensates for any kind of bit length and I scoured fusion 360 to make sure that I had all my Z depth set, right, everything is correct. So eventually, after pulling my hair out for half a day, I take a loop and I get right up on the tool changing position and look at it. Because I have tested so many tools, I've actually dug a slight divot right into the center of my my tool, measurement changer, or measure tool post. That's what they call it, the tool post. And that and that amount of divot that I've pushed into the tool post is about two to 3000s deep, it's not much at all, but now that means all my engraving is two to 3000s deeper than I want it to be right
on insofar as you could see that it was two to 3000 deeper.
Yeah, no, you can totally spot Yeah, it's and here's the thing that's crazy. So we use a lot of three, two and three millimeter bits, flat end mills. They're, they're unaffected by that because it's it's the little divot in there is only 4000s wide and about two to 3000 steep so they're not affected. That's why I'm pulling my hair out because I'm like, these other bits are cutting perfectly. But the engraver is not. So I had to figure out how to trick the machine into thinking that the tool position is one millimeter away from where it was. And I just think that every three months or so I'm going to have to say, oh, no, it's not there. It's over here, you know, like, just moving around the tool thing, which is super annoying. But that's why I say like, that's not a solution. But it is, you know, like, it gets us making product right now. Yeah. But I mean, how do you how do you handle that? Like, I guess you could make the tool post out of a ridiculously hard metal. And then diamonds are forever. Yeah, it gets really expensive then, but also, you don't want to damage your bid. And it's a spring loaded, tool changing. I mean, it's not like I'm driving the bid and do it at 1000 millimeters a second. So I just think it's sort of with any machine that you work with, there's always so much nuance that you don't know about, and you just find them out because something went wrong. Yeah, luckily, like an extra 1000. Deep on this engraver one to 2000 deep, doesn't cause it to engrave poorly. It just the lettering comes out a little bit shinier. And it's enough to like notice it be like that it's a little odd. So the the angle of the engraver is 15 degrees. So it doesn't really add much to go
with to it. Yeah.
Cool. So and then I've got one other thing that I've been kind of hammering on that guitar preamp that I was working on at the end of last year. Everything is working fine with that. But there was always one thing that kind of irked me a little bit, the the power supply situation that I put in there, I use two back to back transformers to go from from mains voltage down to the heater voltage, which is 4.6. And then I took that 12.6. And I boosted it back up to high voltage. Which is you know, it's an okay trick for what I was doing, I wouldn't do that in a production thing. But for building two of them, it's not a big deal. But the Transformers I used, what was 115 volts down to a 12.6. And then on the other end, I use the 12 volt to a 230 volt, kind of backwards to bring it back up. And if you do the math on that, if you're assuming like perfect efficiency and no issues with the transformer, you get a ratio of 19.16 to go down to the to go up to the 230 volts. And then if you put 12.6 volts into that ratio, you should end up with somewhere around 341 volts DC. And if you take the normal like rule of thumb thing where you use 90% efficiency on a rectifier circuit, you know 90% efficiency still is over 300 and some odd volts for that circuit, where in reality I'm getting 250. So like, my efficiency is like 60%. It's awful. It's so bad. And it was never it was never intended to be like a specific
like I voltage you just need you need voltage. Yeah, I
just need voltage but I want but like 250 is the edge of what I'm okay with. So I purchased another transformer that is exact same footprint, exact same size transformer, but it has, instead of a 12 to 230 volt, it's a 10 to 230 volts. So it actually has a higher ratio. And it actually also has a slightly higher current capability, which means that in this abusive way that I'm using it, it should handle that a little bit better. So I'm hoping so the difference of a 12 to 230 and attended 230 will give me about if you just take the numbers, you know, straight up, that's a 20% change. So I'm hoping that a 20% change on 250 volts will will net me 300 At the end of the day and 300 was sort of what I was shooting for somewhere around 300. But 250 versus 300 is a huge loss that I you know, well I mean, straight calculation told me 341 If I didn't take any, any issues or any inefficiencies into account, and so 341 and hitting 250 That's, that's a pretty bad bullseye. So yeah,
the good thing is in order to Bullseye the size of a barn,
I didn't even hit the barn. I hit the hill that's behind the barn. But I mean, the funny thing is, so I actually at one point One time I took the trend, I took the whole power supply out of the equation, and I plugged it into my variable high voltage power supply. And I ran it from 250 all the way up to 400 volts. And I didn't hear a lick of change in it. So you know, I'm sort of just doing this out of principle just because like, it must be 300. So the cool thing is, since it's just a drop in, all I have to do is just rip out the old transformer. It's like a five minute job. So that arrived today, so I'll probably get it in sometime this week. All right, cool. Yep. So that's what I've been up to. Cool. Yeah.
