Increase charging output with stronger rare earth magnets?

[Paul LeClair]

Hi all

dealing very recently with stator/rotor/regulator-rectifier issues got me thinking.... Not always a good thing. Anyway, I have also recently been looking at rare earth magnets that are so much stronger than "normal" magnets, the question that came to mind was whether anyone was adding stronger magnets to charging systems to increase output?

Google being a dangerous thing, it soon became obvious I am far from the first to start thinking along theses lines, Harley for example apparently increased magnet strength when they needed greater output    http://www.cycleelectricinc.com/48%20amp%20vs%2050%20amp%20three%20phase.htm  but experienced charging system failures from increased heat....

anyway, I got to thinking about possibly increasing older Laverda charging system output by adding much stronger rare earth magnets. Anyone more electrically inclined than me think that might be possible  :-[ Some possible sources of strong magnets.

https://www.rare-earth-magnets.com/  for max N 40 magnets but easily available

http://www.kjmagnetics.com/  carry N 40 but also some in the very strongest category N 52

attaching or mounting them would also have to be figured out so they don't go flying away........

Paul LeClair

 

[IAG]

Interesting,  Paul. My first thought is that greater magnetic force would slow engine RPM down-so on carbed bikes could it cause a low idle stall w/ accessories on? On EFI bikes idle compensation is controllable via an IAC motor so potentially more feasible.

 

[2622]

Paul
Seems like a lot of work !! for what gain..

I would have thought now with modern batteries, ie: Gell or even better Lithium, modern ignition systems and globes etc, ..oh and most important of all a good regulator to prevent over charging,  that the need to increase the output of the alternator is not that important as it once was.

I dont have any issues with the 3C in terms of battery undercharging and I ride always well most always with the headlight on.

( being an ex rider trainer some habits are hard to break )

 

[chrisk]

When I raced speedway, our bikes ran a magneto, the points ran off the end of the armature.
After changing to dead loss battery system, I raced like that for a couple of years. Then I turned down all the magnets on a lathe (a difficult mess to clean) so there was just a shaft to run the points.

The result was an amazing increase in power to the back wheel. Starts from the gate were fantastic and  l could pull wheelies everywhere on the track.

The argument was, was it the weight loss or removed resistance from no more magnets. I lean towards the latter.

Point being, IMHO, those magnets suck a lot of HP. The stronger the magnets the more power loss.

I could be wrong though, I was once before. 

 

[GregT]

The rare earth magnets are being used in the latest moderns. GSXR1000 alternator rotor for example is a fraction of the weight of older models. Visually they're a lot thinner in the magnet area. Saves crank weight too.
Starter motors were one of the first uses - they've shrunk but the output has risen.

 

[breganzane]

I've been running the very light GSXR1000 alternator rotor on my injected RGA since about 2008 on and off.  Works well, my only problems were with being greedy saving weight and making the adapter housing out of aluminium, the sprag ramp piece eventually cracked.  Revised version with a different type of sprag is made but just need to adapt the freewheel which got shelved before christmas as I couldn't get access to the machine I needed.  Should give it another crack...  haha.
In terms of ChrisK's comments I thought maybe the extra electrical drag might make starting harder, but it was the opposite - I never measured it but the alternator seemed to actually improve cranking, almost like it charged at cranking rpm.  Just an impression, maybe also due to lower mass but it's fairly small compared to overall crank MOI.
I have also used the mosfet regulator since the same time, problem free, battery voltage is dead stable.  No problems using a little ETX14 battery.
Coincidentally with Greg's comments, I also have a modern type starter motor too, that is in line to be looked at after the new sprag is proven.  All part of general electrical upgrades deemed useful when the injection went on.  Probably part of why the bike got set aside for a few years... project fatigue.  One day...

 

[Paul LeClair]

as usual it looks like I am several years or more behind some of the rest of you, especially SteveB and GregT.......  :

unfortunately I do not have an original early triple charging system on a bike to experiment with, my oldest triple is the 79 1200 which was converted to an IIS system a long time ago. Hopefully some other tinkerer may give the rare earth magnets a try and report back? In the meantime, I am going to go dig through my parts storage boxes and see if I kept the original stock charging system from the 79.

for regulator/rectifiers, I only recently discovered the advantages of a MOSFET regulator/rectifier, this is the one I am now using  http://www.ebay.com/itm/UNIVERSAL-MOTORCYCLE-REGULATOR-UPGRADE-KIT-SHINDENGEN-MOSFET-FH020AA-/380801823383?hash=item58a98eb297:m:mCXcVj2Cg4ukmJ1vP4gijuA&vxp=mtr

Oddly enough the Mosfet technology has been around pretty much as long as the diode technology in more common use in regulator/rectifiers. Way more information than I followed, here    https://en.wikipedia.org/wiki/MOSFET

a photo of the Mosfet regulator/rectifier on my 82 1200 TS Mirage. It is larger than the stock unit, and would not fit in the stock mounting location. I mounted it to the top of the rear fender.

Paul LeClair

 

[breganzane]

Hi Paul,
Because the rotor is manufactured as a unit, I doubt it would be practical to adapt modern magnets into it.  Easier just to modify a rotor/stator already engineered to suit, which is pretty much exactly what John Wilson did and Red has carried on.  I do recall John saying that the original Bosch rotor gave lots of stray fields which affected earlier versions of his pickups, which was as much the reason for going to ZZR250 rotor/stator as the added output.  The Bosch rotor is a very antiquated design, as we know.  Backing this up is the fact that some versions of the bosch pickups were in fact shielded with co-netic type material which is a very expensive magnetic shielding alloy.
Running a modern rotor requires a modern stator, which does not allow space for the original pickups, so overall the best available option at present is the redax manufactured setup, preferably using Kawasaki components.
Cheers
SteveB

 

[Vince]

So is the plan a Hybrid Laverda with a couple of electric motors tied in ala Maclaurin, Porsche etc