Minto Wheels and Modifications Page 2
Minto Wheel Modifications
While the regular minto designs will work OK, they still don’t have the enough power output capabilities for me so the next versions went a different route. I saw plans for a rubber band engine years ago and built it. It actually worked pretty well and so I decided to try something along that line. All the rubbr band engines I can find on the net when I looked a few minutes ago use gravity to actually turn the wheel by off setting the axle. That’s no better than the the original Minto wheel to me. The version I saw and built used an offset second axle that the bands connected to and worked much better. It also allows the use of hot water instead of a heat lamp.
The first two only have one set of air cylinders drawn in for simplicity. The various ouputs indicated are only ‘at best’ approximations. Real world output would probably be somewhat lower.
The wheel on the left is more or less the high output version but it would cost quite a bit to build too and is way out of my price range. . All the air cylinders used in the various versions are available at www.surpluscenter.com I used their catalog for a parts source as they sell everything that would be needed to build one of these except for the copper tubing, pipes and fittings or small propane tanks used in the various versions..
The drawing on the right end is a simple solar panel setup and shows the wheel horizontal setting above the water tanks. The solar panel shown is a very simple thing made from plywood and painted with that black plastic bed liner stuff for trucks and the sealed along the edges with silicone before the plexiglass panel is screwed down or clamped down with a frame of some type. One would probably not supply enough heat to make the wheel go fast but hot water can be made a number of other ways to if needed.
Any of these wheels could use propane, butane, freon or it’s modern equivalent for the pressure source gas.
Going with the horizontal wheel I setup, I drew up a couple more designs. The one on the left uses 3 air cylinders while the one in the middle uses 6. The drawing on the right shows the offset axle wheel and a closer view of the air cylinder used with these two setups. The offset wheel edge is rounded and pusher wheels edges are concave to help keep the piston shafts of the cylinders from turning out of proper alignment in operation.
The middle drawing shows much more info. That wheel should be theoretically capable of about a maximum of .25 hp but real world is probably about one-half that at one rpm. That works out to be about 5 amps of charging current into a 12vdc battery bank depending on water tanks temperatures. The wheel is capable of turning more than 1 rpm and probably will.
It also uses to seperate water tanks, one hot and one cold shaped into a each half of a circle under the wheel. The pivoting pressure tank that is immersed in the water can be something as simple as 6-7″ of 3/4 copper pipe capped on the ends with a connection to it’s corresponding air cylinder. It doesn’t need to be very big as the cylinders when fully expanded only contain 1.32 cubic inches of gas. The idea is to use the smallest tank that will work as the gas will cool and heat faster that way. The pressure is provided by either propane gas or todays freon equivalent. I think propane would work slightly better.
The frame of the wheel would be made from cast aluminum plates. (casted at home) The total cost of the wheel should be less than $100 and most of that is hardware and the brass gas fittings. The wheel would be mounted on a 1″ shaft that is mounted solidly in a 6×6 post in the ground. The wheel would need to be about 3-4′ off the ground so the solar panel supplying the hot water could use natural convection. The action of the gas pressure tanks flowing moving through the water would also aid in circulation from the hot and cooling panels to the hot and cold water tanks.
Still working with the horizontal wheel setup, and the different possibilities on the ‘boiler’ tank that could be used I redrew the design one more time to get as much torque output as possible in the smallest possible size and still be able to use a hot and cold water tank. The ‘boiler tanks’ at nothing more than sections of 1″ copper pipe with a small wheel attached to the bottom and a pivot hinge attached to the top and connected with a flexible hose to the cylinder. The pivot will allow them to swing up the tank ramps when switching tanks. The tanks would only have to be 3-4″ wide at most and about 6″ deep.
A big factor in the repeated design is still what it would cost to build so it just adds a couple more cylinders to the design. The shorter frame link pieces would also be easier to cast.
The measurements for this wheel is about 16″ in diameter and 3-4″ thick depending on the bearings installed on the top and bottom cover plates. The bottom cover plate could use an upside down trailer wheel hub that would also act as a thrust bearing to support the entire wheel with an output sprocket attached or welded to the small end of the hub. The axle is still a 1″ shaft mounted fixed into a base support that the wheel rotates around as the pistons force the small rollers attached to the piston shafts to roll around the offset cam fixed to the axle.
