Armchair Military Strategists

Welcome to the macro fab engineering podcast a weekly show about all things engineering, DIY projects, manufacturing, industry news and armchair military strategy. We are your hosts, electrical engineers, Parker, Dolman and Steven Craig. This is episode 312.

So before we get started, just wanted to give a thank you to everyone who joined us last Saturday for our TIG welding stream, we had a bunch of people show up and it was a ton of fun. We spent about two hours, maybe a little bit longer a welding and the results were actually pretty good for what our anticipated results were.

I thought it was gonna be like, way worse and it actually ended up being

both of our results. Were like, Okay, this is not bad. We can do this.

Yeah, we can totally stick metal together.

Exactly. Yeah. Neither one of us choked too hard during any of those welds.

I only dip the tungsten into the my puddle only once.

I did I did it twice. But for like an hour. I didn't have any problems like that. And then like, did it twice in a row right after that. Oh, yeah. fatigue sets in. Yeah, pretty much.

Yours gets stuck enough where you had to like snap it

off. Oh, no, no, no, no, no.

Oh my My went like diving in.

You will did the electrode do your? Yes, I did. I I've dipped my electrodes so many times that like I've got this reflex now where it's like dip and then I just pull it out and let go. And I'm like, Okay, I've done because it's annoying to have to unscrew things get your pliers out and stuff. So yeah, yeah, I got lucky. But yeah, no, it turned out it turned out well. Super happy. And Parker and I we we did a bunch of small welds on some practice coupons. And then we made some little

pyramids. Yes, pyramid. That kit was kind of cool, actually. Yeah,

it's, that's that's a great little practice kit.

And I would say that was really like we should. We did that last because we wanted the welds look good. And they did except that by then we had already been welding for like an hour and a half. Yeah. So it was really it. So what we were doing is we had a piece of steel that we got a kit that you fold up into like a triangle pyramid does a special name for that kind of pyramid. Yeah. It's a pyramid with the base is also an equal lateral triangle. Yeah, I

don't remember what that shade. I'll look it up instead of

a square like the Egyptian pyramids. Let me look it up. Anyways, and so you can weld all the corners up and you get a really nice like, practice piece. Because you can't tetrahedron. tetrahedron. Okay. Yeah. Is you you have to weld either going down or up on every single weld.

Right. But and it's not exactly down or up. It's it's down up 3d at an angle.

Yeah. And it was fun. But after it was, yeah. Also trying

to dodge a a webcam is really hard. Time. Yeah, it's really hard. Yeah. But that was fun. So thanks to everyone who joined us. And I'm sure we will do more things like this in the future. So stay tuned. Yeah,

the next TIG welding stream, we don't have a date yet for it. But what I want to do is I have a gas can holder I want to weld up for my Jeep that I want to build out like angle iron, and I'm gonna design it all up, and probably Autodesk fusion. And then I'll make all the cuts, like cut all the pieces, and then we can weld it up on the stream. That's what I'm probably going to do next time. We have one of these TIG welding streams.

So I have some ideas for some projects myself too, but I haven't decided on any so before we have another stream, Allah, I'll come up with something to do something that's less practicing and more like,

practical. Yeah, in the meantime, we're still gonna keep practicing because it's still one of those at the end of the day. It's like, my, well, it would look so much better if I just make that big. Well.

Yeah, yeah. You know, one thing I noticed that was different between ours is the stacking of the dimes. Like we actually did get some pretty good ripple and stuff, but your stacks were a lot bigger than mine and mine were a whole lot more a lot finer, which means that I'm moving less and dipping more often, but dipping A lot less. So you're making larger moves and feeding a bunch and a large moves. That's That's what I was. And I was doing the exact opposite. And so I want to kind of practice your way just to like, get a feel for what both look like.

I don't know which way is better, I don't either. Because I was kind of doing the same motion I do when I make weld, where I'm kind of like wiggling the torch and kind of like, like a continual cursive II. And then basically, when I would go forward, I would pause just a bit the DAB and then circle back around to kind of blend it back into the weld. That's what they call that. There's got special term for it and MIG welding, we that's how you like stitch, you know, an overlap joint or something like that together, right? Or different thicknesses of material. You sweep, sweep up into your thin material, and then stay longer in your thicker materials, stuff like that. Seems to be pretty good technique.

Yeah, that's interesting, because every every weld I did the other day, I did straight lines. I didn't do any kind of circle motions or anything like that. And I would control the size of things based off of the angle of my torch was I pointing more at, you know, a thicker piece or a thinner piece, or controlling my amperage to change the size of the weld pool?

Because I was, so I wasn't really controlling the amperage at all.

Oh, you're just gonna have a full 100 100%?

