A ground is necessary, but as you saw in this video there are many ways of doing the ground. Even just holding the end of the ground wire in my hand worked fairly well. Putting the ground wire inside another can worked great! In fact I don't even use the ground wire going all the way to the wall socket anymore, I just use the second can approach.
Good point. A good ground for this case is one that readily accepts or gives electrons. The soda can is small but you're connecting to the inside of it. Connecting to the inside allows the Faraday ice pail effect to take place. That effect causes the wire to always see a neutrally charged inner surface even though the outer surface might be hugely charged. And a neutrally charged surface readily accepts or gives electrons. Connecting to the outside of the can would make it a bad ground.
You're right on. The triboelectric effect that causes the static electricity when you walk on the carpet is the same thing that's going on between the rubber belt and the rollers in these Van de Graaff generators. When you walk on the carpet, the material in your sock is making and breaking contact with the carpet and that causes negative electrons to transfer from one to the other. As a section of belt makes contact with a roller and then breaks contact, the same transfer takes place.
Good question. My guess would be that the sparks would be the same length but thicker/brighter/louder/more painful. The latter would be because when it sparks, there'd be more charge/current in the spark. I think it'd be the same length because the curvatures of the surfaces involved haven't changed. You should get the same length sparks near one spot on the dome with and without the can. But you said below that you're getting longer sparks, and experiment is king, so, so much for my guess. :)
Thanks and you're welcome. I use every day items so that others can make their own easily. I hadn't thought of your reason. Makes sense. I'll keep that in mind in the future.
You can increase the length of the arc by moving your finger farther away. Sounds like a silly answer but the increased distance gives the can more time to build up charge, though the arcs will take longer to happen. You'll probably still find a limit so using a bigger, more rounder dome instead of the can will help. In case losses are happening too fast you could spin the belt faster - faster motor, more power to the motor (but stay within the motor's ratings), grease the shafts.
What materials are you using for the belt and the two rollers? How are you doing your grounding? If you're using the second can as a ground, are you connecting to the inside of it? The faster your motor turns the better it'll work, but be careful not use more than your motor's rated voltage and current. The wires facing the belt must have sharp points, multi stranded wire is good for example, but space out the strands. The wires facing the belt must be close as possible.
I used my homemade power supply. What you need for power depends on your motor. Motors are rated for a maximum voltage and a certain amount of current/amps. You can try running it on batteries, but it depends on the motor whether it's powerful enough to turn the belt. Another option for power is wall adapters, the ones that come with many appliances. Check the writing on them to see if they supply the voltage and current your motor needs.
It didn't really hurt as much as it sounded like in the video. I was just surprised by it - it worked better than I expected. :) But I'll keep that in mind for the future. Thanks.
Did you try to pull it off somehow (with a pliers or something) while it was heated? You may need a hotter soldering iron. The soldering gun I used was 150 watts. Most soldering irons are 10 to 30 watts. I'm not sure what the minimum you'd need it but that is a difference. If you can find a way to hold it you can put it on an electric stove's heating element, but put a pot of water on the same stove element beside it to protect the stove element.
Having said all that, surprisingly, people have had success with using the same vinyl electrical tape as the belt. Just make sure the sticky side is facing out.
When you were using the tape, either one, as a belt, did you have the sticky side facing outward? It should be. What are you using for the brushes facing the belt at the rollers, where I use the fanned out ends of stranded wire? Multiple sharp points are needed here, so if you're using stranded wire, separate the ends and put them as close as possible to the belt. Try different locations facing the belt. Just because it's nylon wire doesn't mean it's not coated. Experiment with other materials.
To start and stop it put a switch on the positive wire going from the batteries to the motor. Make that wire long enough so the switch can be in a handy place. Your Ghostbuster idea's brilliant. That way you can also put as many batteries as needed, including spare ones, in the backpack. Be careful to not cross the streams! Don't use rubber bands to hold the brush wires in place. With all the moving around you'll do you should use something that'll hold them more rigidly facing the belt.
Do you mean nylon fishing wire for the surface of one roller? What's the surface of the other roller? In the triboelectric series table one roller needs to be towards the positive side, one towards the negative side and the inner surface of the belt in the middle. Do you connect your wire to the aluminum ball's outer surface or did you make a hollow ball and connect the wire to the inside surface. It needs to connect inside, and have a gap around it where it enters the ball, like an open mouth.
Oh, that's hard to say. The sphere would be rounder so it would have less leaky edges, but the coke can is larger so it the charge would be spread out more anyway. They're so similar in size I couldn't even guess which would be better. Sounds like you should do a test and let us know! :)
Go to wikipedia. Search for "Triboelectric effect". Part way down on the right is a Triboelectric series table. Glass is on the + side, vinyl (electrical tape) is on the - side. The belt material should be in between those two in the table. I doubt that the elastic in trousers and shorts would work. It doesn't have a very smooth surface so there wouldn't be as much contact with the rollers and I suspect there's a lot of die to color it. But that's just a guess, I haven't tried it.
It's not grounded in the strictest sense. The two wires going to the outlet are called hot and neutral. The neutral in the US should connected to ground at your main breaker panel box. However, depending on who wired your outlet, the hot and neutral may be backwards or the ground to neutral connection may not have been made in the breaker box.
