ROF Upgrade?
 

I'm running a TM that comes stock with a Ver.3 gearbox and an EG1000 motor. Since I got the gun I've added a Systema helica gear set, had the mechbox reshimmed, had stainless bushings installed, upgraded the piston and head, and had a moderate spring upgrade so it chronies around 340-350fps.

The problem is that since the upgrades have been installed my ROF has SIGNIFICANTLY suffered with the stock 8.4v battery. I am going to pick up a 9.6v battery this upcoming week, do you think that is enough, or should I go higher? Also, are there any other upgrades that I can put in that will raise the ROF back to the stock level if not better?

are you using a 600mah nicad battery?

My 8.4v was a 1500mah NI-MH. The gun is a SG552 so the batts have to stay small, unless I run a box or bag system. Let me know what you guys think.

If you can fit a 9.6v and still maintain over 1200mah, go for it.

can you even fit a 9.6 in a 552?
gears will increase you ROF but then it's questionable if your battery will have enough amperage to pull the spring back.
a large battery (3000mah) would definetly solve your problem of ROF though

What ratio of Helical gears,stock or high torque? mAh only gives you more shoots per-pack,but voltage gives you the push your looking for! Voltage is push,mAh's/Current is capacity.I think it worked out to roughly one BB per mAh,in stock form(this is just a guide,not dead on mind you!) and when you upgrade it just goes down from there as theres more Current draw with harder springs= less shoot's per battery! You can go with a high-speed motor or 9.6v battery would help some,but depending on the spring your using,might need that high-torque gear set! I'm not a fan of ROF,it just seems to waste too much ammo,but thats just me.Hope it gives you some ideas on what you what to do with your unit(no jokes Pls. lol),Cheers!

It's not that clear cut, Death March. Mah is not just capacity, it also influence ROF.

Well you'll get more,run time (for lack of better term,I'm comming from the R/C hobbie lol). But adding mAh alone does not add the "Push" per say by it's self.I know where your going with this,it needs both to a point,but for easy to understand point of veiw,thats all.I'v done a three year electronics program,and thats about as simple as it's going to get with out going into novels of liner current lol. ie. I used a 8.4v battery with a G&P M4SO,shoot at 17 rnd's a sec. switched it over to a 9.6 v gave me 19 rnd's a sec.not a big difference,stock gear box!But as I was saying I know where your going with it,but I just don't see it as being something needed per say in Airsoft! I like the Idea of batterys being cheeper for this sport/hobbie.The R/C batterys were killing me for the price of "pushed cell's".Like I said,to me ROF is over rated for me.Guys don't seem to like it if your using an M-249 @ 400fps with crazy ROF lol.All in fun!My self I like to see what guy's can come up with!We'r all here for the same reason,fun!I hope lol.Cheers!

helical gears are generally (but rather rarely) installed to generate huge torque to pull back a very stiff spring. the last choice of gears for a high ROF setup. high ROF setups also should use bearings rather than bushings. the bearings make a huge difference in reducing friction. the stiffer the spring, the lower the ROF. judging from your FPS, you probably installed a M110. highest ROF will be achieved with either a stock M90 or an M100. most folks would go with an M100 for a little extra FPS boost. a short to medium length barrel is also an essential ingredient, so each BB can clear the barrel before the piston pulls back for the next shot.

we just built a high ROF gun for a customer. 7mm bearing gearbox. M100 spring. high speed gears and high speed motor. stock M4 length barrel. 9.6V 3800mah Intellect crane battery. FPS was 320 with 0.2g BB's. ROF was an absolutely insane 36 BB's per second (according to our chrono)!! it empties an entire 300 round high-cap in just under 10 seconds. most amazing stream of BB's we've ever seen spew forth from a gun. it looked like a clothesline coming out of the end of the barrel. just a solid white line of plastic. far faster ROF than a CA MkII SAW. we put a 5000 round box mag on it and dumped the entire magazine in under four minutes, including the time to stop and wind it.

