Electro Powered paintball gun? [Archive] - Automags.Org Online Forums

FutureMagOwner

06-05-2002, 03:26 PM

i was thinking something along the lines of a current gun. except instead of the parts being moved by gas and blow back and such instead electricity of course to get that to work you would need to have a bolt that goews really fast(to get it to go that fast would need a derlin bolt and breech alnog with a heck of alot of energy) of course the way you guys suggest is a better possibility.

the baseball type thing could work if somehow you could get it to go around 300 fps no matter what rate of fire and have it go straight(not like a grenade launcher by lobbing it) and accurate of course

xatle

06-05-2002, 07:48 PM

an alcohol turbine engine powered compressor would work, but air gets hot when you compress it and without time for it to cool down before fireing i think it might start to melt shells in the barrel at high rates of fire. also the high pitched whine of the thing would drive you mad by the end of the game.
just my thoughts

Telefragged

06-05-2002, 09:51 PM

Everyone just wants to build a better mousetrap so to speak, eh? I had a really cool idea for an electromagnetic 'rail' based paintball gun before. instead of a bolt, you have a 'cup', a cradle more or less for the paintball. This cradle, when activated, is propelled down a rail towards the target(very quickly!), once near the end of this rail, it stops abrubtly, and slings the paintball towards the target.

Many, many, many problems though, large, bulky, HEAVY, inneficient, poor velocity, and very poor accuracy if not properly controlled. Physics says that inertia should help out a bit though.

[edit] Or, we could add trace amounts of magnetic materials into paintball fills and use an electromagnetic rail to throw the now magnetic 'paintball' would probably make paintballs much more expensive though...hmm..."nyeodmium (who knows how to spell it?!) added for improved flight characteristics!", a whoole new marketing scheme

Redkey

06-06-2002, 01:40 PM

Vegeta....

The circumference of a wheel is 2 x PI x Radius

What this means is that a point on the outer edge of a 1 inch wheel will travel 3.14 inches or 0.262 feet per revolution. If this wheel is spinning at 600 rpm (10 revs per second) the outer edge of the wheel is travelling at a speed of 2.62 feet per second.

To get the outer edge of a 1 inch diameter wheel to travel at 300 fps the wheel would have to be spinning at about 68,755 rpm. Doubling the diameter of the wheel will reduce the rpms by half… a two inch wheel would need to be turning at 34,277 rpm.

The contact point between the ball and the wheel would be so small it would probably just rip the shell before the ball went anywhere.

nicad

06-06-2002, 02:16 PM

..instead of wheels, use tracks, like conveyer(spl?) belts, on each side..
hehe good luck getting them up to 300fps surface speed..

Nomad

06-06-2002, 10:15 PM

I don't think any type of electrically propelled type of marker would be practical at this day in age. Probably not until we're all in wheelchairs, so meh.

What I would suggest is that they make improvements to the propellent that we're currently using. Use a different type of gas (I don't think there is much else that works better then nitrogen)

Note:
I just got a dumb thought. What is we put something like charged neon into a tank and used that as propellent? Stupid yes, impratical and quite possibly dangerous, but wouldn't it be really neat if we could put a glowing gas of some type into a tank and fire that? It would be just perfect for night time play. You'd get muzzle flash of various colors.

Yes. I am insane.

El Pipi Fantasma

06-07-2002, 09:37 AM

Here´s an Idea.
Use concave wheels spaced a little apart (one pair at breech, one pair at muzzle) making an inner circle of about 1 in. Then take two very soft rubber belts (like soft dye stickie rubber) and string them from the breech to the muzzle (making the inner cirlce about .65. Then spin those suckers up and put a paintball into the breech and watch that sucker fly. The soft rubber would make an autosizing barrel. Also I think the barrel would be veryy accurate, as the belts hold the paintball in the same place through the acceleration and release it with absolutely no spin at all. You could also get a flat-line effect by spinning the bottom belt faster than the top. You could also use a very large solenoid as the bolt and make it so that it pushes the ball into the breech but does not touch the belts. Fully electric, you would have to have a gearbox of the appocalypse on the motors and a serious solenoid for the bolt.
Barrel or bolt breaks would not matter at all!
This thing would be LOUD, the gear boxes would scream.
No blowback!
As fast as the solenoid.