Yeah, so I would adjust my so I'll do a little test spot and figure out what kind of amperage I would need and just the machine for that. I still don't have the dexterity down on my foot to properly do like the 474 70 kind of thing, the pool scene basically. So that was kind of like a hack around it. Maybe? I don't know, the welds are not pretty good. Yeah, yeah. I mean, they look fantastic. And then like, afterwards, I took a big sledgehammer to him, and I could not get them to break apart. So it looks they look fine. The definitely that Instagram welds, that's for sure. No. Yeah, I want to get before the next stream too. I want to get one of those like finger controls. Because actually, I did was practicing that kind of like, if I had a fake finger of control, like, could I still maneuver the torch and the way I needed to? And like very my finger pressure. And I was able to do that. I'm like, that's way easier than control, at least for me. So cool. Yeah. So yeah, thanks, everyone for showing up. We'll do it again. So on with the podcast, I guess. So this is a article that one of our friends Smith, Mike Smith sent us. And I thought it was really interesting, because I was one of those. Like, I said, I want to comment more about industry news on the podcast. And he was like, bam, slap this thing down. And I'm like, well, there we go.

And it's a it's a spicy one.

So the article title is destroyed. TSMC if China invades to make Taiwan unwarrantable says US military paper. So is this a US military paper? It's not like the US military says this. It's like, it's a paper that some people in the military wrote probably has like a thought experiment or some or an opinion piece or something like that.

I'm sure there's a bazillion documents out there that that like if this country is invaded, open this envelope, and it'll tell you what to do. You know, like, I guarantee you there's all kinds of contingency plans for probably.

But what this basically I haven't read the actual paper, I just read this article about the paper. Yeah. But the idea is to destroy the economic reason for West Taiwan to want Taiwan. And it's written by Jared McKinney and Peter Harris, for those that want to look up those people. But basically, it goes into kind of like the history of how Taiwan has been able to maintain its sovereignty in the fact that you know, US military just kind of parks a big aircraft carrier offshore and the projection of power basically preventing China from invading and capturing Taiwan. So how so this paper basically goes into how do you keep Taiwan sovereign and free and not enter world war three at the same time. And what would a invasion of Taiwan have? It's like my thing rather read this was when we already have unstable global electronic supply chain, how more worse can it get? Much worse, right? Yeah.

I mean, everyone's having problems. But right now, when it comes down to sourcing electronics, the answer is like, eventually, you'll get what you want. I think this paper is more, that eventually becomes a lot longer. Yeah.

And then it also goes into you know, what if China just wants Taiwan because they believe Taiwan belongs to them, which is what they that's what the CCP believes. And what the idea behind destroying TSMC in that regards, is it basically would shut down all their high end military chips, because all that stuff comes from TSMC right now. And so it would be China going into a big war effort. And then they can't make anything anymore, at least the high end stuff. You can make ak 40 sevens in your basement and garage. So doesn't prevent that prevents high end military airplanes and tanks and that kind of stuff very manufactured. But on the global electronic supply side, I had to look it up, but I wanted to see kind of like who T s MC makes chips for. So TSMC is like a one of the premier chip manufacturers, they don't really design their own chips. I'm sure they do. But they're mostly known for being a contract chip manufacturer for a lot of chip designers. Notably, I think Apple is their biggest customer right now. I think Apple is like 30% of their revenue. And because Apple, they have those new, like all their chips in the, in their iPhones, for example, are apple chips. But Apple doesn't own a chip fab, they contract that out to TSMC, for example. So you have Apple, AMD, Nvidia. And so when you go down that list, you're like, Okay, those aren't like, if Apple AMD and Nvidia couldn't get chips anymore, because T TSMC got blown up, right? It wouldn't really affect us. In terms of like you and I, Steven.

Oh, as we don't mean as designers, it would affect us in terms of like, we can't get cheap computers and things like that when we're trying to write.

Like our designs, we don't typically use those kind of those really high end chips. But then what's also on this list is Broadcom, which Raspberry Pi's.

That's the one thing that's gonna affect this is

like the first one on the list. I'm like, Well, I don't buy Apple devices. I buy Intel CPUs. And then I do have an Nvidia graphics card, but you can't get those anyways, no matter what right now. So it doesn't really affect me.

TSMC has, gosh, it's so I don't remember the number. I'm trying to look it up right now. But it's like 20 Different fabs in Taiwan. It's an enormous amount. And they have in fact, I'm looking here, what is it? Four Giga fabs that are 300 millimeter wafers for 200 millimeter wafer fabs.

Yeah, so this is this is so those four I listed, yeah, are doing the high end, small nanometer stuff. This is not even getting to everyone else that's using their large nanometer scale stuff like 45 and larger, which is what stuff that Steve and I use all the time.

Right. Yeah, your jelly bean stuff. Yeah. So I'm sure they make they, I mean, they make a ton of stuff. Let's just be

yes. Yeah. Does that go I'm gonna bet you're like Silicon Labs is probably on that list.

And NXP some of their stuff is on there. NXP? Yep. I'm trying to see like, I'm trying to see what other names that we would just know right off the top of our head is just made fizzle, like grow on that list. I'm not seeing that. But was it Altera some analog devices? I don't know a lot of stuff.