I'm not sure if a drinking straw will work well. I don't think so. I tried it when I was making that section of video and it wasn't giving good results but then the glue I used to hold it to the motor shaft failed and the straw started slipping. I'm pretty sure that before it started slipping it was giving bad results but you could give it a try anyway.
You could try. I guess if it's so fine that it doesn't put much pressure on the rubber and contacts it tangentially instead of with sharp points facing it directly it might be okay. I was getting good enough results without it touching so I'll just leave a gap from now on.
Great video. Its so easy to understand how things work when you make them with every day items that laymen (like myself) can imagine. Thanks for uploading, enjoyed it.
There are two portable ones in this video. At 10:14 the small commercially bought one is small and battery operated and with a better motor the version of mine with the two cans or with one can and a person's body as ground are both portable, well mine would need a rigid structure but that's simple enough. I was thinking of making a gun shaped one for fun where the ground wire could go to the hand grip and make electrical contact with the hand, or maybe one with the can on the end of a staff!
Cool. I can imagine your son got a delight out of the sparks. I have a box of lego that I haven't used in ages. Now that you remind me, I should keep it in mind for future projects.
Sure, as long as your heating pipe goes to ground somewhere. Mine actually goes into the concrete foundation of our building (hard to believe, but true.) But even if it isn't I'd suggest giving it a try anyway.
He gets bigger sparks due to the materials for the rollers and belt, which is really just a case of luck in what you have around, and because of the wider belt. The wider the belt, the more charge you pump. In fact, given the slow speed of his motor, I think it's mostly due to the wider belt. His wire ends are also pretty small, which may help. Nice touch using a plastic bottle, though that's not an option when using rubber bands, unless you cut the bottle shorter. How about a video of yours?
A looser belt would help with motor load for sure. Trial an error with a few different distances between rollers would find the sweet spot. Rubber bands don't last forever so best would be an adjustable distance. It's hard to make tinfoil keep a steady pressure over time but some way could be found I'm sure. There's definitely capacitance between the cans. Another way of looking at it is there's an high voltage electric field between them. "too much stuff on the bench" I know what you mean...
My support for the top roller (nylon) often grinds against the roller, si can I use some tape to smoothen that inner part? Also, how do you use isopropyl to clean your equipment ? I am using an rubber exercise belt for my belt, and am unsure about what to use for cleaning it.
It sounds like your two ends might be too close together for the voltage. The shape of the dome might not be rounded enough on the side facing the belt and rollers. This little one is useful for home experiments with high voltage, for school science projects, teaching and for fun. You can do all sorts of demonstrations with the ions it produces and with its high voltage.
You use a can for the dome but would, let's say, a door knob cut down work? I happen to have one that I salvaged from a curb alert. I was thinking of trimming down the throat to where it starts to dome out. But I think its brass or maybe a pot-metal as its not magnetized. Being that would it make a difference?
By the way love your channel you answer a lot of questions I cause myself to have as well turn me onto new projects that keep me entertained and learning. Thanks a lot.
If the 9V motor makes it turn faster then it will generate sparks more frequently, not greater sparks. To get greater sparks, use a bigger can/dome. Just make sure it doesn't have too many sharp edges.
After much tinkering I found if you cut out bottom circle shape part from a can and attach that to the top of ur can so it forms a dome rather then an indent, I used electrical tape to smoothly attach, it increased the device 10000000%
Putting the end nearest the dome right inside the dome so that the roller and shaft are inside the dome helps. The materials on the surface of the rollers may have room for improvement. In my part 1 video I used nylon thread for the top roller and got an improvement when I switched to a glass roller in part 2. Use the triboelectric series table for ideas for roller surface materials. For noise, grease the shafts but be careful not to get any on the surface of the rollers or belt.
You could try cutting up a balloon. Some have had success with vinyl tape, like the black electrical tape you buy in hardware stores. Put the sticky side facing outward.
I was thinking a more rigid arrangement altogether would be better. For example, see 0:23 in the video (How to Make a VDG Part 2). You'll see that the small commercial VDG I have uses a stiff wire holder to hold the brush in place. I'm not suggesting that specifically, just that it be something less flimsy than a wire bent around in space like I did, which is susceptible to movement.
I don't see why they would, unless the surface material is one that works well triboelectrically. Unless of course some other effect would take place, though I can't think of any offhand.
I just used the shaft of the motot for one of the rollers and wound some ducttape around it. for the other one I used an old pen and wound the fishing wire around it. I just made a solid ball of aluminium, but I think I have to make it hollow, one way or another. Could I role it around a paper-tube so that it's hollow? thanks for replying so quickly
thanks! I used a rubber belt. but I'm going to look for a glass fuse. If I can't find one I'll buy some elektrical-tape. thanks for helping out, great vids man!
This little one is useful for home experiments with high voltage, for school science projects, teaching and for fun. You can do all sorts of demonstrations with the ions it produces and with its high voltage. But it isn't useful as a practical energy source in any way I can think of.
