Brand-new FAMAS died quietly

[lotmr]

Originally Posted by Mysteryfish

sounds like:

A bb got smashed on the way thru the gun, or got jammed and caused a backup.

I doubt that is was this because I use the cleaning rod right after noticing this with not change occuring or being able to feel anything abnormal, I'm quite sure that it was the cement floor that shattered the BB.

[Avenging Angel]

Originally Posted by Kos-Mos

In fact, the battri voltage should not make a difference that much.... the capacity of the pack if by far more important when talking about torque....

if the motor needs, let say 3 amps to turn when stall, and you pack is only a 600mA, then it will have a hard time giving enought power to the motor....
what an other proof???

the formula for power is Volts*Amps.... so if you drop the voltage, but rise the amp, then there is no power lost...

simple as 3*2=6 and 3*2=6....

voltage only change speed of the motor, but if you have higher voltage, and the motor is working bad, you will so need less amp to have it turn....

To an extent you are correct. The theory is kind of right but the application is wrong. Formulas are nice for a starting point but you also need to take into account how many wraps there are around the coil and what gauge of coil is being used. The guages of wire and wraps of coil directly affect the output of any given electric motor. Pending on the designed torque output, the engineer will pick a desired voltage to meet the requirements in conjunction with capacity and then design the motor around those specifications. Based on the prior specs, the engineer will determine coil wraps, gauges and resistance. If a lower voltage battery is used on a motor that is designed for something that requires a higher voltage less torque will be produced. The only way to compensate for it is to increase your amperage rating. While you gave the equation for power, I don't see what you're trying to get at, due to the fact that Torque and Power are two completely different things.

lotmr - With that mAh rating, it should be enough to cycle your gun. What kind of motor is in those Famas?

[skaterjoe]

they have an EG 560

[Sadiztix]

if it's an sv then it's a 560HT motor. and there pretty fucking strong

[Avenging Angel]

If I remember correctly, (which I may not) the 560's were higher torque motors in comparison with eg700 and eg1000 series. In my mind, it would make sense that it would need a higher voltage and mAh rating to run. In turn, that would explain why the 7.2V doesn't quite cut it when it tries to start from a complete stop in the higher compression phase of the spring. I mean, I could be wrong but, I really don't feel like pulling out my Machine Elements in Mechanical Design formula sheet just to prove or disprove a trivial point. Nor do I feel like ripping up a 560 motor. =p

[Mysteryfish]

WK, nobody said the 7.2 was inadequate...

just BLAH <--- and they are.

Besides, the guns were designed for 8.4 volt batteries. But y'all can take that to mean what you want.

Anyways, I only suggested the BB's shattered inside because that's happened to me, and it stopped my piston dead...

[Gryphon]

Nine hundred rounds per minute is BLAH? Geez, I'm guessing you're on the waiting list at Piper's Precision! :lol:

[Avenging Angel]

A 3300mAh 7.2V Battery would work fine on just about anything provided that you are not using a high torque motor. The AK 47 has an EG 1000 motor and I do believe that it has a higher cyclic rate than an eg 700 but, it also does not produce as much torque as the eg 560 motor. Granted, the 7.2V battery should be A.O.K in pretty much any gun with the kind of mAh rating that you are suggesting W.K.

900rpm is okay for a 7.2V battery for sure! At the current moment, my TM M1A1 is shooting 1267rpm with an eg1000 motor and an 8.4v 1200mAh battery. (Yes, I did do a photogate test to get an exact number and yes, I am a nerd. =p )

[Gryphon]

Jesus, a Thompson's supposed to shoot at 800 RPM! What's with the bullet hose mentality... Then again I live in Milsim Central.

Unless I'm mistaken the AK comes with the EG700. Does anyone have specs for all three motors?

[Mysteryfish]

I wouldn't knock a 7.2 cos of the ROF...

But I personally wouldn't feed a healthy rottweiler diet dogfood if I could feed it the regular kind.

I kindof look at it that way. The dog will survive, but why diet? ... um... :xmas:

[Daes]

Go here:
http://www.airsoft-guide.com/default.asp?view=61&ad=1

Yeah, it is a SystemA comparison table, but is gives you some exact numbers to work with. And seriously, engine upgrades are cheap and effective... I currently am using a Super Torque Up on one gun and a High Speed on another. The STU keeps a good rate of fire despite upgrades (470 fps) and the high speed makes a stock TM mechbox into a bb hose, without doing insane battery sizes...

-Daes-

[Avenging Angel]

Thats an amazing chart! I wish they had data comparisons with the Eg 560 and Eg 700 though. That would be cool. I wonder what would happen if you used that high speed motor in conjunction with highspeed gears... I'm wondering if the spring could even keep up...

[Drake]

Both the SV and the F1 use the 560HT, nothing has used a 560 in recent years. ('cept crappy knockoff aegs)

The 7.2v batt, with a high enough mAh rating, will turn a stock gun fine, but will suffer with upgraded springs.

Personally I'd say the 560HT performs similarly to an EG700. With an upgraded spring, I prefer the 560HT personally. I favor the EG1000 overall. I can't make a 100% accurate comparison with the EG560HT since the FAMAS gearing is different from the V2/V3 boxes (I only own V1/V2/v3)

By way of comparison, I'm getting ~1000 RPM with a 560HT and PDI 140% spring, 8.4v 1700mAh pack.

Also another note about batteries... the lower voltage may not affect performance per se, but it will stress the battery more, causing it to drain faster. But like Mysteryfish said, I just don't see the point of using a 7.2v pack when you can get 8.4 and 9.6v just as easily and for about the same price.

[Avenging Angel]

Originally Posted by W.K.Shuridys

Jesus, a Thompson's supposed to shoot at 800 RPM! What's with the bullet hose mentality... Then again I live in Milsim Central.

Unless I'm mistaken the AK comes with the EG700. Does anyone have specs for all three motors?

I try to get the high speeds not so much for how many BB's I can shoot in a given time but for how fast I can get the BB to leave my barell when I pull the trigger. I play lots of CQB and we're only allowed to use single fire. So basically, the faster my gun cycles through a single shot, the better. When an opposing player comes around a corner, you want to make sure that you hit him first. So you slam on the trigger and hope that your gun is faster than his. Every millisecond helps =p

[Daes]

Originally Posted by Avenging Angel

I try to get the high speeds not so much for how many BB's I can shoot in a given time but for how fast I can get the BB to leave my barell when I pull the trigger. I play lots of CQB and we're only allowed to use single fire. So basically, the faster my gun cycles through a single shot, the better. When an opposing player comes around a corner, you want to make sure that you hit him first. So you slam on the trigger and hope that your gun is faster than his. Every millisecond helps =p

I agree, for those of us who try to make an AEG sniper, PSG-1 excluded, then the turn-over speed is very important. Nothing more annoying than pulling the trigger and waiting for the shot to come out and by then, the person has shifted position...

-Daes-