Yeah, they Yeah. Basically, I think probably any Every single fabulous chip manufacturer or chip maker probably has something made at TSMC.

Yeah, there's, I'm sure there's a lot of cross pollination with all that.

This is a very interesting question to ask. As electrical engineers, I guess is, where does your morals lie on this kind of stuff? is would you be willing to give up all that? For the freedom of a country, basically?

Yeah. You know, what's interesting is, so I'm looking at the, I'm looking at the Wikipedia page for TSMC. And it says that they're their revenue in, what is it 2020, their revenue was 1.3 3 trillion. And if you go to Taiwan, and look at the GDP, the nominal GDP for the country is 759 billion. So like, just TSMC, itself, their revenue is larger than the GDP of the entire country. So yeah, it's obviously like, that's the thing that you're, you know, like,

well, it's part of the thing. Because what it's, it's kind of the, it's part of it. And so this is also another thing to think about is TSMC. TSMC, has a lot of US company IP, as well, this is actually not touching this paper. But what I thought about is that there's a lot of IP that, basically is to say, China took it over. Now, the Chinese government has your IP for your high end microcontroller, or high end CPU now. And that's, that's probably making a lot of a lot of business people squirming a little bits.

Oh, yeah, I'm sure. Yeah, I'm sure people are sweating it. But at the same time, I, you know, I would not be surprised if we have a few choice nuclear subs floating around over there. You know, just keep in peace.

Yeah. So it's gonna be interesting to see how that goes forward? Because it would it's one of those like, what's worse? China taking over Taiwan, and it's and, or is not being held by microcontrollers for another couple years?

Yeah, it's, I mean, it's tough. There's not there's not a really easy answer to there's

no, there's no solution. But because the right now it's just been status quo for like, the past 20 years. And that's also not a really good, like, situation to be in. Right. You know, and parking aircraft carriers off the coast of investors, like you better not come over here. You know, what, if they do come over there? What are you gonna do at that point?

Well, that's when it gets real sticky. Right? You know, how many how many? I was looking this up the other day, not necessarily wars, but confrontations. Start with, with, you know, a simple target being attacked. We've had multiple in our history as, as the United States, where it's like a boat get sunk, with some, with some Americans on it. And we go to war because of that. And like, there's, there's plenty of reasons yes and no, around those kinds of things. So like when when tensions are high, it doesn't take much to spark a fire. I would

say Taiwan is probably going to be our generations. Cuban Missile Crisis, probably.

That's interesting.

I'm hoping it never gets that tense. But I could easily see it being getting that way.

You know, I also wonder like, if, if something like this were to be enacted, would they just instantaneously destroy all the fabs and tried to do it all in one sweeping movement just like get it all done? Or are there like a handful of the fads that are the most desirable? So in other words, like take out five of the top fads and then the remaining 15 Is that still worth invasion?

It's partially about the economic reason. What Chris in our chat brought up to and I brought up earlier is the CCP believe they believe that Taiwan is still as actually part of China right now. Right? Like that's what they believe in. And like, like when you listen to a lot of politicians talking about they tried to dance around, when not they call it China, or they call it Taiwan. There's a whole fumble what earlier or late last year about that? Yeah. Were we had a US, oh, US diplomat called Taiwan, Taiwan? So

I mean, economically they're treated separately. Yes. I don't know. That's scary.

I think I think it's gonna it will probably escalate to that. Because there's also we talked about little bit like Ukraine and Russia right now. I honestly think with that this is my personal opinion, nothing with Matt crab or anything like that, or Steven, I personally think the US will probably stay out of that. But Taiwan, on the other hand, there's a the US has vested economic interest in Taiwan being Taiwan. And same thing with South Korea being South Korea. So yeah, as Chris said, in chat, Taiwan can be a smoking pile of rubble and China will still want it because they have to save face.

Ah, well, I think it may be more than save face, I think it would, if there was something have to happen. It kind of goes back to your what you were saying earlier about ethics and morals. It's like, not even ethics and morals. They just believe it's there. So like, regardless of its state, it's it's theirs in their mind. So

you preventing them from having it. But it's also you're making sure they don't have that economic advantage at that point, by getting rid of it. So yeah, it's interesting to think about everyone out there that's listening to this podcast, think about when you buy that next piece of that components, or buy that next thing on Amazon that's made in China, maybe you can shop around and find something that's not that's maybe made in Taiwan, or maybe United States or Mexico or Canada,

there are alternative sources, China's not the only place.

And that is not a don't buy anything from China. Because there's sometimes you need to buy something. And that's the only place totally understandable. But where you as an individual can hurt the CCP the most is with your wallets. So

I don't know let's I mean, we'll keep an eye on it. But like, this is, this is a hard topic. That's that's nervous laughter by the way. Yeah. I love why it's not wish there could just be peace.

Me too. And nuts. Man, wouldn't life be so much better? That would be the case. Okay, all right, down myself. Onto the next Alright, let's

let's let's move on to some.

I'd love to talk about this in our Slack channel, by the way, because this is a very interesting topic. And I'd love to hear what other people have to say about it. Yeah, for sure. Next topic.

