Geoffery an Efficient Variable Capacitor Generator

Geoffrey

A Variable Capacitor Generator

I have up loaded videos on YouTube as a intro and guide on how to assemble.

part 1 https://youtu.be/YWbl4BkAayg

part 2 https://youtu.be/cxm6p0kkwVQ

part 3 https://youtu.be/jWDWDH8mpF4

part4 https://youtu.be/n4F2kBLBO4w

This has been designed with Fusion 360 if you want to make changes just Import the file and have a go at improving. I used an Ender 3 with 0.8mm nozzle, 30% infill on a glass bed with and a generic Pla filament. I set up a safety shield for its first few runs and started slow in case something went wrong. Your safety and the safety of others when operating this machine should be of your highest concern. If you build as I have done you will have a safe reliable machine able to conduct various other High Voltage experiments.

You should use a durable high quality filament if you want this to last for years. All printed parts have been sprayed with a clear lacquer to help preserve and protect them from deteriorating the more coats the better.

Currently it's Nov 2022 I hope to be making this machine from the very beginning so will be reposting better pics as I go and hope to be completed by January 2023. I am wanting to try to 3d print the electric circuits in the capacitor and holtz sections but this will take time and I'm un sure if it would work as desired. I can see some people have downloaded from https://www.thingiverse.com/thing:5542372

Teslas explanation here https://en.wikisource.org/wiki/Alternate_Current_Electrostatic_Induction_Apparatus

Please post any questions or improvements you may have found.

Thanks Raef

I will try to repeat the parts you require as I work through each section. Following is a basic list to start.

4 x 10mm and 1 x 6mm threaded bar, 8 x 45mm length x 10mm Outside diameter roll pin, 8 x 6mm grade 8 bolt with a counter sunk head, 19mm bearings, electrical wire, 2 x 60v 20A SSR (solid state relay), LD Resistor, Diodes, 50v 4700uf capacitors, 4g 6g stainless screws, 2 gang potentiometer, Conductive paint or foil, 10mm Alu rod stock .5 m, various 3d filament, Power supply, 4 pin plug,5A Circuit Breaker. 30mm and 20mm neodymium ring magnets 5mm thick, glued and 6g screwed into place, 2 x can of spray clear lacquer.

Basically start with printing ( I use 4 brim loops to help stick it to the glass bed. )

2 x Base support - One will be used for the base one for the top.

4 x Foot support

1 x Timing holder and 1x timing tensioner. Depending on the type of LDR (light dependent resistor) you have available wire in a 5mm Led and LDR as recommended by the manufacturer of your components. Leave more then enough cable to reach the board ( approx 350mm ) cut off excess later to tidy up when you use your 4 pin connector plug.

I used a 510 ohm resistor on the negative side and wired the two LED's in series so the LDR got full positive input. I used one positive line in to power the LDR and the LED giving me a positive signal out. Depending on what LDR you use you may have to check that the signal out is not drawing too much current through your trigger switch and over heating it.

I used a BDX 53C transistor (with 1.8 K Ohm resistor on the transistor signal input ) to signal a 60v 20A SSR (solid state relay) this runs cool and helps with the efficiency.

If you use a Tacho meter, mine had to have another transistor that would give a positive signal out.

You can cut now or later the Stainless Steel threaded bar to 600mm lengths. When it's finished and you are happy you can take the excess off it should be 30mm but wait until the end in case you want to add to the top etc.

The Centre hole needs to be threaded for 6mm to suit your threaded bar. I pre drill to 5mm then use a 6mm tap. You could grind a notch into a 6 mm bolt and use it to gently work in a thread if your stuck for a Tap.

The 4 Foot supports get threaded with 10mm to suit the big bar.

Pre drill your base and thread with a 10mm Tap then assemble with foot supports.

On the top I used a 10.5mm drill because it needs to be removed many times during testing, fixing etc. So the easier it slides on the better.

Assemble your parts so far. Screw 2 nuts on each rod about 50mm. Screw bar through the base and use the feet to tighten. As long as you get the 10mm Rod tight into the foot at least 10mm then tighten down the nut.

Video here Building Geoffrey 1 Base and feet https://youtu.be/6U43MjzYlvY

Next is to start with the drive coils and holders.

Start printing: Make sure to lacquer spray all parts to strengthen and protect.

16 x Drive coil They are a bit delicate, use good quality filament these will need to last.

Glue 2 Drive Coils onto each of your 8 x 45mm length x 10mm diameter roll pin , lining up the slot with the gap I have made in the print. This is where you feed the wire through to loop back to the start. I used a spray can, clear lacquer as the glue and sprayed the part when I was happy with it for protection. If needed re-glue with araldite or similar.

