Rick's Overbalanced Water Wheel Concept

[rickoff]

Update on the 3/4 inch build

Well, my 27 millimeter cutters arrived, and so I was able to complete the bore hole drillings on the two 1/4 inch thick hardboard wheels. I'll show this process from layout to completion in case anyone else would like to do a small build. I purchased a 2-foot by 2 foot piece of 1/4 inch thick hardboard at Home Depot, which worked out nicely. The panel was actually about 1/4 inch larger in both dimensions, and as I would be able to cut four 12-inch wheels from the panel, I decided to go with 12 inch circular wheels. The dodecagon wheel diameter for a 3 inch build was figured at 46.5 inches, so proportionately the 3/4 inch build would call for an 11.625 inch diameter. I could have built to that specification, but chose to go with 12 inches as it will only make the build more stable, since each pipe will have more wheel surface to lay upon. Here's a photo showing the means that I used for laying out the circles and their radian lines.





The circle scriiber is a Stanley Fatmax Chisel Compass, and works far better than an ordinary compass for drawing circles this size or larger.

The True Angle layout tool is a 23 inch model and allows for very accurate angle settings and scribing of the radian lines. Since two wheels are used for this build, the radian lines are scribed 60 degrees apart, and when assembled on an axle the wheels will be rotated for a 30 degree separation.

In the photo below, you can see that I scribed another smaller circle upon the wheel. The radius for this circle is 4.5 inches to be in proportion to build specs. The bore holes for the pipes will be centered where the smaller circle intersects the radian lines. I cut out the 12 inch wheels with a saber saw as I didn't have a jig saw available, which I would have preferred using. The idea is to cut close to the 12 inch circle's pencil mark without cutting into the mark. Next, I drilled a 1/8 inch hole at the wheel's center and followed that up with a 1/4 inch hole so that I could attach and secure a 1/4 x 3 inch round head stove bolt. Starting with the smaller drill allows for better accuracy in following the mark left by the chisel point compass. This allowed me to insert the bolt in a a drill chuck and spin the wheel so that I could true it by applying a sanding block to the perimeter as it rotated.





After truing the wheel, the last step was to drill the 27 millimeter bore holes which the pipes must pass through. I used an awl point to accurately make a depression at the centers where the smaller circle intersects the radian lines, and passed a 1/8 inch drill bit through those centers using my bench-top drill press. I then mounted the 27mm cutter in the drill chuck and carefully lined up the cutter's 1/4 inch center drill with each of the 1/8 inch holes. Here's what each of the completed wheels look like.




The work on the wheels is now completed, except that the center holes must be enlarged to accept the 3/8 inch x 6 inch shaft. To place the wheels the desired 1.250 inch distance apart, and lock them to the shaft so that they are set 30 degrees apart in rotation, I will be using shaft collars. The collars are attached to the shaft with set screws to lock them in place, and I will use a small drill to bore a hole through the side of each collar that will also pass through each wheel when in proper alignment. That will allow me to insert a small screw to lock the wheels to the collars. Two more collars will be placed further out towards the ends of the shafts, and these will be used to maintain the rotational plane at the center of the holding device. I haven't drawn up any plans yet for the holding device, but in my mind it would appear to be a wood block used as the base, with support arms extending upwards from the sides of the block. Nothing extravagant - just simple and supportive. The next step now is to assemble the pipes and fittings up to the 90 degree elbows, attach the short pipes to the elbows, pass these through the bore holes in the wheels, and secure the end caps. Since the elbows and end caps allow the pipe to be inserted 3/4 inch until it bottoms out, and since the wheels are 1/4 inch thick, this means that the short pipes which pass through the bore holes should be no more than 1.750 inches long. I prefer to actually finish them to slightly less than that so that when the end caps are cemented in place they will tightly sandwich the wheel surface between the end caps and the elbows so as to avoid any sideways play as the water sloshes about.

Here's a link where you can read or download the dimensions for the 3/4 inch build.