Vegeta

06-07-2002, 11:34 AM

To get the outer edge of a 1 inch diameter wheel to travel at 300 fps the wheel would have to be spinning at about 68,755 rpm. ..i was damn close.

They suggested- instead of adding size to the wheel (like you said, doubling it), instead, making the gun have two paralell wheels or three. And you also have to think about barrel friction. How fast wil the ball slow down in the barrel? How many more RPMs wilt he wheels need to be going to overcome that?

It is widely impractical for the wieght, battery, and large motors that would have to be involved.

xatle

06-07-2002, 03:36 PM

makeing a gun with high velocity spinning weels in it would be kinda neet, the wheels would resist lateral movement and twisting, hook em up in pairs, one on either side of the ball, and have the second set be at 90 degrees to the first so that the gun resists movement horizontaly and vertically, possibly reduceing the muzzle rise of each shot making it easier to hold steady when fireing at speed.

shrug, just a thought

El Pipi Fantasma

08-03-2002, 11:50 AM

I was wrong about the thing having to have a gearbox of the appocalypse. Being that the Bands would be just over 2 feet long (on a 12in barrel), the bands would only have to spin at about 150 rps. This means that the thing would have to spin at 9000 rpm. This speed can be achieved by a dremmel hand tool. You could use the dremel on a 12-24v power scource to achieve this speed, granted you may have to modify the dremmel. If you could find a dremel that ran off of a rechargable battery that is contained inside the toold, this would work even better. I will most definately try this idea once I get back to the states. This will be in a year, so I will probably post some more before then.

SlartyBartFast

08-05-2002, 10:41 AM

Using wheels or a belt to 'throw' paintballs would just reult in lot's of broken paint.

:(

Think about it. The wheels or belt would not accelerate the paint to 300 fps, they'd just grab the balls immediately at 300 fps. Doubt paint can withstand that kind of force.

Maybe belts could work, but you'd have to figure a way to alow for slip to let the paintball accelerate under tolerable forces.

*edit*: I also think your RPM calculations are off.

nicad

08-05-2002, 03:13 PM

..going with this idea of belts or multiple sets of wheels even.. about the only way to accelerate a ball to 300fps would be to have the belts slightly wedge out so that the ball is gradually introduced into them (how to feed i dunno??).
the multiple sets of wheels would have to be stepped increased in speeds of the next set of wheels on down the "barrel"..

oh and El Pipi- your calculations are wrong about the belt speeds. you seem to be trying to figure the surface speed of the belts, given one full rotation of THEM in a minute. your not accounting for how fast the wheel would have to be spinning which is turning the betls. IT (the drive wheel(s)) would have to be rotation at a very high speed.. for a 2" diameter wheel driving ANY length belt would have to be turning in the neighborhood of 68,755 RPM to have a surface speed of 300fps. put anyting you want on the that surface (belt, ball, boogers, etc..) but it will still have to be spinning that fast.

out!

Emagster

08-07-2002, 09:59 PM

a totally electronic gun would be awesome. a gun that uses a battery to somehow create pressure to shoot a ball. I've wondered this miny a time my self in the past.

