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Current time:0:00Total duration:13:53

Video transcript

okay so this is our black & decker coffee maker want to take a look at what it's made out of and how it works this is the coffee holder and the carafe or whatever you would call it and so it's made out of glass and I believe the way this glass is made is is it's heated and blown into a mold and and then it's allowed to cool and and there's a little while it's still molten there's a mechanical device that creates the the shape for the for the spout there and this is a band of stainless steel that wraps around the edge here it's it's molded into the indent in the in the in the glass and there is a handle here this matte handle looks like it's made out of polypropylene it's a fairly low cost plastic it's no texture on it or anything fancy you can actually feel some of the the mold seam there but it's a very low cost handle and you can see this part just pops out it's got a snap fit there and again polypropylene lid and in handle and so it's that that stainless steel piece there really does a good job of holding all this together I think we can probably pry this handle apart and see what is inside of it I might need to get a larger screwdriver a smaller screwdriver so I can pop this apart and see if we can see if we can see what's on the inside of it it's not meant to come apart and it may be it may be solvent bonded or or something like that so we may not have a lot of luck with it but we'll give it a go oh it's not it's just a snap fit okay so you can see that that's how they molded the part there are two different pieces there and we're gonna go ahead and remove this this screw here just show you how it all goes together all right oh wow pops apart there so you can see there's a little bracket on the inside that the screw goes into and holds this steel band in place and that's what um the handle is held on by and then at the top there's just a little lip that holds the top of a handle there in place just a little piece that like folds over the glass and snaps on and so that's how that that that's held so this is made out of one molded part this is made out of another and this is made out of another and so that's how they made the handle there's three different molded plastic parts there and the mold came together like this and you can tell that because you can feel the mold seam on the inside of the handle there and you can also tell it because of the way the handles shaped that it would make it easy to pull the mold out this way and they they probably also had it was probably a three part mold and there was a section that also came out in this direction and yeah and then this is just another injection molded part that snaps on to this one as we've seen and this is the part that holds the handle on very important part and I think they they definitely paid the extra money for a stainless piece there because it's really important that that doesn't come loose and it probably gets fairly wet and so if it was you know made out of a regular steel or another material it might rust and could potentially come apart and we wouldn't want hot coffee on us now would we all right so that's the that is the coffee kettle all right so inside here's our coffee maker so we know that hot water we've got a we've got a container here and in in this container on the inside of the coffee maker is a is a space where we put our coffee filter and then we put our coffee grounds and we fill this with water and then we close the top and we turn it on and we wait and what happens is that hot water or that water that we pour in drains down a little spout in our drains down a little hole on the inside there you can see it right there and point to it with the screwdriver drains down that hole and it goes down into this underside so we'll take a look at the underside and see what happens down there okay so I've modified a screwdriver this was a low-cost screwdriver was a 99-cent one so I modified the end of it so I could take out these safety screws don't do this at home unless you have a professional with you because this is this is not meant to be taken apart that's why they use these special screw heads so you won't take it apart but I did want to show you what was inside and there we go okay again this is an injection molded part this is a co molded part it looks like which means that there were two different materials molded together and see if I can knock that screw out okay it wants to stay that's fine okay so this this material here is a these feet are made out of a softer material and this is a polypropylene material and so it's plastic a low cost plastic so the mold comes together in the injection mold this material and then once this material has begun to harden the injection mold the softer material so it's co molded or it's a dual molded part and you can see other parts are done like this like sometimes you'll see screw toothbrushes that have a soft santoprene and then the hard toothbrush um and they're molded in in one mold it's a dual shot mold in any case so that's the bottom and this this allows heat to get into our louse air to get into the heater chamber to vent out you know I think a little heat in there and so here is the heater this is where all the magic happens so the water comes down this tube and it goes around this horseshoe shape and then it comes up here and what content what can what causes the water to raise back up and go all the way up this tube which it does it goes all the way up the tube here and then it comes out this this apparatus here and it goes and drains out of these holes right into here and there's just a little piece of plastic that causes this part to line up right over the top of this when