Wind your 8 coils, take your time it gets frustrating.In the model I am building for this project. I used 30m of 0.7mm Magnet Wire. You can use whatever you have available there's heaps of room if you only have insulated wire available. I bought a big roll and use it on all the different machines I build as it seems to be a good size for these magnets and roll pins. Usually I go to 7 layers you could go for 9 if you wanted to but over 7 encourages losses in your coil. I leave at least 150mm excess on each end to make it easier to solder etc when wiring it up. As I wound the coil, I brushed PVA glue over the each layer to strengthen and protect.

The coils are wired in series with 2 groups of 4. You could do groups of 2 or even single but this will draw more current and speed up the machine encouraging more losses higher rpms and risk of injury or harm. Beware high velocity could hurt someone probably you or your family. For experimenting purposes 600rpm to 1200rpm is more then enough. when you have perfected it then you can easily re wire it to run as fast as you dare but please start out slow.

Print 4 x Coilholdermounts

Drill out with 10mm or 10.5mm to make easy to slide on. Slide 2 onto the threaded bar now pushing down to about 20mm of the base. One of these will be the front of your machine the other will be the back. Put 2 more nuts on each threaded bar one to tighten down the other to support the next 2 Mounts .For a 2 rotor model I put my next 2 on in the opposite direction to give strength to the rods. There should be about 10mm to 20mm gap between nuts. No need to tighten yet this will be done when rotor is installed and everything adjusted to hights.

Later I also covered the outside of 3 mounts with aluminium stick on, this acts as a static collector and neutralises any build up of stray charge. The 10mm nuts & rods act as conductors. I left the mount at the front blank as its too close to the main control box.

Print 4 x Coil holder bottom and 4 x Coil holder tops.

Drill out the top hole with 6mm drill bit and clean out countersink/ taper the hole as best you can to accept the 6mm grade 8 bolt with a counter sunk head neatly to the surface. Tap the other end with the 6mm thread same as you did for the base. Bolt in the coils the same way up for each one you will have 4 cassettes. The bottom 2 will have bolt heads up the top two will be turned upside down and have bolt heads down. This will offset the top from bottom and they will be on different phases. I ground down my bolt heads a bit so they weren't too mushroom headed but still held down in the counter sunk hole.

Posted a YouTube video here Building Geoffrey 2 coils. https://youtu.be/lW21ZgHR0qQ

If you want to run smoothly at highspeed take time with your rotors. Use good filament, centrifugal forces can build up with the rotor this will be the part that fails at high speed if not done properly. The weight of the magnets may shred the rotor at high speed. It could explode and fragments will be thrown around you. Be aware of the danger act in a safe responsible manner. Go slow use a safety shield when first testing keep others away until you feel its proven itself to be safe. I run mine no more then 1500 rpm.

Start printing: Make sure to lacquer spray all parts to strengthen and protect. I used pillars support for the Bearing Journals and the Disk Body Centre. Pre drill the screw holes 2mm for timing light 3mm for 6g screws else where.

1 x Disk Body Bottom

1x Disk Body Centre

1x Disk Body Top

1x Timing Tensioner

1x Timing ring

1x Connecter Socket Male

1x Connecter Socket Female

I made the design of the rotors 2mm undersize for my bearing journals so I could machine them out on the lathe and have a nice fitting bearing. It took about 15 minutes on each part. If your school or friends don't have a lathe take it to any machine shop. Hopefully their interest in what your doing, will encourage them to help you out and not over charge you on the job. Alternatively edit the bearing journals and print to the size of your bearing. You wont be able to run at high speed but it will still run. I removed the dust seal from my bearings for less friction.

Install your magnets (16 of 30mm x 5mm ring magnet + 16 of 20mm x 5mm ring magnets) all same orientation (north or south facing up) on the disk use a good quality glue ( I used water activated Gorilla Glue ) and screw with 6g stainless screws 12mm, 6mm on the Centre disk for the little magnets as they are close to each other and the screws push on their mirrored one. I pre drill these little ones angle so the screw would miss each other. I should have allowed another 5mm between them. (stainless bolts M4 x 20mm with locknuts for the V2 rotor with 32 of the 30mm x 5mm ring magnets.).