So for for macro fab. I think we talked about this a little bit last week is we're starting to do some webinars. And so we have one every Wednesday at two o'clock central time. So it's Texas Standard Time. Link will be in the show notes. I do one March 11. I think it's March 11. Yeah, march 11. Isn't what is when I do one. And I was looking, apparently April 1 also falls on a Wednesday this year. So I want to request that I get to do a webinar on April 1. Yeah. So
that's cool. Do you know what? What is this week's topic?
I think they are like the same topics. It's just going over the macro platform. Why is it useful stuff like that if you're an engineer or a purchasing manager?
So Parker, why is the macro fed? Actually no, no, we're not gonna. We're not. Cool.
So yeah, if you want to learn more about macro fabs platform and how to use it, tune in Wednesdays at two o'clock pm Central Time, cool. So I found this really cool sensor on the fierce electronics website, and it's a sweat sensor. And as a Houstonian we, I sweat a lot during the summer. So this caught my eye. And it's kind of interesting how it's working. Is it's designed to are these this one is designed to find stress hormones in your sweat,
like so it's not just like conductivity of liquid.
No, no, no, it's looking for cortisol. Cortisol. Right? Yeah. Cortisol. Yeah. And so what does it has a, like a microscopic array on on the surface. So that increases its surface area, and then it has a, an antibody on it. That said, basically, it's a molecule that can bond with cortisol. And so that's how it detects this compound. But I just found it interesting. Like how they were testing it is they basically had people run at with a sensor attached to them. And so they can detect, you know, when you start running, you make more cortisol. If you dunk your hand and ice Well, basically, if you like, shock your system, you start producing this this molecule, so
if you just step outside in Houston, like you shock your system, right, yeah. You know, that's, that is actually one of the nice things in Houston. The only time it's actually nice about being hot, like there's a lot of places that they have the air conditioning turned up or turned down so low that it's like absolutely freezing in their building. And then you step outside and it feels really nice for like three seconds.
Three seconds of bliss. Yeah. But one thing I was thinking about when I was reading this article about the sensor was it actually this around me of while I was going skiing was all my friends. They have these like crazy, smartwatch smartwatches that like monitor like your Skeen. Like it does like your heart rate, but also does altitude and GPS and all this other stuff. So you can figure out like, where you're at on the mountain and stuff like that. But it also figures out like your heart rate and, and your temperature and all that stuff. And I'm like, Oh, that would be cool. If you had this. I want to say we'll probably see more and more of these kinds of sensors in those smartwatches like monitoring you all the time.
Yeah, but I guess I mean, I don't know the chemistry of things. But if you have to impregnate this board with something, eventually it'll deplete it right?
Yeah, but I mean, if it lasts a couple years that's how long a consumer product lasts for Yeah, I guess so. Yeah. One thing that was interesting about the but this I was also thinking is, I don't know if you've seen like the commercials for auto insurance where like, you can plug something into your car and it like spies on you so you can get a lower rate. Yeah, that might happen with this smartwatches and your your health insurance.
Oh, geez, that's that's big brother watch Oh, yeah,
this guy's got a lot of cortisol, you know, levels so he's stressed out all the time. So he's rates are going go up more likely to have a heart attack
or not get this like you have like like like blood blood tests that you have to take on the regular or your insurance goes up. But if they detect you know licit substances in your blood then it'll go up or if they if your LDL cholesterol is bad then it goes up. Yeah, that's that's some big brother stuff right there. I mean, not that well. That's that's
you have to go to the doctor for that and take your blood. This is like it's a watch that you're just where it's like, you know how smart TVs why they're so cheap is because they're spying on you. Getting your data for ads, so it can serve you ads on the TV that you bought. Whatever. I've never owned a smart TV ever. But yeah, think about that, like your smartwatch is selling the company that makes your smartwatch is selling data to like your insurance company
probably would not surprise me. Yeah. Join us.
And we need some open source smartwatches.
We didn't macro fab make one of those.
It was just a binary watch. I'm talking about a smart like a watch that can monitor your heart. And that kind of I swear
when I was there. Maybe we quoted one. I can't remember there was one that was happening. Cause he was kind of early on. They were trying to do an E Ink display on a on a smartwatch.