[rickoff]

3/4 inch build update

I have completed the preparation and assembly of the 12 pipes that will be used in this build, and will drop in an image of the pipes below. I included an explanation at the bottom of the photo that gives the pipe length dimensions and details how these pipes will be placed upon the two wheels. I have also started working on the support apparatus, the base of which is made from a 4 inch x 10 inch piece of 3/4 inch thick birch plywood that I had left over from another project. The two upright arms extending from the base, which will support the 3/8 inch shaft and bearings, are made from 14 inch long pieces of 1/8 inch thick x 3/4 inch wide aluminum 90 degree angle stock. A shorter 1/8 inch thick x 1/2 inch wide piece of flat aluminum stock will project upward at an angle, from the base to the upright shaft supports to lock the uprights in place. I'll be showing that assembly soon. Here's the photo showing the completed pipes.

[Cadman]

Rickoff,

I have been following this with interest.
Check to see if your pvc tubes are at the angles you anticipated after they are placed in the wheel.
I drew this out in CAD with a 4.5” radius and 1.05” OD tubes and it looks like the larger OD of the elbows may interfere, at least as compared to your drawing in post #2.

Regards

[rickoff]

Rickoff,

I have been following this with interest.
Check to see if your pvc tubes are at the angles you anticipated after they are placed in the wheel.
I drew this out in CAD with a 4.5” radius and 1.05” OD tubes and it looks like the larger OD of the elbows may interfere, at least as compared to your drawing in post #2.

Regards

You are quite right, Cadman. With the pipes inserted in the bore holes, and positioned to touch the elbows of adjacent pipes, the angle that I measure is about 72 degrees (a guesstimate), which is 4 degrees larger than the 68 degree angle that I showed in my post #10 as being the optimal angle. The reason for this variance, of course, is that after figuring the correct proportions for the 3-inch build (3.5-inch pipe O.D. and 4-inch elbow O.D.) I figured my 3/4 inch build in a proportional scale. Since 3/4-inch pipe is 1/4 the stated scale of 3-inch pipe, if it actually was directly proportional then the 3/4 pipe O.D. should be 0.875-inch, and a 3/4-inch elbow should be 1-inch. In reality, the pipe O.D is 1.050-inch and the elbow O.D. is a whopping 1.318-inch. Since the pipe O.D. is actually 0.175-inch larger than expected by scaling, I should have moved the centers of my bore holes further outward by half that difference, or 0.0875-inch just to make up for the larger than expected pipe size in order to maintain a 68 degree angle. Of course I would need to move it even further outward to make up for the much larger than scale elbow O.D. which causes the adjacent pipe to lay against the elbow 0.159-inch (half of the.318-inch oversize) before expected even after correcting for the pipe O.D.

I had figured the distance to the bore hole centers, from the wheel center, to be 4.5-inches which is 1/4 the scale of the 3-inch build at 18-inches, but did not take into consideration the actual variance from scale of the smaller pipe and elbows. The info given for larger than 3-inch builds would work well enough as stated, but these small pipe sizes are out of whack with what they are supposed to be. For instance, a 3/4-inch pipe should have an inside diameter of 3/4-inch (0.750), but 3/4-inch PVC pipe has an actual inside diameter of 0.824 inch.

Here's a photo showing the prepared pipes inserted in the bore holes. In comparing this to the drawing shown in post #2, the bluish colored "clear" pipes in the photo are somewhat similar in position to pipes A and G in the drawing. Notice, though, that in the simplified drawing of post #2 the elbows are shown same O.D. as the pipes, while the #8 post drawing was more appropriately scaled to show the actual lay line and angles.




As you can see, even the 72 degree angle provides enough of an angle for the A pipe to allow water to flow outward before that pipe's elbow reaches the 12-o-clock position in a counter-clockwise rotation, and the G pipe would have its water flowing inward before reaching the 6-o-clock position. Therefore, I feel confident that the wheel would still rotate, although perhaps not as well as it would with the 68 degree angle. It's a tough call to make, because while the wider angle means that pipe positions A and G do not transfer water outward and inward quite as soon as with the lesser 68 degree angle, thus detracting from rotation, it also means that the water weight centers will be moved further outward from the vertical centerline, likely aiding rotation.