The Rotor ends must have a bearing in them I used long 40mm to 50mm screws to join the rotors together. You can tighten or loosen the screws to adjust for wobbles ( sand or file the rotor ends where needed to make a flat surface ). Attach the timing ring to the bottom Disk with 4 x 4g x 9.5mm screws. Slide the rotor on the 6mm threaded rod / shaft. I used Ny- lock nuts one each end to hold in the correct position on the 6mm rod / shaft with approximately 5mm extending out the bottom past the timing ring ( Video part 3 ). Attach the timing tensioner it should be 6mm tap also. Install Rotor into base turn until tight down in the base. Don't over tighten either nuts or rod. Put on the top push it down close to rotor and give the rotor a spin by hand. Check to see it spins freely without rubbing, fix any issues before proceeding. I balanced the rotor on a 6mm shaft before installing to make sure there were no heavy sides. If your rotor is heavy on one side unscrew the top turn 1/4 turn clockwise re-screw re balance repeat if needed. If its still out of balance apply a metal washer to the light side of the rotor. Keep testing and adding until it rolls freely without a heavy side.

Video Building Geoffrey 3 Rotor here https://youtu.be/HQaE6dSDW4E

Your nearly ready to run your motor.

Start printing

1x Control Board

1x Control Panel

1x Label

I used 2 x 6mm x 50mm bolts to attach the front panel in hinge and screwed off to front, low enough so the coils could slide out without being obstructed.

I use a 12v -14v battery to start. when your confident then swap over to a power supply that can plug into the wall for reliable power. It's your choice how to supply the power and ultimately what sort of experiments you'll be running when completed, indoors, outdoors, etc.

I used a speaker terminals clip style socket for battery input its colour coded I also allowed a hole beside that for a 12v power supply plug you'll need at least 30 watts supply. Alternatively you could go straight to a laptop 19v power supply. Cut off the output plug and replace with one that suits your socket. Be careful you don't burn out your transistors or LED's though.

Use a Diode for protection. I used it on the negative and ran the negative through the 5 A circuit breaker up to the Amp meter. You don't need an Amp meter or a tachometer but it will tell you if your drawing too much current and let you know what's going on inside the circuits / motor without the need for an oscilloscope. Then I run to the capacitor on the SSR (Solid State Relay).

I brought the positive up through the switch and into 50v 4700uf capacitors attached straight to the SSR on the negative side, before the coils. This way when the SSR switches there's heaps of power ready to run through the coil. The coils are statically charged positive to the power supply awaiting the SSR.

I use the SSR as a common where I can tap into for power for the Timing light LED's and LDR. I also used it for the power for the signal transistors I used a variable resistor at first to stop the transistor from drawing current as a signal when I found the right resistance I then hard wired in a resistor to suit. If you are drawing more then 15watts when running check your transistor temp it's probably heating up. Everything should run cold on this machine no cooling required.

I used a double potentiometer to bleed off the positive signal to negative from the LDR and again a variable resistor until I found the right value then hard wired in a resistor. Now you have 2 tuning methods the potentiometer to hold the signal on for longer and turning the timing light for early or late firing of the coils. if you can use an oscilloscope and you will see what's right or wrong.

If you can't get a volt meter you could make a little panel with LED's at different resistance values to give the voltage. If your using a power supply it should remain constant.

When you think your ready to go, give the rotor a turn with both hands then turn on the switch. The motor should turn a couple of times and stop or go faster or go backwards, turn the power off. Don't leave the power on if it's not turning this may draw heavy current through your coils and burn them out. Don't be disheartened now is the time to look closely at where the rotor stopped. Whichever coil aligns with the rotor magnet is the coil that needs to be energised to repel the magnet. Turn your timing light holder one way or the other until the LDR is signalling the SSR that coil is aligned with the slot on the ring. The motor prefers one direction, mine is running anti clockwise it will depend witch way up you installed the rotor. Once you have it aligned it may still not run, reverse the polarity of your coils to make sure you are pushing and not pulling the rotor.

The bolt inside the coil is being used as a flux conductor for the magnets. Energising the coil stops the flux from flowing through the bolt. The other rotor now does the work of being attracted to its coil. This process could take a while to get right. Have a rest if you get frustrated and work on it early in the morning when you can think clearly. Trust me the magnet wants to align with the coils.

You will notice the label name panel "Geoffrey" this was my Dad's name. He was very supportive of my interest in making generators. He grew up in the depression and had to hunt for food for his dad. His father would drop him and his brother Allen off in the bush for weeks on end. They would catch fish for him to sell in town. He taught me many things in life. Common sense things many people would never think of mainly how get food and shelter in the most unlikely of places. In turn I have built simple tricks /cheats /hacks into this machine common sense things that others have not thought of.

posted a video Building Geoffrey 04 Power Board https://youtu.be/czSB4MfvGMw

Review Part 3 and Part 4 video for assembly refresher and understanding high voltages.

Start printing. Spray all parts before applying conductive foil / paint to protect the Filament from the ozone etc.

2x Connecter Socket Male

11x capacitor disk

20x capacitor plates.

