Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

Custom Search

[niente]

In attachment the files needed for the 13 stators simulation (not run yet). I calculated the initial orientation of every stator magnet according to the position of the rotor (they're not casual, but in latch... :-) ).
Before running the simulation you can modify the mash to obtain a more precise result.
Good luck! 

[MeggerMan]

@niente,
I will try running with the stator only 2mm away from the rotor, may be able to get it closer.
This is to see if I can increase the torque.
I think it will be impossile to sync by hand but once synced will create loads of torque.
With 13 stators all in sync the output will be impressive.

I was wondering if Al has tried to sync the stator, wait for it to reach its running speed, then using a screw thread, adjust the distance to decrease the stator/rotor gap, in theory the speed should increase as the torque increases.
I suspect that the reason he cannot get the stator closer is because the stator is too jumpy with the increased field strength and the sync speed may increase as a result.

Regards
Rob

[sterlinga]

Here's a simple analysis (by using FEMM) of the torque of the rotor covering 45 degrees of the motion (then it repeats itself because of the symmetry).

When the fulcrum of the rotor and of the stator are connected with a line, and one of the magnets on the rotor is perpendicular to this line, the stator position shows a difference of about 25 degrees in respect of that line (as in the third Alsetalokin video). This fact is included in the simulation (visible here: http://www.metacafe.com/watch/1060658/oc_mpmm_magnetic_simulation/).

Hi Niente,

Would you mind posting this animation to YouTube so I can embed it at PESWiki?  I don't like sending people to metacafe because of all the smutty video thumbnails they offer on the side.  YouTube is much cleaner.

Or you could send it to me by email and I could upload it.

Thanks for pulling this together.

Sterling

[evil-doer]

In attachment the files needed for the 13 stators simulation (not run yet). I calculated the initial orientation of every stator magnet according to the position of the rotor (they're not casual, but in latch... :-) ).
Before running the simulation you can modify the mash to obtain a more precise result.
Good luck! 

i tried running your thing then got several errors after about an hour. couldnt write to file, then couldnt find poly somethingorother.

[Jdo300]

ummm just realised I layed up the stators as per jdo's cad drawing, but I think it may be wrong.

(http://www.overunity.org.uk/ocpm/diff.jpg)

Cheers

Sean.

Hi CLaNZeR,

You are right. That drawing was incorrect. A bunch of other people pointed that out right after I posted the original pictures and I have since replaced the incorrect ones. You can see the correct pictures here:

http://www.overunity.com/index.php/topic,3871.msg68853.html#msg68853

God Bless,
Jason O

[mikeytown2]

@JFK or anyone else with a good ideas.
Try Google SketchUp http://sketchup.google.com/download.html Or at a minimum draw it out on graph paper. I find it easier to follow if there are pictures to go along with the words.

[JFK]

Yes mikeytown2, a picture is worth a thousand words... I am not an artist, but I did find a picture of flyweights used on a model steam engine to regulate the steam pressure.
Instead of regulating steam flow, this would activate a friction brake assembly... the faster it spins the more braking action would be applied.
With the braking action beginning at the "sweet spot" ( the most torque ) of RPM's... wherever that ends up being.
Based on Al's video my guess would be around 850-900 RPM's. ( rotor speed )

(http://img167.imageshack.us/img167/3204/flyweightshq5.jpg)

What I had pictured was something like this scaled down and mounted directly to the rotor spindle.
.
If you wanted to get fancy, you could make these weights out of magnets and put a pickup coil
( with a full wave bridge rectifier and capacitor ) in close proximity to them and drive an LED with that.
That would prove beyond the shadow of a doubt that it is creating an output with no input. 

But like I said, that is a thought for the future... let's let the engineers here get an overrev situation perfected first. 

[Bruce_TPU]

Hello All,

Well, the good news (for a moment!  LOL)  Was that my machined parts came in.  I put it all together, and started to look for some of the things I had seen on my self built wooden one. 

I notice that my stator magnets simply stuttered as I rev'd up the rotor.  And then I measured the distance from edge of Stator, to edge of rotor.  Distance was 8 mm.  It should be 5 mm.

To make a long story short, they cut Hanks, Jason's and my rotor 3/8" short.  Go figure!   

Hank is going to have him recut and resend our proper sized one.

The base is correct, and my stators are great.  N35 magnets.  Bearings for the stators are super precision ABEC 7's.  Very nice feel to them.  Dual rotor bearings, very nice.

Concerned about slippage where the delprin slip over the stator bearing.  But I will wait for new rotor before addressing that. 

So we wait another few days.   

