systema motor + batteries

[krobinson103]

Well my AUG has finally had the last JG component replaced. The motor failed last game and is now replaced with a systema turbo. Oddly though, I can only get around 18-20rps from the motor using my intellect 9.6v batteries. After use they are very warm indeed. I know the gearbox internals are all up to the engine and the shimming and motor height are what they should be.

It seems to me that as destuctive to the piston as it may turn out to be, the engine is capable of 30 rps+. The only reason I can think of is that the batteries are incapable of supplying the nessecary power to the motor to get any further increases. With a lipol battery this very same motor was.... destructivly fast to the piston. Question to those with more experience.

What sort of battery do I need to get 25 rps? I'm thinking lipol 7.4v won't cut it and 11.1v will be too fast. Leaves a few options

1) get a 10.8v mini type battery
2) Get a large capacity 9.6v battery

What works better?

[Righteous]

I got 22+ rps out of my 430fps SAW back in the states with a Systema Turbo and a 7.4v. LiPo. LiPo are especially sensitive to the mah rating since they can produce 20-40c instantaneous draws that give ridiculous rates of fire. Try a 7.4v 2000mah or higher LiPo. One should fit the stock of the Aug.

[krobinson103]

Just added an extra tamiya connector to one of my crappy 8.4v 1100mah batteries. Using this connector I then connected another 8.4v 1100mah pack in a parrellel configuration. The result? One pack won't even budge the systema. 2 packs spin it at 20rps with ease without even getting warm. Unfortunately I can't fit more than 2 small 8.4v packs into my stock/battery bag setup. I'm thinking that 2 9.6v batteries would yield a silly rate of fire.

Systema turbos seem to like lots of current... don't seem to care much about voltage.

[Righteous]

Switch to Dean's connectors if you can. They have about 1/10th the resistance of Tamiya connectors and even less than an equivalent length of copper wire as they are gold. You'll have to solder them yourself, though.

[krobinson103]

2 times 9.6v 1500mah packs yields 25rps. Problem is they are too bulky to fit anywhere. Makes me wonder what it takes to max out one of these motors. Taking that sort of power with ease suggests you could really feed these things a lot of juice.

[Righteous]

VFC claims to test their motors on a 12v car battery. Systema probably can take that much. You'll wreck your piston, gears, bearings and gearbox before you find the limit of the Systema motor. At least I did in TX with my M249 while screwing with it.

[krobinson103]

What rof did you hit before it all came unglued?

[Righteous]

22-25+ with a 7.4v 2000mah LiPo. I think I had a motor/gear mismatch though. It was a Systema Turbo with Systema High Torque gears. That may have helped speed things along. Most of the initial testing was with a partially discharged battery. When I charged it fully all hell broke loose. The trigger switch arced and then things got progressively worse in a hurry.

[krobinson103]

Sounds like 20 is a good place to be...

[Righteous]

I was really trying to do too much with a 430fps gun in TX. It was an A&K M249 GB with systema, CA, prometheus and other parts at various times. It's probably fine at 300fps but, as others have experienced but probably learned nothing from, trying to get 25rps and 420+ fps out of a Chinese clone M4 just won't work. You'll strip your piston at the least and ruin bearings if things get going too far.

However, TM has come out with a G3 SAS that is claimed 25 rps.
http://shop.ehobbyasia.com/tokyo-mar...rsoft-aeg.html
There's an MP5 version as well. It has a drum magazine that fits other MP5 versions.
http://shop.ehobbyasia.com/tokyo-mar...rsoft-aeg.html

[krobinson103]

Pretty sure the gearbox will handle it. It may be a clone shell but everything else has been replaced. More concerned about the trigger contacts. At 9.6v 3000mah the arc every shot is going to be very powerful. That will lead to carbonized contacts. I'm thinking you would want a mosfet to deal with sort of power. The AUG has a known issue with the semi contacts being carbonized so adding more power will surely kill the semi function.

Also, at 25rps+ you have an issue with the piston not returning to neutral fast enough to keep up with gears. Chris managed to rip the back off a promethius piston because of it. You really need to do the short stroke modification to get that rate of fire.

The last issue is simply that at 20rps a full 300 round hicap barely lasts 15 seconds. at 25? You're going to winding and changing mags more often than shooting. Tried using a standard capacity for fun... 2 seconds and you're out of ammo. The AUG has no box mag options. I think I may just install my 2 8.4v batteries for 20rps or a single 9.6v for around 18rps.

Still... a 30rps aug would be fun for taking out all those Zombies :P You were saying we needed a 'special' gun?

[Righteous]

I was thinking more along the lines of that double barrel gun Chris posted a few months back. The Twin Hunter less all the LCD nonsense.

[krobinson103]

Thats quite a build... the components are just basic ak boxes but it would take a lot to get that sort of thing working right.
Still, with the right budget I could see a 50-60rps gun within the realms of possibilty.

[3One]

What sort of battery do I need to get 25 rps? I'm thinking lipol 7.4v won't cut it and 11.1v will be too fast. Leaves a few options

If you want to control your rate of fire... Another option is using a computerized mosfet (MF-CHEETAH from 3OneAirsoft.com or SW-CHEETAH from Extreme-Fire)...
With this mosfets you can control the motor speed and reduce your RPS...

[krobinson103]

Worked it out. Running a Relay to get the current from the lipol away from the trigger group. Running 7.2v 2500mah 25c lipol you get 21rps. That is more than enough to not strip pistons and not empty clips every 3 seconds.

[krobinson103]

I like the look of the cheetah computer. but the aug has a 2 stage trigger that doesn't work with the burst mode. Also I want a no frills options. Don't need motor speed or burst functions. Just want active braking and basic mosfet trigger bipass functions. That way the gun is 'plug and go'.
If there was a decent no frills mosfet for sale in Korea that didn't cost the world I would buy a few.

[3One]

Installing a Computerized Cheetah to an AUG is simple... The wiring is identical to a P90 (also a 2 stage trigger) which i personally use...
I can offer you the MF-CHEETAH "Lite" Edition which has the default SAFE-SEMI-FULL firing mode... but with Active Braking and protects your LIPO via Low Voltage protection... And it costs less than the Standard "MF-CHEETAH CE"... Do send me a pm if you might be interested...