What did you use for power supply??/Can u explain in detail???? Can i run it on batteries?????I have a toy motor dunno how many volt motor but it does not run the belt when i give little tension to the band.....can u help me......how many volt motor shud I take??? Reply as soon as possible
Your video is very detailed and easy to follow! My son is planning to build a prototype to attract rubber particles for his science fair next year. We were wondering if a Van de Graaff can attract rubber particles to the metal dome or can it be altered to attract such particles? Thank you
Thanks! I don't know about rubber particles but I do some demonstrations with it starting at three minutes and twenty-three seconds into this video th-cam.com/video/Gf6EbRmYImI/w-d-xo.html Make sure to also see the Part 1 video th-cam.com/video/fsT69XnjxgU/w-d-xo.html
I built a slightly larger, vertical, generator out of k'nex recently, and was wondering if u had any other ways of getting better/longer sparks out of the generator? (Since ive used all of your techniques and have a craving for more sparks!) (And a better demonstration for science class!!!!)
Oh, by little ones I was thinking of ones that people like us have or make or ones found in classrooms. The bigger ones are huge ones used in labs to produce ions for research.
Wow I am amazed how much difference that setup has made.I believe you have doubled the voltage to 8000volts.The pull tab sharp edges might have been responsible for some loss. But having the top inside the ball is common it seems that is important.
Nice set of videos, really nice. Next time, for the highest possible negative charge roller, use the tube but wrap it with teflon plumbing tape. I built one using a 3/4" rubber band and teflon on the top roller, making the ball positively charged, and even with a quicky small coffee can (not the best dome at all) it would put out around 1-1/4" sparks. It was enough to prove conclusively that cats can levitate! (Tabby got curious and sniffed the can.)
Yes, but it must have rounded edges, the rounder the better. Sharp edges will leak charge more easily because the electric field will be stronger there and you won't be able to build up as high a voltage.
Hi Rimstar! I tried using ducttape as well as some nylon_fishing_wire. But my van de graaf didn't seem to work. I tried grounding it at the bottom. I used a big ball of aluminium foil as the dome, is that a problem? great vids mate!
thanx I believe I have an ungrounded outlet anyway cuz there are just two pin holes and nothing else.. anyway I am going to to ground it to my heating pipe instead of a "coca can" is this okey?
It depends on what material you have on the outer surface of your rollers. The charging works because of the triboelectric effect that happens between the outer surface of the rollers and the inner surface of the belt. So if you look up a triboelectric series table, the bottom roller material should be at one end, the top roller at the other end and the belt should be in the middle. See my "How a Van de Graaff Generator Works" video for illustration of this. See link in this video's description.
Awesome channel...I just subscribed. I know this is an old video but a Bic lighter makes great wire strippers for newbies...just melt the insulation and pull it off. Thanks for sharing.
Meanwhile I've completed my own Van De Graaf generator. As you can see in the last video in my channel, it give spark about 2-3cm which's well enough for a tin can dome. The trick is - it takes time(sometime significant) to "warm up". Like as soon as I turn it on, it looks like it does not work. However, after a few seconds I start feeling very faint electric field. It grows stronger, starts sparking and after about 10 minutes you can see how it works. If I stop it for a few minutes, it's on full power as soon as I turn it on which means it's unlikely that it's because of the rollers taking so much time to charge since they'd definitely discharge in this period of time. Googling did not help - everyone's VDG's start immediately, only mine acts weird. What do you think might be a reason?
Александр Санников Maybe you have a humidity problem. That could explain why it takes a while to "warm up". The roller and inner surface of the belt need to get rid of their humidity, possibly from their interaction or from heat build-up. And regarding stopping for a few minutes, possibly the rollers and belt are still dry or heated or charged a bit.
I didn't try this Van de Graaff with my ball cyclotron because I doubted it would be able to produce a sufficient voltage. It might work with a much smaller ball cyclotron -- maybe a soup bowl or smaller sized one with 8 metal strips of alternating polarity.
That depends on how fast the motor can turn the belt. If it turns slowly then it will take longer to charge up the can. The faster it turns the faster the charge will build up and the more frequently you'll get sparks. Make sure you also watch my "How to Make a Van de Graaff Generator Part 2" video for more construction tips. There's a link to it in the description for this video.
Hello Rimstar, I tried using electrical tape and nylon wire, and it didn't work :( I used a soda can as the dome. I don't know what I'm doing wrong. I tried if the soda can and the wire were well connected by making a peace of PVC static and then hold it againts the wire, heared a little tick, my electoscope also gave a sign of life(when I holded it next to the can). I might try another type of generator, what could I do as a last try to make it working?
I did watch your video.... But I'm still confused with the concept of triboelectric effect...My bottom roller is wrapped up with electrical tape and my upper roller is made from glass fuse and I'm thinking to use an elastic(polyester) band for my belt. It's usually an elastic in trousers and shorts.... Will this idea work??? Because I'm not able find a rubber belt here in shops...
Very informative. Would using a looser (not slack, just not as tight) belt to reduce motor load still work ok? Maybe tinfoil could make the earth brush, then it could contact with less wear? Have you looked at potential capacitance between the two cans? I can see it being advantageous in some situations... I'll try one day, too much stuff on the bench atm....
I hope you're still planning on it, that would be awesome. Go as a Stargate character and carry a staff with a rounded VDG on the end, like the weapons they use. Or a wizard with a magic staff. Or make a gun shape based on one from some video game. Hmmm I was trying to come up with a halloween themed video... but I think everyone's probably sick of seeing VDG videos from me.
