Roll on the 20th June

[sm0ky2]

these bearings im using are sealed hobby bearings, and are the best i can find without spending a great deal of $$. (aside from maybe a polished spindle....)
think these were 30-40 cents a piece at the hobby shop.
rods are just chopped pieces from a yard sign.

im just gonna run them straight, and slightly offcenter to avoid the center-axle
i tried a few tests bending them around the axle, and the rod scrapes when it twists.. so.... there goes that idea

back to the rod-stop problem....
i might can attach it so it uses the outer edge of the wheel to catch on. hard to attach something to a round rod, then you have to worry about twisting and all that..

so if i attach a thing off of the magnet-mounts at the ends of the rod, it can strike the edge of the stone wheel at the end of the slide.
perhaps a threaded bolt/nut so i can adjust the length of the slide...
say i wanted to change it from 3 inches, down to 2 inches of linear slide. then i could just adjust the nut on the rod-stopper. i could even give it a rubber stopper to soften the impact.

i want to make sure i have the best possible solution before i throw this thing together. to ensure the minimal ammount of exteraneous design flaws that made the previous attempts come to a halt.

i made the wheel so it pops on and off with ease. the axle is a socket inside a piece of pipe, nut on one end, and the socket extender bar on the other, so if i need the wheel to remove, i just pop the extender bar out and the wheel drops into my hand.  but its sturdy enough to hold the (pushing 25lbs now without rods and mags) heavy stone wheel.

getting rid of the one-face mount was a brilliant advancement.
thanks to Clanzer for that one (htink a couple other people had also pointed out the center-axle idea too...)

the wheel spins perfectly,even though its still WAY out of balance, theres absolutely no wobbling, or shaking of the frame at all.
frame is made of part of an old desk, with the adjustable feet so i can level it on any surface.
just gave the wheel a nice coat of paint, and about ready to mount the linear bearings tonght, then balance it.  i'll post some pics soon, or maybe another video

[exxcomm0n]

Hey smoky,

Just to muddy the waters a little bit more, I thought I'd submit the following thoughts.

The way you describe the repelling action adding torsion (twisting), and the way I've experienced it seem dead on. The only way I can see to deal w/ it adds yet another level of design difficulty to the loss-less transmission of repelling "force" from magnet interaction.

Yet again I draw from previous art and draw forth the simple, yet effect design of the Lazy Susan bearing to combat the torsion effect.

K then.

As I've pondered the error of my ways in giving quite so much leeway to the feted release of a world changing idea, I've also pondered the reason an idea like this ensnares so many a fertile mind, and come up w/ the concept that it's "just fun".



As to the "Lazy Susan" (LS) bearing, it's a simple device that allows for a rotating table top. My family used it for a table center piece serving condiments like salt and sugar. Turn it 90 degrees and it still serves the same purpose. It allows a turning surface to be in fricative contact with a non-turning surface and still turn.
You know this.

I tried mocking up an offset rod explanation graphically, but it kept being ill-designed and didn't work when I rotated it w/ my mind. I then went back to straight rods and trying to figure out how a rod can avoid the axle when they all would intersect. I had a hard time doing that until I thought about the mechanical device mentioned above.

What I finally came up with was to make each rod of 3 separate sections and 2 Lazy Susan bearings. This "solves" a number of issues.

First, the idea is that each rod will consist of 3 different segments of nearly equal length and assumes a couple (or more) things.

1.) The length of the exposed axle is about 4X's the width of an inner rod

2.) each of the 3 sections in a rod will have 2 "ExxoBearings" (thanks for the kudos man! Mind if I shorten it to "EB"?)

3.) Each inner rod will be just a little less than 1/3 the width of the outer rod sections

4.) Each of the inner rods will be on a different plane, but all the outer rods will be on the same plane (hence 1/3 width inner rods and stuff)

5.) The axle is attached to the face and uses bearing on each end mounted to the frames to turn freely

The idea is that each rod is made of 3 sections. The outer 2 sections can spin to their hearts content. The middle rod does not rotate and only has side-to-side movement. Each of these segments are connected to each other with a LS bearing.
This way you can "stack" the inner rods (bottom, middle, top) and have each go through a hole in the exact center of the axle without running into each other.

