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Main
Date: 29 May 2007 05:50:31
From:
Subject: forget the springs, go with the electricity
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Google answers many questions, if you're just PATIENT enough. just
stumbled across a powerpoint on the web, concise design analysis of
the problem by a professor of mechanical engineering. The equations
show why the patent-office file cabinets are littered with ideas for
spring-stored energy for bicycles which never saw a real factory
floor.... the energy-storage density just ain't there. His
recommendation: optimize the electrical approach.
Ok: who makes the best electrical-assist which encompasses an
efficient regenerative-braking?
what's the state of the art of energy-storage capacitors?
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Date: 31 May 2007 06:38:39
From: ctyankee
Subject: Re: forget the springs, go with the electricity
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On May 29, 3:46 pm, "Paul E. Schoen" <pst...@smart.net > wrote:
> <dances_with_barka...@yahoo.com> wrote in message
>
> news:1180443031.811700.163890@j4g2000prf.googlegroups.com...
>
> > Google answers many questions, if you're just PATIENT enough. just
> > stumbled across a powerpoint on the web, concise design analysis of
> > the problem by a professor of mechanical engineering. The equations
> > show why the patent-office file cabinets are littered with ideas for
> > spring-stored energy for bicycles which never saw a real factory
> > floor.... the energy-storage density just ain't there. His
> > recommendation: optimize the electrical approach.
>
> > Ok: who makes the best electrical-assist which encompasses an
> > efficient regenerative-braking?
>
> > what's the state of the art of energy-storage capacitors?
>
> I had a similar idea to build a small railway on my property which would be
> used to bring down firewood from the top of a hill (about 50' elevation). I
> figured I could run it for free, or maybe get extra energy, by using the
> potential energy of the wood. Probably it would not be economically worth
> the effort, but the cool fun factor made it something I wanted to try.
> Having batteries in the vehicle seemed to be a null factor, except that it
> required bigger motors or slower gearing, and maybe more rolling
> resistance. I also considered electrifying the rails, or using an overhead
> hot line, but it would only be efficient at voltages much higher than would
> be safe.
>
> For energy storage capacitors, try:
>
> http://www.maxwell.com/ultracapacitors/index.asp
>
> From a previous post, here is a discussion of what to expect:
>
> Energy storage for the capacitors is based on 1/2*C*V^2, so your 210,000 uF
> 25 V bank will store 65 J (watt-seconds). If you have 800 watts of motors
> (1 HP), the energy will power the vehicle for less than 0.1 seconds. They
> are most useful for quick energy dumps from dynamic braking, but you will
> need more than that to absorb the kinetic energy of a fast stop.
> Supercapacitors are available, such as Maxwell BPAP1200 - E270, which are
> 1200 F at 2.7 V. Ten in series gives you 120 F at 27 volts, and energy
> storage of 43,000 W-Sec, or 50 seconds run time at 800 watts. They cost
> about $46 each.
>
> Some interesting high surge current capacitors are:
>
> http://www.sbelectronics.com/images/PDFs/Power_Ring_Options_0207.pdf
>
> Paul
1200F @ 2.7 V -- that's not a capacitor! It's a rechargable hearing
aid button cell <g >
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Date: 29 May 2007 14:36:26
From: landotter
Subject: Re: forget the springs, go with the electricity
|
On May 29, 7:50 am, dances_with_barka...@yahoo.com wrote:
> Google answers many questions, if you're just PATIENT enough. just
> stumbled across a powerpoint on the web, concise design analysis of
> the problem by a professor of mechanical engineering. The equations
> show why the patent-office file cabinets are littered with ideas for
> spring-stored energy for bicycles which never saw a real factory
> floor.... the energy-storage density just ain't there.
They obviously haven't seen the proper way to do this...with a really
big rubber band, like in the Swedish film, "The Apple War".
http://en.wikipedia.org/wiki/The_Apple_War
I wish I had screenies, but basically the bicycle guy in the film uses
the rubber band to get to the bus stop really fast, and stretches it
on the way home in the evening.
