HandGen - Mk1

[kenl]

 Now Norm you know nothing is ever that easy 

The simple answer is 1 calorie = .001162 watt hours.

1 nutritional calorie (1000 calories (go figure)) = 1.1620 watt hours.

1000 (nutritional) calories (kCal) = 1162 watt-hours.

The inefficient body the conversion is about 20%.

Therefore 1000 kCal =1162 watt-hours * .20 = 232 watts-hour work output.

kenny

[Norm]

Thats too much to get my head around.
Simplist thing I know is when I check my blood sugar
and it's like 168.....
I jump on the PedGen and pedal about 20 watt/hrs worth
and check it again and it may be 148....thats enough for
awhile...at least it's going down significantly for me.
Don't know how many calories that is .....
but then I vow to cut down on stuff...mostly bread or so it
seems pedaling a little bit when I'm tempted and a mental
picture of the scales showing a couple pounds less is inspiring.

[wadlands]

kenny – hi – yes I think I'll have to get myself an actual “Watts-Up” meter.  The current one I am using is a very similar product I use for my RC hobbies, but it does not have a cumulative watts reading.

Thanks for the Backshed prompt re an arduino project – I remember tripping across their piclog project when I was looking to measure rpm's on my simple vawt.  Eventually I took the “easier” route of a cycle computer to measure rpm.  But will revisit the piclog pages at Backshed.

My approach to the pedgen / exercise bike conversion was to keep it as simple as possible – so picked one up of eBay for £5!!!!! With a simple chain drive to a friction belt on the front wheel.  I cut the front friction wheel diameter down so that I could get the genny rotor / stator to clear the existing frames (by just raising the whole frame on wood blocks).  But still keep the front sprocket which was already welded to the centre of the friction wheel.  Cut the chain down in length and made the crude chain tensioner to stop the chain jumping of the front sprocket….it all seems to work ok!!!!

The pedal sprocket has 44 teeth and the front sprocket has 16 teeth – both as they were originally.  I keep thinking about getting a larger pedal sprocket – if they can be got??

Norm – hi – your comments about using your digital bike speedo made me rethink about the one that I have.  It's a “wireless” one that I got cheap last year from one of the local discount shops to read rpm's. 

After the initial setup I gave up on it because the readout can't be more than about 18 inch away from the rpm counter – which on a full bike is ok cause the wheel rides under the front fork.  But my wheel & the revs sensor is about 30 inches away on the genny rotor – if I put the readout close to it – I'can't see it without my distance specs!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

But it also came with a chest strap / heart monitor which I do remember trying out to see if it worked…..but totally forgot that it could therefore come up with some measurement of calories expended.  Found the instruction manual – so going to thumb through and see how.  Should give me a “simple” way of calibrating what a 15 minute / 30 min stint of Pedgen&TV delivers in calories burnt!!



Gee

[hiker]

wadlands...
nice motor -whats the voltage on that--the higher the better.....
you could get the rotor turned down--or make your own..to bad neo mags are so high priced now!!
it would work with ceramics--just lower output--might not even have to scew the mags..
my little motor started out with ceramics--then i changed over to neos--i belive i got a extra 75 watts out of it...
your motor should work great  on a pedgen...just about any motor works on a pedgen--just have to get the
right gear ratio..car alts-treadmill motors-ac conversion--  take your pick....thats why i like using old exersize bikes
all you have to do is make a pulley for your gen..bolt the gen down to a piece of plywood then slide your bike back and forth to
get the right belt tension--your body weight keeps it tight...a lot of those bikes have a big flywheel --just toss a flat auto belt
on that down to your gen--fun stuff............hiker

[wooferhound]

After the initial setup I gave up on it because the readout can't be more than about 18 inch away from the rpm counter – which on a full bike is ok cause the wheel rides under the front fork.  But my wheel & the revs sensor is about 30 inches away on the genny rotor – if I put the readout close to it – I'can't see it without my distance specs!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You could still run a wire between the 2 units. Wrap a wire around the sending unit and run it to the receiving unit and wrap it around it. This would help to carry the "wireless" signal across. Use insulated wire.

