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Rab

Standard batteries

Bit of a longshot this one, is there any decent performance mods you can do to a flywheel blaster that give you some power gains but still allow it to run on standard batteries?
Twibz

Oh Oh! engineering question. I GOTS IT!

Technically yes, but the trade off in battery life and the regular chemistries for normal batteries would make it realistically a "no".

The yes part:
You can get drop in boost converters like these that you could wire into your blaster, that step up the voltage. Those ones are variable ones, but you can get fixed ones.
Now the no part:
While the voltage would be bigger on the output side of the boost converter, the current would be lower. This comes from P=IV (Power = current x voltage) and the Conservation of Energy Principal*. The power supplied by the module can't be bigger than the power into the module, which is where your battery chemistries come in. So your batteries would have to supply more current to make sure there's enough current to drive the motors.

So a good metaphor for basic electronic theory is water in a bucket with a hole in, going down a pipe with a water wheel at the end.. How high the water is off the ground is it's voltage, the size of diameter of the pipe is the current, and the waterwheel is the resistance.
How fast the waterwheel turns depends on three things:
1 - How wide the pipe is
2 - How far water travels down the pipe to get to the wheel
and
3 - How stiff the waterwheel is to move
Using regular batteries even with a perfect boost converter would only raise the bucket while narrowing the pipe, so therefore it would only able able to spin the wheel at the same speed

Long story short (I could chat about discharge curves and current under load from various chemistries all day, but I won't cause it's a bit of a dry subject, unless that kind of thing is your bag baby, yeah! You know who you guys are...) standard batteries can't supply enough current to do it.

LiPos or LiFes are your friend

*Energy can neither be created nor destroyed, but transferred from one form to another. Thank you Mr Dempsey, you Irish madman. That's etched into my brain for LIFE
UKNerfWar

You could go oldschool and drop a couple of RM2 motors.

As Twibz rightly said, anything you do to boost performance from standard Alkalines will be superficial. They simply don't have much more oomph to give.
Rab

I kind of thought this might be the case, was thinking of modding a blaster for a mates kid but didnt want to make it any more hassle than them sticking in normal AA 's in it.

Ok, thanks guys, I have a plan b though
SayYesToCress

When you say standard do you mean alkaline only, or are you including nimh rechargeable aa's? Supergripper mods and sells stryfes that use nimh aa's and tamiya motors and I have done something similar for my son's stryfe but converting the tray to 2s2p and slightly undervolting the motors which means less fps but more current available from the batteries.  it will be more expensive and worse performing than a proper pack and Nerf specific motors though.  It depends on your goal though. You'll be pushing the nimh aa's hard and alkalines are unlikely to put out the current demand tamiya motors require.
blindgeekuk

Not all aa's are made equal, and often cheaper ones like ikea perform better than duracell. One thing I found,argos sell a 2300mah rechargeable 4 pack and charger which have a bit more oomph
Rab

I was going for something that could use any bog standard batteries bought from a normal shop with no extra expense like a charger. Think i might try to get hold of one of the new dart zone scorpions or enforcer. Thatll do what i want. If i can find one, no rush though.
SSGT

Following on from Twibz and energy conservation, the mechanical power delivered by a motor is the product of it's torque and it's speed. The amount of power you put into the motor is the product of the voltage across the terminals and the current through the motor winding. The mechanical power out equals the electrical power in minus power lost as heat, you can effectively say that Voltage * Current (* Efficiency) = Speed * Torque. You can change any of these variable as long as you make a proportional change to one or more variables on the other side of the equation (i.e. to keep the power in matching the power out).

The problem with finding a motor that can perform well on standard AA alkalines is that if you keep to the same voltage (i.e. 6V) but want to a motor with a higher speed or torque that motor must also be either more efficient or draw more current. You can account for this by using larger (C or even D size) alkaline cells, or by using banks of AA cells in parallel, which have higher capacity and are capable of higher discharge rates compared to a series string of AA cells but that defeats the purpose of using alkalines in the first place i.e. keeping the standard tray. One alternative option is to use a motor that can achieve the desired speed or torque at a higher voltage as that can have the same current draw as a lower speed/torque motor running at a lower voltage - the problem there is that to significantly increase the speed or torque you need to find a motor that produces that speed/torque at a proportionally higher voltage (i.e. twice the speed with the same torque at twice the voltage with the same current or twice the torque with the same speed at twice the voltage with the same current). This is made worse if you want to increase both the speed and the torque (i.e. twice the speed and twice the torque needs quadruple the voltage if the current draw is the same). This is where Tamiyas, and other 1S motors, fall short - since they achieve the same speed as other motors at a lower voltage they must either draw significantly more current or produce significantly less torque. Not a problem if you have high performance cells but again that defeats the point of keeping the standard tray and using standard AA cells. High performance NiMH cells, such as the sort that Super Gripper uses, may be a viable option (although I don't know for sure what sort of discharge rates they're capable of) but you're still fighting against physics rather than working with it in that transmission of electricity at higher current results in greater resistive losses in the wiring loom itself (power lost due to resistance is equal to the product of the resistance and the square of the current - P=I2R) especially since using 14500 (AA) size cells leaves you stuck using the poor standard spring terminals.

That said, none of this will likely affect the peak performance/velocities over a chrono (after all, even though it's highly unrecommended, standard motors with 3 Trustfire cells can achieve similar velocities to MTB Hellcats, a high torque 180 size motor, on a 3S LiPo - as will RM2s or Tamiyas on 4 alkaline AA cells) but it will worsen motor response, as it effectively throttles the low-end torque and attempts to draw more current from the cells than they are capable of supplying (not good with alkaline or NiMH cells but highly risky with Lithium chemistry cells).

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