Yeah. Okay, so yeah, let's, let's, let's change this up a bit. So I've got something that I've been wanting to make for a while now. And I actually have a reason why I need it. I actually just need what I'm calling the mega load resistor, which I just need a giant, low valued resistor for doing some tests on some amps that I have. So most of most of my amps have outputs of 248 or 16 ohms. And for the most part, the only loads I actually have for most of my amps that can handle the output power are actual speakers. And I don't want to do any really heavy testing with speakers that are just continuous 200 Watt, you know, obvious reasons,

then you can make your neighbors love you. Oh, yeah, absolutely.

You know, what's what sucks. So my basement is a walkout basement goes right to my backyard. I've got kind of got lucky with that. But that also means that, like, if I'm really super loud, my neighbors can still hear me on that. So I don't get super loud very often. It's a it's a rare occasion. And it's, it's fun for a short period of time, but I just don't do it very much. Now, here's the thing I had, I had a friend of mine, purchase an old amp and was like, Hey, will you take this app? Will you fix it up a little bit for me and just take a look at it? Sure. Yeah, absolutely. So I got it. I did a bit of a rest restoration on it. It had a bunch of unsafe stuff in there because it was just old and just a bunch of stuff. That was scary. The like it had the death cap. It had a death cap, just a two prong cord. And then like the fuse was on the neutral, and there was just like a handful of other things that were just like, oh, I don't like this. Also it runs 750 volts and there was a lot of wires that We're close to the chassis at 750 volts. So like I rewired a big chunk of it just to be like, I don't like this. This is not cool. I gave it to the guy. And, and he took it. And like the very first thing he did was he spent an entire day recording on it. He had this amp, it's 150 Watt, just monster amp. He had it running full tilt, like DOD, like the peg, all the knobs for everything I live in everything we live in for eight solid hours. Now. I mean, it wasn't producing sick signal wasn't going through it all the time. But he had it for eight hours doing that. And I'm guarantee this guy's deaf. But regardless, he had this thing completely juiced and records an entire album on it and was like, Man, this thing is great dog so much. This is awesome. And then a week later, I start getting texts from him, dude, it's blown fuses what's up? Like, oh, great, of course. So like, we ended up finding out that he, his buddy bought him a guitar pedal. And he plugs this guitar pedal in. And the first note he plays it just the amp blows a fuse. So like a regular thing that goes in the front blows a fuse on this, he tried like three different fuses. And it blew consistently. So it's like, oh, there's something wrong with it. And then can you fix this? Like, I really don't think there's something wrong with the amp. I don't think I did a bad job on this one. And so I go pick up the amp, and I get a text the day after I pick up the amp. So this one that blew up is in my hands. I get a text from him. And he's like, Hey, man, I plugged that pedal into another amp and it's blowing fuses to now like, yeah, okay, I see what's going on here. So I'm actually going to pick up that pedal because I've never this Never once have I ever had that happen. I've never seen a pedal cause an amp to blow a fuse. So I have no idea maybe maybe it's just outputting nine volts, just straight up, like the it's just a battery on your nine volt sine wave. Yeah, just will not even not a sine wave, I'm talking about just straight up nine volt DC, and that just might just cause the app to go into. It just revises the app to just be shorted effectively. Yeah, maybe I have no idea. So regardless, I've got this app that I that it's, it's still working, I just need to go and like, double check it and give it back to him. But what I realized is all that story to be said I don't have a load for something like 150 watt amp. And for like, two or three seconds, I can take an app like that and put it ping it maximum. And and listen to it for a second. And then you know be like oh my god that's louder than I need right now. But for like prolonged full volume test on any the amps I make, I don't have that. So all this to be said, like this whole story is just, I want to build the mega load resistor, which is just like, I don't know, maybe like 1000 Watt, two fours force eight to 16 Ohm resistor, something like that. Something that I can be confident of putting a signal source into an amp, turning the amp on maximum and just dumping it into a resistor, I can be confident that it's not going to catch on fire, and it'll just sit there and cook all day long. You know, 150 watts or something like that. And I would love to get that pedal from my buddy and test it on this 150 watt amp without me having to have speakers be the actual load? Like, no, I'm not doing that. So what it boils down to, it's easy to make just a bunch of resistors in series, right? Okay, whatever I can make a two ohm or a four ohm or whatever. My question is. I've been looking for resistors out there that that suit this need. I can buy a 300 watt, one ohm resistor and put two of them series and have a 600 watt, two ohm resistor, right? I can do that if I wanted. But would it be better to buy a bunch of 50 Watt resistors and spread them out? Would it be better to buy a whole bunch of one watt resistors and spread them out? Or is it better to concentrate all the heat into a resistor that's rated for that heat? And I guess I really don't know the answer to that. What

I would say that it comes down to the parasitics

just like the the additional capacitance and inductance. That gets added in there. I mean, there's so minor that I don't like I don't think that that matters, right?