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Date: 31 May 2007 12:13:57
From: YD
Subject: Re: forget the springs, go with the electricity
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Late at night, by candle light, landotter <landotter@gmail.com > penned
this immortal opus:
>On May 29, 7:50 am, dances_with_barka...@yahoo.com wrote:
>> Google answers many questions, if you're just PATIENT enough. just
>> stumbled across a powerpoint on the web, concise design analysis of
>> the problem by a professor of mechanical engineering. The equations
>> show why the patent-office file cabinets are littered with ideas for
>> spring-stored energy for bicycles which never saw a real factory
>> floor.... the energy-storage density just ain't there.
>
>They obviously haven't seen the proper way to do this...with a really
>big rubber band, like in the Swedish film, "The Apple War".
>
>http://en.wikipedia.org/wiki/The_Apple_War
>
>I wish I had screenies, but basically the bicycle guy in the film uses
>the rubber band to get to the bus stop really fast, and stretches it
>on the way home in the evening.
Yeah, a big bunch of bungee cords can't be all that expensive. Needs a
rather straight stretch of road, though.
- YD.
--
Remove HAT if replying by mail.
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Date: 31 May 2007 15:31:33
From: Michael A. Terrell
Subject: Re: forget the springs, go with the electricity
|
YD wrote:
>
> Late at night, by candle light, landotter <landotter@gmail.com> penned
> this immortal opus:
>
> >On May 29, 7:50 am, dances_with_barka...@yahoo.com wrote:
> >> Google answers many questions, if you're just PATIENT enough. just
> >> stumbled across a powerpoint on the web, concise design analysis of
> >> the problem by a professor of mechanical engineering. The equations
> >> show why the patent-office file cabinets are littered with ideas for
> >> spring-stored energy for bicycles which never saw a real factory
> >> floor.... the energy-storage density just ain't there.
> >
> >They obviously haven't seen the proper way to do this...with a really
> >big rubber band, like in the Swedish film, "The Apple War".
> >
> >http://en.wikipedia.org/wiki/The_Apple_War
> >
> >I wish I had screenies, but basically the bicycle guy in the film uses
> >the rubber band to get to the bus stop really fast, and stretches it
> >on the way home in the evening.
>
> Yeah, a big bunch of bungee cords can't be all that expensive. Needs a
> rather straight stretch of road, though.
Use a pack mule. Its what they were created for.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
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Date: 29 May 2007 15:46:59
From: Paul E. Schoen
Subject: Re: forget the springs, go with the electricity
|
<dances_with_barkadas@yahoo.com > wrote in message
news:1180443031.811700.163890@j4g2000prf.googlegroups.com...
> Google answers many questions, if you're just PATIENT enough. just
> stumbled across a powerpoint on the web, concise design analysis of
> the problem by a professor of mechanical engineering. The equations
> show why the patent-office file cabinets are littered with ideas for
> spring-stored energy for bicycles which never saw a real factory
> floor.... the energy-storage density just ain't there. His
> recommendation: optimize the electrical approach.
>
> Ok: who makes the best electrical-assist which encompasses an
> efficient regenerative-braking?
>
> what's the state of the art of energy-storage capacitors?
>
I had a similar idea to build a small railway on my property which would be
used to bring down firewood from the top of a hill (about 50' elevation). I
figured I could run it for free, or maybe get extra energy, by using the
potential energy of the wood. Probably it would not be economically worth
the effort, but the cool fun factor made it something I wanted to try.
Having batteries in the vehicle seemed to be a null factor, except that it
required bigger motors or slower gearing, and maybe more rolling
resistance. I also considered electrifying the rails, or using an overhead
hot line, but it would only be efficient at voltages much higher than would
be safe.
For energy storage capacitors, try:
http://www.maxwell.com/ultracapacitors/index.asp
From a previous post, here is a discussion of what to expect:
Energy storage for the capacitors is based on 1/2*C*V^2, so your 210,000 uF
25 V bank will store 65 J (watt-seconds). If you have 800 watts of motors
(1 HP), the energy will power the vehicle for less than 0.1 seconds. They
are most useful for quick energy dumps from dynamic braking, but you will
need more than that to absorb the kinetic energy of a fast stop.