Maybe even a metal bowl signal reflector to put the sending unit into.

[wadlands]

hiker – hi –it's a beefy motor originally offa BIG wood lathe I was told – 7.5HP & 400 volts @ 10.5 amps; turns over by hand very easily. 
Originally got it (cause it was at a bargain price!!) do link up with a one cylinder diesel engine (not got yet) so that I could tinker with veg and bio fuels??!!

Takes two people to lift – so I'm not really sure about having it inside – would never get it out again….but who knows which way the worm will turn? ….thanks for the positive nudges though…..

wooferhound  - got really excited about such a simple & neat trick with the wire between sensor & readout – BUT no matter how I wrap a piece of wire or how many turns – I couldn't get any more distance between the sensor & readout.  Can't see what I'm doing wrong – perhaps its Bluetooth type and not proper wireless?

Had a go with the chest strap and heart monitor this morning – I can get a readout in calories.  Just need to reread the manual and understand what the figure for calories really is?  Because the wheel circumference is set at 166.7 cm so that the output display in km/h is actually equivalent to the rotor rpm – the cycle computer must be using this value to get to distance travelled and my weight (which I have to enter) to calculate the calories….hmmm not sure if it's a real number though?

The general consensus on the various cycling forums seems to be 300kcal to 500kcal per hour of “leisurely cycling (bit of a wide spread) – but then they get lost in wind factors , uphill downhill.....etc etc etc !!!!

….kenny I think I'll end up using your 232 watt-hours work output ~ 1000 kcals formula when I get my WattsUp meter

Gee

[wadlands]

WattsUp meter arrived – so can now talk the same language as the rest of you!

Initial readings from PedGen exercise sessions:

30 mins of steady pedalling shows ~ 23 to 25 WattHrs on WattsUp meter and a calorie burn of ~ 130 to 150kCals on cycle RPM / Distance meter. (kenny's formula gives about 107 kCals for 25 WattHrs effort.....so both seem in the same ballpark -- good enough for me!!).

So numbers seem to indicate a reasonable efficient pedgen?…..now using it regularly for three 30 minute sessions per day. 

Free TV while generating and surplus amps go into recharging the main 12v lead acid 35Ah battery.  Which is also connected to one of my RC battery chargers to charge 6 or 10 cell NiMh cells of 2500mAh each.

Extra bonus of keeping glucose levels down and double bonus of drop in weight……all seems rather worthwhile.

Gee

[REdiculous]

If you were putting in a 50w effort, yeah, that's pretty efficient.

I hope to be able to put in a 100w effort for 30mins or more. 50wh is nothing though - that would move an ebike a mile or four, depending. It would almost be enough to charge my laptop.

But, hey, even if you could only make 15wh per 30min session, that's enough to run a CFL for an hour.

[wadlands]

REdiculous - hi - what setup have you got for your pedgen to get 100watt out for 30mins effort - if you can share it may help me to improve mine??

Otherwise - reasonably satisfied with my pedgen setup so revisited the HandGen - now got it coonected through a 50F capacitor to the LED television via the inverter.

 Using the capacitor means that every ounce of effort is going to free TV!!
Lower hand crank rpm's mean that I can't charge a battery at the same time - probably could cahrge some NiMh's at the same time - not tried yet though.



But still worthwhile forearm & shoulder workouts whilst watching tv - in built auto motivator as well - if crank speed drops then inverter cuts out on under voltage!!!

Gee

[Norm]

Gee, Thats about what I get about 50 to 60 watt rate....since my WattsUp meter
broke and have to rely on distance, time, speed on the digital bike thing
I figure just real easy pedaling I'm at a 30 watt rate....2minutes = 1 watt/hr.
1 mile in 20 minutes charge a 2.6 amp/hr 12 v Nicad in 10 min.-3.5 mph
Charging 14.4 cordless drill batteries is too easy at the ratio that I have now
would be better suited for hand cranking and my speed goes from 3.5 to 5mph.
I'm on a plateau on weight loss....just hanging in around 185lbs.