Inspirational! I would use a carbon fiber tow (or a carbon fiber antistatic LP record brush) for the electrical brush at the rollers and Ikea stainless steel bowls for the spheres. They're not perfectly hemispherical, but reasonably close.
I got it working except for it shocks a little from the can. It throws a bigger and more painful spark when I touch or get close to the negative connections from the battery side or motor side. Any idea why it's shocking from the negative motor to battery wire?
When you configure it so that both sides are connected to cans could you short them ot to create larger arcs like a "biopolar tesla coil" but in Van de Graaff form?
Well I attached two coke cans to a plastic ruler which sits on the side of the structure and I then ran a wire between them so the charge could travel through them, then I attached one wire at the end of the ruler from the last coke can to the dome on top of the structure itself. the charge goes from:: Belt-wire-coke can1-wire-coke can2-wire-Metal Dome
Hi sir how important it is to remove humidity i live in a tropical area and its rainy most of the time so i bought calcium carbonate powder , is it useful? And i cant find rubber band in proper size so is it ok to use rubber gloves wrist area for my belt
I'm not familiar with using calcium carbonate powder but will it remove the humidity from the room that the Van de Graaff generator is in? I guess you can put the Van de Graaff and calcium carbonate in a box with a window in it so that you only have to dry out the air in the box. From here www2.ece.rochester.edu/~jones/demos/humidity.html around 70% relative humidity (RH) is too much. They also give good tips for humidity.
I tried every single step you have shown here in the video...........but my van de graaf generator is still not working........everything is ok the motor the rolling of the balloon rubber band........can you guess what exactly the problem might be??........I am very tensed as it's my school project.........will be thankfull if you help and oblige.......
Sai Kiran Yes, it's important to have the earthing. Notice that in this video one of the earthing options I showed was simply a wire connected to the inside of a 2nd can, so it's not hard to do. The earthing provides a supply of electrons or a place to dump electrons depending on the polarity of your Van de Graaff. Without that supply or dump (called a source or sink) then it doesn't work well or at all.
i need to get my motherboard for my computer build so i can edit together a how-to video for my design. only problem with mine is that it wants to build up a high voltage, but it cant, it keeps arcing down to the motor, especially when i have the ground connected to the power supply. electrical tape seems to worsen it (as if the adhesive is conductive!) by the way, what are these electrostatic generators in general useful for?
Can I connect a dc battery's (+) near the lower roller's strip and ground the (-) .so that positive ions can be attracted to the strip more in quantity. .......I know protons don't flow just saying
So duct tape roller and belt with an nylon roller. That's not optimal since only youe nylon to duct tape belt will be doing real work but I've seen similar setups that worked (vinyl black tape roller and belt with other roller glass.) The way you did the solid aluminum ball is a bad ground, so I'd fix that first. Rolling aluminum around a paper-tube and also covering one end should be good. Insert your wire through the remaining open end and attach it to the inside of the aluminum.
I had success with balloon rubber belt and one roller of pvc tape and other of nylon thread on plastic. It gave spark for some time but it stops after some time. What's the problem may be?
Check your rollers. Maybe there's the surface material is wearing down? Is the belt getting looser over time from stretching? Did the air in the room get more humid? Is the belt still positioned properly on the rollers? Are you sure the rollers are still turning; maybe one of them is stuck? All just suggestions to look at.
WARNING. The following can be dangerous. To test if I have a grounded neutral at my outlet I use a voltmeter on the AC scale. I measure the voltage between each of the two rectangular holes and the ground hole. If the voltage is around 0VAC then the rectangular hole is neutral. If the voltage is 120VAC for both then your neutral is no good as a ground. I'm not sure it's such a good idea using neutral as ground anyway. Probably best to go with one of the other suggestions in this video.
Glad to hear it got you building one. That's part of why I do these. And welcome aboard!
A ground is necessary, but as you saw in this video there are many ways of doing the ground. Even just holding the end of the ground wire in my hand worked fairly well. Putting the ground wire inside another can worked great! In fact I don't even use the ground wire going all the way to the wall socket anymore, I just use the second can approach.
Good point. A good ground for this case is one that readily accepts or gives electrons. The soda can is small but you're connecting to the inside of it. Connecting to the inside allows the Faraday ice pail effect to take place. That effect causes the wire to always see a neutrally charged inner surface even though the outer surface might be hugely charged. And a neutrally charged surface readily accepts or gives electrons. Connecting to the outside of the can would make it a bad ground.
You're right on. The triboelectric effect that causes the static electricity when you walk on the carpet is the same thing that's going on between the rubber belt and the rollers in these Van de Graaff generators. When you walk on the carpet, the material in your sock is making and breaking contact with the carpet and that causes negative electrons to transfer from one to the other. As a section of belt makes contact with a roller and then breaks contact, the same transfer takes place.
Good question. My guess would be that the sparks would be the same length but thicker/brighter/louder/more painful. The latter would be because when it sparks, there'd be more charge/current in the spark. I think it'd be the same length because the curvatures of the surfaces involved haven't changed. You should get the same length sparks near one spot on the dome with and without the can. But you said below that you're getting longer sparks, and experiment is king, so, so much for my guess. :)
Thanks and you're welcome. I use every day items so that others can make their own easily. I hadn't thought of your reason. Makes sense. I'll keep that in mind in the future.
