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View Full Version : From Flanders I greet you all.



maddox
01-16-2011, 07:06 PM
Hailing you from Vilvoorde, Belgium.

After some nights of internet seaching and a hint from a Dutch budy, I arived here.

The reason, getting the information needed to aquire a recumbent bike that won't cost me an arm and a leg.

Maddox,
Chief Mechanic Team RCC

KoolKat
01-16-2011, 09:35 PM
Welcome to the Atomic Zombie family Maddox!

maddox
03-07-2011, 07:32 PM
Thanks Koolkat,

I settled on the Streetfox. A trike has some interesting abilities, like not falling over when standing at traffic lights. And the tadpole is just cool.

For now, I'm gathering raw materials and making some of the smaller parts. There is no rush for me to finish the bike, so I can spend on thinkering. One thing that I want to include is a power gauge. Not a speed gauge. Speed is just counting RPM on the wheel, any cycle computer can do that.
No, I want to invent/build or joint venture a thingamajig that messures power exherted by the driver. That information should make it easier, at least for the start, to switch gears and learn how it all behaves. A potential upgrade for that is an automatic gearshifter.

Anyone a workable idea for a power gauge?

savarin
03-08-2011, 01:43 AM
Welcome but you realise you are now a suitable case for treatment.
This addiction is a pernicious disease with no cure.
What do you want to measure the power in?
Just thinking out loud here as I've done no research.
The average rider puts out or burns 100 -150 watts, (approx 400 -480 calories/hour) if your very fit and work very hard you can get up to about 250 watts but not many of us can keep that kind of power output for long.
so total weight in pounds x ((speed in mph/234)^3) = horsepower
multiply by 746 to give watts.
(dont trust my numbers they are only from memory)
I'm sure there are bicycle computers that give most of this info including calories burnt.
A small computer to take gear sizes, speed, weight of machine and driver

Gerald_G
03-08-2011, 03:38 AM
Welcome Maddox.

I read in another bicycle forum too, and I keep hearing about riders training with a "power tap". I did a google search for the term and came up with this article and plenty more.

http://en.wikipedia.org/wiki/Cycling_power_meter

John Lewis
03-08-2011, 06:38 AM
Welcome Maddox,

Glad to have you along for the ride.

John

maddox
03-08-2011, 08:36 AM
Thanks for the acceptance and information guys.
The digital thingies don't do what I want. Yes they tell how fast you go, and what amout of calories you're burning. But to wire a whole bike with expensive stuff, ain't realy the "AtomicZombie way".

I talked this over with a fellow roboteer, and he had an idea for a mechanical setup. A spring loaded idler on the powerside of the chain. The more power exherted, the straighter the chain well be, and therefore, the position of the idler will tell me what I want. From there it's not that diffucult to get more elaborate.
Shift gear lights for example. Idler to low, shift gear up, idler to high, shift down.

maddox
03-10-2011, 10:32 AM
Some anglegrinding and welding later I'm coming to the tricky part od the Streetfox build. The steering.

Lacking some limbs to hold everything steady, I'm making some supporting tools.

Here the first result. Not ready , a bit to tall. But the idea is there.

http://i172.photobucket.com/albums/w13/Babetheke/Vanalles/1112.jpg

Martinierius
07-13-2011, 04:22 AM
As you are in a robot club, do you know if this is an interesting deal:
10€ for 12 NiCd's 1500mAh = a replacement batterypack (14.4V) for a cordless drill.
I'm considering buying 6 or 8 of these to make a 28.8V, 4500/6000 mAh power source for electric assisted warrior.

maddox
07-13-2011, 05:26 AM
Nickel Cadmium? Whow, ancient technology. Didn't realise these were for sale anymore.
It seems I overlooked a backdoor in the law concerning NiCd. They are still allowed to be used in cordless tools and alarm systems.
Meaning, if you want to use them for a recumbent with electrical assist, you have a tiny problem with the law. (on the other hand, how many police officers would know that part, and how many can see the difference between NiCd and NiMH sub C cells?)
Other issue with NiCd is the hight weight per watt. 45Wh per kilo.

Oh well, for that money I buy an equivalent ready to rumble 6S Lipo pack (http://www.hobbyking.com/hobbyking/store/__10357__Turnigy_5000mAh_6S_20C_Lipo_Pack_DE_Wareh ouse.html). I know, it's only 22.2V and not 28.8V.
But a S6 charger (http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6-AC_Charger%2FDischarger_1-6_Cells_GENUINE.html)is a lot cheaper than an 10S charger (http://www.hobbyking.com/hobbyking/store/__6609__iCharger_1010B%2B_300W_10s_Balance%2FCharg er.html).

For my streetfox I bought 4 5S 5000mAh (http://www.hobbyking.com/hobbyking/store/__13380__Turnigy_5000mAh_5S_20C_Lipo_Pack_DE_Wareh ouse.html)packs, together with quad charger (http://www.hobbyking.com/hobbyking/store/__10327__HobbyKing_Quattro_4x6S_Lithium_Polymer_Mu lti_Charger_.html)it was less than €220, delivered at the front door. When in use, they will be wired 2 in series 2 parallel, giving me 37V 10Ah.

Now, for out combat robots, we're going for LiFePo4. Safe and does everything we need in a nice, low weight. 250 Wh/kg

Martinierius
07-13-2011, 08:43 AM
Excellent info, THX!

maddox
07-13-2011, 09:55 AM
With pleasure.