Take the axle and on the end draw intersecting 12:00 to 6:00, 2:00 to 8:00, and 4:00 to 10:00 o'clock lines. If you use a drill press, you can use an 90 degree on its bench to line up with one of the lines on the end of the axle to make sure every hole stays equally in line through the center of the axle. Measure where you've figured where the bottom inner rod will be and drill. Move to the next line on the rod end and drill the hole for the middle inner rod. Go to the next line and drill the top inner rod hole. Leave a little space between them so the inner rods won't rub together or on the face.

Put the axle in the wheel face and then mount EB's of appropriate height for the inner rod segments on either side of each hole.

Using a thin, yet stiff, light, and non-magnetic material like fiberglass rod for the inner rod, cut each one to a little longer that the travel length of the entire rod movement. Put each inner rod through the axle and EBs and mount one side of each Lazy Susan bearing to end of each of the each inner rod. The bottom and top inner rods will be attached to the bearings on the edge of the bearing, and middle one will be attached in the center of it's bearing. <see pic>.

Use epoxy putty to attach the bearings to the rods and build it up like the picture for support for the LS bearing/rod connection and to work as a stop of the travel of the inner rod when this larger built up epoxy area runs into the EB.

Mount the outer EB's and rods and attach them to the other side of the LS bearings.

Sound kosher?

I still like the idea of 2 wheels w/ the rod assemblies sandwiched between them. 2X's the mass and mounting areas for the rod assemblies. if you cut slots in line with the rod travel for the outer bearing mounts, you could adjust them in or out to balance wheel weight.
Since you're using a frame on either side to hold the bearings of the wheel axle it might be something to investigate.

Add to this a Rodin coil with a reed switch trigger to pulse that monopole effect it has, and the Mondrasek flipper switch thingy to keep a rod that goes up @ 1:00 from the pulse from sliding back down after the pulse is gone and this thingy might fly yet.

Give it a whirl, Earl.

[sm0ky2]

@ Exx

excellent idea with the lazy suzan!

im thinking, if you fit the smaller (axial bypass) rod to fit the I.D. of a single bearing, and have the O.D. of the bearing fit into a hole in the end of the larger (outer) rod..... that would give it the lazy suzan effect, and allow the central part of the rod to remain stationary. (rotationally speaking)
it might require the use of an additional EB to guide the center rod
or at least a set of guide-rollers..

i designed the Axle so that it is two pieces, like a spindle..
so theres no going "through" it,.. i can only go around.

im already in the process of mounting the rods, off-center
so i'll see how that goes, and if it doesnt work out, i may give the lazy suzan thing a try..... i drew a pic of the single-bearing lazy suzan concept.

my main concern with it being off-center, is a mis-proportionate leverage factor. when the rod is on top, it has more leverage, and also enters into the field sooner.
While when it is on bottom, it comes into the field later and doesnt have as much turning power to it. that might give the wheel an "erratic" motion, it all boils down to mass, leverage, ect..
some wheels jerk, some just slow down normally, with a slight increase on the top side. thus far i havent build a working one with an off-ste center of gravity. not that i think it is impossible, jsut that these concerns have to be addressed in terms of magnetic lift..

it is better to go through the center of the wheel,
which is why (i think) the original design was mounted on one side only.

the center-axle adds stability, but you trade off in convience.
i have a few work arounds for this problem, but they all require a monetary investment and/or great deal of labor involved in the construction of a custom-axle to accomodate the movement of rotating-sliding rods. (If anyone is interested in the design details of that, i can post them later at request.) i dont plan on using those methods myself in the near future, im just using junk that is free.
so i'll have to deal with this axle being the way that it is for now.
all-in-all between the axle thickness, and space between axle and rod,
each rod is right now, exactly:  1 inch from dead-center

and they're predendicular so.. i may need a counter-weight, in the imaginary-convergence spot, exactly opposite the point where the rods intersect. i wont bore you with the mathematics on that, but if you picture the moment when both rods are below the axle, and one goes into the magnetic field, it translates across no problem..
now the second rod comes into the field, and the center of gravity is on the side closest to, but above the magnetic array. wheel tries to turn back the other direction.
the counter-weight, is specifically measured to counter the off-set,
so if i run into that problem, i have a solution from failures of the past..