You can increase the length of the arc by moving your finger farther away. Sounds like a silly answer but the increased distance gives the can more time to build up charge, though the arcs will take longer to happen. You'll probably still find a limit so using a bigger, more rounder dome instead of the can will help. In case losses are happening too fast you could spin the belt faster - faster motor, more power to the motor (but stay within the motor's ratings), grease the shafts.
What materials are you using for the belt and the two rollers? How are you doing your grounding? If you're using the second can as a ground, are you connecting to the inside of it? The faster your motor turns the better it'll work, but be careful not use more than your motor's rated voltage and current. The wires facing the belt must have sharp points, multi stranded wire is good for example, but space out the strands. The wires facing the belt must be close as possible.
I know! Nice long arcs! Better than I expected.
I used my homemade power supply. What you need for power depends on your motor. Motors are rated for a maximum voltage and a certain amount of current/amps. You can try running it on batteries, but it depends on the motor whether it's powerful enough to turn the belt. Another option for power is wall adapters, the ones that come with many appliances. Check the writing on them to see if they supply the voltage and current your motor needs.
It didn't really hurt as much as it sounded like in the video. I was just surprised by it - it worked better than I expected. :) But I'll keep that in mind for the future. Thanks.
Did you try to pull it off somehow (with a pliers or something) while it was heated? You may need a hotter soldering iron. The soldering gun I used was 150 watts. Most soldering irons are 10 to 30 watts. I'm not sure what the minimum you'd need it but that is a difference. If you can find a way to hold it you can put it on an electric stove's heating element, but put a pot of water on the same stove element beside it to protect the stove element.
Having said all that, surprisingly, people have had success with using the same vinyl electrical tape as the belt. Just make sure the sticky side is facing out.
When you were using the tape, either one, as a belt, did you have the sticky side facing outward? It should be. What are you using for the brushes facing the belt at the rollers, where I use the fanned out ends of stranded wire? Multiple sharp points are needed here, so if you're using stranded wire, separate the ends and put them as close as possible to the belt. Try different locations facing the belt. Just because it's nylon wire doesn't mean it's not coated. Experiment with other materials.
To start and stop it put a switch on the positive wire going from the batteries to the motor. Make that wire long enough so the switch can be in a handy place.
Your Ghostbuster idea's brilliant. That way you can also put as many batteries as needed, including spare ones, in the backpack. Be careful to not cross the streams!
Don't use rubber bands to hold the brush wires in place. With all the moving around you'll do you should use something that'll hold them more rigidly facing the belt.
Thank you for the excellent tips. I am making one now. How can i increase the length of the arc? and also, is there a way to minimize the noise?
Do you mean nylon fishing wire for the surface of one roller? What's the surface of the other roller? In the triboelectric series table one roller needs to be towards the positive side, one towards the negative side and the inner surface of the belt in the middle.
Do you connect your wire to the aluminum ball's outer surface or did you make a hollow ball and connect the wire to the inside surface. It needs to connect inside, and have a gap around it where it enters the ball, like an open mouth.
Oh, that's hard to say. The sphere would be rounder so it would have less leaky edges, but the coke can is larger so it the charge would be spread out more anyway. They're so similar in size I couldn't even guess which would be better. Sounds like you should do a test and let us know! :)
Go to wikipedia. Search for "Triboelectric effect". Part way down on the right is a Triboelectric series table. Glass is on the + side, vinyl (electrical tape) is on the - side. The belt material should be in between those two in the table.
I doubt that the elastic in trousers and shorts would work. It doesn't have a very smooth surface so there wouldn't be as much contact with the rollers and I suspect there's a lot of die to color it. But that's just a guess, I haven't tried it.
It's not grounded in the strictest sense. The two wires going to the outlet are called hot and neutral. The neutral in the US should connected to ground at your main breaker panel box. However, depending on who wired your outlet, the hot and neutral may be backwards or the ground to neutral connection may not have been made in the breaker box.
I'm not sure if a drinking straw will work well. I don't think so. I tried it when I was making that section of video and it wasn't giving good results but then the glue I used to hold it to the motor shaft failed and the straw started slipping. I'm pretty sure that before it started slipping it was giving bad results but you could give it a try anyway.
You could try. I guess if it's so fine that it doesn't put much pressure on the rubber and contacts it tangentially instead of with sharp points facing it directly it might be okay. I was getting good enough results without it touching so I'll just leave a gap from now on.
Great video. Its so easy to understand how things work when you make them with every day items that laymen (like myself) can imagine. Thanks for uploading, enjoyed it.
For larger sparks, a larger diameter dome would help, also a wider belt, and have the motor turn faster.
That is cool! Even better since it's homemade. And thanks for the feedback re the videos.
Steve from Ottawa.
There are two portable ones in this video. At 10:14 the small commercially bought one is small and battery operated and with a better motor the version of mine with the two cans or with one can and a person's body as ground are both portable, well mine would need a rigid structure but that's simple enough. I was thinking of making a gun shaped one for fun where the ground wire could go to the hand grip and make electrical contact with the hand, or maybe one with the can on the end of a staff!