I have been able to max at 98 watts....but can only last about a minute...like pedaling
up a pretty steep hill.....LOL
Norm.

[REdiculous]

I've been cycling a long time so I think I can sustain a 100w effort for 30 minutes. Maybe. That's the "standard" number for a reasonably fit person pedaling a normal bike for an hour, I think. I see "100w pedaling effort" thrown around a lot on the ebike sites so I'm running with it for now.

I haven't gotten my pedgen finished yet, but I've got a start..

I've got a 24v 250w brush motor I'm gonna try first since other people have reported success with it. It's got an 11 tooth #25 sprocket. The crank has a 55 tooth sprocket. I'm seeing about 8v on the meter when I spin the cranks as fast as I can, so I'm guessing I'll need to change the gearing from 1:5 to 1:12. I can easily get as high as 1:7.27 in a single stage but I'm not sure that would be enough that I could charge 12v SLAs.

My pedgen frame is a girl's BMX, minus the front half, then flipped over so I can spin the crank. Where the seat used to be, I put the little aluminum handlebars from a little kick-scooter (the type w/ rollerblade wheels) so that the pedgen can stand on its own. Where the rear tire would be is a little room for a battery and inverter (you can get more room by spreading the rear end w/ a car jack ).

[wadlands]

Norm – hi – I'm pleased that my 50watts is in the right ballpark.

…..weightloss……in the first year I was trying to lose 22lbs…..made good progress and lost 11lbs
…..but went through a c****y divorce and gained 7lbs
…..now trying to refocus and get back on the right track but now got to get rid of the carbs habit again!!!!

REdiculous – thanks for all the details ……envious of you being able to sustain 100w effort for 30mins!!! 

You're obviously a lot fitter than I am ……photos of your pedgen setup would be good to see?

Gee

[Norm]

I know from experience that the one good way to get off the carbs
habit is to substitute the bad habit with a good habit ..pedaling everytime
you get the urge to have a snack...good deep breathing  helps also....
think about it....everytime you exhale carbon dioxide! plus the harder
you pedal the more fuel burned....

Hey guys you have to have a watt meter....one that will tell you how many
watt/hrs. you are making if you are pedaling real hard and real fast with an
inefficient generator or set up you could be doing 100+ watt/hrs. worth of effort,
but actually be making 10 watt/hrs going into the battery.

    IMO I'm not really a biker or a walker....on the PedGen at 3.5 MPH. I would
cover about 5 miles a day in my exercise sessions, about as fast as walking,
but as in biking the wheels are supporting my weight taking the load off of my
bad knees.
    If this was a regular bike the effort would take me about 15 miles a day.
don't sound like much but I have virtually traveled about 8000 miles in the last
5 years on a PedGen.

    REdiculous  that "100 w pedaling effort" is thrown around a lot" 
......until you get a watt meter (well actually a watt/hr. meter) you won't
really know what you are making.... the ratio and what voltage battery you are charging
are very big factors.

    On my amp meter and voltmeter the readings fluctuated so much from one second to
the next it was hard to use the volts x amps = watts formula and so when I
got my  WattsUp meter I found that I had overexagerated my pedaling effort by
about 30% !

    Gee, When you got your wattmeter did you discover that your
former 'calculations' were actually more or less than you thought?



BTW  recuperating from the holidays.....bad....190 lbs. (sigh...)
back to pedaling .....more .....lot more !
Norm.

[REdiculous]

yeah, there's gonna be a difference between the effort you put in and what you get out, and it'll be variable over time for sure. I'm hoping I can average about 30w into my batteries semi-continuously, but would love it if I could get 75wh in 30mins or so. That means my effort would have to be a little more than that, but once I train for a minute I should be able to do pretty well if the generator is setup properly.

Here's the only pic I have of the pedgen (pink) so far...