This wheel would be using 4 out of the 8 cylinders at a time for power. This 8 cylinder version is slightly more powerful and with about a 60 degree temp f difference between the two water tanks should be capable of maintaining about .2 hp at one rpm. That would end up about 7-8 amps of charging current into a 12v battery. The wheel is capable of a maximum of 3-4 rpm depending on the load just as the 6 cylinder version is.
The picture is a top view and doesn’t show the top and bottom cover plates. It does show a side view of a ‘boiler’ tank and pivot setup.
I did some more drawings for the last version of the horizontal power wheel. I this version of the drawing I used a couple of small trailer wheel hubs for the bearings. Those give the wheel both thrust and journal bearings. In actually building it I think that only one hub would be used and modified at needed. The way I did it in this drawing is a bit cumbersome.
A simple modification to the wheel also added a couple or more simple piston water pumps. In the drawing they are only one inch stroke and 1 inch diameter but could be setup with as much as four inches if the actual pistons and pumps were below the support frame.
The first drawing is the top view looking down without the top and bottom wheel covers installed.
The next wheel is even smaller but wouldn’t put out as much power as there would only be room for 3 or 4 cylinders and their boiler tubes at the most in the design. It’s a simple nutating type of setup where the pistons push against the bottom edge of a flat plate wheel that is angled on the mouting axle. In operation it works pretty much like all the last wheels I have been drawing. With a small modification this setup could also run a few piston pumps like the last wheel.
The view in the drawing is a side view. The nutating plate is fixed to a one inch axle that is attached firmly in a fixed position to the upper and lower frame while the wheel itself is mounted to one trailer hub that rides the axle. The output gear is mounted on the same frame that holds the cylinders to the hub while the swing boiler tanks are mounted from frames attached to each cylinder. The boilers are simple sections of one inch copper pipe with a hose connection and swivel pivot attached to the top and a ramp roller wheel at the bottom.
While the last couple of power generating wheels would put out enough to operate a small axial alternator, as usual I want more than 5-7 amps of 12v charging current. After converting that up to 24v for my scooter it isn’t really very much charging current. With the layout this time I stayed with the horizontal setup but went back to using hydraulic cylinders in the design for more power. It’s about twice a big as the last wheel at 5.5′ in diameter but much more capable.
This wheel uses six 3.5 inch diameter hydraulic cylinders It would be installed inside a 4×4 or 6×6 treated wood box type frame. (It could also use a metal frame but I’m still trying to keep costs down in the designs – I have a very tight budget)
In this layout the swinging gas boiler tanks are used to pressurize small #5 propane tanks with about 1 gallon of hydraulic fluid in each tank. The fluid would be the piped to the corresponding cylinder. Each cylinder would have it’s own #5 tank mounted under the wheel beside the cylinder. The swinging boiler tanks could made from the small thow-away propane cylinders or possible the small CO2 tanks used with paint ball guns. The system is limited to 300 psi maximum due to the #5 propane tanks.
As usual the hot and cold water tanks are below the wheel and look like a big doughnut with a split in the middle on each side. Cold on one side with hot on the other with built in ramps at the ends so the boiler tank rollers mounted on the bottom of each one can lift over the tank ends as they switch from hot to cold and back as the wheel turns. I did not put the tanks in the drawing.
These can also be setup using plastic flapper valves in the water tanks (one tank in this case) as the flaps would allow the boiler tanks to switch from hot to cold and back without mixing much of the hot and cold water in the process. It simplifies the wheel a little not having to use pivoting boiler tanks and flexible hoses for them. Less stuff to wear out also. The flaps could be made from the plastic sides of gallon milk jugs or some flexible plastic like that.
The drawing shows a top view looking down with two small side view pictures in the corners showing the basic frame and layout on the left and a simple sprocket gear system with both alternator and water pumps for the tanks on the right.
The math on the right hand side shows a psi/temp chart for propane and gives an example output of about 1.5 hp at one rpm which after converting to electricity with an alternator would be around 50+ amps of real world charging current into a 12v dc battery bank after chain and alternator efficiency losses.