Coaster

08-07-2002, 10:24 PM

or.. use a motor that would compress a cyclinder of gas. The gas would then fire the gun.

felony

08-09-2002, 05:07 PM

i skipped most of the posts, but read a bit of telefragged.

his idea may work..

a rail gun is what i had in mind when i read the post first.

my friends and I tried to make one for a science experiment. granted it didnt work, but from what i understand it can. when you read into it a bit, it can be fairly simply to understand. making it is a bit tougher :]

it would still suck the power and be tough to launch a paintball through it

dan

felony

08-09-2002, 05:13 PM

two other things..

someone mentioned a belt that was goin 70,000 RPMS would tear a ball apart. in deed it could, but im sure that is what they though a bolt flying from a HPA marker would do way back when this all started..

also, chronoing could be either easy, or extremly difficult.
maybe if it was somehow based on electricity, it could be easy to dial in. somehow i see a electro rail gun being extremly consisten and easier to work with then the belts.. but who knows, i am 17 and in high school :p

mag-nanamus

08-12-2002, 12:24 AM

i think the major difference between a rail gun and a conventional marker is the bolt starts the acceleration and the air increases it. with a rail gun i think it would be like hitting the paint with a baseball bat.

felony

08-12-2002, 08:18 AM

you would be right.

unless the speed could be controlled?

if i remember correctly, isnt it magnets for the rail, and basically a huge ball of wire on the inside that has a large electric current?

maybe the electric current could be controlled. less at the initial impact and full force at the end.

of course, i could be all wrong with my idea of how it works..its been along time :]

dan

Person

08-12-2002, 11:37 PM

! or you could use compressed air so it could be more consistent then co2! ..doh i forgot tom already made that. I think we should make some paintballgun that feeds through clips that hold bullet shaped paintballs. Tom did a test..or someone and showed that a bullet shape is far more accurate and aerodynamic. we just need to produce the balls somehow and make some massive sized clips...that are affordable :D

chris99506

09-08-2002, 06:15 PM

the airsoft gun concept wouldn't work it would tear the ball apart and so would the belt idea, it wouldn't go through the barrel and it would be horribly inaccurate the best bet is a self recharging air tank like the ones on certain nail guns but it would be hard to make it operate at the same psi.

Micromag Sith

09-15-2002, 02:12 AM

a paintball rail gun huh? well when you can make it small enough to hold in your hand then you can tell me how make a lightsaber he he he

trikonx

09-29-2002, 04:25 PM

what about nuclear power im not quite sure if this works the way i think it does but correct me if im wrong the unrainum or what ever boils water which turns turbines so we make this the size of tanks but after a day of paintball you might glow but while we are throwing ideas out i figured i might as well throw mine

hitech

10-01-2002, 03:33 PM

Another idea would be to have a solenoid drive a large plunger that build enough air pressure/volume to fire the paintball. It would be large and heavy.

madgoat33

10-04-2002, 08:21 PM

A rail gun wouldn't work. Paintballs would have to be magnetic.

paintballbeaver

10-12-2002, 01:26 PM

SUPER CHARGE THE WARP AND PUT A BARREL ON THE HOSE

John Molloy

10-13-2002, 06:16 PM

The problem with all the ideas put forward so far is they rely on instant acceleration of the ball, every fly wheel or belt idea suffers from this problem. But the rail gun idea could (thats COULD) work problems are acceleraring the ball and power. make the balls slightly magnetic and your barrel would be HEAVY and long with hundreds of electro magnets the power supply would weigh about the same as a 12v truck battery which kinda defeats the object.

smilestyler

11-11-2002, 12:14 AM

What sounds more logical to me is to change the air supply by adding an electric air compressor, but again it would have to run at such a high RPM, it would not be feasable. I have heard of some pneumatic power tools (nail guns) that do not require a compressor. They run off of a cell that contains a combustible gas capable of creating enough PSI to operate the nailer. Maybe in the next decade we will see combustable fuels used as a propellant. I can see it now... tiny model airplane engines on the side of my micromag. Where would I run the exhaust? Haha

petefol

11-11-2002, 06:36 PM

why does it seem that so many people want a railgun paintball gun. the only benefit i could see to one is that, since it would be so big, you could sit in the car it was mounted on and roll the windows up, and not get shot!

kenshinkandon

11-15-2002, 06:01 PM

Here's a couple of websites that might help you get started on the Rail Gun Idea.

http://www.railgun.org/

http://www.eng.auburn.edu/department/ece/railgun/index.htm

http://www.emlsymposium.org/posters.html

I'd like to see some idea's that come up here on the AO.