With an 80t sprocket (not shown) on the crank and an 11t sprocket on the 24v 250w brush motor, I saw 14.5v at max speed. When plugged into the emergency jump-start kit I have, it easily lights the 'charging' LED, but to really put anything into the SLA would mean spinning the pedals as fast as possible, and then I think I'd get just a few watts here and there. I need a bit larger ratio, and I need to figure out how much I can push through that little charge port before I over-do it.

The pedgen is portable and comes off the pocket bike, but the pocket bike is the real project. The general/basic definition of an electric bicycle is "electric motor + working pedals", so I'm hoping the contraption above qualifies - and I hope I can ride it recumbent-style but I'll keep it to where my kid can ride it like a pocket bike too. I'm building a custom trailer for it as well that may end up carrying a small gas generator for extra range/comfort. later

[Norm]

You will need about 1:18 ratio to charge a 12 volt battery
of course the easy way is to charge 24 volt battery with the ratio you have.
maybe ....That's the way I did it for a couple of years.
Norm.

[REdiculous]

You will need about 1:18 ratio to charge a 12 volt battery
of course the easy way is to charge 24 volt battery with the ratio you have.

I doubt I need to go all the way to 1:18, since I'm not aiming to make tons of power. If I'm able to get as high as 14.5v with the 1:7.27 ratio, a 1:10 ratio should have me starting to charge an SLA at a moderate pedaling cadence, and a 1:12 ratio would start charging sooner (at an even lower cadence).

Charging a 24v battery with the ratio I have is totally out of the question. If I'm seeing a max of 14.5v, how do I get the 24+ volts out of the generator, again?....gotta change the gearing.

I've actually taken the large 80t sprocket off, since it was meant for the wheel of my bike, so the pedgen now has a 55t on the crank instead. I'll probably make a 1:2 or 1:2.x, for a 2-stage increase with a final ratio of around 1:10 or maybe a touch higher.

[wadlands]

Norm – hi – re “the carbs” – when I started out I was limiting myself to 24gms of carbs in total per day – following the “Bernstein” approach to controlling diabetes – that's what I am trying to get back to – I know I can because I did it before. 
It gave me really tight control of my HbA1c at 5.1% (now slipped to 6.7% boo hoo  ) and excellent weight control. 
I am committed to getting back to there again!!!

Before I got the WattsUp meter my trial measurements had suggested between 24 and 40 watts (1.6 to 2.2 amps into 12v 7Ah lead gel) at 100 to 150 rotor rpm's.  So my actual results now into a 12v 35Ah lead acid battery are marginally better – I tend to stick to about 110 to 120 rotor rpm so that it is doable for 30 minutes.

REdiculous – thanks for posting the pic – ingenious idea to hitch up your pedgen like that when your pocket ebike needs recharging.

With the gear ratios on my pedgen of 44:16 (ie 2.75:1) then at 110 to 120 rotor rpm I think my pedalling speed / cadence is around 40 to 43 rpm – which is what I try to sustain for 30 minutes – hope to build it up for a longer time period gradually rather than faster in the same time period.

Question for anyone who can advise: I leave my 12v 35Ah lead acid battery permanently connected to the pedgen and drive the 28W led tv via an inverter. 
I charge NiMh cells by making up packs and connect them at the same time via a RC charger connected directly across the battery posts – ie it runs in parallel.

Should I wish to recharge back up another 12v 35A lead acid battery – is it ok to just connect this second battery across the posts of the first battery (which is “always fully charged”) ie in parallel and continue pedalling away until this second battery is also fully charged – that's how I connected it today???

Gee

[REdiculous]

ingenious idea to hitch up your pedgen like that when your pocket ebike needs recharging.

Actually, I hope I can ride it with the pedgen attached, so I can help supply some of the power needed to move. I've also got a top secret trailer project going, and there's more to the whole thing that I'm saving back until it's finished.

Should I wish to recharge back up another 12v 35A lead acid battery – is it ok to just connect this second battery across the posts of the first battery (which is “always fully charged”) ie in parallel and continue pedalling away until this second battery is also fully charged – that's how I connected it today???