Cool. I can imagine your son got a delight out of the sparks. I have a box of lego that I haven't used in ages. Now that you remind me, I should keep it in mind for future projects.
You're welcome. I'm glad you liked it.
Sure, as long as your heating pipe goes to ground somewhere. Mine actually goes into the concrete foundation of our building (hard to believe, but true.) But even if it isn't I'd suggest giving it a try anyway.
He gets bigger sparks due to the materials for the rollers and belt, which is really just a case of luck in what you have around, and because of the wider belt. The wider the belt, the more charge you pump. In fact, given the slow speed of his motor, I think it's mostly due to the wider belt. His wire ends are also pretty small, which may help. Nice touch using a plastic bottle, though that's not an option when using rubber bands, unless you cut the bottle shorter. How about a video of yours?
A looser belt would help with motor load for sure. Trial an error with a few different distances between rollers would find the sweet spot. Rubber bands don't last forever so best would be an adjustable distance.
It's hard to make tinfoil keep a steady pressure over time but some way could be found I'm sure.
There's definitely capacitance between the cans. Another way of looking at it is there's an high voltage electric field between them.
"too much stuff on the bench" I know what you mean...
My support for the top roller (nylon) often grinds against the roller, si can I use some tape to smoothen that inner part?
Also, how do you use isopropyl to clean your equipment ? I am using an rubber exercise belt for my belt, and am unsure about what to use for cleaning it.
hey this is bigfoot from canada.awsome videos!!i made a van de graaff and it lights up small fluoresent lightbulbs.cool!!!
It sounds like your two ends might be too close together for the voltage. The shape of the dome might not be rounded enough on the side facing the belt and rollers.
This little one is useful for home experiments with high voltage, for school science projects, teaching and for fun. You can do all sorts of demonstrations with the ions it produces and with its high voltage.
Thanks and my pleasure. Let us know how it works out.
You use a can for the dome but would, let's say, a door knob cut down work? I happen to have one that I salvaged from a curb alert. I was thinking of trimming down the throat to where it starts to dome out. But I think its brass or maybe a pot-metal as its not magnetized. Being that would it make a difference?
By the way love your channel you answer a lot of questions I cause myself to have as well turn me onto new projects that keep me entertained and learning. Thanks a lot.
If the 9V motor makes it turn faster then it will generate sparks more frequently, not greater sparks. To get greater sparks, use a bigger can/dome. Just make sure it doesn't have too many sharp edges.
What kind of material do you suggest I use instead of the rubber bands?
And I only just finished doing the annotations. You're way ahead of me! :)
After much tinkering I found if you cut out bottom circle shape part from a can and attach that to the top of ur can so it forms a dome rather then an indent, I used electrical tape to smoothly attach, it increased the device 10000000%
Putting the end nearest the dome right inside the dome so that the roller and shaft are inside the dome helps. The materials on the surface of the rollers may have room for improvement. In my part 1 video I used nylon thread for the top roller and got an improvement when I switched to a glass roller in part 2. Use the triboelectric series table for ideas for roller surface materials.
For noise, grease the shafts but be careful not to get any on the surface of the rollers or belt.
You could try cutting up a balloon. Some have had success with vinyl tape, like the black electrical tape you buy in hardware stores. Put the sticky side facing outward.
I was thinking a more rigid arrangement altogether would be better. For example, see 0:23 in the video (How to Make a VDG Part 2). You'll see that the small commercial VDG I have uses a stiff wire holder to hold the brush in place. I'm not suggesting that specifically, just that it be something less flimsy than a wire bent around in space like I did, which is susceptible to movement.
I don't see why they would, unless the surface material is one that works well triboelectrically. Unless of course some other effect would take place, though I can't think of any offhand.
I just used the shaft of the motot for one of the rollers and wound some ducttape around it. for the other one I used an old pen and wound the fishing wire around it. I just made a solid ball of aluminium, but I think I have to make it hollow, one way or another. Could I role it around a paper-tube so that it's hollow?
thanks for replying so quickly
Thanks! The more junk used from around the house, the cooler it is! :)
I'm currently making a Van De Graff to work off of a drill, so it's portable. would using a larger aluminum can hlep?
thanks! I used a rubber belt. but I'm going to look for a glass fuse. If I can't find one I'll buy some elektrical-tape. thanks for helping out, great vids man!
thanks for both of those awesome videos ill make one soon and lets see if your idea works!!
This little one is useful for home experiments with high voltage, for school science projects, teaching and for fun. You can do all sorts of demonstrations with the ions it produces and with its high voltage. But it isn't useful as a practical energy source in any way I can think of.
What did you use for power supply??/Can u explain in detail???? Can i run it on batteries?????I have a toy motor dunno how many volt motor but it does not run the belt when i give little tension to the band.....can u help me......how many volt motor shud I take??? Reply as soon as possible
Cool! Let us know how it goes.
Is the ground cable necessary, I just made my generator and I cant get it to work im not sure if its because of the lack of a ground cable?
Can you describe what you mean by running it through multiple coke cans.