This power wheel is quite capable of an output of 1 – 3+ hp depending on the hot and cold water tank temperatures. Using all high psi compressed gas tanks (paint ball tanks would work well) instead of propane versions and freon instead of propane the system could be made to put out even more power but it would really have to be strongly built as even this version can create over 4 tons of operating force within the wheel’s frame itself.
This wheel is a bit smaller at 4 feet in diameter and even more powerful. It uses 4″ cylinders versus the 3.5″ ones the last version did. That half an inch can make a pretty big difference and this wheel would also have to have a VERY solid mounting frame.
The drawing shows a top view looking down. I didn’t redraw the two small side view pictures in the corners as they would be pretty much like the last wheel.
The math on the right hand side shows a psi/temp chart for propane and gives an example output of about 2 hp at one rpm using the same example temperatures I used with the example on the last wheel. This time after converting to electricity with an alternator the output would be around 65+ amps of real world charging current into a 12v dc battery bank after chain and alternator efficiency losses. This wheel is capable of turning faster than one rpm and like the others is limited mainly by the port sizes in the cylinders.
Just as an exercise in pure ‘what-if’ sillyness I drew out another horizontal wheel. This time a 12 foot in diameter version that rides on rollers along the outside rim and would be the perfect thing to build a nice little sun pagoda around! The floor would slowly rotate around about once a minute or so and the roof could have the hot water panels incorporated into the design if the frame for the roof and sides where built around the outside of the wheel. Even the cooling water could be incorporated into the design by using a cooling rain type curtain wall around part of the outside wall. It would use propane tanks and water tanks like the last wheel just bigger to match the size of the cylinders.
Taking another direction while still using the same pressure and tank setup I tried designing a simple wheel that drives piston pumps only. I used a fixed nutating plate setup this time to both turn the wheel and operate the piston pumps. The way it is setup in the drawing it will only pump between 2 and 4 gallons of water an hour. It’s designed to supply a trickle setup for watering a garden. With a minor modification it could pump about 90 gallons an hour.
It could be hooked up directly to a shallow well and combined with a good sized solar hot water panel it would probably run about 20 hours a day (possibly all 24). If the outside temp is colder than the ground water it would turn at night too but in the opposite rotation direction but would still pump water.
About the only easy way to stop it from operating would be to lift the boiler tanks out of the water tanks and tie them up with a string or something like that.. Theorectically it would operate with one side in the sun and one in the shade. It doesn’t take much temperature differential on the opposite sides to get it to turn.
These below are also both designed to operate piston pumps built into the wheel setup itself. These are not designed to be fast but more or less trickle water so they only pump a few gallons per hour.
The first drawing is a pure pump system, the second also has a shaft output drive while the third drawing is basically the plumbing would be used for the hot and cold water tanks. The top layout for the tanks matches the the two wheels shown in this blog entry while the bottom one matches the wheels with the pivoting boilers that lift out of the water between the tanks.
The two wheels below do not have the pivots and the boiler tanks change from hot to cold water by simply going through a couple of plastic flaps that seperate the hot and cold sides on the tanks. I know it will tend to mix the water a little but not enough to make any real difference in the wheels operation.
This one is going to be built as a test setup. Initially it will be setup vertically using only one hot tank but eventually will be remounted to operate in the horizontal position. This one will use 8 of the little 1.5″ by .75″ air cyclinders.
This one will should put out about 5 amps of charging current once it’s geared up to speed and mounted with an axial alternator but it should be able to supply current for more hours of a day than a regular solar panel will and being that it’s only about 2′ square before I add the speed-up chains and sprockets which will be in another small frame mounted beside it and it’s alot smaller than a wind turbine too.
This one should cost me less than $100 to build so I can afford to try it and see if it works like I think it will. If it does (and it should) I will then start saving up to get the hydraulic cylinders to build one that is much more capable (I already have plans made up for it!) . That one will cost about $500 or so to build so this one is definately getting done first. Once it’s up and running it will also be used to drive a slow speed piston type pump to trickle water my wife’s garden.