Supercapacitors are available, such as Maxwell BPAP1200 – E270, which are
1200 F at 2.7 V. Ten in series gives you 120 F at 27 volts, and energy
storage of 43,000 W-Sec, or 50 seconds run time at 800 watts. They cost
about $46 each.
Some interesting high surge current capacitors are:
http://www.sbelectronics.com/images/PDFs/Power_Ring_Options_0207.pdf
Paul
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Date: 01 Jun 2007 02:11:25
From: Anthony Matonak
Subject: Re: forget the springs, go with the electricity
|
Paul E. Schoen wrote:
...
> I had a similar idea to build a small railway on my property which would be
> used to bring down firewood from the top of a hill (about 50' elevation). I
> figured I could run it for free, or maybe get extra energy, by using the
> potential energy of the wood. Probably it would not be economically worth
> the effort, but the cool fun factor made it something I wanted to try.
> Having batteries in the vehicle seemed to be a null factor, except that it
> required bigger motors or slower gearing, and maybe more rolling
> resistance. I also considered electrifying the rails, or using an overhead
> hot line, but it would only be efficient at voltages much higher than would
> be safe.
I would think the coolest method to use the potential energy of the wood
to run the railway would be to burn it in a steam engine. :)
Seriously though, I've seen small "railroads" in shopping malls that are
run off 12V running through the rails. They're big enough to carry a
bunch of kids so something similar should be able to lug a cartload or
two of firewood. It doesn't have to be terribly efficient to be useful.
Slow is also probably quite acceptable. If it saves you from having to
make several trips then it can be quite slow and yet still faster than
the alternative.
You could even go all renewable on this and fit out solar panels on the
top of the "engine" for this railroad. When the sun shines the thing
will slowly work its way up the hill using whatever energy the panels
produce. Add a stop switch at the top (of course) to keep it from going
too far. So what it if takes a day or two to get there? It's not like
you would have to be driving.
Anthony
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Date: 01 Jun 2007 06:40:37
From:
Subject: Re: forget the springs, go with the electricity
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Paul E. Schoen had a similar idea to:
> build a small railway on my property which would be used to bring down
>firewood from the top of a hill (about 50' elevation)...
How about a cable loop with 2 pulleys? Hook a piece
of firewood onto the bottom cable and let it go,
with a trip gadget to release it at the bottom.
Nick
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Date: 01 Jun 2007 10:21:43
From: Frithiof Andreas Jensen
Subject: Re: forget the springs, go with the electricity
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"Paul E. Schoen" <pstech@smart.net > skrev i en meddelelse
news:465c83f4$0$16279$ecde5a14@news.coretel.net...
> I had a similar idea to build a small railway on my property which would
> be used to bring down firewood from the top of a hill (about 50'
> elevation). I figured I could run it for free, or maybe get extra energy,
> by using the potential energy of the wood.
Maybe you should try with a fly-wheel first?
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Date: 31 May 2007 19:13:17
From: Lostgallifreyan
Subject: Re: forget the springs, go with the electricity
|
"Paul E. Schoen" <pstech@smart.net > wrote in
news:465c83f4$0$16279$ecde5a14@news.coretel.net:
> Supercapacitors are available, such as Maxwell BPAP1200 – E270, which are
> 1200 F at 2.7 V. Ten in series gives you 120 F at 27 volts, and energy
> storage of 43,000 W-Sec, or 50 seconds run time at 800 watts. They cost
> about $46 each.
>
Do you have a link to more on those?
Google's only references to "BPAP1200" are archived copies of your post.
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Date: 29 May 2007 09:33:29
From: DougC
Subject: Re: forget the springs, go with the electricity
|
dances_with_barkadas@yahoo.com wrote:
>
> Ok: who makes the best electrical-assist which encompasses an
> efficient regenerative-braking?
>
> what's the state of the art of energy-storage capacitors?
>
I think the Bionx can do regenerative braking....
I don't think the electrical means would be the best solution however. I
have already found that the cost-per-mile of operating a Bionx is
greater than for operating a gasoline-engine of comparable power, and
that was assuming flat ground.