I'm not looking for a ridiculous ROF, but something that gets me back up to the stock rate. The spring increased my fps by 50 or so, I put the Systema gears in for reliability. I can fit a 9.6v 1200mah battery in the foregrip, but do you think it is worth while for me to re-wire and spring for a battery bag with a large 9.6v battery? Capacity doesn't really matter in the sense that I can charge the pack during lunch. Does the total Mah significantly affect the discharge rate, enough so to warrant the switch to a parge size and batt. bag?

You might want to look into getting a Systema Magnum motor.

Then you won't have to deal with larger batteries that may not fit and what not.

The Magnum motors have EXCEPTIONAL torque with a slight boost in ROF.

There is an aftermarket handguard you can get that can hold a 9.6V mini.

Where is this handguard you speak of?? I've been searching around for something like that! I already dremmeled out the inside of the stock one to fit a 1500 8.4v.

Increasing the mAh of the battery has a huge effect on the rate of fire. Period, can't argue the point. I run an 8.4V 140mAh battery in my spare MP5, has a 110SP spring in it, and it has a great rate of fire, maybe 800rpm or so. When I've used it with my main MP5's 8.4V 3300mAh battery, I swear the rate of fire goes up to 1000 to higher rounds per minute. Literally, it's a white line of BBs that comes out.

The more current available, the more the motor will draw for a certain load. Gears, spring, etc. will increase the load, but providing more current ability means the motor can work faster.

Seeing how airsoft is about realism, I cant understand people doing upgrades like that 36bb a second m4, and playing with Hi-caps. This is becoming Speedball.

I will have you know sir, that I don't use any mags that hold more than 50-60 rounds. But that's besides the point.

Nah I was referring to the other gun mentioned.

Sorry for sorta jacking your thread.

Cheers,
Alex

sorry to contradict you, but yes it does.
i was testing my G3 with a full 8.4v 1200mah battery, and after 3 or 4 shots the piston 'jammed' at the point of highest spring compression. Pulled the trigger 3 or 4 times and it remained jammed, so i hooked up my 8.4v 3000mah battery and it unjammed just fine. I tried this 3 times and it was ok on full auto (depending where you end the cycle) but it would always jam after a few shots on semi auto.
amperage is your torque, and your voltage dictates how fast the torque gets where it needs to be.

I agree with Death March's statement.

Larger mAh really doesn't provide my "push".

What it does do, is allow more current to be "pulled" from the pack by the motor. Larger cells exhibit a lower internal resistance, and thus, motors can pull more current from the battery. The result is exhibited as increased rate of fire.

Ok,well I missed something in my three years of electronics classes then.And my teck's lic. to install Immobilizers for MPIC.I'v been doing elctronis for 12/13 years now.I'v wired Cars to Buses,VCR's yada yada lol.mAh's can give some sustain to the "push" per say,but Voltage is "push" mAh's are Capacity.Hence why you get more shots from a 3000mAh battery than a 1200mAh. I had a goofey problem a while back.When I upgraded my ICS to a M-120 (@397 fps) the gear box barley turned over using 8.4 1400mAh NiMh and would die shortly after.Now poped in a 9.6 1700mAh NiCad and the unit fired with out a prob. and gave me half a days worth.The mAh's provided alittle more sustain for the voltage,but the extra cell,with an extra voltage push did the trick.You can see by the two packs listed the mAh wasent that different.I'm trying to keep the as simple as possible as not to lose others that don't know all the teck'e stuff.Yes the two need one for the other as they are linier two each other,in most cases.If you look at a simple Capacitor,you can have two at the same voltage,but micro-farad ratting that with provide the current.Cap's on your Sub's (speakers) alow power to build up in the Cap. befor the next hit from the bass as not too over tax the AMP,making it easyer and more effective for the to get that nice boom and not have all your lights dim out on ya.If your into that sorta thing lol.Like I said I want to keep it as simple as possible.TC the statment you make at the end of your post is close to what i'm saying,as you say dictates speed somewhat! The two work in Conjunction with each other.E over IxR ohoms law!