 the Dyson, except DIY. So yeah, some time ago, my partner and I were talking, and we didn't want to deploy the large vacuum cleaner because it had a cord, and it was very annoying to deploy. And so the room kept getting dirty, and we decided that we wanted a cordless vacuum. But cordless vacuums are expensive, so we looked for something we could treat different. And there's this hackaday page about the Dyson, and open source vacuum cleaner. So this is how it looks, more or less. Yeah, there is a V1 and a V2. At the time that we started planning it, there was only V1 available. But we procrastinated until V2 came out, and we completed V1 anyway. So the Dyson, more or less, looks like this. And it's made from RC parts. Can you go see the camera? Let me see this. Yes. All right, so it looks like this. It has an RC battery, one of these things. And for whatever reason, the person who designed this decided that it would be a good idea to use a battery as a handle. Yeah. And so it's a C60 connector. And then it goes to this ESC over here, which controls the mortal. And this is an EDF, an electric duct fan. Yeah. Inside, there is a servo controller, which is in one of my tabs somewhere here. OK, I can actually click on my tabs. So this is the duct fan. This is the ESC. This is the battery. This is the exploded, I mean, how it's supposed to go together. And this is a project planner that my partner did. So yeah, price comes down to about $123 bucks. And here is my photo album of stuff, which hopefully you can see better. So yeah, I'll click that. And over here, I think we'll be able to view it. Oh yeah, I forgot. You can't hear, right? But it is really, really loud. So yeah, it works. And here's another shot. Yeah, that's about it. I have some, well, these are the models that I printed. And this is sort of how they all fit onto the plate together. Yeah. So yeah, it is quite a janky thing. I didn't have the right screws for it. Yeah, this thing demanded for self-tapping screws, but I only had metric screws and some weird assault run through self-tapping screws that some fit in. So it was kind of like clutched together with this match screws and duct tape and hot glue. But it works. Yeah. So any questions? The battery is 12 volts, is it, something like that? No, the battery is, it's a 2S battery. So it's two lithium-ion cells in parallel, I mean, in series. 7.4 volts and 4,000 milliamp hours. OK. How much does your stand? Sorry? How much does your, how much does you spend for the whole thing? $123. Do you have a internal, like the Dyson, the QMATRI has like a filter, have multiple layers of filter in it. So do you have like any sort of filter in there? Oh yeah, there is a filter. Hang on, I'm just going to pop it open. It is kind of disgusting. But yes, there is a filter. My pop it up, or? It's a paper cup. I got it off Aliexpress. It's some, I forgot what it was. I think it was an air-con filter. Oh, OK. But it works. Yeah. Have you considered using a centrifugal fan instead of the XO fan that you are using? Because if you're higher pressure, if you can do it with a much better pressure suction, then maybe you can run it slightly lower RPM, maybe softer. Yes, that is true. That is absolutely true. And I would have done it that way if I designed it, but I didn't. Overall, it was designed by someone else, and all I did was 3D print and assemble the thing. So technically, you could make like a conversion kit for people who have like spoiled vacuum cleaners and it re-use their long floor suction head, right? Oh yeah, that would be good, yeah. Yeah. It looks like it's already centrifugal because the inlet is also. It is a cyclone. Yes, it is a sort of a cyclone. It is a cyclone mechanism, right? So it's the cyclonic dust collector type thing. But the fan itself is not a centrifugal fan. This is an axial fan. Yeah. The centrifugal fan that I don't know who was talking about is the, you know, the screw cage fans, the kinds that are in laptops that blow out the side. They suck in the center and blow out the side. Oh, OK, OK. Go ahead. And you have a couple of questions in the chat. Someone is asking, what's the running time until you have to charge the battery? And someone is asking, do you actually use it for chores? Yes, I do use it for chores. As for runtime, I'm not sure, actually, because it hasn't. This is the first charge, and we've used it a couple of times already. It's been a couple of weeks since we assembled it. And yeah, it's still running strong. Also, well, while we do use it for chores, some time ago, before we assembled this thing, AliExpress went on sale. And I bought one of these flow vacuums for, I think, 40 bucks. Yeah, it turns out that this is a much better purchase. Do we have any more questions? Can we see the cost breakdown again? Cost breakdown, yes. Do you show the spreadsheet? Yeah, yeah, no one. So where's the, what are the costly items? OK, let's see. OK, charger and battery are 2,000. Yes, yes. The charger was, the charger is actually quite a nice one. There it is. Yeah, it is a very nice charger. So that's pretty amazing. Just looking at how you could get $120 down to support it. You would need to have a much cheaper charger, a much cheaper battery, and a much cheaper fan. Yeah, honestly, I think the fan was quite a decent one. OK, actually, this price might not be accurate. This price is more like it. It's, yeah, very good. Yeah, I didn't manage to get the exact same fan. HobbyKing was out of stock. Cool, thank you. Yeah. Do we have any more questions? OK, if not, let us move on to our big speaker, K-Ming, who will be talking about radar systems