John Molloy

11-15-2002, 06:39 PM

Have any of you guy's looked at airsoft guns? just took one apart and the use a high power spring and electric motor to pump air under pressure to shoot the BB now I know that the pressure to fire a 0.2 gram BB any distance is a bit differant than required to shoot a paintball that is significantly larger and heavier, but the same principle(in principle:D ) could be applied (large motor huge spring huge air resevoir)

Question does anyone actually know how much pressure must be applied to the paintball to shoot it at 300fps?

With the size of the spring known and motor known then all that is left would be the power source, and we come right back (at the moment) to the same problem we have had from the start. The battery would be large, maybe not as large as a 1.9 l bottle (88cu) and with NiMH technology it would be robust.

speedyejl

11-17-2002, 02:02 AM

The way it works is like this, the paintball falls in the breech, you pull the trigger, the motor pushes the piston back on the spring, then releases causing the piston to preasureize the air infront of it which hits the paintball.
The drawing is very rough but it gets the point accross.

Just to note a paintball weighs 12x as much as an airsoft bb, and its diameter is 30x larger.

to get a paintball to shoot at 300fps you need about 100psi, I dont know how much volume. But this would be big

John Molloy

11-18-2002, 01:47 PM

Yeah thats right ;) but like I said the Piston would be huge the air chamber would be huge the spring would be very strong (so far all do-able) and the motor to run it would be huge, last but not least the battery isn't going to be small either. The whole package may end up weighing less than a Cocker with bottle but it'll be bulky and it may well be fragile.

mag-nanamus

12-07-2002, 09:38 PM

Tried that a couple of years ago Hitech. It sounded good, but I wasted a lot of money and paint.

FutureMagOwner

12-08-2002, 11:31 AM

wow my deep blue threads last a long time it seems ;) anyway it seems doable but with todays technology it would be large and implausible. but worth a try :)

hitech

12-09-2002, 06:42 PM

Originally posted by mag-nanamus
Tried that a couple of years ago Hitech. It sounded good, but I wasted a lot of money and paint.

You actually tried to make one? Did you have something big enough to fire the paintball at a reasonable FPS or did you give up trying to find something big enough? When I said big I probably should have said HUGE! :D

KingMob3

12-13-2002, 02:27 PM

it( the paint) wouldent have to be magnetic, just conductive to eletcity. See site www.railgun.org
fun eh? also you could use a hig cappacty lithum ion battery( laptop type) on a body harness kind of ike a remote harness. Also i have an Idea for a possible e-conversion to thefront block to an auto cocker. replace the block with a high power solniod (25v+), put a roler switch in behind the sear( like when you intell a warp in a non electro), and hook it all to a EPERAM timeing chip in the handel. finish it off with a harrnesed laptop battery to power? (AM i crazy?)

John Molloy

12-15-2002, 05:01 PM

Originally posted by KingMob3
(AM i crazy?) (snip)

Er yes

:D

speedyejl

12-15-2002, 08:23 PM

blow back!! lol

11_Mile_TMaster

12-28-2002, 12:32 AM

Originally posted by Redkey
Vegeta....

The circumference of a wheel is 2 x PI x Radius

What this means is that a point on the outer edge of a 1 inch wheel will travel 3.14 inches or 0.262 feet per revolution. If this wheel is spinning at 600 rpm (10 revs per second) the outer edge of the wheel is travelling at a speed of 2.62 feet per second.

To get the outer edge of a 1 inch diameter wheel to travel at 300 fps the wheel would have to be spinning at about 68,755 rpm. Doubling the diameter of the wheel will reduce the rpms by half… a two inch wheel would need to be turning at 34,277 rpm.

