Dia. Mag. Alternator

[z.monkey]

I made a lot of holes this week.  Gonna make some more too...

This is the stack with a lot of pilot holes in it.  The center three holes are for the magnets, and will get bored out to 1.125 inches.  The piece of wood with the bolts sticking out of it is the jig for boring the large holes.  I'll take each plate from the stack and bolt it to the jig.  Then clamp the jig in a vise.  Then use a uni-bit to widen to 1/4 inch pilot holes to 1.125 inches.  Then we have two more groups of holes for the bearing plates and for the stiffeners / mounting holes.  The bearing plates are designed to use 10-32 hardware (3/16 inch holes) and are on the perimeter of the magnet holes.  The stiffener and mounting holes use 1/4-20 hardware (1/4 inch holes) and are around the edge of the stack.  At the bottom of the picture are the new neo-dia-mags.  These are going to stay in their package, far away from the machine area until I am ready to do the final assembly.

I have had a problem with the neo-dia-mags picking up the machine dust and I cannot remove all of it.  I don't want the machine dust contaminating the rotating parts.  The plan is to finish machining the stack, and then coat the plates with a "laminate", in this case some clear epoxy spray paint I think will do it.  In addition to separating the plates the laminate is to seal the steel plates so they don't rust, and to cut down on the machine dust contamination.  The idea is to get all the parts into a finished state and then assemble the magnetic parts in a clean area which is far away from the machine shop.  I am still probably a week away from the final assembly.

This version is considerably more work and expense than I had planned.  I had estimated that to build an alternator like this would cost $200.  The magnets (3) for this version were $45, the bearings (6) were $60, the steel sheets (2.5) were about $20, and then the tooling cost (drill press, Bitmoore vise, drill index, and hand drill batteries) was around $360.  But labor is by far the greatest expense.  I have spent two weeks working on it so far, and its going to take another week, at least...

At least I'm not bored, hehe, get bored, lol, uulgh...

[Mk1]

@Z

Nice work man !

I think however that you will find your self wishing for bigger pieces of metal there is not much room for the coil , once the magnets are in the core it self is a magnet , you can put the away a bit to have more wire.

But we will see , great work again!

Mark

[z.monkey]

Thx Mk1!

This is boring...  hehe...

Finally got back to the metal shop today.  I had built a jig to bore the holes around 10 days ago.  Basically just a 2x4 that I planned to squeeze in the jaws of the Workmate.  So I experienced some slippage trying to bore the  magnet holes.  So I revised the jig to be a surface clamped device so that it would have support from the bottom.  The first two steel plates are a little funny, but after I got the jig stabilized, and a process figured out, then I starting boring some nice holes.  I have a couple extra plates in the stack.  I can adjust the spacing between the plates to use fewer plates and increase the magnetic conductivity between the plates until it is optimum.  I can adjust the holes as needed with the high speed micro grinder thingy...

Here are a few pics of the day...

[z.monkey]

The boring part is over...

Now moving on to cutting the slots for the windings...

[z.monkey]

This weekend was stellar.  Zen and the art of cutting steel.  Man it was hot too.  I mean the outside temperature, 104 F on Sunday.  I finished fitting the plates last Friday, and have been getting ready to cut the slots.  Each vertical slot took about 20 minutes to cut with a hacksaw.  Once I got these 8 cuts in I can take apart the stack and to the rout in the bottom of the slots.

This rout is the main reason I got the Bitmoore Vise.  I am using a 1/8 inch end/side mill to make the rout.  I take each individual plate and bolt it on the the large hole tooling jig that I used to bore the large diameter holes.  Then put the jig in the Bitmoore Vise.  We are doing this on the drill press, so the table is the Z Axis.  So I position the table to where the mill is just below the bottom of the plate, cutting into the wood a little.  Lock the table, Lock the Vise, tension the X and Y adjustment tables, then rout the slot.  I am still getting used to the process.  If you don't have all the things locked and tensioned the table will do funny things when you start to cut.  Also cutting to fast causes tension on the table and the spindle and the mill goes in funny directions.  But, once I figured out the quirks, then I started cutting some decent routs.  I am scratching a line in the steel with an hardened scribe, so the line is permanent.  I can cut right down the line, and leave the line there, within a few mils...

You can see below the first plate routs are kinda curvy.  This is moving too fast, and not knowing the quirks.  This is an outer plate, so that area will be filed down to form a chase for the wire.  From a side view the core will look like a square with round chamfered corners.  I don't want the windings on corners.  I am thinking about getting a radiused mill to do these chamfers.  Also, someday, I would like to do this whole operation on a mill.  An automated 3 Axis Mill could probably cut one of these plates in an hour, where it takes me weeks to do it with hand tools.