What I could do, to determine actual performance comparisons, would be to prepare two additional wheels from 1/4" hardboard, and move those bore holes further out. I could install the pipe caps for the current wheels using silicone sealer instead of PVC cement, and that way I could disassemble the build, after testing, to reinstall the pipes on the correctly bored wheels.

By the way, as can be seen, one of the pipes has a pipe plug installed at its outer end. I did this to measure for the amount of clearance I would need to allow for with the support fixture, which I found should be a minimum of 13 inches as measured from the top surface of the fixture to the center point of the wheel. That would be for the wheel as pictured, of course. A wheel bored correctly to achieve the desired 68 degree angle for this 3/4-inch build is probably going to be much larger in size. I'll figure the actual dimensions and show that in my next post.

Cadman - Seeing as you have already mapped this out in CAD, could you alter your drawing just enough to show the corrected dimensions for the pipes and elbows, and the distance from the bore hole centers to the wheel center, and then post it here? I'd really appreciate that, as it takes a huge amount of time to make drawings the way I have been doing it with Microsoft Paint. Thanks in advance for any such assistance you can provide.

Rick

[rickoff]

An angle relationship study for the 3/4-inch build

Today I decided to make a graph showing the angle relationships for the lay angle of 3/4-inch PVC pipes against the 90 degree elbows of adjacent pipes in order to determine what angles would be achieved at specified distances from the wheel's center point. This was drawn to actual scale, though the photo taken of the drawing may appear smaller than noted. As shown in the photo below, I drew a vertical radian line at the right side of the drawing, and another radian line angled 60 degrees from the vertical. Along each of the radian lines, I measured out inch markings from the convergence point (center point of the wheel), beginning at 3-inches and ending at 10-inches. At each of these measured inch marks, I drew a circle. The circles on the vertical radian line were drawn to the actual outside dimension of the PVC pipe, which is 1.050-inches, while the circles drawn along the 60 degree radian were drawn same size as the PVC elbow's outside diameter, which is 1.318-inches. I then drew lines from the bottom of each circle on the vertical radian line to the top of each circle on the 60 degree radian line to represent how the PVC pipe would actually lay upon the elbow at each measured distance. Once drawn, I was then able to measure each of the angles precisely using my True Angle layout tool. Here is the photo showing the results, with each angle marked at the right side.




While some of the lines in this drawing appear not to be straight, and the vertical and horizontal lines appear not to intersect at quite a 90 degree angle, this appearance is caused by the camera lens and the actual lines and angles were drawn very accurately.

As can be seen, the lay angle that would be achieved if the bore hole centers were set at 3-inches from the wheel's center point would be 85 degrees, which is very close to horizontal. If bored at that location, water would not flow outward in a pipe until it's bore hole was nearly at the 12-o'-clock position. In comparison, a pipe with a lay angle of 68 degrees would transfer water outward at a point 30 degrees before its bore hole reaches the 12-o'-clock position, and this is why I believe that a 68 degree angle would be ideal.

Notice how the angle at the 4-inch bore hole narrows to 78 degrees, a 7 degree difference from the 3-inch angle, but at each successive bore hole, moving upwards, the degree change becomes smaller and smaller, until the degree change between the seventh and eighth bore hole is just 3/4 (0.75) of a degree. At this rate, we don't achieve the desired 68 degree angle unless we mark the center of our bore holes at slightly less than 9 inches outward from the wheel's center point. Of course this would mean that we would have to either use round cut wheels of 20.5-inches in diameter, or build two dodecagon wheels, and it also means that the vertical support arms would have to be made somewhat higher than those needed for the current build.

I do plan to complete the current build as is, as I do feel confident that the wheel will self-rotate, but will also begin planning for a corrected 3/4-inch build based upon the above drawing factors. I think it should prove interesting to see what difference there may be in performance level when comparing the two different angles. I had guessed that my current wheel may have an angle of about 72 degrees, but the drawing would prove that the actual angle is somewhere closer to 73.75 degrees.

