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John K's Superpole Bike Wheel SSG
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About the superpole magnet distance,
Today I finished my new 9" 20 magnet SP wheel weighing 2,4 Kilo. I first put only 10 magnets on the wheel and it run at 570 RPM and pulled over 600 mA.
And the charge was real good. After that I mounted the additional 10 magnets so I had 20 SP magnets on the wheel.
So the wheel is now almost doubled in weight but instead of less RPM to maintain the same coil freq it went up a lot. It run at 924 RPM and because I could
not go up in base resistance it stayed there but I can go over 1000 RPM I think. I also expected more input current at this higher speed but it went down
a lot. It run at 924 RPM at 360 mA and charging was about the same as with the 10 magnets on it.
The gap between my magnets is about the same as the distance of the combined magnets.
So my conclusion is that more SP magnets is far better if you keep the gap between them small.
Karel
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Originally posted by knagtegl View PostAbout the superpole magnet distance,
Today I finished my new 9" 20 magnet SP wheel weighing 2,4 Kilo. I first put only 10 magnets on the wheel and it run at 570 RPM and pulled over 600 mA.
And the charge was real good. After that I mounted the additional 10 magnets so I had 20 SP magnets on the wheel.
So the wheel is now almost doubled in weight but instead of less RPM to maintain the same coil freq it went up a lot. It run at 924 RPM and because I could
not go up in base resistance it stayed there but I can go over 1000 RPM I think. I also expected more input current at this higher speed but it went down
a lot. It run at 924 RPM at 360 mA and charging was about the same as with the 10 magnets on it.
The gap between my magnets is about the same as the distance of the combined magnets.
So my conclusion is that more SP magnets is far better if you keep the gap between them small.
Karel
you will probably find that that rotor will "shift" like a car engine does when it changes gears. it will go to a certain speed, then a resistance change will cause it to accellerate more, and maybe one more after that. walk your base resistance down and see how it shifts, if it does. it depends sometimes on coil spacing also and how well defined the scalar south is.
Tom CLast edited by Tom C; 04-19-2013, 07:42 AM.
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Hi Tom,
I know about the shifting gears but normally this is when your resistance is high and the speed to low and you have additional pulses.
I now have a situation where my signal is a well looking h form and it performs more like a car with a automatic gear it just speeds up very
fast but no shift in pulses just the high end of the h is getting wider as it speeds up and I have to make the resistance higher so it keeps a good
h shape. I now have it running at 955 RPM at 260 mA in on one coil and three transistors. The base resistance is around 800 ohms.
http://www.youtube.com/watch?v=tSrXH8hMZis
KarelLast edited by knagtegl; 04-19-2013, 01:00 PM.
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Originally posted by knagtegl View PostAbout the superpole magnet distance,
Today I finished my new 9" 20 magnet SP wheel weighing 2,4 Kilo. I first put only 10 magnets on the wheel and it run at 570 RPM and pulled over 600 mA.
And the charge was real good. After that I mounted the additional 10 magnets so I had 20 SP magnets on the wheel.
So the wheel is now almost doubled in weight but instead of less RPM to maintain the same coil freq it went up a lot. It run at 924 RPM and because I could
not go up in base resistance it stayed there but I can go over 1000 RPM I think. I also expected more input current at this higher speed but it went down
a lot. It run at 924 RPM at 360 mA and charging was about the same as with the 10 magnets on it.
The gap between my magnets is about the same as the distance of the combined magnets.
So my conclusion is that more SP magnets is far better if you keep the gap between them small.
Karel
Can you give me the measurement between the outer corners of adjacent mags. It sounds like your distance reference is center to center. It sounds like the distance between 2 mags pairs would be less than .5".
Thanks bro d
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[
Hi Bro d,
This is what I can offer, it's in cm because I live in Europe so you have to make some conversions.
The magnet_pairs are 2cm x 2cm x 4cm the gap between is also 2 cm on the outside and the diameter of
the wheel is 26 cm so around 10 " I guess.
Karel[/QUOTE]
Thanks Karel for the info and pics.
Looks like CNC quality.
Beautiful work.
I have a mill, drill, lathe and can turn up to 13"
Ready to go again with matched mags and components.
bro d
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Bro d,
It is CNC made, if you are interested you can see how it is made here: The making of the new 20 SP magnet wheel - YouTube
Karel
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Originally posted by knagtegl View PostBro d,
It is CNC made, if you are interested you can see how it is made here: The making of the new 20 SP magnet wheel - YouTube
Karel
The CNC movie is very informative.
What material is the rotor made of?
Thanks,
bro d
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New Rotor
Hi All,
Just finished a 9.875" rotor with 15, SP mags.
Have it running on a 1" steel shaft for the moment.
It doesn't want to run on 12v with one coil, so I'm running it on 3, 6v batts and pulse charging a 100Ah 12v batt and it looks effective.
This rotor can handle 5 coils and I'll probobly turn a shaft out of AL with .5" bearings.
The present setup is a rough draft with one coil and pulser according to the intermediate Bedini manual.
I see the need for a comparator cct to get best efficiency with the cap discharge.
Also I've recently learned from an expert at switching mosfets at high power and keeping them cool.
I built one of his circuits and have switched 1800W at 5khz, 70% duty cycle and the mosfets stayed at about
83deg F.
The load was 6, 300W bulbs and powered with 9, 12V Batts in series.
I'll see if I can remove the heat from the mosfets in the pulser cct.
The fets that I'm using now are the same one's that were cool in the previously mentioned example and the first one
in line is running at about 125degF.
Keepin on,
bro d
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Originally posted by knagtegl View Postbro d,
It's made of MDF a sort of pressed sawdust with a lot of glue.
Very nice to work with but the dust of it is not very healthy I think.
Karel
I've machined rotors out of pvc and the last one is delrin but too expensive for trial rotor.
I've got some new material coming and will see how it goes.
I machined the slots at .75" which is the same as the SP mags and with a soft mallet I drive them into place for a pressed fit.
I should take additional safety measures for high rpm. I had a 6 coiler throw a mag at 7400prm and it wrecked all six coils and bent
the 17mm AL shaft. BigBang!.
bro d
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Hi All,
Got the new 15 mag SP rotor to run on 12v after running it all night at 18v.
While it was running today I machined a shaft with a 1" knurled section to press rotor on and the rest is .5" and we'll use .5 inch bearings. Should have less drag and run free-er.
I'm planning on 5 coils"
7 pwr strands per coil
20 awg wire
Don't know what is reccomended for triggier resistance.
for multicoiler.
JohnK, can you say anything about that.
Tanks,
bro d
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Originally posted by John_Koorn View PostHey bro d,
i would go with #23 for the trigger.
John K.
Thanks
I have one coil done with #23 for the trigger.
My question now is what do I want for trigger resistors
I need good advice because of the job of matching components for a 5 coiler.
Thanks
bro d
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