The problem with electrical vehicles is that everybody WANTS small
lightweight batteries, but they tend not to last very many discharges
before failing if they are deep-cycled, and if they aren't deep-cycled,
then you don't get much practical energy storage from them.
The only way to make electrical batteries that will last a lot of
discharge cycles is to make them lead-acid and make them BIG and only
ever discharge them lightly--but you see then,,,, if you want a vehicle
that can climb hills, then the last thing you want is a bunch of heavy
batteries powering your hill-climbing vehicle.
-----
I would suggest a gas engine kit, such as a Golden Eagle belt-drive. The
belt drive is simple and reliable and a 4-cycle engine is easy to fuel.
~
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Date: 29 May 2007 06:52:57
From:
Subject: Re: forget the springs, go with the electricity
|
> I still like my cable/pulley idea better.
ok, you do it on your mountain. maybe you have an angel giving you
capital at zero interest expense. i don't.
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Date: 29 May 2007 21:14:19
From: A Muzi
Subject: Re: forget the springs, go with the electricity
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>> I still like my cable/pulley idea better.
dances_with_barkadas@yahoo.com wrote:
> ok, you do it on your mountain. maybe you have an angel giving you
> capital at zero interest expense. i don't.
And we've all seen 'Zorba the Greek' with the wire guided logs.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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Date: 30 May 2007 06:15:53
From: Homer J Simpson
Subject: Re: forget the springs, go with the electricity
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"A Muzi" <am@yellowjersey.org > wrote in message
news:135png7kbjls84c@corp.supernews.com...
> dances_with_barkadas@yahoo.com wrote:
>> ok, you do it on your mountain. maybe you have an angel giving you
>> capital at zero interest expense. i don't.
>
> And we've all seen 'Zorba the Greek' with the wire guided logs.
I've also seen that work OK.
--
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--
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--
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Date: 29 May 2007 11:42:42
From: default
Subject: Re: forget the springs, go with the electricity
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On 29 May 2007 06:52:57 -0700, dances_with_barkadas@yahoo.com wrote:
>> I still like my cable/pulley idea better.
>
>
>
>ok, you do it on your mountain. maybe you have an angel giving you
>capital at zero interest expense. i don't.
Mountain topography and type of cargo aside . . . You figure high tech
state of the art is going to be less expensive than a piece of wire
and some pulleys? It won't take capital?
You wouldn't be the first person wanting to get a weight down a
mountain. Or hill - any mountain worth the name wouldn't be bicycle
friendly.
I worked a place in Alaska where we wanted to haul supplies up to a
mountain lookout, and do it cheaply. We had a very steep cliff face
and they were using airlifted supplies. Some guy got the idea to use
a rope and buckets. Water filled a bucket and pulled the supplies up
in another bucket. Daily re supply with food and equipment versus
weekly and at a lot lower cost.
Still needed the copter for changing observers, and no one could take
more than a month in the 5 X 8 aluminum box they called home. They
were working on a steel cable to lift men up. The idea was to put one
guy in a sling at the base another at the top, add enough water to
bring the up guy down (if necessary). Plan was to use something like
the old style dial telephones - centrifugal brake to regulate the
speed - or an off the shelf centrifugal clutch from a riding
lawnmower. I never saw that working, but have no doubt they could
make it work.
--
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Date: 29 May 2007 09:37:47
From: default
Subject: Re: forget the springs, go with the electricity
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On 29 May 2007 05:50:31 -0700, dances_with_barkadas@yahoo.com wrote:
>Google answers many questions, if you're just PATIENT enough. just
>stumbled across a powerpoint on the web, concise design analysis of
>the problem by a professor of mechanical engineering. The equations
>show why the patent-office file cabinets are littered with ideas for
>spring-stored energy for bicycles which never saw a real factory
>floor.... the energy-storage density just ain't there. His
>recommendation: optimize the electrical approach.
>
>Ok: who makes the best electrical-assist which encompasses an
>efficient regenerative-braking?
>
>what's the state of the art of energy-storage capacitors?
Search on ultracapacitors lots of info.
I still like my cable/pulley idea better.
--
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