Your video is very detailed and easy to follow! My son is planning to build a prototype to attract rubber particles for his science fair next year. We were wondering if a Van de Graaff can attract rubber particles to the metal dome or can it be altered to attract such particles? Thank you
Thanks! I don't know about rubber particles but I do some demonstrations with it starting at three minutes and twenty-three seconds into this video th-cam.com/video/Gf6EbRmYImI/w-d-xo.html Make sure to also see the Part 1 video th-cam.com/video/fsT69XnjxgU/w-d-xo.html
I built a slightly larger, vertical, generator out of k'nex recently, and was wondering if u had any other ways of getting better/longer sparks out of the generator? (Since ive used all of your techniques and have a craving for more sparks!)
(And a better demonstration for science class!!!!)
Oh, by little ones I was thinking of ones that people like us have or make or ones found in classrooms. The bigger ones are huge ones used in labs to produce ions for research.
Wow I am amazed how much difference that setup has made.I believe you have doubled the voltage to 8000volts.The pull tab sharp edges might have been responsible for some loss.
But having the top inside the ball is common it seems that is important.
Nice set of videos, really nice. Next time, for the highest possible negative charge roller, use the tube but wrap it with teflon plumbing tape. I built one using a 3/4" rubber band and teflon on the top roller, making the ball positively charged, and even with a quicky small coffee can (not the best dome at all) it would put out around 1-1/4" sparks. It was enough to prove conclusively that cats can levitate! (Tabby got curious and sniffed the can.)
Yes, but it must have rounded edges, the rounder the better. Sharp edges will leak charge more easily because the electric field will be stronger there and you won't be able to build up as high a voltage.
Hi Rimstar! I tried using ducttape as well as some nylon_fishing_wire. But my van de graaf didn't seem to work. I tried grounding it at the bottom. I used a big ball of aluminium foil as the dome, is that a problem?
great vids mate!
thanx I believe I have an ungrounded outlet anyway cuz there are just two pin holes and nothing else.. anyway I am going to to ground it to my heating pipe instead of a "coca can" is this okey?
It depends on what material you have on the outer surface of your rollers. The charging works because of the triboelectric effect that happens between the outer surface of the rollers and the inner surface of the belt. So if you look up a triboelectric series table, the bottom roller material should be at one end, the top roller at the other end and the belt should be in the middle. See my "How a Van de Graaff Generator Works" video for illustration of this. See link in this video's description.
Would fishing line work as the nylon thread? Please reply ASAP it's urgent. Thanks
Awesome channel...I just subscribed.
I know this is an old video but a Bic lighter makes great wire strippers for newbies...just melt the insulation and pull it off.
Thanks for sharing.
Meanwhile I've completed my own Van De Graaf generator. As you can see in the last video in my channel, it give spark about 2-3cm which's well enough for a tin can dome. The trick is - it takes time(sometime significant) to "warm up". Like as soon as I turn it on, it looks like it does not work. However, after a few seconds I start feeling very faint electric field. It grows stronger, starts sparking and after about 10 minutes you can see how it works. If I stop it for a few minutes, it's on full power as soon as I turn it on which means it's unlikely that it's because of the rollers taking so much time to charge since they'd definitely discharge in this period of time.
Googling did not help - everyone's VDG's start immediately, only mine acts weird. What do you think might be a reason?
Александр Санников Maybe you have a humidity problem. That could explain why it takes a while to "warm up". The roller and inner surface of the belt need to get rid of their humidity, possibly from their interaction or from heat build-up. And regarding stopping for a few minutes, possibly the rollers and belt are still dry or heated or charged a bit.
+gramahL hope I'm not too late but these voltages will surely damage a DVM. perhaps old style TV repairman type high voltage probe.
will this van de graaff gen. help in providing necessary voltage for your ball cyclotron ????
I didn't try this Van de Graaff with my ball cyclotron because I doubted it would be able to produce a sufficient voltage. It might work with a much smaller ball cyclotron -- maybe a soup bowl or smaller sized one with 8 metal strips of alternating polarity.
That depends on how fast the motor can turn the belt. If it turns slowly then it will take longer to charge up the can. The faster it turns the faster the charge will build up and the more frequently you'll get sparks. Make sure you also watch my "How to Make a Van de Graaff Generator Part 2" video for more construction tips. There's a link to it in the description for this video.
Hello Rimstar, I tried using electrical tape and nylon wire, and it didn't work :( I used a soda can as the dome. I don't know what I'm doing wrong. I tried if the soda can and the wire were well connected by making a peace of PVC static and then hold it againts the wire, heared a little tick, my electoscope also gave a sign of life(when I holded it next to the can). I might try another type of generator, what could I do as a last try to make it working?
I did watch your video.... But I'm still confused with the concept of triboelectric effect...My bottom roller is wrapped up with electrical tape and my upper roller is made from glass fuse and I'm thinking to use an elastic(polyester) band for my belt. It's usually an elastic in trousers and shorts.... Will this idea work??? Because I'm not able find a rubber belt here in shops...
Very informative. Would using a looser (not slack, just not as tight) belt to reduce motor load still work ok? Maybe tinfoil could make the earth brush, then it could contact with less wear? Have you looked at potential capacitance between the two cans? I can see it being advantageous in some situations... I'll try one day, too much stuff on the bench atm....