So I think in the end, it probably doesn't matter as long as the concentrated one is also rated for what you need. And it has the surface area to radiate usually, usually resistors are rate the least power resistors are rated at a constant wattage, so like temperature, right? It's like, you know, 70 Fahrenheit is usually what they rate them to. Yeah. So it's like at 70 Fair in height, it's rated at 5050 Watt this and there's a derating curve, right? Yeah. So I would say, as long as you're in that, then it doesn't matter, right? Doesn't matter for this application, because there have been some applications where like, oh, I need it to be super skinny and long. So I'm going to chain a bunch together, right? Yeah. One question I have about this is Rs. Is that an actual decent representation of a speaker?

No, it's actually a really bad representation. Yeah, because the speaker is not a constant impedance curve. It will, like a lot of times, like when you say, an eight ohm speaker, you're sort of averaging out its whole curve, in a way, but it's eight ohms. At steady state, pretty much, it will be eight Ohms, at maybe two or three frequencies, because every speaker curve has like a resonance point. And then it trails off and does some other stuff at high frequencies. So it will be eight on somewhere, it might be somewhere on that resonance peak. But but the whole thing is like that, where that whole curve lies in is around eight ohms. So it's safe to design with eight ohms in mind, and, and that will work. So for long term testing, where you're not where you're testing the viability of the components inside the amp, it's safe to use a constant resistor, in my opinion. Now I have seen people purchase, like just the drivers and not have them connected to a cone and then drive that so you can get more of a read representation of the curve, right? The impedance curve, I don't care that much. I just want resistance. I just want something that I can just dump heat into for a few hours. Yeah. So

like you want to you want to load up your, your drive tubes.

Right, right. Right, right. Yeah. Because if I'm manufacturing amps, I'm thinking, every amp I manufacture I always play on, but I, I rarely take them to maximum for a very long period of time, mainly because I don't want to sustain that. But I'm thinking if I'm manufacturing them, it would be nice to torture test. Every amp I make for say, like 1015, maybe 30 minutes, whereas, you know, take a take a sweep generator and have it sweep frequencies nonstop at maximum volume for 30 minutes, it can survive that. Sure. So I don't I don't know the answer to that. So regardless, I just want to make like a big chunk of something with a bunch of resistors tied to it, and it goes to a quarter inch cable. But it just had me thinking like, is it better to buy fewer resistors or more resistors? And what is the trade off between that? I guess it's just spreading out your heat,

right? Yeah. matters in the end? Yeah. Oh, for sure.

It doesn't matter for that. From the amp side. The amp doesn't care. It's just like as a big old eight. Oh, no, I'm

saying this from a dissipation standpoint it probably the probably it does matter. But a lot of times when you look at power resistors again, the rated for whatever wattage at and you have to look up whatever standard it was tested to like, yeah. Is it like enclosed in chassis or exposed to like just the room? Basically, you have to look at that what standard it was says

maybe just get the big ones and put them in a bucket of mineral oil. And, and just leave it like that. Right. Leave it outside. Yeah. So I don't know. That's the megaload resistor. I gotta go. I gotta go buy some resistors and just solder it up.

What would you could just do a big coil wire

into a bucket. Just cut it to length. Yeah, cut blank. Yeah, I do. I

mean, that's what the speaker does. Effectively. Yeah.

I was thinking, just making one long string of resistors and having different tabs for two ohms. four ohms am 16 ohms. Okay, yeah, just so I can select it based off of any app that comes in, because I'm doing repairs on a fairly regular basis. Now. Mainly, I have a handful of friends around here in Denver that are all like, oh, yeah, if something's broken, go to Steven. He'll fix it. And I'm that kind of guy. That's like, every single time I get. This is the last one. And then they're like it's broken. I'm like, Okay, I'll fix it for you. So like, but like it would just be nice to have that with cars. Oh, yeah. If your buddy's like, hey, Parker, will you come fix this? Yeah, yeah, yep, you

will bring my house. The problem with you is that they have to like they leave the amp with you. Which is fine because like most people Don't need their amp with them all the time. Oh, great cars or whereas a car, especially here in Houston, you need to get around. And so a lot of times I'm like, I have like a checklist of what I won't do, because I know I can't do it that like one day, right? So, but like if I'm like, okay, I can get that done in like three hours. Yeah, you can come over and bring the parts and we'll wrench on it. But, uh, but I'm like, yeah, if it takes more than a day, no, you're not parking your car here.

So, okay, next topic. This one will be fast. This is this is a PSA to everyone.

Public service announcement. And it

I don't know if you've ever run into this Parker. I doubt it. Because this seems to be like an audio thing. This seems to be like a musical instrument thing. But like, okay, gooped electronics You Ever Have you ever run into Gupta electronics? Do you know what I mean by Gupta electronics?

He talked about this. Don't goop your electronics gooping. Your electronics is a brand of adhesives.

No, no. Good. Okay, so goop electronics is when you purposefully put like epoxy or paint or something over your electronics to make sure that people can't see what it is. Or no circuit is.