As a side note of some interest, it occurred to me, after reviewing the drawing, that if each of the lay lines was extended several inches beyond the circles on the 60 degree radian line, they would very likely intersect at the same convergence point.

[Cadman]

Rickoff,

Here is the CAD layout. The radius works out to 8.5" to get the desired 68 degree angle.
Pipe OD = 1.050"
Elbow OD = 1.318"
The circles are equal to the elbow OD to show the contact point between pipes.

[Cadman]

Rickoff,

It occurs to me that it would be advantageous to construct the device with 3 disks. Each disk with 4 pipes mounted every 90 degrees. Then offset each disk 30 degrees. You could get a very small mounting radius this way.
And you could put pipe stops wherever you need to get a particular angle.

Regards

Edit: Some quick CAD work shows a minimum mounting radius of 2.1875" for a 3 disk device using 3/4" PVC.

[rickoff]

Hi Cadman,


Thanks for your CAD drawing. After seeing that your drawing comes out to 8.5 inches as the necessary distance from the wheel center to the bore hole centers, I decided to check the angles shown in my last post, and to make corrections to the drawing as necessary. I had previously taken the angle readings from my True Angle tool using my eyes, but this time used a magnifying glass. The degree lines, marked on a 1.875-inch diameter circle, are very accurate but make it difficult to read accurately unless the angle falls directly upon one of the degree lines. Using the magnifying glass helped quite a bit in estimating 1/4, 1/2, and 3/4 degree angles between the marks.


I went back to my drawing and added circles for the 8.5-inch specification and, after making several angle measurements to assure precision, I came up with 68.75 degrees. My measurement for the 9-inch bore hole came out to 68.25 degrees. This made me wonder why the CAD drawing is at variance with my manual drawing. Not that a 3/4 degree difference is enough to worry over, it's just that I rechecked the angle between my radian lines and found it to be a perfect 60 degrees, and my inch marks on both radian lines were also very accurate. The photo of the drawing makes it appear that some of the lines are not quite straight, and that the vertical and horizontal lines are not quite at a true 90 degrees, but these are distortion effects caused by the camera lens. The only explanation that seems to make sense for the variance is that while I attempted to draw the circles as close as possible to the actual 1.050 and 1.318 specifications, using a draftsman's compass, it appears that they came out to be slightly larger than intended. If either circle is drawn larger than specified then of course the lay line angle would be larger than if the circle had been precisely sized, and if both circles are just ever so slightly larger than intended (which appears to be the case) then this could easily account for a 3/4 degree difference. Thus, your CAD drawing is probably highly accurate.

[rickoff]

Cadman - I didn't notice your latest post until after I had posted a response about your CAD drawing. In regards to a 3 wheel design, yes of course that would work just fine to allow keeping the 4.5-inch radius as the center for bore holes if drilled 90 degrees apart. I had mentioned somewhere in my writings that any number of wheels could be utilized. As you say, a third wheel would allow for the 68 degree angle to be achieved without interference from an adjacent elbow. I'll have to give some thought to perhaps cutting a third wheel. Since my other two wheels have bore holes at 60 degree radians, I would have to drill bore holes at all 30 degree radians on those in order to keep balanced wheels while allowing for the 90 degree pipe placements. Of course I'd also need to acquire a longer shaft and utilize a wider support base.

As things stand, I may have to acquire a longer shaft anyways, unless I can find some shorter end caps for the pipes. The end caps that I found locally have a domed end, so require 1-inch minimum clearance between the 1/4-inch thick wheels if I use them, so that takes up 1.5 inches of shaft length alone. Then I must have 2-inches clearance at the outside of each wheel to allow for rotation clearance between the elbows and the bearing support stands. And as you can see, adding a third wheel would involve the need for an additional 2.25 inches of shaft length. If I do that, I could still use the domed caps if I obtain a longer shaft.

Perhaps I'll order a longer shaft and prepare a wider base so that I could use it first with a two wheel build and then add in the third wheel to experiment with angles and determine whether there is any difference in performance. When I say performance, I'm not talking about faster rotations - I'd be looking for smoother, steadier rotations. I could also utilize the wider base, with extended bearing support arms, for a build using the larger wheels with bore holes 8.5-inches on the radians.