The contact point between the ball and the wheel would be so small it would probably just rip the shell before the ball went anywhere.
40k RPM is doable.
I stumbled on this thread, and thought of my roommate. He's got a 43k RPM motor that runs on 7.2Volts for an RC Car. He's also a bit smarter than me.
I'm probably stating the bleeding obvious, but just in case;
Basically, we figured out the following, and even then, alot of this is my thinking, which COULD be wrong...:
-7.2 Volt power source. 6 rechargable cells, could be easily displaced.
-If 2 rollers were used, they would require less rpm than a single roller, plus the force displacement is more even, reducing the chance for tearing even more.
-We'd get a theoretical run time of around 10 minutes of constant operation.

I have an idea for the operation mechanism as well...
think of this -- When the trigger is pulled back, a hall sensor type dealie (like the one in the e-mag) is triggered to rev up the motor... and once the trigger is pulled all the way back, a trap door at the top would be open to let a ball drop in... The issue would be to keep it from keeping the trap door open the whole time... Although if it was left open, it does raise the interesting concept of a gun where you've essentially got a load time that is limited only by the speed of the loader, as opposed to having to wait for the bolt to cycle.

The Ideal trigger type for this freak of nature would be an Autococker Style Sliding Trigger, the first part start the Electronics... And as it is pulled back the trap door would open up to the door.

Again, I could be all wrong... But this sounds like a possible approach.

Bucky

01-09-2003, 01:55 AM

well i was thinking more along the lines of an hydrolic (spelling) pistion that pushes some sort of cup shaped of half a paintball. now the pistion would push the cup with paintball in it down a barrel, such as a modern gun does the same thing. now this is just an idea, but instead of air doing the muscle working of moving the parts, the pistion would do that instead.

nerobro

01-21-2003, 02:50 PM

It can be done. But, like in the last thread. All you need to do is do the math to figure out the energy necessary to fire a paintball and you'll figure out why we use compressed air ;-)

athomas

01-21-2003, 10:03 PM

The energy used to power the paintball is stored in the compressed air. How does that energy get there? The compresser used to fill the bottle puts it there by transfering the energy from fuel (gas compresor) or electricity (electric compressor).

If your bottle gives you 1000 shots from your gun and you want 1000 shots from your electrically powered pneumatic gun, then your battery has to be able to provide the power to run a compressor to fill a bottle (same amount of energy used). If it can't then it doesn't have the necessary energy required to fire a ball either.

Note: A good battery doesn't have the required energy to fire more than a few shots, and these shots would have to be spaced out in time to allow the gun to fully recover from the previous shot because the battery couldn't deliver enough power fast enough.

The batteries running solenoids in todays guns barely have enough energy to release the stored energy in the compressed air let alone compress the air.

nerobro

01-21-2003, 10:25 PM

Originally posted by athomas The energy used to power the paintball is stored in the compressed air.

Well.. Obviously. Right, the compressed air tank is just a battery.

If your bottle gives you 1000 shots from your gun and you want 1000 shots from your electrically powered pneumatic gun, then your battery has to be able to provide the power to run a compressor to fill a bottle (same amount of energy used). <snips the repetitive stuff>

Right, but the relation isn't direct. Compressors are mush less efficant. So even on the best of days you won't get more than say 80% efficancy out of a compressor. You'll need a more battery power.

Note: A good battery doesn't have the required energy to fire more than a few shots, and these shots would have to be spaced out in time to allow the gun to fully recover from the previous shot because the battery couldn't deliver enough power fast enough.
This utterly contridicts the measurement of battery capacity. Batterys are rated in amp hours. That's how much energy the battery stores. Period. Ah ratings are kinda amorphus, if you draw too much amperage from the battery you will get less energy from it. If you draw slowly you can get more than the rated power. This ties into the next point... AGD builds their battery packs to not need capacitors, and makes them so the gun does not outstrip the batterys rated discharge amperage. This is something you need to design for. (and is easy when you figure out how big of a battery pack you need to power one of these)

The batteries running solenoids in todays guns barely have enough energy to release the stored energy in the compressed air let alone compress the air.
This statment makes half sence. To release the energy stored in compressed air just requires a hole in the contanier. That's all. This requires no extra energy.