I don't remember anymore. Yeah. That was Gosh, that
five, five years ago, something like that. Almost five. Yeah. All right. So on our last topic, it's kind of a weird deviation for me. But I got a phone call just the other day from Autodesk. Because I use Fusion 360 at work. And I guess my name was on the is who that subscriptions through. But they actually called and asked what EDA tool I use. And I told them dip trace. And they're like, Well, do you use Eagle at all? And I was like, Yeah, occasionally if a customer needs us to, it's tough. But they were mentioning that Autodesk is actually about to pour a boatload of money into Eagle.
So that's an interesting thing that a salesperson would say it is it is? Well,
I mean, obviously they want
it. It's like the salespersons like, I know you don't like it, because it's kind of shitty, but we're gonna put a lot of money into it soon. Hey, then you might
I've got my own shitty program to deal with. I don't need another one. Yeah, no. So but honestly, like, if you see what if you go to Autodesk, it's really clear that they have a vision and a goal. And that they're like, this is our not only like, our EDA platform, but this is our like, whole ecosystem thing. And a lot of times, like, I don't know, Google does a lot of that. And it feels really hit and miss with Google. But Autodesk is pretty good. If he asked me at it, like their stuff is really well organized, and really well integrated. So frankly, I'm really curious to see what they're going to do with Eagle like, this guy's saying, you know, the next year or two is supposed to be like a lot of push with Eagle. And what I wonder about that is does that mean that they're just really trying to integrate eagle with everything else? Or are they trying to change eagle in some fundamental way?
Every interest and see what they do? Because I use their fusion 360 and Eagle like meld of mines kind of thing, which is awesome. Yeah, it's pretty good. I do like the fact that like, you design your board, and then you push it over to Autodesk. And then you're like, oh, I need to move this connector because like, there's a screw boss in the enclosure, or something like that. You can move it and they'll actually push the change back to Eagle. Yeah. Which is pretty, pretty sweet. Yeah, that's, that's really the only thing I've like it does. So I wonder if I wonder if it's going to be more no meld of minds between the programs or is there gonna be more ego features that you know, like, was it lacking? I don't know.
i The electronics are so integrated nowadays that it's it's becoming more and more difficult to just design the electronics in their own bubble, like it's less and less Are you just seeing like a circuit board that has four mounting studs that goes on a wall somewhere right like it has to match up? Perfect. With your special 3d printed or not 3d printed your injection molded plastic enclosure and like how do you design those separately? It's hard. It's really hard. And it seems like Autodesk is really, this is not as, like a sales thing for Autodesk at all. But I, I realized it's starting to sound that way. But I just the integration thing, I think is super freaking cool. And, you know, it's it's one of those things where like, if Eagle had a different user interface, I'd be all over that right now. I would be I'd be like the standard bearer flag waving on from them right now. More than I already am.
I guess we need see if we can get a Autodesk if you're listening out there. Come on our podcast
there is there is an Autodesk location out here in Denver. And I think they mainly just do sales there. But I might, I might reach out and see if Autodesk wants to spill the beans on their Eagle future. Yeah, that'd be cool.
Maybe you can get your your your interface change.
What one copy one special copy,
if you go to preferences, drop down menu, layout, and then they'll have a Steven radio button that you
can click Yeah. I'd be selling on that. I subscribe tomorrow. So what would be the be the change?
If you could just pick one. I noticed probably more than one.
I could pick one. If it was like DipTrace No, no, no, no. Easy, easy, easy, easy. Make the left mouse button work like any other sane, regular red blooded human being program that Windows does like it left selects and make it such that if I click and hold down, I can drag a box around things and select things just like any other regular program does. You don't have to be special and unique that way just make it you know make make Eagle work like a drawing program not a drafting program. That's the change I guess I would say.
Yeah. So rather disagree on that one. But
you asked me one change and that's that I can I can do an ego I have to do it all the time at work. I can do it. It's just like, I have to rearrange my brain and to be like, Okay, well, you know, be certain actions that work in every other freaking program don't work in Eagle. I have to think about it a different way. Cool. Yeah, well,
that brain broke there for a second. Maybe we'll have a drawing mode. We called the MS Paint edition.
I've designed a board and paint before and it worked.
I think we were talking about that before. Back back way back in the day, like how we started building boards, or design boards. So anyway, this has wrapped us up for almost an hour.
That was the maximum of engineering but I guess we were your hosts even Greg
and Parker Dolman Take it easy. Later, everyone
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