Dia. Mag. Alternator

[z.monkey]

I hit the Metal Shop early today.

I found a piece of 1/16" Aluminum which is just right for the DiaMag7 mounting plates.  I got it marked up first, then got busy spotting.  The piece was a little long, so I trimmed off the excess and also made a slot between the two plates to help separate them.

[z.monkey]

Now that I have the piece roughed out, I can start getting it ready to assemble on the rotary table for the fabrication process.  First I need to mark the slots.  Also had to redraw a few lines that got smudged.  I use a carbide pencil to scratch lines into the Aluminum, and then a marker to color them.  Then I needed to finish off the holes.  The holes are matched to my fixturing clamps for now.  Then after this process we will take them out to the finish diameter.

I separated the two mounting plates with a sheet metal shear do that I wouldn't loose any material between them.  The shear bent the plates a little so I flattened them out again on the anvil, with the blacksmith hammer.  Also made a sacrificial block to ride underneath the mounting plates during the machine process.

Then both the mounting plate and the sacrificial block get mounted on the rotary table for the fabrication process.  The two plates are aligned, and locked in place, so in the end we will have two identical pieces, hopefully...

[z.monkey]

Bet you thought you wouldn't see the Bitmore vise again...

The assembly was too high for the Palmgren Table, so I had to backpedal and use the Bitmore table.  Its not a bad table, just has some quirks.  I had to get some shorter metric (M5) screws to secure the mounting plates to the rotary table.  Also had to fit them, of course I couldn't find a screw that would fit right without modification.  After that I was ready to cut.

I started with the circular peripheral cut to isolate the mounting tabs.  Then cut the slots.  The slop in the two tables was troublesome, but by making slow cuts, and really clamping everything hard I got around it, somewhat.  I had a few SNAFUs, but I think I can work them out with the small files.  So, basically, the new mounting plates are rough cut, and we're on to the finishing process...

[z.monkey]

These mounting plates are not purrfect, but I didn't breach the magnet space with the slot cuts.  So, hopefully the magnet will spin freely.  I'll apply OTF fixes (On The Fly) as needed to make it work.  I am cleaning up the mounting plates with tiny diamond files.  They are great for precision work, but are very fine, so making big cuts is time consuming.  Some of the clearances are not even close to what I want, but you know, we'll make due with whats we got...

Next step is to cut some aluminum tubes to be the stand offs between the plates.  I have some brass bolts for the supports inside the Aluminum tubes.  Then I need to fit the mechanical pieces together, and square them up to make sure there is adequate clearance for the spinning part (1 inch diameter Neo-Dia-Mag).  Then once the mechanicals are happy I can get to winding the polyphase coils...

[z.monkey]

In case you have been having trouble visualizing the end product, here it is...

The 1/16" Aluminum is a lot more rigid than I thought it would be.  I didn't breach the magnet space, and now this is visually verified.  I have somewhere between 30 and 50 mils of clearance around the magnet.  The Aluminum spacers are a little short on purpose.  This puts a little tension on the plates so that there is no lash in the bearings.  The bearings are happy, and the shaft spins freely.  There is no motoring on the chassis because there are no ferrous elements in the chassis for the magnet to latch on to.  This is a 40 pound pull magnet, so I think we can get good performance out of this one...