Cheers,

Bruce

[0c]

In attachment the files needed for the 13 stators simulation (not run yet). I calculated the initial orientation of every stator magnet according to the position of the rotor (they're not casual, but in latch... :-) ).
Before running the simulation you can modify the mash to obtain a more precise result.
Good luck! 

i tried running your thing then got several errors after about an hour. couldnt write to file, then couldnt find poly somethingorother.

Ran twice. Failed twice in mo_blockintegral(). Output 766 lines first time, 765 lines the second time. Error message said it couldn't select the area. Checked task manager while running, no shortage of memory or disk space.

[crash_uni8]

@Bruce_TPU

i hate to bother you but could you post a picture of one of your stators....or explain how they are put together
ive been having the worst time figuring out how to make them....

[vipond50]

Hello All,

Well, the good news (for a moment!  LOL)  Was that my machined parts came in.  I put it all together, and started to look for some of the things I had seen on my self built wooden one. 

I notice that my stator magnets simply stuttered as I rev'd up the rotor.  And then I measured the distance from edge of Stator, to edge of rotor.  Distance was 8 mm.  It should be 5 mm.

To make a long story short, they cut Hanks, Jason's and my rotor 3/8" short.  Go figure!   

Hank is going to have him recut and resend our proper sized one.

The base is correct, and my stators are great.  N35 magnets.  Bearings for the stators are super precision ABEC 7's.  Very nice feel to them.  Dual rotor bearings, very nice.

Concerned about slippage where the delprin slip over the stator bearing.  But I will wait for new rotor before addressing that. 

So we wait another few days.   

Cheers,

Bruce

Nice rig Bruce, really to bad they muffed the rotor Dee's. Hoping for success for all.

Take Care
Bill

[Bruce_TPU]

@Bruce_TPU

i hate to bother you but could you post a picture of one of your stators....or explain how they are put together
ive been having the worst time figuring out how to make them....

Hey Crash,

Base is threaded for 4-40.  I use a 1" 4-40 brass screw through the ABEC 7 bearing.  The head holds the inner race of the bearing firm.  A brass nut goes on the other side of the bearing and is tightened.

This then is screwed into the threaded base, until the brass nut contacts the top of the base.

The circular N42 magnet is glued inside of my delpin holder (Great Job on that Hank!) This then is placed on the bearing, which fits snugly into the bottom of the Delprin. 

JDO300 has drawings that show that part.  If someone could put together an assembly diagram, that would probably help some of the replicators, as well.

I hope that helps!  (If I had DSL, I would post lots of pics to assist.  It just takes too long with my dial up)

@ Bill
Thanks.  I too hope for success.  I really think N35's or N38's with better (not heavier) bearings should help.  Have you had any more time to test?

Cheers,

Bruce

[Mr.Entropy]

Here's a simple analysis (by using FEMM) of the torque of the rotor covering 45 degrees of the motion (then it repeats itself because of the symmetry).
[...]

Your boundary is way too close for FEMM to give you accurate torque readings.  I think you'll find that the extra torque disappears when you move it far away.

Thanks for providing the source, though!

Cheers,

Mr. Entropy

[Bruce_TPU]

OK, I just ordered some 6061-T6 Aluminum Alloy, from:
http://www.discountsteel.com/index.cfm/go/main.itemDisplay/itemID/54.htm

I believe that the softer, pure aluminum bar from Home Depot, will dampen too much, (excess of eddy currents, too much braking applied).  The alloy has not just Teflon, but also copper in it's composition.  So the braking effect will be identical as with Al's setup. 

I believe that Sean's test will show a longer run time with the alloy.  (even if not by much, for the wind down test.)

Cheers,

Bruce

[vipond50]

@Bruce_TPU

i hate to bother you but could you post a picture of one of your stators....or explain how they are put together
ive been having the worst time figuring out how to make them....

Hey Crash,

Base is threaded for 4-40.  I use a 1" 4-40 brass screw through the ABEC 7 bearing.  The head holds the inner race of the bearing firm.  A brass nut goes on the other side of the bearing and is tightened.

This then is screwed into the threaded base, until the brass nut contacts the top of the base.

The circular N42 magnet is glued inside of my delpin holder (Great Job on that Hank!) This then is placed on the bearing, which fits snugly into the bottom of the Delprin. 

JDO300 has drawings that show that part.  If someone could put together an assembly diagram, that would probably help some of the replicators, as well.

I hope that helps!  (If I had DSL, I would post lots of pics to assist.  It just takes too long with my dial up)

@ Bill
Thanks.  I too hope for success.  I really think N35's or N38's with better (not heavier) bearings should help.  Have you had any more time to test?

Cheers,

Bruce

@Bruce

In the middle of a New rig with different Mea's for the radius, of coarse it is base off Al's spec's, So when the time comes we'll see. I'll post  the data regardless of the out come.
Also waiting on parts too ........

HI Ho, Hi Ho off to watch a Movie I go

Later Bill