I still favor the simplicity of a 3-inch or larger build, as with those sizes only one wheel is needed, but I did want to try a small build first just to see if the smaller diameter pipe would work. I had guessed that building much smaller than with 1-inch pipe would be restrictive to inflow and outflow of water in the pipes, and there would of course be some point in downsizing where restriction would not allow rotation. Besides restriction, there is also substantial loss of torque in smaller builds.

[rickoff]

I received a question today, in private messaging, that I thought others might also be wondering about so decided to post it here, along with my answer. I'd prefer that anyone having a question related to the water wheel concept post their question here, rather than in private messaging, so that others can see and benefit from it.

Interested in your opinion. Do you think that water is necessary to make this concept work, or would steel ball bearings rolling inside the tubes work? Just curious.

Yes, steel ball bearings would work, as would any material or substance that will easily transfer from the top of a slope to the bottom. I chose water because it is freely available and does the job nicely. If one doesn't mind the cost of steel ball bearings then of course they could produce a greater overbalance effect than water, since steel weighs about 16 times as much as water if compared volume to volume.

One thing to keep in mind, if using a ball bearing, is that when returning from the outward position towards the center of the wheel the bearing will easily roll into the 90 degree elbow, and should stay there while being lifted towards the 12-o'-clock high position. Notice, though, that it would be laying upon a horizontal surface of that elbow, which means that it would have no cause to roll back outwards. To overcome this, though, one could use two 60 degree elbows placed together rather than a single 90 degree elbow, and rotate them to achieve a final angle something greater than 90 degrees in relation to the pipe. This, of course, would allow the ball to roll out of the elbow quite easily when near the top of the wheel, but to stay inside the elbow when nearer the bottom. With a liquid, of course, there would be no such problem to overcome.

Another factor to consider, if you are thinking about using a steel ball bearing, is that it would likely be destructive to the pipe's end caps because of the harsh impact involved. The impact might not be nearly as harsh if you used many small ball bearings rather than one large one. By the way, you can buy 500 1/8-inch diameter stainless steel ball bearings for $8.50 with free shipping at this link.

[rickoff]

Hi folks,

Sorry that it has been awhile since I last posted on this water wheel project. I found that I had to set things aside temporarily in order to devote the time required to repair my Jeep Liberty's 3.7 V6 engine. The engineers who drew up the plans for this vehicle probably never considered that someone would have to work on it, since no matter what needs to be done becomes an extensive and difficult project due to very poor engineering foresight. Anyways, I had to replace the right bank cylinder head because of a broken casting which one of the valve lifters rides up and down in.

Then too, I have been straight out between the work on the Jeep, mowing and gardening, wood cutting, home repairs, and work needing to be done at my summer cottage. Summers are short here in Maine, and very soon it will be getting cold again. We already had a morning frost a week ago. I now have completed the work on the Jeep, but need to go up to the cottage to close it down for the season, and then return home and stow all my tractor implements under cover. After that, I can return to working on the water wheel.

I definitely haven't stopped thinking about the water wheel, and I did manage to cut out a new, larger base adequate for the taller build that will be necessary. I'll show some specs for building the base and shaft supporting apparatus in my next post. I'm going to build it tall to begin with, so that I can use the same apparatus for the wheels I already cut out, and then swap over to the larger wheels that will allow for the 68 degree lay angle of the tubes. I have the material for the larger wheels, and just need to find the time to prepare them. That should happen soon. Thanks for your continued interest in the water wheel project.

Best regards,

Rick

[Cadman]

Hi folks,
... The engineers who drew up the plans for this vehicle probably never considered that someone would have to work on it, since no matter what needs to be done becomes an extensive and difficult project due to very poor engineering foresight...

Sir I take great umbrage at that remark! Do have any idea the trouble and effort we engineers must put forth to design a vehicle that is impossible for the average shade tree mechanic to work on? Do you think it is easy to put a component in the way of every other component plus require a special tool to remove it?

