Monday Jan 3

[DanB]

Monday was kind of slow this week.  I think we were still recovering from Scott & Bonnies very fun new years eve party, and George was sick with the flu so he never made it up.  I did get a bit of work done on the new machine though.  A recap - pictured above are the magnet rotors, 22" in diameter each with 20 magnets 3" long, 1.5" wide and 3/4" thick.

We're making the mould out of 5/8" baltic birch.  The stator will be 28" in diameter, there will be 15 coils.  I started by making a compass and drawing the circle on the board which will be the bottom of the mould.

The machinists handbook is full of handy charts and information.  This page explains how to divide the circle into 15 equal segments.  Simple high school trig... but I forget all that stuff so I need to look it up.

Pictured above I've drawn lines.  This isn't really necessary - if the coils are sized right and equally spaced everything would be perfect, but its handy to make sure the coils are the right size.  It also helps me design the coils.

Then we draw two more circles so that we know the path of the magnets.  When putting the coils in it's nice to know they're in exactly the right spot.

We used Scotts rotating table clamped to the bandsaw to cutout a 28" diameter circle for the 'middle' of the mould.  It does a nice job.

There's the stator mould about finished up.  Now we just need to glue/screw it all together.  It'll be a big casting.  In the past I've had minor problems with big castings cracking.  This one I think we'll be very light with the hardener, use some filler and hope for the best.

It was a smaller party than average for a Monday.  We ate leftovers from the party (no pizza).  Fun as usual...

[Waterfront]

Nice post DanB!

Those rotors look pretty darn powerful!! How much do they weigh?? I'm sure you'll need quite a prop to turn those under load...

Nice compass to make circles too, simple yet effective! I use a string, but I always end up a less then perfect circle...

Have you started to think about a tower? I'm guessing that too will need to be quite solid, with nice big guys...

Can't wait to see more!!

[DanB]

"Those rotors look pretty darn powerful!! How much do they weigh?? I'm sure you'll need quite a prop to turn those under load..."

Each rotor weighs 68 pounds - 49 pounds of steel and 19 pounds of magnet if I recall.  I'm hoping it'll be a 20'ish diameter machine.

"Have you started to think about a tower? "

I've thought about it... though I prefer not to.  ;~)

[force9BOAT]

When you cast the mold how do you prevent the resin from sticking to the plywood?  Do you have to wax the mold or lay down plastic rap first?  Or is there a resin that does not stick to wood?

Looks great!

Rob

[Victor]

Hi Dan,

 Speaking of towers.

 Did you get my e-mail about the bending strength of pipe?

Victor

[nothing to lose]

I think the common practice is to wax or grease the mold.

[nothing to lose]

Well, I hope George is feeling better.

Looks great as always. Say I was wondering about that bandsaw. Is that a bicycle wheel on there? Looks like a commercail frame but I wonder about the wheel.

If that's a homemade band saw by any chance, good pictures of it and some details would be helpfull. I been planning to build mine for awhile, can't really decide how I want to build it, several ideas.

I like your compass too

Are you going to cast a full size stator or just the outer ring where the coils are located and mounting points and leave the center empty? Can't really tell but looks like the mold is only void at the hub. Wouldn't you save alot of resin and weight yet still have a strong stator casting only about the outer 6" area.

I saw Hughe only cast the outer portion on Nirvana I think it was. How did that work out? I thought it would be a good Idea myself to make the inner uncast area larger, but  I thought Nirvana might have been to close to the coils myself. Course Hughe and you guys know alot more about these than I ever will.

[Norm]

  Yeah...I was wondering the same thing ...

cause the spokes are a blur just like bicycle

spokes would be....??

               ( :>) Norm.

[DanB]

They're not bike wheels.  They're cast iron wheels with 6 spokes ea.

I think Hughs Nirvana machine is running nicely  now, there's a link to it off his front page now.

I thought about casting this stator like that-  but I think Ill waste a bit of resin (let the coils get a bit warmer....) and cast it further in.  I think having some casting inside the coils will provide some rigidity and perhaps hep it from warping.  Who knows..

[nothing to lose]

Thanks. I was looking at a different picture of the saw a few weeks ago, then I thought it looked like bicycle wheel and thin spokes. Geuss I looked at it wrong, thanks.

Glad the Nirvana is working well. I thought the resin was cast maybe a little to close to the coils perhaps. I would stay further from the coils and add rigidy like you say, but thought about 1-2" would be sufficeinent. Sorry for the spelling, good beer you know

 Don't drink much or often though, and speeling is alwayds a problem as well as just bad typing errors.

 Hmm, the above was not on purpose but proves the point! Speeling and alwayds? Just plain bad typing, not good beer at all there!

Say, I may be heading to AZ soon, driving past you guys. Maybe not all that close, but if I can drive 2,000 miles to Northern Canada, 200 miles is not out of the way at all for me!!

If I happen to be nearby sometime do you mind if I drop by for a weekend and a Monday madness perhaps? I sent an email once a year or two ago but never really got a reply to that one. Right now I plan to head for Canada agian for a cold snow filled winter, too warm here in MO. now, but about Feb or March I should be around home and traveling USA agian. I have freinds in AZ I have not seen for a couple years and they have a new baby too. So sometime this year I will be driving by you guys.

Well keep up the great work and great posts about what you are building. Mondays are about the highlights of my life perhaps

Well at least the monday madnesses are uplifting for me anyway. I really like those and  look forwards to seeing them.

[healerenergy]

Did you cast those rotors or have them cast by somebody else. I work in a big foundry where our bigest casting is over 65 tons.

[BigBreaker]

I believe DanB has his rotors cut from plate steel by an abrassive jet at a local machine shop.

[healerenergy]

Thanks for the info.