1060 An Unusual Wimshurst Generator

[Music] hi so i'm sure you know i'm a lover of old technology and one of the technologies i just think is fantastic of wimshurst machines now normally i make these things out of plastic actually the rotating discs but i came across these these are display shelves actually circular display shelves with a center in it and it's an enormous piece of circular glass so of course what are you gonna do with something like that i mean the first thing that comes to mind of course is build a massive wimshurst machine i've made a few wimshurst machines but never have to put the sectors on those little metal petal shapes that get stuck onto that glass now there's a lot said about these things but i follow a guy called antonio carlos quieros he's a brazilian professional electrostatics and he says that really it's going to be somewhere between kind of 18 and 40 depending on the size of your disc pretty popular is 24 to 36 so in order to draw a template to get all this stuff on you just great big circle divide it up by the number of sectors you want so if it's 24 it's every 15 degrees if it's 36 is every 10 degrees and then draw an inner and outer line of where these sectors are gonna go so if you put your sectors too far here you'll get leakage across there if you put them too far here you get leakage into there so somewhere in that band is where you're going to want to put them and you're just making quite random guesses about it now sector sizes you need to leave a gap between the sectors let me show you the on my template and we can talk about that a little bit more so here's my circle it's the same size as those discs you can see that i've actually divided into 24 sectors so they're 15 degrees apart and then we've got the petal drawn here and here that gap between them needs to be in this size of disc more than a centimeter but on average the average sort of thickness of this should be the average thickness of that kind of thing you can see mine are a little thicker doesn't really matter that much because i'm going for area and i've got enough distance here now these corners are rounded and you can calculate that if you want what i actually did was put a washer on there and draw around the washer as long as the washer hit that edge and hit those there that's all i actually did and the same with the bottom joined them up when i'd done that i created this little card template then i went around the whole ring with the template because these are for position only i also took that card template and put it on my metal foil now these foils that's obviously copper i like copper it's a harder wearing metal though it does oxidize but the number of options you've got really are copper or this stuff aluminium this aluminium tape is what's used for heating ventilation if you use thicker tape and aluminium then you're going to need to glue it this comes pre-glued as a tape the negative is it does wear out a bit quicker but obviously the copper is harder metal so that's going to be longer wearing again the size of the sectors how they're positioned really it doesn't matter that much it depends what you're going for high voltage high current um the metal that you use again it's not really that important copper tin aluminium whatever you can get stuck on there easily but once you've done that you need to cut out a whole bunch of these petal shapes because that's what we're going to stick on the glass to attach it peel back your backing i line up the bit with the packing paper still on into one of the petals hold it down that bit down and then peel that bit on there we go now you need to give it a rub over with your finger or a spoon get rid of all those sharp edges and any air bubbles and then go around the whole disc and stick all the rest all then down that's what you get you see what i mean about the copper i just think it's lovely actually two of these discs and we're ready to put them in a frame so now we've got these things of course what we need is a cradle to hold the whole thing together and i've done the bosses so that you can do a traditional one if you like but i'm gonna go a slightly different way so we remove those bosses because this is a great big bit of glass i don't know if that's centered or not if i try to spin it on that it may well be out of true i'm not 100 sure but i want to go a different way with it because i think that's looking really funky and my way that i'm thinking about is like they do a hubless wheel rather than having a central drive to put some support around here so that the thing can rest in a cradle and then drive it off the rim of course got two of them so we drive one off the rim in one direction and the other off the rim in the other direction now to do that what i've got is some poly wheels that i got from the local store these pulley wheels are 30 millimeter pulley wheels and they do fit rather nicely on there leaving me a little bit of a gap which i want anyway so i'm going to arrange the pulley wheels around the rim so i need to make a cradle and arrange those polygons now the material i'm going to use to make a cradle with of course is ah builders board now i often mention this and regular viewers will know exactly what this is but for those who aren't regular viewers and have just tuned in this stuff is used for roofline in europe and the uk and in the usa you're going to need to get something called cintra board it's a really cheap really strong structural material used for roofing so it's going to last now the wonder of this stuff is it glues this super glue so the glue joint is stronger than the original material and i make loads of models with it i absolutely love it because it's so easy to work with so we're going to make a cradle for this using this so that's all there is to the cradle i mean it's a couple of bits of that with some bearings in it skate the bearings of course and then this little pulley section here and what i love about our world actually is how everything is so precise i mean they have to do it that way you know to mass produce but it still gives you a lot of precision so these spaces here they're olives they're eight millimeter olives from plumbing section with some eight millimeter washers to make sure that those pulleys which were eight millimeter all line up so we've got them lined up we've got them in some bearings we can pop that board on there like that and then this says he will ride in there so i've offset the pulleys so this pulley and this pulley sorry this bottom on the top one are further that way these two are further this way so the two glass discs will actually be separate but resting on their own pulleys anyway let's put that bit together okay so there's the cradle finished and we've slotted the glass in now the glass is clearly a bit wobbly so we've got to do something to stop that wobble which either means putting something at the top there or something at the side so we need to build out this frame and then correct that wobble okay so that's the cradle complete i'm loving it actually i think it looks really weird and kind of different now the main things we've got to do to it now are add the neutralizers add the collection combs and the capacitors so the capacitors are going to stand like here and here neutralizers will go here and here and then obviously across the center we're going to have the collection calms but that is the heart of the machine now in order to drive it what we've got is a couple of motors here and they're just a friction drive using those pulleys with a bit of rubber on them straight against the glass and so they just press against the glass and rotate those wheels one in each direction that's because the positive is connected to the positive on here but that positive goes to negative on here and vice versa so those two motors rotate in a different direction give it a bit of voltage and we'll see that thing spin up that's awesome it really is so we've used a couple of large bits of glass we weren't sure where those centers were so doing it like this with the uh resting in the cradle and instantly in this top is another of those poly sections to keep everything here from wobbling this is just made out of um west pipe actually uh 36mm west pipe but that keeps everything close together and in true without us having to put a central axle in there when we're not really sure of where that center is anyway i'll continue with this but there's the heart of the unusual windshield machine i hope it was of interest and thank you very much for watching

Channel: Robert Murray-Smith

Views: 7,164

Rating: 4.9503107 out of 5

Keywords: generator, electrostatic, wimshurst, machine, robert, fwg, murray-smith, energy, generation, renewable, disruptive, alternative, design, technology, physics, dt, stem, steam, science, fair, project, lesson, education, how to, build, make, diy, d-i-y, home, built, made, equipment, industrial, arts, school, engineering

Id: dcW2If3NVPc

Length: 9min 9sec (549 seconds)

Published: Thu Apr 08 2021