I believe you can exceed the recommended charging rate pretty easily doing that. I wouldn't worry too much if they're kind of close in voltage, cause I've done it too, but that's 'cause they're cheap so I don't worry about abusing mine a little.

Undecided.

[Norm]

Should I wish to recharge back up another 12v 35A lead acid battery – is it ok to just connect this second battery across the posts of the first battery (which is “always fully charged”) ie in parallel and continue pedalling away until this second battery is also fully charged – that's how I connected it today???

Seems like you could put a double throw switch from one terminal of the PedGens output throw the switch
one way to charge one battery....throw the switch the other way to connect to the other battery.
Just a simple knive blade switch would work.
that way no worries....right?
Norm

[Norm]

RE........
When I'm talking ratios it's the ratios I'm talking with my EMC conversion....
your's and Gee's are different gens and the cut in speeds would be different.
Have you ever tried to charge a 6 volt battery with your present ratio.
If Like mine it's a real bear....like trying to pedal up a Very steep hill.
Charging a 14.4 cordless drill battery on the other hand is like pedaling a 10 speed
in the lowest gear.....better suited for hand cranking....
Norm.

[REdiculous]

When I'm talking ratios I'm just talking about the mechanical gearing. When I put in 100rpm at the cranks I get 500rpm at the motor shaft since I've got a simple 1:5 gear ratio for now.

Anyway, I'm holding off on fixing my pedgen gearing for a bit but I'm probably gonna try something close to a 1:12 ratio. I'm pretty sure a 1:15 ratio would produce 24v if I pedaled it as fast as possible (based on seeing 8v w/ a 1:5 ratio) so that could be a bit too high. *shrugs*

[Norm]

Would be nice to use variable speed pulleys then you could know
exactly what ratio you need....temporarily.
Then chain drive once you hit on the right ratio.
One variable ratio pulleys from a snowmobile.
Friction drive bicycle wheel into the sheaves .....pulley
driving the generator......
Norm.

[REdiculous]

Variable pulleys, nah. This, maybe.

[TimS]

cool link.  That's a pretty nice setup!

[Dinges__]

Variable pulleys, nah. This, maybe.

I like the technology of the NuVinci hubs and am very partial to internal-gearing bicycle hubs (I'm planning for a Rohloff), but keep in mind that the NuVinci hub is notoriously inefficient, in the range of the mid-70s (~75%). You may notice on that website they provide quite a bit of technical data, but that hub efficiency is ominously absent. Not by accident.

I once had the opportunity to measure one of their hubs on a DeProny-brake dynamometer. The result was shocking to me, though more or less expected (just didn't expect it to be *so* bad).

I understand Fallbrooks also supply variable-ratio gearboxes for windturbines, and I've always wondered whether they got such lousy efficiencies there too, or whether that was accepted as the price of (claimed) lower maintenance costs of CVT windturbine gearboxes.

So far, there's nothing that beats good old sprockets and chain if you want an efficient transmission.

[wadlands]

Dinges - I'm with you .......sprockets & chain ........only three parts ........easy to see & easy to fix - K.I.S.S.

and in that vein - Norm re the double throw switch - good idea and then I thought ......why can't I just move one battery out of the way and move the other one in!!!!!! ....seems to be less for me to get wrong and it is also K.I.S.S.   

Gee

[ghurd]

I like the ....

Peter?
G-

[dinges]

Peter?

Click....

 

[Norm]

Variable pulleys, nah. This, maybe.

variable....Yah!.....but just temporary cheap just to determine the better ratio.
for your/my capability.
The ratio on my machine is like 1:7.45 .....I feel that I could handle maybe 1: 8.11 if not
I could try ....say 1:7.86 .......etc.
then comes the sprokets with the number of teeth
course a real seemingly good variable ratio drive is nice to day dream about
while you pedal away the pounds....bring down your glucose level and charge batteries
ah this stuff is just so much fun....
there's just bound to be some A.... that will find a way to tax it...
Norm