35-inch rods, 19 & 3/4-inch wheel 25-26lbs that i need to get a weigh again after i finish balancing it, i'll weigh it without the rods, and weigh each rod independently. make sure there arent any inconsistencies
then calculate the counter-weight if necessary. THEN.... we lock the rods at "dead center" and check for balancing issues.....

anyways...  here is the "lazy suzan" 1-bearing thing i drew

[exxcomm0n]

@ smoky

Thanks again man! Keep bringing the insightful questions you have about the construction difficulties you run into and I'll keep spouting this fluff that seems to be making sense to you ('cause others would be scratching their heads about it for days I bet!).

1st off, I wanna apologize for not keeping up with the design details of your build, I don't come to OU as much as I once did and almost never do due diligence when investigating a thread anymore.
That's why some of my ideas are running into your build design head on.

I'm with you on the "standard bearing" being used as a lazy susan. Countersink into the inner end of the outer rod and you can mount the standard bearing there and mount the inner rod in the inner part of the bearing. Much stronger than a surface mounted bearing and it doesn't mess up you lengths.
For a stop you could use a rubber end like those used on pool cues, just drill out the center where the screw holds it onto the cue and glue the outside edge the the outer rod. This assumes that the EB's you build can take repeated impact.

Very nice refinement of the idea there smoky!

As much as I sympathize w/ not wanting to re-engineer the axle, the "axial bypass" idea might suffer strength issues at any of the 90 degree bends it has. Beef up the 90's enough where this is not an issue and you have significant weight to contend with.

BTW, even if you do the axial bypass, you'll still have to keep the issue of rod height in mind IMHO.

The newly attached pic has both types of rod displayed. The only thing that is really different about this one vs. the last one I posted is that it has both ideas displayed and has "EB adjustment slots". These slots are routed out of the wheel face and allow the mounts for the EB's to be attached to the wheel face by going through the wheel face and then using threaded post of the EB mounts going through the face and using a wing nut/washer to tighten it in place.

Ease of adjustment for wheel balancing, and rod travel limit.
If you do the sandwich wheel, you only need to attach the axle to one face and use the EB mounts to attach the other face which allows you to take it apart for easy maintenance.

Look man, you're the one building this and I'm the one throwing up pipe-dream ideas, so keep that in mind.


P.S. I know my magnet polarities are whacked in the pic attached but I didn't wanna take the time to fix it.

[sm0ky2]

ok so, i got the EB's mounted and balanced the wheel

i mounted the rodends and the magnets,
then discovered i was about 1/8th of an inch shy of clearance,
so the magnets drag on the frame..

took it apart, and switching from 2-inch to 1.5inch magnets seems to do the trick, now its just a matter of finding enough of them to put this together. i hope to have some pics or a video up soon,

i think we talked enough about the balancing last year, so if anyone is serious about building one of these, i suggest you go back and find that part of the thread. but in short, the wheel needs to be balanced,
then the rods center-locked and balanced again.

The next step, is the arc and placement of the magnetic array.
i think what i'll do is as i build it and adjust the mount as i go,
i'll make videos to explain the whole process and how it works.
theres WAY too much confusion, and arguments and what-not about that particular part of the device, so i'll do my best to make it as clear and simple as possible for everyone that wants to build one.

i spewed enough already about the mass-to-flux ratio and the verticle lift-distance of the magnet-pair, i would urge anyone interested to go back and read that part when selecting which magnets to use
and designing your wheel, as far as length and mass of the rods, as well as travel distance, as all these things are directly related to the Mass:Flux ratio and will determine the range of parameters of the wheel that can be built with those magnets.

the overall design is not as important as the magnetic performance.
each design has its own difficulties and flaws, which i hope this process of building, and rebuilding will help to resolve. copying my exact design probably isnt important at this point. as long as your magnets operate the rods the way they should it can still be a viable design. Mine is certainly not without its problems at this point in development.

so, we're going to talk about the arc, and how the repulsion fields interact, as well as how the diameter of the wheel effects the arc, with respect to travel distance of the rods. i'll start with a few drawings to explain a couple of things, then the rest will be in video form, explaining it as i build it.

my array will be mounted on an adjustable mount, so that i can set each magnet the way it needs to be for the rod action,
the array must follow the curve of the rod-end as it spins around and slides inward. so it starts further away from the surface of the wheel,
and personally i like to angle the first couple of magnets even further out so the arm gradually comes into the field, this minimizes the "wall"

it takes a little bit of playing with your magnets to feel exactly where the "fields" are as the two magnets come close to each other.
but once you narrow down that distance, and swing the rod into the field its easy to find the best entry angle for those particular magnets.

more later...