2x cap plate holder

All disks have to be machined to suit the electrical conduit. The conduit stops the rotor from discharging through the 6mm threaded rod. Cut your 27mm ( I have since downsized to 25mm ) OD electrical conduit to 180mm length. Roll it on glass or similar surface to make sure its straight. Have it ready for the lathe work. I checked each piece would fit before I took them out of the lathe.

I used stick on Aluminum foil but am having trouble with the sharp edges making high voltage points that are burning through my insulation. ( I have I am considering doing foil in the middle of each capacitor section and using a conductive paint around the edges. I will also be making a jig where I can put each part and apply a high voltage with a whims Hurst or similar machine to look for breakdown before assembling. This is time consuming and frustrating job but should help save time assembling faulty parts. )

When the disks are stacked they need to be all electrically connected my first go I went on the outside but this was probably a mistake I should have painted the conduit with conductive paint to help connect them all. The whole rotor must charge up equally with out breaking down to work at maximum output.

The capacitor plates need to have wire attached to take the electricity to and from the transformer I used 100mm length with the intention of shortening later when completed. I am now using a sticker cutting machine. It's fast and accurate with a really nice flat finish.

I post a video here where I remake the new Caplate VB : https://youtu.be/VTY0z3falQE

I also made a Caplate desk mount. Because there is 20 plates for every 10 disks I decided to make somewhere to put them while printing the group of 20 plates. Print 2 of each part and it makes a little holder to sit the plates when working on them.

The top disk is reversed so the charges stay inside the rotor then the male connector socket and again I machined the bearing journals to suit.

This rotor can be installed down over the 6mm shaft / rod and you are ready to test run and make sure it runs nice and smooth before proceeding.

I made a video of how I make the CapDisk : https://youtu.be/HCnt7lY65Fw

Slide in your plates and get ready to hook up the transformer spark gap your ready to go.

I use a whimshurst machine to charge the module with an adjustable spark gap so I can measure how much charge it takes before breakdown inside the machine.

Also there needs to be more work done on getting the right dielectric one that really increases the capacitance.

Print 1 x all following parts.

The transformer is basic the wires coming off the capacitor plates attach to the common rail and connect with the spark gap. I used foil to contain any leakages around the bare wire ends. I used 10mm Aluminium rod stock turned down on the ends and polished all over. This gives you the option to turn the rods a bit when the arcing begins to burn them out. I use chopstics to touch this section of the machine or a well insulated poky stick. My machine gives a decent repetitive shock that let's you know you have touched it. Be careful if you enlarge this machine and increase the output even though the electricity here isn't attracted to you it will pass through your finger to get to the other terminal.

The 2 vertical rods can be connected with a short piece of wire.

Here is the output and you can combine all sorts of different apparatus to output through. Trust me there's heaps of things that can be done with 20000 v at frequency you just need some imagination.

If you don't use the gap you will have a lower voltage higher current output this can be run through coil transformers etc but is outside this project scope of works.

Happy experimenting.

In video 4 I do a quick run through on various books mainly " A. D. Moore Electrostatics " that I believe will give good guidance on understanding the Toppler Holtz Machine.

You should have some basic understanding of static electricity generators to make it easy for you to get this working correctly. This electricity is usually unseen but if you get the room dark enough any mistakes you have made will hopefully become visible. If in doubt get a separate Whimshurst machine that does work and use it to test your work. If it's not right wave your finger or knuckle around until you get a shock then you'll know where the leak is.

Start printing and lacquer first to protect filament from ozone.

I used 4G screws of various lengths 6mm to 12mm Or something similar.

1x Holtzdisc this needs to have conductive foil or paint applied to the sectors. ( I am wanting to improve this part a bit in the future.)

2x Holtzframeholder

2x Holtzplatebottom ( this needs to be conductive foiled on the top at collector end ( mine is the left end ) it's not insulated and the equalizer end needs to be insulated as the disk is leaving. Again you should have a basic understanding of topler holtz machines for this to work the first time you try. But when you get it running it will be fine.)

2x Holtzplatetop ( this needs to be conductive foiled on the bottom at collector end etc same as its opposite.)

2 x HoltzplateSL (Support leg) Screw onto the left leg.

2x HoltplatelegL (Left leg)

2x HoltzplateR (Right leg)

2x HoltzplateSR ( Screw onto the right leg.)

Assemble the plates onto the legs top and bottom screw in place. Then slide into the holder plate and into the top slot on machine. Install your equalizer with wire as required and your collecter wires. The edge of the disk has a groove for the electricity to be collected etc. If in doubt refer to A.D. Moore's book or some other literature on how a Toppler Holtz machine works. It's a standard basic run of the mill design and it has to be that way.