To put it in prespective, a nicad battery has less than 100mah capacity. An alkeline has somewhere around 220mah, but but you can't draw on it fast or else the battery looses most of it's capacity. You also run into problems with internal resistantce of the cells. With dry cells it's very high, and when you start to try to draw a lot of amerage the voltage drops hard.

On seartripping guns, they have a cap on there to help level out the power availalbe to the solinoid, and provide a high amperage power source. When fireing 20bps, the voltage on a dry cell drops down to around 5 volts. Versus the 9 it starts at.

A 9 volt battery can run a compressor so long as the compressors amp draw is low enough. but you'll never put in more energy than is in the 9 volt battery.

That's Where I was going with what i was saying. I feel like digging up the conversion from jules to watts. And that would give us the answer as to how much battery power we needed.

Anyone feel like digging up how much energy is behind a paintball?

HoppysMag

01-21-2003, 10:48 PM

i donno if its been said but RAIL GUN!... i can picture that toms next post " guys we lost john today in a freak testing of our RMag221, aperantly well gave the system too much juice, who coulda known a paintball would pass through a concrete wall at March 3..." lol it could be done, youd just need to give the ball some polarity... mabey something in the paintballs fill.

nerobro

01-21-2003, 10:49 PM

http://web.media.mit.edu/~aries/portable-power/node5.html#SECTION00030000000000000000

ah, i love seraching forums for the info I need... That url is a link to someone who did the math for us as for how much power a 1l n2 tank holds. 1l is a 68ci tank. so we're talking in the region of 12kwh. Say we go with a 6 volt battery pack. We're talking two thousand mah. This sounds reasonable. A 5 cell 2000mah pack could be easily assembled. Now, we need to factor in a few other things. First off electric motors aren't that efficant. And the pump it'll drive isn't very efficant either. And then, electric motors get less efficant as they warm up.

We are also assuming a gun that can get 1000 shots off a 68/3k

Going for homebulit, first run devices, probally the best we could hope for is half that efficancy? As soon as we get into gearbozes and electric motors, all bets are off. efficancy and calculations will need to be on a case by case basis.

nerobro

01-21-2003, 10:51 PM

Rail guns dont' need polarity. they need a very very low resistance slug to pass electricty through. the injector speed for rail guns seems to be in the 100 fps range.. and they use compressed air to inject the projectiles.

to do this you'd need conductive paintballs... VERY conductive.

HoppysMag

01-21-2003, 10:58 PM

Originally posted by nerobro
Rail guns dont' need polarity. they need a very very low resistance slug to pass electricty through. the injector speed for rail guns seems to be in the 100 fps range.. and they use compressed air to inject the projectiles.

to do this you'd need conductive paintballs... VERY conductive.

and im lost.... your saying the rail gun just accelerates an object? doesnt actualy get it moving just boosts it? um ok... i thought it worked like those japanesse trains... same polarity behind an object pushes it away while oposit polarity infront pulls it too.. then as it gets over top, it goes nutrual and then switches to same polarity to push it onward to the next um... magnet i guesse... im probibly wrong but is there any truth to that

nerobro

01-21-2003, 11:02 PM

You're thinking about a gauss gun. A linerar electric motor of sorts.

Rail guns operate on a different theroy. Lorenz effect IIRC.

athomas

01-21-2003, 11:28 PM

nerobro:

I was commenting generically on the the ability to use stored energy to do work. Everything is a transfer of energy. No transfer of energy is 100% efficient but I didn't want to calculate every exact joule of energy used in each process just to explain an idea.

