Practical Guide to Free-Energy Devices

Chapter 18

Build Your Own Gravity-Powered Generator

Author: Patrick J Kelly

Chapter 18:  Build Your Own Gravity-Powered Generator.

A man called Bhaskara, an Indian mathematician living in 1150 (more than 850 years ago) produced a design for a gravity powered wheel using liquid mercury as the driving weight.  The arrangement is generally presented like this:

Each container is half filled with the liquid and the fixed angles of the containers causes an imbalance of the forces caused by the weight of the liquid.  That causes the wheel to rotate and as it does, the liquid flows across the containers, maintaining the imbalance.  The longer the containers are relative to their width, the greater is the imbalance.  Mercury was used because it flows freely and is very heavy.  However, it is poisonous and we definitely do not want it scattered around in the environment, so instead, we will use water which is much cheaper although not nearly as heavy.  If you add salt, that can make the water 20% heavier.

At this time, I am not aware of any serious implementation of this design.  The YouTube on-line video https://www.youtube.com/watch?v=7KqOwJKWIAw shows a really minimal version of the design.  I find it highly suspicious that in that video, the wheel is stopped from rotating and restarted, suggesting that that particular implementation has too little imbalance power to keep the wheel rotating and that fact is concealed by not showing the rotation for more than a few seconds.  That, of course, is just a doubt on my part.

None of the drawings in this document are to scale.  This project is mainly for fun and to test the Bhaskara design with a serious weight of liquid.  For that, I suggest that we use a form of construction which is so cheap and simple that it can reasonably be considered to be crude.  Plastic bottles can be used to make boats, canoes, yachts, greenhouses, buildings, etc. so I am suggesting that we use them to create a gravity-powered wheel.  We do not want to have to buy the bottles and so, even though better shaped bottles are made, we will just use this type which we should be able to get free:

This bottle holds 2 litres and while it’s proportions are not as good as the 1.5 litre bottles, they are probably the easiest to get.  If these bottles can’t be got free, then my local supermarket sells “still” water in a bottle of that type, for just 17 pence, so a dozen would cost only £2.  We will use these bottles half filled with water, so each bottle will weigh one kilogram (2.2 pounds).  We will use twelve of them (or just six of them if you find it hard to believe that this gravity wheel can work).  The turning power of the wheel can be increased very substantially by using more bottles, but that can be done quite easily at any time later on.

In broad outline, here is what we will do.  We make a circular disc.  Mount it on a strong central shaft supported by low friction bearings at each end, and attach the half-filled bottles to the disc.  None of the construction needs any particular skill and no special tools are required.

We start by making the disc.  It can be made from any convenient sheet material which is rigid and which will not warp.  This design uses a disc of 1 metre diameter and so the sheet needs to be at least 1000 x 1000 mm in size.

A common sheet size in the UK is 2440 x 1220 mm or 1220 x 1220 mm so if using one of those, mark out a square of perhaps 1020 x 1020 mm at one corner because it is not easy to cut right at the edge of a sheet.   Having marked the square, draw the diagonals from the corners to locate the central point:

Then, drive in a nail at that central point so that it can be used as a temporary pivot.  Tie a loop in the end of a piece of string and drop it over the nail.  Using the string around a pencil or marker and holding it taught, draw a one metre diameter circle on the sheet material and then remove the nail and make a 25 mm diameter hole at the central point:

Next, use a jig saw to cut out the disc of material and sand around the circumference to make it smooth.  The circumference of any circle is 3.1416 times longer than the diameter and as our circle has a one metre diameter, it will measure 3142 mm around the edge.  We will use six pairs of bottles and we want to position them evenly spaced around the circumference, so we mark the circumference at six evenly spaced points.  Mark the first point anywhere on the circumference and then measure 523 mm along the edge and mark the next point.  Repeat that so that you have six points marked around the edge.  Measuring around the edge can be done with a cloth tape measure, or a metal tape measure (bent in the direction which rolls up anyway) or with a straight edge which is rolled along the surface, or with a strip of paper which has the wanted length marked on it.  Alternatively, using a yardstick or aluminium one-metre ruler, the points can be located where a 500 mm straight edge touches the rim.

