Decrease the ROF.
 

My gun is shooting 750 - 850 rpm with a stock TM m16 motor, and im looking for a way to decrease the ROF down to 500 - 600 rpm with a 8.4v.
What motor or other parts should i get? Will a more powerful spring decrease the ROF?


-Heinz

Could always get:

- torque up gears
- stronger spring
- a less powerful battery. An 8.4v 3600mah battery will increase the rof say over an 8.4v 2000mah battery.

I'm no expert with the torque gears/stronger spring but im just going off things I think ive read on the forums. The battery I know for sure will make a difference.

using a stock unported TM piston head will slow down the rof quite a bit

I found that my fully stock AUG increased in ROF when I upgraded it with a ported piston head and Guarder SP90 spring (lol I didn't expect that at all at the time)

edit: it might have also been because the O-ring on the new piston head didn't have as good of an air-seal

7.2V batteries will do it.

7.2 sounds good, but is there an AK stick type battery that is 7.2?
and thanks guys for the suggestions on spring,piston...etc
since the gun is only shooting around 270 fps, i'l upgrade the spring and see if that will get it down to 600 RPM!

Open up the battery pack and take 1 out. Use some cotton balls/tampon or something to prevent battery from rattling in the housing.

People knowledgeable in electronics: Would adding a resistor somewhere in the wiring (just before the battery) or a tiny pot slow the motor RPM down???

Adding a resistor has the same effects of lowering the batteries voltage.

Sounds good mate! Thank you for the sulotion!
But wouldn't that lower the mah tho?

No. mAh is determined by the cell, voltage is determined by the number of cells. So you're providing the same mAh at a lower voltage with fewer cells.

i can see there being lots of heat and decreased battery life in the long run but it would work.

1) Get a lower voltage battery pack
2) Get a lower mAh battery pack
3) Get a high torque gear set
4) Get a heavier spring.

Adding a resistor to soak up the extra voltage may require you to heatsink the resistor, as it will convert the voltage it's blocking in to heat.

Doesnt the mah determine the stamina of the battery pack?

A resistor will get quite hot since it will use the same amount of current as the motor itself (which will be a lot). Also, it will mean your battery pack lasts less time overall since power is being wasted on the resistor.

The best way to reduce the RoF is to use some electronics to control the AEG motor and make it run slower and more consistent - but without wasting power.

I'm working on something to do exactly this as a matter of fact and will have them for sale. If you're interested, you can watch for an announcement I'll make for them in the next week or two.

That's true, but generally higher capacity cells have a higher discharge rate, thus usually a higher rate of fire. It's not always good to go by that rule, and I suggest that instead one does in fact switch to 7.2v.

+1, I just cut my batteries down myself, not terribly complicated.

Generally, it does, but there is a lot more happening with the chemistry than your basic Ohm's law.

The larger the pack, the lower the cell internal resistance it has - and the lower the cell internal resistance, the more current the pack is able to crank out. If the pack is able to release more current, then the motor can draw closer to it's full potential. Limit the bandwidth of current by dropping to smaller cells, and the motor won't get as much juice as it needs which results in lower ROF and slower trigger response time.

ROF drops are less noticeable between say... a 1700mAh sub-C cell pack and a 2400mAh sub-C cell pack than it is between a 1700mAh A cell pack and a 2400mAh sub-C cell pack.

So in general, physically larger cells will exhibit higher ROF versus smaller cells.

At an extreme end of the scale, try powering a 400fps setup with an 8.4v 600mAh 2/3A cell mini pack and then try powering it with an 8.4v 2400mAh sub-C cell pack. Despite having the same voltage, you'll notice a HUGE ROF increase and a massive decrease in trigger response time when using the large pack.
On top of that, you'll notice the mini pack will get noticeably warmer than the large pack - this is the effect of all that internal resistance. The resisted energy has to go somewhere, and is released in the form of heat.

Quoted for truth, though wouldn't you have a snappier trigger response with the larger pack?

Exactly, as I mentioned, it will result in a massive decrease in trigger response time when using the large pack.

Haha, that was a Freudian slip from Illusion. Or just bad wording. He means a decrease in response time i.e a decrease in time between pulling the trigger and the gearbox cycling i.e BETTER trigger response time.

errrr. yeah. I can see where the confusion lays, now. I actually paused when typing that out...