Running 22.2V

[lurkingknight]

really isn't much point.. even with 14.8v dsgs you can't get them to feed.

[Kos-Mos]

I am typing this on my phone, since I have time to waste waiting for a bus.

Fisrt thing, all batteries are rated by their nominal voltage. For a LiPo, that is 3.7v/ cell. Times 3 cells is 11.1v. But all battery types actually have a higher actual voltage. In fact, when the voltage no-load of a pack is it's nominal, it's empty or just dead (if it's fresh off the charger). That means that a3 cells LiPo is actually up to 16.6v when full charge, as each cell can peak at 4.2v.

If you have to wire batteries in Series, you want to make sure that both are exactly the same brand and model, where made in the same batch and have the same wear/nuber of cycles. Otherwise the pack will fail, and in the case of LiPo, probably explode.

I am not sure what FET is in the MERF, but 99% of high power FETs are rated for 40v DS. It's more likely that the CMOS microcontroller fails, as it is made to operate between 10 and 15v. And there is probably not an on-board regulator for such a simple device. In theory, a homemade "simple" FET can take 40v/100A easily (yes, that's 400W).

The problem comes from the motor. The ones in our Rifles are designed for 5-7v, and we run them at 10-12v most of the time. You would have to increase the number of coils on the rotor and probably need to reduce the size of wire used to fit it. That would result in a more efficient system (less heat waste due to current), but equivalent RPM.

So all in, running a 22.2v/6 cells LiPo on a gun designed for 14v will simply result in a burnt motor, FET and potentially gearset/piston.
Keep in mind that once the insulation on the motor rotor wires is melted, that will short out your battery until the FET blows, so you also add a pipebomb in the mix, LiPos in metal tube are nasty.

[lurkingknight]

I think there's enough of an airgap between the stock and the buffer tube to allow for escaping gas.. I mean when she starts to go, it'll go in the path of least resistance.. which is out the back. If it ignites.. then you have a flame thrower if you've got an open back LE stock. lol. I don't think it would pipebomb itself... but you never know.... I'm kind of interested in trying now.

[Bakasaur]

Thanks for all the input guys. This was in no means something I was gonna risk without proper knowledge. I was wondering if it's theoretically even.. useful. It was more of a question I suppose than something I was even considering trying. I assumed the motor was going to burn out/meltdown, the gear axles would break, and the lipos would explode.

I wouldn't have used it with the MERF, I woulda made my own for the voltage capacity. As the lipos would be wired in series, it would cause an incredible amount of current when combined with the voltage, I figured I'd have to run 10 or 12awg wire just to even get power to the motor.
As for trigger contacts, I bought a set of "high voltage" ones from G&P (back before my mosfet days), they were $30, and are apparently good up to roughly 28V

I would also have to put in a thermal cut off, but this seems completely useless as it would overheat instantly.

As for feeding, that would be a damn near mess. You'd have to have a delayer at LEAST 1/3 the size of your sector, and that might not even be enough to help it feed properly. You would most likely get two cycles for every bb feed, and it would end up snapping the tappet plate under the stress.

Anyways, thanks for your input guys. Glad to know I was on the right track with the "holy hell the gun is exploding STAHP" theory.


TL;DR It was a theoretical question, wasn't gonna risk it. I wanted to know motor capacities, to see if a motor could even handle that much voltage

[ThunderCactus]

So let's say you ARE going to run it at a peak of 25v
Assuming the electronics are custom built to handle that and you're using a brushless motor
No idea what gear ratio you had in mind, but let's assume standard ratio
You'd probably need either a very long soft start on the motor to ramp up to max RPM, or you'd have to actually run herringbone gears with larger teeth for the amount of torque involved lol
The pinion gear would also need a redesign for extra torque transmission.

You'd absolutely need to use a systema revolution/PTW style piston head and air nozzle since a tappet plate would never be able to keep up with the sector gear at that speed.
You'd probably need a revolutionary light-weight swiss cheesed carbon fiber piston with a titanium rack and seriously reinforced first tooth both on the sector and piston. In fact at that speed you might even need a pre-engagement bumper to help soften the blow.

Basically your major weak points would be the springs, piston rack, and the mags being able to load BBs fast enough.

Forget about using a DC brush motor though, it's hard enough on them being run at 12.6v, anything past 14v is the danger zone. Like kos-mos said, they were originally designed with 8v in mind.

[Sloth]

+5 for Kos Mos.

If you Ever try this insane idea, record the testing! Preferably while wearing EOD gear