The reference for the "gun" not being able to recover fast enough was because the battery probably couldn't power a compressor to compress the air fast enough. Ie; the same as your reference to the 9v battery running a compressor.

Ah ratings are kinda amorphus, if you draw too much amperage from the battery you will get less energy from it. If you draw slowly you can get more than the rated power.

Most batteries are not rated for the energy that they hold. They are rated for the useable energy above a determined thresh-hold. The fact that the battery still contains energy below this point is ignored in the rating. Because the battery delivers power more slowly, it is more likely to be able to chemically generate the electricity required for a stable current draw from the cell(s). For the most part, the useable ampacity of the battery will be the same whether the current draw is high or low. The current draw can only be as high as the battery can produce or you get voltage drop.

nerobro

01-21-2003, 11:49 PM

Try drawing five amps from a dry cell and find how much total power it delivers. then try drawing at a few microamps. you'll see a huge difference in capacity. Same goes for nicads. Draw 50 amps from a nicad cell and you'll generate a lot of head, an get a lot less electricty out of it. Draw one amp, and you'll get at least the rated capacity if not more.

There are more effective ways of getting electrical energy into a paintball rather than running a compressor... But I don't know how effective they are.

Either way, I think this is a dead end discussion. I'ts been hit before a few times in deep blue. Do you want to carry a heavy battery pack? or a relitively light air tank.

athomas

01-22-2003, 12:04 AM

Originally posted by nerobro
Try drawing five amps from a dry cell and find how much total power it delivers. then try drawing at a few microamps. you'll see a huge difference in capacity.

The capacity will still be there You'll just have to wait for the cells to cool to produce the rest of the electricity.

You can't draw more than the rated instantaneous load capability of the cells. Thats like saying I have the power of the sun at my fingertips, but I only have this tiny skylite with which to let the sun into my room.

That being said, 1 Amp hour drawn at 1 amp over a one hour period is the same as 1 amp hour drawn at 200mA over the period of 5 hours.

I think we all agree the idea of using a battery to compress air in real time is not an efficient way to go.

314159

01-22-2003, 12:07 AM

Originally posted by athomas

Most batteries are not rated for the energy that they hold. They are rated for the useable energy above a determined thresh-hold. The fact that the battery still contains energy below this point is ignored in the rating. Because the battery delivers power more slowly, it is more likely to be able to chemically generate the electricity required for a stable current draw from the cell(s). For the most part, the useable ampacity of the battery will be the same whether the current draw is high or low. The current draw can only be as high as the battery can produce or you get voltage drop.

Power = Amps x Volts

the more amps you draw out of a battery, the more the voltage drops

the maximum power you can draw from a battery, is when you draw enough current out of the battery, to drop the batteries voltage to half of it's voltage when nothing is connected to it.

athomas

01-22-2003, 12:14 AM

Originally posted by 314159

Power = Amps x Volts

the more amps you draw out of a battery, the more the voltage drops

the maximum power you can draw from a battery, is when you draw enough current out of the battery, to drop the batteries voltage to half of it's voltage when nothing is connected to it.

Exactly. That's the true capacity of the battery.

HoppysMag

01-22-2003, 02:23 PM

Originally posted by nerobro
You're thinking about a gauss gun. A linerar electric motor of sorts.

Rail guns operate on a different theroy. Lorenz effect IIRC.

yup thats what im talking about then... cause i had to explain oit to some one once and thats how i explained it... like cuting open a motor and unroling it

bjjb99

01-22-2003, 04:57 PM

Originally posted by athomas

The capacity will still be there You'll just have to wait for the cells to cool to produce the rest of the electricity.

That's not entirely true. The amp-hour ratings for batteries are listed for a specific discharge time--around 20 hours if I remember correctly. When I was looking at batteries back in the days of battlebot-mania, I quickly learned that if you need 120 amps for 5 minutes, a 10 amp-hour battery will simply not do the trick... you'd be lucky to get half the battery's capacity.