We will use the very simple arrangement for attaching the bottles to the disc, that is, tying them with string.  Sounds like a poor method?  Well, actually, it isn’t, and it has the added advantage that it is very easy to try different bottle angles at a later date if you decide to experiment and see if there is a better angle.  This method just involves drilling four holes in the board and attaching the bottles like this:

The string goes around a bottle on both sides of the disc, feeding through two holes in the disc.  If only six bottles are to be used, then the string just goes across between the two holes on one side and then around the bottle on the other side.  If only six bottles are being used, then put successive bottles on opposite sides so that you have three on one side of the disc  and three on the other side.  Put the string around the two bottles several times as that produces a firm strapping holding them in place.

So, to position the holes relative to the six marks on the circumference of the disc, we do the following, assuming that your bottles have a 100 mm diameter and 300 mm length:

1. In the direction of the centre of the disc, mark a point 10 mm in from the edge and another 90 mm in.  Those are hole positions for the binding 75 mm up from the bottom of the bottles.

2. Place the base of the bottle on the circumference mark and the top of the untapered part of the bottle on the edge of the disc.  Mark that line in pencil.  Measure up that line 150 mm and mark it.  Draw a line from the centre of the disc to that new point as the second string binding will be on that line.  Measure in from the circumference along that line and mark off the two drilling points at 15 mm and 95 mm in along the line.

3. Drill those four holes.

We now need to fix an axle to the disc and I would suggest that the easiest way is to use threaded steel rod:

I suggest a 24 mm or  25 mm diameter rod with two washers and four nuts as the finished wheel may have tens of kilograms supported on this axle.  One big advantage of using a threaded rod as the axle is that if the central hole is a bit loose, then nuts and washers can be used to clamp the disc exactly square to the axle and then lock nuts used to clamp the  main nuts permanently in place.

We need to support the axle in a low-friction bearing and the most readily available type is the sealed ball or roller bearing:

These have a rubber seal to keep dust and dirt out of the grease packed around the ball bearings inside and that spoils the free movement.  One way to overcome this has the bearing outer ring clamped stationary and an electric drill used to spin the inner ring until the movement becomes low-friction.  An alternative method is to remove the rubber seals and remove the grease by immersing the bearing in paraffin (known as ‘kerosene’ in America).  Then the ball bearings or rollers inside the bearing are lightly oiled to give a very free-running bearing.

To support the bearings, we need two side pieces.  We can cut these from a similar piece of 9 mm thick Medium Density Fibreboard available from any builder’s providers.  The board is marked out with a central line and then marked like this:

When the board is marked, turn the board round and mark the other side piece.  There is less wasted board if the second side piece is marked from the other side like this:

Now, take your two bearings and treat them to make them as free-spinning as possible.  The bearing is designated “6005” and has an inner diameter of 25 mm and an outer diameter of 47 mm and a thickness of 12 mm.

Measure carefully and mark a circle of exactly 47 mm in the centre of the 150 mm face and far enough in so that there remains 10 mm of board outside it.  That is, the centre of the hole will be 34 mm in from the middle of the 150 mm edge.  Use a power jig saw or a coping saw to cut out the circle staying just inside the line.  This gives a rough opening which is just too small for the bearing to fit into.  Enlarge the hole very gradually using a wood rasp or coarse sandpaper until a bearing can just be forced into the hole.  Leave the bearing in place but don’t do anything further to attach it at this time – that can be done later when the axle is in place and the rotor has been proved to spin freely.