you close it and then water just comes up that and drains right out and into the into your coffee grounds and then makes your coffee so the heater does two things it causes the water to to go down this pipe expand out and to drip into your coffee maker but it also heats up the plate this plate right here and so the way it does that is it uses a material called nichrome wire which is a it's a alloy of nickel and chrome and it heats up really easily and it's a good it's a good resistor and so when it heats up the aluminum is also an excellent conductor of heat so it conducts heat very well into the plate and also into the water that's inside of it and there are a number of different safety mechanisms inside this coffee maker we've got two thermal fuses here and if it gets too hot those'll those will blow and prevent it from getting hotter there's also a temperature sensor here that can shut the coffeemaker down if it gets too hot and I believe what's inside of that is a bimetallic strip and so it could be a strip that has something with a low thermal expansion coefficient like invar which is which is an alloy that doesn't expand very much at all in heat and then it could be alloyed with another metal like say copper which expands fairly well in heat and so what happens is when those two metals are next to each other one of them the invar doesn't expand very much so it sort of sits still but the other one expands and it causes the bimetallic strip to Bend like that and when it bends if if it was conducting the electricity it moves away from the contact so so let's say this is the contact here it moves away from the contact when the temperature is too high and so they they choose those bimetallic pieces based on they calibrate them based on how much temperature they think it's going to take so though they'll pick how much you know the size of the metal and the the amount of metal and the types of metals that they alloy together for that strip or based on the temperature that they want the coffeemaker to get to so they don't want it to get to like 500 degrees or anything close to that so there's there's probably a temperature that they have chosen and and then they select a bimetallic strip that will respond to that temperature and shut the circuit off and that's I think that's how this temperature sensor will will work so we're gonna go ahead and take a rep take apart the rest of this so this piece right here is kind of cool it's a little bar that holds the heater in place and this little bar has the screws on it and the screws have these curious little washers on them and the washers are made out of a fibrous material that does not conduct heat very well and that is very helpful because you don't want the screws conducting heat into the plastic into this because otherwise if they conduct the heat into the plastic then the plastic will potentially get soft and deform and maybe even melt so we don't want that to happen so that's why we isolate the this bar that holds the heater in place so we're going to continue to take these screws out here and they are the screws are set in something called a boss a screw boss so that is just a protruding piece of plastic on the inside that holds the screw in place and you can see that the heater is is held in place that's got this it's got this paste around here and that's called thermal paste and that aids in the conduction it helps that it helps the hot temperature to be conducted from this horseshoe-shaped heater to the steel plate that the coffeemaker sits on and so we're gonna take these screws here out so these screws hold the they hold the plug in place or the wire in place and you'll notice that the wire is looped around itself and that is so that you can't pull the wire out of the coffeemaker and that's important because you don't want to pull loose any contacts because if you have any loose wires in the coffeemaker potentially that's a cause for a fire or an electrical short so we don't want that and that's that loop helps to prevent that if we go down a little further here I think we can take this part here loose we're taking the the two halves of the coffeemaker apart and you can see I don't know if you can see inside of that very well but down in there there's a little symbol that says P P and that stands for polypropylene so that's how we know what kind of plastic this is and polypropylene is a low-cost plastic that's widely used in commercial products one of the lowest cost plastics they use it in everything from dishwasher tubs to you name it coffee makers to hair dryers in any case some trick take this trying to get this screw out it's kind of in there pretty good and you can see like as I'm taking these screws out it's separating the two halves are separating so there see if we can finish getting this apart for you all right we got one more screw here okay so you can see this is how the two halves of the coffeemaker come come together whoa right so they come together like that and you know there's a bunch of screwballs is here and they actually line up with holes on this side so that you can press the two pieces together so these these two halves are injection molded the molds come together like this and like this and then the two parts come together and that's how they're able to create this shape and you can see that the that the water comes in this tube here gets heated and Rises out this to here and this right here is the is the ring that went around the inside right here and this is the the metal plate that the heater sat on and so there's a separate ring here that the metal plates that's inside of gives it a nice finish and um yeah I think that's about it for our coffee maker that's that's how it works and that's what it's made out of hope you've enjoyed it