Muller Dynamo

[woopy]

Ho !

Khabe

if Lasersaber is 8 to 9 config , he will have the smallest cogging possible.so far as you sayd and as we all know. the system in this case , is balanced.

But if you  add a single magnet  on the top ferrite core of "one part " of this config ,  you simply imbalance the system, and the cogging comes back. yes or not ?

It is what i can experiment on my bench ,in front of me, on my real replication attempt, Don't you have the same on your replication test bench h ?

all the best

Laurent

[Ren]

Hi ChrisC,

Hey, we are all having fun. 

Spent 8 hours today (measure 5 times, drill once) so far drilling, match drilling, progressive drilling to size, 5 disc from Tap Plastic.  The fun part was when I test spun my Rotor.   It is 35 thousands out of round and it is NOT a center shaft placement mistake. Runs just fine at 3600 rpm using the drill press, with low vibration but I don't like to see the slight wobble horozontally there. Did someone say these were use for cake work....that might explain the "close tolerances! Ha" .  The top and bottom coil mounting plates, the top and bottom magnet adjustment pltes, etc., are fine as the match drilling takes care of errors and they don't rotate, but now have to figure out how to true up that darn rotor as I don't have a nice big lathe so will do it some how in the small drill press I have (slowly).....It is only time and I have lots of it! 

Having Fun

Ben K4ZEP

Hi Ben,

I have run into this problem with acrylic before. Ive found that one of the faces is usually true and the other can be out by a whisker. I think there is just a slight difference in the thicknesses from side to side.

Ive run into this with multiple pieces of varying thickness of acrylic, its a pain, because the only way to fix it is to true up the face on the lathe, and you lose your nice finish.



Good luck.

Ren

[khabe]

Ho !

Khabe

if Lasersaber is 8 to 9 config , he will have the smallest cogging possible.so far as you sayd and as we all know. the system in this case , is balanced.

But if you  add a single magnet  on the top ferrite core of "one part " of this config ,  you simply imbalance the system, and the cogging comes back. yes or not ?

It is what i can experiment on my bench ,in front of me, on my real replication attempt, Don't you have the same on your replication test bench h ?

all the best

Laurent

Laurent,
Short answer is - NO,
This "you simply imbalance the system, and the cogging comes back"  just shows you do not understand the point from what cogging comes and why it will be reduced when  9_8 or 9_10 or what ever such kind combination used. Imbalance will come when some of coil top magnets are missed and even then this is not a problem because very large air gaps, if not to say - implausibly large gaps
When all coil top magnets are NS or all coil top magnets are SN - there is  no act to cogging when unipolar rotor magnets.
cheers,
khabe

[k4zep]

Hi Ben,

I have run into this problem with acrylic before. Ive found that one of the faces is usually true and the other can be out by a whisker. I think there is just a slight difference in the thicknesses from side to side.

Ive run into this with multiple pieces of varying thickness of acrylic, its a pain, because the only way to fix it is to true up the face on the lathe, and you lose your nice finish.



Good luck.

Ren

Thanks Ren,

About 2 hours slow work with a coarse file then a fine file around the circumference and I got it within +2 -0 thousandts, good enough for now.  Not worrying about face, just diameter, my kingdom for a good lathe!.  To do this thing, rotor needs to be turned totally from a piece of solid stock or a built up work piece, then turned down, Indexing head, etc.etc. but it can be done within reason by hand......for me, time is not money, just time...and this is definitely a "one of" device, if it works, lots of ideas, if it doesn't for me, sit it on the shelf and say "WOW"!  Win loose or draw, we all are having fun!  Now to enlarge the 1/4" magnet holes to 1/2" without trashing rotor., My motor/gen is slightly smaller than R's, just want to self run................LaserSaber has greatly encouraged me!!!!!

My Hall effects came in from China today and my PNP's from HongKong, faster than some USA providers!!!! Now do I make a PC board or do
I simply breadboard.........

Ben K4ZEP

[bourne]

Hi Guys

Not sure if this has been 'gone over' before but I will post it anyway. It is a struggle keeping up with the posting during the week.

I have been busy with scissors and sheets of paper waiting for parts to arrive.

I have something to show regarding the 'event' travel. The 'event' being the single passing of a magnet and coil,

approach/TDC/recede

which has been shown to be magnified by the odd even arrangement of magnets/coils (number of magnets times segments of rotor)

Muller Dynamo. Comparison between numbers of coils and magnets

http://youtu.be/BaqRXKRSFOc

Conclusion
It does not matter if you have an odd or even number of rotor magnets, if you want 'Events' to travel 'with' the rotor direction you must have a lower number of stator coils.

I have a pdf of the sheets I used if anyone wants to play with the combinations.

All the best