UABMM2 Unfurled 4

This morning I depopulated the eight degree rotor to put the magnets on the ninety degree rotor.

 On the new rotor the magnets fit well in the slots, but they are not "jammed in" tight.  They need some help maintaining their position.  So I wrapped the perimeter with electrical tape for a test spin.

The electrical tape didn't last long, but I got a few spins in.  The rotor doesn't have the strong cogging like it had with the other two rotors.  It is much easier to start and spins longer with when you give it a spin.  Then the electrical tape tore, and bunched up in the clearance between the rotor and the stator.

UABMM2 Unfurled 3

OK, here is the Poly rotor, we're cutting the slots now.  This time using the table clamps to keep the slots straight, and use the Y Axis of the table to move the piece.  It took a few hours to cut 36 slots.

The Polyethylene is a lot softer than Aluminum, and easier to cut.  But, the trade off is the rigidity of the piece.  Where I could probably press fit the magnets in Aluminum, the Poly is too flexible, and I'll need another way to secure the magnets.

I'm thinking that I'll wrap the perimeter with electrical tape to start with.  If that doesn't work then I'll try the quick epoxy.  I really don't want to use the industrial epoxy because this is a test piece, and I want to be able to get the magnets off of it again.

I still have to make the holes to mount the rotor to the split taper bushing.  Then we'll be ready to add the magnets.

UABMM2 Unfurled 2

We I wasn't able to find a suitable piece of Aluminum laying around, but I did find a piece of Polyethylene.  The Polyethylene is structurally more stable than plywood, but also considerably softer than Aluminum.  I figured the Polyethylene would be suitable for a test rotor, to see if this unfurled idea works, then I replicate it in Aluminum.

I'll mark up the part using drafting tools by finding the center first, then draw a couple circles for the outer limit of the rotor, and the inner limit of the slots.  There will be 36 magnets on this rotor, so we'll use the compass to make ten degree increments around the periphery.  Then last thing to do before it goes on the Mini Mill is to make a half inch tooling hole directly in the center of the plate.

To hold the plate to the table I am using a T Nut, and a screw that has been modified to be jammed into the table to make the pivot point.  Then to hold it down I'll use a half inch Machine Washer, a Flange Nut, and a Lock Nut.  Line up the Pivot Point, the Mill, and the Drill Press Support Shaft to keep everything square.

The we'll do vertical cuts every couple of degrees around the periphery to cut the outer limit of the rotor, which is six and three eights inches in diameter.  Next we'll add some table clamps and cut the slots to hold the magnets.  The magnets are a quarter inch wide, so I am going to press fit the magnets in quarter inch slots.

UABMM2 Unfurled

I often do things the wrong way, before I figure out the right way.  Lessons-n-stuff...

When playing with the UABMM2, after installing the shunts, I thought "Why so Repulsive"?  Its a push, literally, directly opposing forces balance, as if the rotors magnet's are furled.  Why not try to swing them around the other way, and use the attractive forces as well as the repulsive forces.  I'm happy with the stator at this point, which is the race, or track that the rotor rides in.  So, looking to quickly test my theory I fabricated a test rotor out of plywood.

This is where the drill press broke, and I had to go run all over town to find a new belt.  Once I got back to work I made a 6 3/16 inch circle of 3/8 inch plywood.  I'm using a similar setup on the machine table that I used to make the Aluminum rotor, except that I am going to cut the cants with a saw.

I am only going to put 4 magnets on this one, at ninety degree increments.  Then also the cant will be ninety degrees, or perpendicular to the stator magnets.  This way one side of the magnet is attracted to the stator and the other side of the rotor magnet is repelled from the stator.

Once I got to cutting this only took a couple of hours.  After playing with the finished rotor I can see that I need to make an Aluminum rotor to try this full scale, 36 rotor magnets.  The plywood is too fragile to be a rotating assembly, and I had trouble getting 4 magnets to stay on.

When the rotor is spun it seems to be propelled a little, until the inertia, and the cross fields stop it.  This is why I need to fully populate the rotor to get the help of the uniform asynchronous idea, so not all the magnets are crossing the cross field points simultaneously.  Some are pushing, some are pulling, and some are on the cross points.  So now I need to go and find another piece of Aluminum.

Drill Press Belt

I broke a belt on my drill press.  Trying to fabricate a new test rotor for the UABMM2, the drill press started making a knocking sound, and I realized one of the belts was coming apart, and immediately stopped it.

The drill press is from Harbor Freight Tools, so I went there to get a replacement.  Guess what?  They don't sell replacement belts.  Big Sigh...  Then I went to the auto parts store, nothing that small.  Big Sigh...  Next I went to the Home Labyrinth store, no belts at all...  Fork!  The place I should have gone first is Turner Hardware, and they had the right one, but I got the wrong size, Doh!  Made two trips.

Now that I had the right belt, and was putting the drill press back together, I noticed something about the idler pulley.  The arm that holds the idler pulley is bent, making the idler pulley canted.  No wonder the belt wore out, the idler pulley was chewing it up.  Another lesson in not buying cheap tools at the cheap tools store.  This defect cost me several hours on a Saturday afternoon, and also cost Harbor Freight Tools my business...

Cayenne Chiles

I harvested a lot of Cayenne Chiles this weekend.  These are the first set of Chiles off these plants so they are not as hot as the Fall harvest.  They are larger, and contain less Capsaicin than the Fall harvest will.  I'll wash them and put them in the food dehydrator to preserve them.

UABMM2 Shunted

Now I have all the shunts inserted between the magnets.  The rotor requires less torque to get it started, and the rotor turns for a longer time when spun, so I think we're making progress.  Eliminating cross currents between adjacent magnets is the key to getting this thing to run.  This set of shunts is 16 mil sheet metal.  What we need is something that conforms to the spaces between the magnets better.  So, the next thing I am going to try is the iron powder mixed with epoxy, and injected into the spaces where I need to control the cross currents between the magnets.  We are starting to see the potential of the UABMM2 now.