Yeah, okay. I've run into that before. Yeah, don't goop

your electronics does just just don't if you're manufacturing stuff for

this reason? Well, there's reasons to do that.

No, okay. Well, okay, no, there's plenty of reasons to apply epoxy or things to here electronics, or to, you know, pop them or anything like that. But don't just trying to like keep your trade secrets by just pouring a bunch of black goop all over it or, or other methods. Like, if somebody wants to reverse engineer your circuit, they're going to do it. Just don't, don't try to protect your secrets by making it annoying. And here's, here's the story. I'm not going to call out the company here because I don't want to but it's just, I had another amp that another friend brought to me. And this was a very high end, one, many 1000s of dollars. power transformer bit the dust on this thing, magic smoke. Okay, great, whatever power transformers are replaceable. But because it's a very nice amp and a very nice power transformer, I wanted to replace it with as close to the original as possible, because that can have effects on the sound. And that's not what the person paid, the person isn't paying me to replace it with something that changes in sound, they're having me repair it. I have tried for two months to get in contact with the company to just ask, Hey, I'm repairing this. I'm not trying to figure out your amp. I'm not trying to do anything special here. I'm just trying to repair for a buddy, can you give me specifications? Can I purchase a transformer from you to replace this, like I'm literally just trying to fix it I've gotten they won't answer my phone calls, they won't email me, there's just nothing whatsoever. And on the transformer, they had painted over part numbers on it, so you can't see any of that stuff. And finally, today, I was just like, You know what, I got a brand new thing of acetone, I'm just gonna go at it. And it took the paint right off, and I got to see the part numbers on it. And and of course, it's a it's a, from a transformer company that's no longer around. But I can get the specifications. And I can find a suitable replacement, that it's not as perfect as getting exactly what I'm looking for, I would love to get one from the manufacturer. But like, if you're going to do things like goop your electronics so that people like me can't find out what things are and then have no customer service, like it doesn't doesn't really reflect well on your company. So I don't know, like, in my opinion, that's just not very helpful. I'm not here to make money off of your stuff. I'm literally just fixing it for a friend kind of thing. So I'm gonna be able to get it done. If I wanted to reverse engineer to your circuit, I could do it. It's not very hard. That's not my intent. That's not what I want to do. So I had to, you know, bust out some acetone and get through your goop to just find out a part number so I can go and fix this thing and get it back to the person who likes your product. You know, so yeah, all said and done. Don't goop electronics, especially something that's intended to be repairable, don't goop something that it has replaceable parts in it, you know?

Yeah. There's other reasons to goop stuff like vibration. Oh, environmental. Yeah. Environmental and that kind of stuff. But yeah. What was it? The term security through obscurity is not real security. That's what that's why, when, in hardware, your schematic is not your trade secrets. I am sorry people out there that had designs. All you got to do ship that board to a reverse engineering house. And then you got this schematic or you just do it yourself like Steven just said,

yeah. Like, if your product. I don't want to make this sound super bleak. But if your product is so amazing that somebody wants to reverse engineer it, then putting some crap on your parts is not going to stop them, they'll they'll just do it. You know, even if it means destroying the thing to get to the parts and see them, they'll they'll still do it.

Yeah, and this is the thing about if you because there's some people that will some manufacturers that will like put paint, or laser off the tops of chips. So the paint, you just rub, it just comes off, and you can read the laser marking underneath it. But I have seen some manufacturers laser it off. Just what you can do. You can decap it, and then you can figure out what chip it is. Right, right. Yeah, it's, it's frustrating.

The frustrating part isn't that like, I'm not saying don't be proud of your thing or don't want to make money off of your product? Of course do that. But if it is intended to be repairable, don't arbitrarily make it difficult to repair, and then don't have terrible customer service. past that. You know,

are you flipping your stance on right to repair Steven?

Oh, no, I don't think so. Because you know what, I'm still going to be able to repair this. Yeah. Whatever. So sorry. We're getting a little ranty here. But don't goop your electronics is the is the bait the basis.

So I have completed my first project of 22. My mother's golf cart is now fully operational and ready to go, like, like ready to deliver. Ready to deliver Nice. So it's all all the paints done, it's all assembled back together, all the wiring is good. I drove it 35 miles an hour, which is, by the way, way too fast for a golf cart. That's written. And so I had to I had to feature creep the golf cart. I put it in a user mode selector switch, so that it's keyed as well. So it has three modes. It has normal, which is capped at like 2930 ish miles an hour, which is borderline too fast for that cart. And then there's a warp speed, which is unlimited power, basically the motor, it the motor will pull everything. And it actually has a very interesting mode in that motor controller too called turbo that's also enabled. It's like the you know, the old 386 or 46 that he had turbo button on it. Oh, yeah. So with the turbo button does on the golf cart. Is once it's because basically that motor has a it's not a permanent earth magnet motor DC motor on it, it actually has field windings that can be energized. And so you can you can you basically have a field map for your for your electric motor. But what the turbo motor does is that high RPM, so once you hit like the cap, is it reduces the field voltage. So it can spin the motor even faster. at much lower torque and efficiency, right? The efficiency goes through the toilets. But the RPM just flies the RPM can shoot like another 1000. And that's where you go from like 30 to 35.