Do a search for battery discharge curves. Many manufacturers describe just what I'm saying.

Originally posted by athomas

That being said, 1 Amp hour drawn at 1 amp over a one hour period is the same as 1 amp hour drawn at 200mA over the period of 5 hours.

True in terms of the amount of energy drawn. However, in terms of the amount of extractable energy remaining in the battery these two scenarios are surprisingly not equal. The "low and slow" discharge will result in a greater amount of extractable energy left in the battery, even after both batteries have reached thermal equilibrium with their surroundings.

Originally posted by athomas

I think we all agree the idea of using a battery to compress air in real time is not an efficient way to go.

Absolutely true.

BJJB

athomas

01-23-2003, 06:21 PM

The rating for instantaneous charge or discharge of a battery is the "C" rate. Eg; When rating a battery, a C rating would mean the battery would be able to fully discharge its rated capacity in 1 hr. A 2C rating means it could discharge its rated capacity (milliamp hours) in 30 min. A battery rated at 1000mA with a 2C rating could discharge at a rate of 2000mA for 30 min. A 1000mA 0.1C rating means the battery would last 10hours at a maximum discharge rate of 100mA. The battery is capable of its rated discharge until the battery reaches the knee voltage, at which time the battery is considered "dead". Exhausting the cell(s) beyond the knee voltage is detrimental to the life expectancy of the battery. A battery can exceed its rated "C" rate but will overheat and increase the internal resistance. This will have an effect of reducing the available current until the battery returns to normal. For batteries used in continuous duty operation, over stressing the cells by using under rated batteries is not recommended and will result in reduced cycles of operation.

einhander619

01-28-2003, 11:38 PM

I have an idea that noone has proposed yet, and possibly for a very good reason. So far, all the talk has been about motors powering things and railguns. What about static electricity, you know, alike charges repel each other? Perhaps there would be a way to bring the ball and the breach to a high electric charge quickly...

One more thing, a railgun is never powered by just a battery. A capacitor bank(usually huge,on the order of 50+ Farads)that charges in series and then discharges in parallel is used to fire one. I don't think we're up to the task of hauling 4 50 gal. drums of copper plates and silicon oil around, are we?

askman

02-26-2003, 11:24 PM

At work (I work at designing printhead for printers), we had problem with off axis shooting of drops off jets. One idea we looked at was using large electric charge in front of the stack to speed/straighten the low conductive ink drop. We hooked up 1-5kv power source in front of the printhead, and looked at result on strobe. it did visibly speed up the drops. Of course we are talking about small distance, high voltage charge and relatively slow speed. (compared to paintball) Thus railgun idea will require hugh power source to accelerate low conductive material.

Col Sanders

03-09-2003, 02:11 AM

Can some1 say one word, Airsoft. Basicly same design with a smaller projectile, but one would need a significantly stronger motor and battery. Tokyo Mauri the pioneer of the nice little machine called the gear box has been around for quite some time. Search up airsoft and find a technical sight, it's all there my friends.

ALex "Col Sanders"
SubzeroMTH@AOL.com

speedyejl

03-09-2003, 11:39 AM

Col Sanders, before you flame them, take note that I already mentioned that, heck I even drew a pos diagram.

ShadowCruiser2K3

03-09-2003, 05:05 PM

Something I haven't seen mentioned would be to stick the power source on a vest or similar article of clothing, with a wire attaching to the handle or back of the gun.* This would take the weight off the gun, and disperse it over a larger surface, aka, your body. This would allow for more batteries, or whatever else you would use for the power source, and allow for more to be put into the gun.

And, theoretically, if you use multiple batteries or power sources, couldn't you pull from each one in turn, taking the strain off just one, allowing them time to "recharge"? Or even pull from all at once, thus reducing the strain on them?

I mentioned this to my friend and he said why not put contacts on some gloves and the handle of the gun?