Never considered ... poor foresight indeed! How dare you!

We engineers are geniuses I tell you! GENIUSES !!


Looking forward to seeing your progress.

Cadman

[rickoff]

Good one, Cadman. I have often wondered if the engineers are really as stupid as they seem to be, or if the car companies tell them to design the vehicles to be a nightmare to work on just so that they can bleed the owners dry on parts and labor charges when they come back for service needs. I worked for many years as a mechanic, and also as an automotive machinist, so have always done all my own work. Now that I'm retired, I still do my own work - and for two reasons: 1. I want to be certain it is done right. 2. There is no way I could afford to pay someone charging $100+ per hour, plus tripling the price of parts, to do the work.

[rickoff]

Project continued...

Very sorry for the delay in continuing postings with updates on the 3/4 inch build. Some folks may have thought that I had dropped off the face of the planet Earth, but that didn't happen. I did, however, run into what seemed like one thing after another that continually either distracted me or took precedent, including the unexpected death of my younger brother late in March. I see now that it has been nearly a year since I last posted. I had to read through my thread to refresh my mind as to what I had already shown. Although I'm still not entirely "out of the woods," so to speak, and have several more things that I must attend to before the cold weather sets in, I decided to at least get a head start today on moving the project along.

I had already purchased two sheets of 24 inch x 24 inch hardboard for constructing the larger wheels I had talked about. These wheels are laid out for a 24 inch diameter, and with an 8.5 inch radius bore hole circle, which is the dimension that Cadman determined (see his 06-11-2018 10:07 AM post) would result in a 68 degree from vertical lay angle for each of the pipes. There will be 6 bore holes cut into each wheel, so the radian lines are drawn at 60 degree intervals. The two wheels will be positioned upon a 3/8 inch diameter shaft, and spaced as close together as the construction allows. (about 1 inch, as previously figured). I'm attaching a jpg image file so you can have a look at the layout lines for one of the two wheels, which are of course laid out identically.



The wheel layout and cutting process is the same as covered in my post # 19, except of course that the diameters of the inner and outer circles are larger for the wheel now being shown. Previously the inner circle was drawn at a 4.5 inch radius, and now we have an 8.5 inch radius. That may seem like an extensive increase just to get from the previous lay line angle of 73.75 down to a 68 degree angle, just a 5.75 degree difference, but as I noted in post # 23, the further out the bore hole is located from the center of the wheel, the less effect it has on the change in angle.

A 68 degree from vertical lay angle is what I had estimated would be optimal, as it would allow tube A, as seen in post #2, to have moved all its water to the left side of the vertical center line when the bore hole center for that tube is located 15 degrees before the vertical center line with the wheel turning counter-clockwise.

The 27 millimeter bore holes will be centered on the inner circle, at the points where the radian lines intersect that circle. After I cut out and true the wheel, and drill the bore holes, I'll begin the process of assembling the pipes onto both wheels and fitting the wheels to the 3/8 inch diameter shaft. I may do this with the smaller wheels first, just to prove whether or not that version, with a lay angle of 73.75, was adequate for continuous motion. As I had mentioned in an earlier post, the end caps can be attached to the elbow extension of each tube using silicone sealant, which will allow me to remove the end caps later and change over to the larger wheels. The supporting base and uprights will be the same for either build, so changing out to the larger wheels will be relatively easy.

Even though I had stated early on that a 3/4 inch tube build might restrict water flow inward and outward to the point where the wheel might not function that well, or function at all, I do believe that both the 12 inch and 24 inch wheels will work to some degree simply because they will be overbalanced at the left side of the vertical center line. Also, the actual inside diameter of the tubes is 0.824 inch, rather than the 0.750 inch that one would expect of a 3/4 inch tube. I do believe, however, that the steeper lay line angle of 68 degrees as offered by the larger wheel will prove to work best. We will soon see, and have a visual video comparison for the two builds. If the 3/4 inch build size does work, as is expected, then builds using larger tube sizes should work even better.

[Sawt2]

Very sorry for your loss, my prayers are with you.