Yeah, I was about to say like incredibly diminishing returns, right?

Yeah, way diminishing returns. Because like you hit 30, you hit 30 in like, oh, man, a couple seconds in that that cart, it's that quick. And then to get the 35 it takes a lot longer because that the there's just not enough torque to get that faster. But it will get that speed. So basically normal mode has turbo turned off and I limited the current a bit so that it's not, you know, dumping all like 400 amps into the motor at once all the time. And then it has warped speed, which is turbos enabled all the amperage. And then there's another mode wrong Call on the Kubi cruise mode. So that's when you're like just cruising around the beach and you got your, your, your cocktail. So everything's like turned way down. Like I turned off a turbo was turned off amperage just turned way down, the throttle response is like, zero. So like, it won't jerk around or anything. It's for cruising. It's a cruising time.

Everything's a bit mushy.

Everything's a bit mushy, which is what you want when you're trying to enjoy your dream. Oh, 100%. Yeah. So that's, that's honestly what that carpet is used most for is just like, cruising out and watching the sunset and then cruising back. So do you go 35 miles an hour to do that?

In warp speed mode? Do you have it where turbo kicks in at a particular

throttle position? It automatically does it? And does it based on speed. So it looks at the field map. And RPM I think because it's just a toggle in the configuration, you can't actually like set the parameters. So basically, what it does is it extends the field map out and drops the voltage from my understanding to the field. So it allows it to spin faster at much like it it starts to gobble energy.

Yeah. Because in other words, you don't really ever want it to do that.

No, you only doing that because you want to go an extra five miles an hour.

Yeah, I guess it's worthwhile.

Yeah, that's only doesn't warp speed and I put it in a key switch. And when you're in normal and Kubi cruise mode, the key is not captive. Because the because there's this key switch has, I should have the part number that's really cool is key switch came with two keys. So the idea is, the golf cart key is also attached to this key, right. So you put your key in, and you can turn it to normal. It's usually normal mode. So let's say you want to turn to Kubi put your key in a turn to Qb and pull your key out and then you put your key in the golf carts. Right. So you can't, the idea is you can't separate the two keys, right. But in warp speed, the keys captive in it. And so you can't turn on the golf carts. So you have to have the spare key that's not attached to the golf cart key to put it into work mode. So it's kind of like a safety neck. They don't want to accidentally turn it the warp basically

seems like a Hollywood activate the new kind of situation where you have to example you know, on the kind of three turn the key.

Yeah, we got we got blow up TSMC. So

yeah, take Parker's turbo golf cart all the way over there. Yeah.

It is. It is a blast to drive around. I did find one problem, the first first test drive, I have to set up the post a picture of like, it was like half like I didn't have the front on the golf cart at all, like the front housing or like the roof or anything. Like I was still waiting on some some fender parts by Mike it's all electrically done. Let's go around the block and make sure it doesn't, you know, burst into flames and drive it around. And from a dead stop. I just mash the throttle. And it almost wheeling the golf cart almost really. And I was driving that straightway as fast as I could go on in my neighborhood. And it had a slight bend to the road, right? And so I'm like, oh, I'll just turn the wheel. Just steering it right. Correct. Correct, Stuart, nothing happened. My dad My dad is with me, right? But he

almost pops a wheelie with two male demons in it. Yes. Oh, wow. Okay.

Now, I didn't have the whole front on so like 60 pounds of stuff in the front stop there. Okay. And, and so I'm like, I'm like trying to correct it. I'm like, nothing's happening. And then my dad's like, you need a turn. And I just took the wheel and I spun the wheel and the wheel just spun around in circles. And then my dad's like, Ah, it's like hit the brakes. Which by the way, I already did a brake check. Because I was the first thing I did was like, does the brakes work? Yes. I hit the brake. Unfortunately, I still hit the curb going like 15 miles an hour. Good thing I didn't hit going 35 So you have been launched out of the golf cart. Oh, there's no seatbelts so it was like an actual crash. Yeah, I just curved it. So like didn't even go over the curb, it just bounce off the curb and then into the into the road. Basically what happened is on it can accelerate so hard that the intermediate steering shaft will decouple from the splines. So where it because they cause the steering boxes on the axle itself. And so it the steering column steering rack basically can move up and down with the axle. And but your steering wheel is and shaft is like on the frame. And so there has to be movement in between. So it uses a spline slip shaft to do that. And so yeah, that's spline ship, slip shaft came apart. And we drove going like 35 golf carts,

that's scary. Yeah.