The base panel is just a rectangle 900 x 600 mm in size, and it is fixed to the sides using two 50 x 50 x 900 mm pieces of wood using screws to connect the pieces of wood to the base and then to the sides.  The arrangement looks like this:

Considerable clearance is needed for the disc as one of the methods of boosting the wheel power is to add more bottles.  In the six positions mentioned so far, we can have a total of 36 bottles by adjusting two hole positions inwards by 90 mm.  That allows three bottles per side and the bottles project about 200 mm out from the disc on both sides:

Also, it is possible to put extra bottles in intermediate positions inside the line of outer bottles:

As shown here, the positions are staggered so that there is a more even force rotating the wheel.

There is, of course, no particular reason why the axle should not have one or more additional discs mounted on it, effectively doubling or tripling the rotational force.  There is also no reason why two discs should not have the gap between them spanned by thin planks which have many bottles side by side on them.  However, here we are talking about the most simple form of construction and I suggest that you start with six or twelve bottles.  With twelve 2-litre bottles half filled, the axle has to support 12 kilograms which is quite a lot for a rotating shaft where we do not want any flexing.

So, you now have built a wheel that rotates powerfully under the effects of gravity.  Unless there is something seriously wrong with your construction, the wheel is going to rotate for years if left alone.  The question arises – how do you stop it turning?  The answer is that you tilt the whole unit sideways until the disc is horizontal, or certainly, far enough over that gravity no longer creates a rotational force.

However, most people would want the wheel to generate power, to demonstrate that it can if for no other reason.  Many people will want to get as much power from it as possible and have that power do useful things for them.  How can we do that?

Probably the most simple way to extract power from this slowly moving, very powerfully turning shaft is to connect the shaft to a motor and use that motor as a generator to get an electrical output:

As motors operate at high speed, we gear the motor up by using a small diameter pulley wheel on the motor and as large a pulley wheel as possible on the axle.  A wind-powered generator would work particularly well here as they are not very difficult to turn and they work well at lower revs than a motor or mains generator needs.  It is, of course possible to attach another gearing axle to the side of the unit and make the motor gearing much higher by using two belts and four pulley wheels, or to power more than one motor.

Some people may want to use the disc itself as the electricity generating mechanism.  For example, powerful N52 grade neodymium magnets might be attached to the circumference of the disc and one or more coils placed on the base.  As the disc circumference is 3142 mm, if we were to space the magnets at 100 mm centres, there would be room for 31 magnets.  But if instead of putting just one magnet in those 31 positions, we were to attach a wood strip with, say, eight magnets spaced out along the strip, then we could use 248 magnets, and eight power collection coils.  There is, of course, not the slightest need to have just one row of eight coils and so there could be rows of 8-coil strips along the full 900 mm length of the base board and that would give nearly 5000 output pulses for every revolution of the disc.  That, of course, is an excessive number of coils, but it would be quite easy to add additional rows of eight coils if additional coils were wanted.  If using coils, each output coil should have a circuit like this for it to feed into:

The capacitor can be 1000 microfarads and nowadays, those capacitors are small and very cheap and as a set with a separate capacitor across every coil’s diodes, they actually work more effectively than one large central capacitor would.

Mind you, neodymium magnets and coil wire are expensive and if used would push up the overall cost of the unit.  This ancient design has the possibility of being very cheap and so might possibly be something which could be helpful in rural areas of some countries where there never will be mains electricity.  The water for the bottles does not have to be shipped to those places.  The rotational power is free and no fuel of any kind is needed (which is why I would call it a “free energy” device).

The design so far has suggested using a threaded steel rod.  I am told that those are not available in some parts of the world.  An alternative would be to use a circular wooden shaft for the axle (a broom handle or a curtain rail), making the central hole fairly loose.  The axle can then be clamped perpendicular with four angle brackets strapped temporarily to it (without using screws).  The disc can then be placed horizontally on the shaft, supported by the brackets and the upper side secured with epoxy resin:

When the resin has set fully, the clamping can be removed, the sheet of material inverted and the other side secured with epoxy resin.   There are many possible variations on how this gravity wheel can be built.

Patrick Kelly

www.free-energy-info.com

www.free-energy-info.tuks.nl

www.free-energy-devices.com

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