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#1368973 - 01/04/19 10:01 PM New generator ?
ConRAD
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… actually I was just jocking !!! … but now it appears that somebody took it pretty seriously and, simply, “did” it!!

Will it work ??


Edited by ConRAD (01/04/19 10:01 PM)
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#1368974 - 01/04/19 10:14 PM Re: New generator ? [Re: ConRAD]
Happy Birthday! Keine Ahnung
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It's a rather open design, which might in practice create problems with dirt, corrosion etc.

In principle, it of course should work ...
Gruß, Arnulf

"Ein Leben ohne Radfahren ist möglich, aber sinnlos" (frei nach Loriot)
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#1368978 - 01/04/19 10:30 PM Re: New generator ? [Re: Keine Ahnung]
ConRAD
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... oh sure, of course it works !!!
But, besides being totally exposed to the atmosphere with dirt, dust, mud, water and corrosion implications, there are some other very critical points such as:
1. To produce somehow aceptable power rotor and stator must be very close to each other
2. Axial forces might trigger unacceptable vibrations
3. The magnetic circuit is very poor and so far the output power might be not enough
4. And what about the weight ...
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#1369172 - 01/06/19 08:35 PM Re: New generator ? [Re: ConRAD]
derSammy
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Can you explain in more detail, how it is supposed to work? I only see screws, some cable and an non-circular housing mounted around the rear axis.
Komm wir grillen Opa. Es gibt Koch und Suppenfleisch!
Satzzeichen können Leben retten.
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#1369177 - 01/06/19 09:29 PM Re: New generator ? [Re: derSammy]
ConRAD
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HERE how it works !!
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#1369184 - 01/06/19 09:56 PM Re: New generator ? [Re: ConRAD]
derSammy
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Oh, I see. Well, you listed a series of cons, so where is the benefit?
Komm wir grillen Opa. Es gibt Koch und Suppenfleisch!
Satzzeichen können Leben retten.
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#1369189 - 01/06/19 10:12 PM Re: New generator ? [Re: derSammy]
ConRAD
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Ok, perhaps the first post isn't clear enough !!
1. the 1st picture shows my own prototype that I did a few years ago.
2. the 2nd picture shows what a guy somewhere in the United States is trying to put into production through a crowdfunding scheme financing.
The system is definitely working, the rotor is fitted with permanent magnets, the stator with coils wired in series to increase voltage.
One of the possible advantages compared to hub dynamo is that you do not have to dissamble/assemble the wheel and it can work without introducing any additional mechanical friction !!
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#1369194 - 01/06/19 10:44 PM Re: New generator ? [Re: ConRAD]
derSammy
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Ok, but this seems to me a kind of solution for a no-problem. There are hub dynamos in very high quality available for almost all kind of bikes. Yes, probably you need to build a new wheel, but is this really so much more afford than buying and installing such an alternative (non StVO admissible) dynamo?
If you really care that much about friction, you might also use one of the available detachable dynamo solutions. But basically I don't see, where e.g. a hub dynamo causes more friction than the crowdfunding soltuion? Both have the hub bearing as only mechanical source of friction, or do I miss an aspect?
Komm wir grillen Opa. Es gibt Koch und Suppenfleisch!
Satzzeichen können Leben retten.
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#1369200 - 01/06/19 11:17 PM Re: New generator ? [Re: ConRAD]
MajaM
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Nice to see someone trying something new - and let us know! Just sitting at the screen and criticising is easy...

Did you measure the electrical power output? Do you have more information or a link about the guy in the USA with the similar generator?

Liebe Gruesse
Maja
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#1369225 - 01/07/19 08:53 AM Re: New generator ? [Re: MajaM]
ConRAD
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1. Yes, mechanical friction is indeed exactly the same one valid for a standard hub dynamo, both so far use bearings.
Friction is of course much better whether compared with bottle type or spoke dynamos
2. The advantage compared to a hub dynamo is that you don’t need to build a new wheel
3. Another advantage is that you can install one of them either on front or rear wheel, or on both wheels just in case you need more power
4. Might be available with different output rated powers just playing on number and strength of magnets and coils arrangement
5. Conversely among possible critical points and disadvantages I can see
- overall design that doesn’t allow for pole-claw configuration typical of hub dynamos
- total exposure to atmosphere
- requires accurate installation to reduce to a minimum the airgap in the between rotor and stator
- possible strong axial vibrations
- weight

In my prototype:
- the output power was pretty low, yet enough to light-on at very low speed some RGB leds
- rotor-stator airgap was very big
- magnetic circuit was extremely poor (I used a disk brake!!)
- coils were recycled junked relay coils

For the crowdfunding model/prototype you can visit SPINETICSINC
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#1369274 - 01/07/19 06:53 PM Re: New generator ? [Re: ConRAD]
MajaM
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Thank you for the link to SPINETICS. But it's not clear there what's the actual status of the project. It seems they didn't succeed with their Kickstarter-campaign back in 2015.

Liebe Grüsse
Maja
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#1369388 - 01/08/19 05:54 PM Re: New generator ? [Re: MajaM]
derSammy
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Hi Maja,
I do not just want to criticize. I really like all kind of new ideas about bike techniques. I am convinced that there are still opportunities with the dynamos if you drop the traditional StVO requirements. Three-phase-current might e.g. be a realy promising idea.
I just wanted to know, where the possible benefit of this kind of dynamo is and apart from the easy installation on some (bikes using disc breeaks don't seem to be compatible), I don't see it. But lots of difficulties to solve...
Komm wir grillen Opa. Es gibt Koch und Suppenfleisch!
Satzzeichen können Leben retten.
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#1369389 - 01/08/19 06:09 PM Re: New generator ? [Re: derSammy]
MajaM
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Originally Posted By: derSammy
I just wanted to know, where the possible benefit of this kind of dynamo is and apart from the easy installation on some (bikes using disc breeaks don't seem to be compatible), I don't see it.

The new generator construction might deliver more power (at some speeds), it might be possible to adjust the distance between coils and magnets during the ride to increase power output in one situation and decrease losses in other situations. Just the possibility to make a powerful DIY bicycle dynamo is appealing to me.

Liebe Grüsse
Maja
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#1369416 - 01/08/19 09:41 PM Re: New generator ? [Re: MajaM]
ConRAD
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As far as I can see:
1. If the purpose is to generate "power", remaining of course within the limits of electrical safety, traditional hub dynamos might become somehow obsolete
2. Traditional hub dynamo is by its own design and construction not "flexible" at all
3. Conversely, the generator presented above can modulate the power just adjusting the distance (airgap) between rotor and stator, or adding/removing magnets if you like!!
4. In case of disk brake you still can install it onto the front wheel
5. The big drawback, imo, is represented by vibrations; the only way to overcome this problem is redesign the coil-array and give to it a "U" shape to encompass the magnets passing through it
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