Great thing is all it was really easy to fix on the road, because all I had to do was like, lift the front of the golf cart, like, seriously, like three quarters of an inch. And it's that. And so that's what I did. That was the last thing I had to do was I took the steering shots, I cut it and I added another inch and a half on to it. And so I have basically the it's now right in the middle night, but the reason why it was never a big problem before is because still the the suspension was so blown out on the old on the old setup. And it also had 300 pounds of lead acid batteries in it. Because now it has lithium and I think the whole lithium battery pack weighs like I want to say like 90 pounds, instead of like the original original ones, like 400 pounds, so you have 300 pound less of battery in it.

Wow. So so it's got a lot more spring in it step.

Yeah, that's for sure. But it's a blast to drive. I'm gonna let my mom drive it with turbo once and I think she's going to like be like me and be actual, like, you have to put the fear into yourself of how scary that thing is to drive. Because the it's not the speed. Really. It's just the geometry of that golf cart is not set up to go that fast.

Yeah. That's way too fast for a golf cart. I mean, are the tires rated for that?

Yeah, they're rated for that. Okay. It's that big problem. The when you go online, and there's a couple different like online forms for golf carts, buggies unlimited. It's like one of the big ones. And people are talking about like, I want my golf cart to go like 45 And I'm like, holy shit. Yeah. Why? I don't think people real and like my golf carts are only going like 16 I want to go like 45 I don't think people realize how fast that isn't golf cart.

cars nowadays, like decouple you from like, reality, like so like, because they're so quiet and smooth and everything. Like, the first time I went 85 miles an hour on a motorcycle. It's like, oh my god, like, that'll scare you.

Yeah. Why I drove my my dad's new Tahoe was like that, is I was driving to work. And I was going 85 And I did not know I was going to a five. Yeah. Whereas I drive either one of my jeeps and oh, you know, you're going above 75 Is, is something else in a jeep?

For sure. Yeah.

It's the noise and just like, yeah, it's actually just how smooth is because?

Yeah, with power steering, you don't feel anything? You don't feel

like everything's damping out now. It's all electronic.

Yeah, yeah. 100% and you don't feel like when temperature changes in the in the in the air? You don't get hit in the face with bugs. You know, like, this kind of stuff like yeah, when you're when you're out there and in the elements going 85 or faster. I you know, I I swapped motorcycles. I used to ride a cruiser back in college, and I swapped motorcycles with a guy he because I've never driven a crotch rocket and he had never driven a cruiser. As we were going down the freeway, there was no one around. We're doing freeway speeds is 6570 Something like that. And it's like, you know what, I'm on a crotch rocket. I'll give it a shot and I pulled the throttle. And I just went went past that. It didn't even feel like a few seconds. I looked down. I'm doing 110 on this thing. And it's just like, oh my god, like it's crazy. It's absolutely nuts. Like, no, thank you.

Yeah, it's it's interesting for sure. Yeah. It's a The relative speed, I guess, I can't imagine what it feels like when you're flying, because when when you're a passenger in the airplane, you just look out the window and like, especially like when you're up and up and altitude, it doesn't really feel like you're going 600 miles an hour. Whereas a bunch of the pilots get more of that, because they're facing forward, they can see out forward, maybe yeah. And actually, when you're like, near closest to the ground, you're not going as fast anymore, but you can definitely get your speed because you have a reference closer references now. But one time, I went on one of those touristy, like airplane rides where I flew in a b 17 Bomber. And by the way, if anyone gets a chance to do that, it's a lot of fun. Go do it. That feels like you're going to bazillion miles an hour. And you're only going like 300. Like 747 feels slower than that be 17 Does just because of how smooth it is. Noise. Yeah, the noise. The fuselage is not perfectly sealed, everything like that. And by the way, if you ever can do that experience getting in the nose of the plane, because you are in front of everyone on the airplane at that point. Even the pilots are behind you. Right? Yeah. And you can watch all the engines turn on.

That's that's another thing. Like you don't want them making that sound. When I started out, yeah, the prop planes I flew in one few years ago because I needed to hop from one city to another and it was like a 30 minute flight in a prop plane. And like, talk about like, vibration and noise and just like not smooth like it's It's insane how smooth and how much comfort there is, you know, minus the seats in modern flights. Like it's incredible that they can do that. So you get in an older like just prop plane and it's like okay, yeah,

this is yeah, now I feel everything. It's the Jeep of the skies.

Yeah, a brick with with wings on it. Yeah.

I think we're gonna leave that topic off for the next week.

Yeah, I think yeah, we got we had one more but we'll push it off. So

well, I'd love to hear what people have to say about that or that TSM is TSMC article that we talked about? Yeah. So so that was the Mac fab engineering podcast we are your hosts Parker Dolman

and Steven Gregg letter one take it easy

Thank you. Yes, you our listener for downloading our podcast if you have a cool idea, project or topic. Let Stephen and I know Tweet us at macro hub at Longhorn engineer or at analog ag or emails at podcasts at macro live.com. Also check out our Slack channel which you can talk about everything we talked about on this podcast at macro hub.com/slack For the free invite. And then if you want to listen to us live stream our recording. That is twitch.tv/macro Fab