I hope you're still planning on it, that would be awesome. Go as a Stargate character and carry a staff with a rounded VDG on the end, like the weapons they use. Or a wizard with a magic staff. Or make a gun shape based on one from some video game. Hmmm I was trying to come up with a halloween themed video... but I think everyone's probably sick of seeing VDG videos from me.
Inspirational! I would use a carbon fiber tow (or a carbon fiber antistatic LP record brush) for the electrical brush at the rollers and Ikea stainless steel bowls for the spheres. They're not perfectly hemispherical, but reasonably close.
If i ran it through multiple coke cans would the spark be increased in length?, (because tests so far would suggest this)
What else material can we use for belt instead of a rubber belt???
I got it working except for it shocks a little from the can. It throws a bigger and more painful spark when I touch or get close to the negative connections from the battery side or motor side. Any idea why it's shocking from the negative motor to battery wire?
When you configure it so that both sides are connected to cans could you short them ot to create larger arcs like a "biopolar tesla coil" but in Van de Graaff form?
Well I attached two coke cans to a plastic ruler which sits on the side of the structure and I then ran a wire between them so the charge could travel through them, then I attached one wire at the end of the ruler from the last coke can to the dome on top of the structure itself.
the charge goes from:: Belt-wire-coke can1-wire-coke can2-wire-Metal Dome
i made one, it gives me continuous arcing at 1-3 mm and (painless) hot juicy sparks at almost an insh and it is smaller that yours too!
I like how you can see the burn spot on his thumb where he's been arcing the tesla coil
Hi sir how important it is to remove humidity i live in a tropical area and its rainy most of the time so i bought calcium carbonate powder , is it useful? And i cant find rubber band in proper size so is it ok to use rubber gloves wrist area for my belt
I'm not familiar with using calcium carbonate powder but will it remove the humidity from the room that the Van de Graaff generator is in? I guess you can put the Van de Graaff and calcium carbonate in a box with a window in it so that you only have to dry out the air in the box. From here www2.ece.rochester.edu/~jones/demos/humidity.html around 70% relative humidity (RH) is too much. They also give good tips for humidity.
Can i use a 9V motor for generating greater spark
I tried every single step you have shown here in the video...........but my van de graaf generator is still not working........everything is ok the motor the rolling of the balloon rubber band........can you guess what exactly the problem might be??........I am very tensed as it's my school project.........will be thankfull if you help and oblige.......
Yes, a larger can means higher voltages.
A door knob would work. Try not to have any sharp edges. Make sure you connect the wire to the INSIDE of the door knob. Brass, or any metal, is okay.
Wait a second does more of this space for charge, equal larger sparks or have i undermined the whole idea of larger sparks?
Is it important to have the earthing ? Cant it all be fine with just the power supply for the
motor( + and -) ?
Please do reply.
Sai Kiran Yes, it's important to have the earthing. Notice that in this video one of the earthing options I showed was simply a wire connected to the inside of a 2nd can, so it's not hard to do. The earthing provides a supply of electrons or a place to dump electrons depending on the polarity of your Van de Graaff. Without that supply or dump (called a source or sink) then it doesn't work well or at all.
Also, is there a way to make a portable version?
i need to get my motherboard for my computer build so i can edit together a how-to video for my design. only problem with mine is that it wants to build up a high voltage, but it cant, it keeps arcing down to the motor, especially when i have the ground connected to the power supply. electrical tape seems to worsen it (as if the adhesive is conductive!)
by the way, what are these electrostatic generators in general useful for?
Can I connect a dc battery's (+) near the lower roller's strip and ground the (-) .so that positive ions can be attracted to the strip more in quantity. .......I know protons don't flow just saying
So duct tape roller and belt with an nylon roller. That's not optimal since only youe nylon to duct tape belt will be doing real work but I've seen similar setups that worked (vinyl black tape roller and belt with other roller glass.) The way you did the solid aluminum ball is a bad ground, so I'd fix that first. Rolling aluminum around a paper-tube and also covering one end should be good. Insert your wire through the remaining open end and attach it to the inside of the aluminum.
my power supply got only two pins in the socket/outlet/cable, not three as yours, is mine grounded?
Do you think that a Van de Graaff generator could have been used as the ignition system for early gas engines?
Sure, that would have worked.
what else can one use instead of the rubberband
What else can we use for a Power Supply
what about bigger ones? i redesigned the thing a little, i don't get internal arcing, but still the same output, and no visible corona
Thanks! I try!
I had success with balloon rubber belt and one roller of pvc tape and other of nylon thread on plastic. It gave spark for some time but it stops after some time. What's the problem may be?
Check your rollers. Maybe there's the surface material is wearing down? Is the belt getting looser over time from stretching? Did the air in the room get more humid? Is the belt still positioned properly on the rollers? Are you sure the rollers are still turning; maybe one of them is stuck? All just suggestions to look at.
It rained yesterday . Humidity might be the problem. .. thanks for the response sir...
WARNING. The following can be dangerous. To test if I have a grounded neutral at my outlet I use a voltmeter on the AC scale. I measure the voltage between each of the two rectangular holes and the ground hole. If the voltage is around 0VAC then the rectangular hole is neutral. If the voltage is 120VAC for both then your neutral is no good as a ground. I'm not sure it's such a good idea using neutral as ground anyway. Probably best to go with one of the other suggestions in this video.