[Dynamo]

i had to modify my team mates PTS ACR and remove that shitastic switch assembly. it now has a normal (modified) V2 switch and trigger. im sure that horrible switch works fine on a stock setup with just a plain battery, but MOSFETs HATE! that switch.

i just could not get the damn thing to fire in full auto yet alone semi without it hiccuping. that switch does not take shock loads along its operational axis well at all. which is why it doesn't work well with a MOSFET.

with a normal setup, the switch arcs and sticks in the closed position when you pull the trigger. due to the low voltage of the trigger wires on MOSFETs, there is no arcing, so the switch gets bumped open when the piston slams forward cutting power to the motor, causing the hiccuping.

my team mate even bought new switches with stiffer internal springs to see if the stock switch just had a weak ass spring, turns out that even the strongest switch still could not keep the circuit closed during full auto. after replacing the switch with a normal V2 switch assembly, all issue concerning cycling went away. his ACR now runs on a MOSFET with 11.1v Lipos without any problems.

this was just one of many issues i had to fix on his ACR. there was a major issue with the gear box it self and its internals. the metal piston tooth on his stock piston was too long and scraped two nice deep groves along the full length of the cylinder. this not only completely screwed the airseal, but also FUBARed the piston head o-ring. the only reason why i even bothered to check the piston was due to the crap load of metal filings covering the gears.

that brings me to another problem. the stock gears were all oversize when compared to other brand name gears. so much so that the sector gear would wedge the piston against the top inside surface of the gearbox.. that was a fun day trying to unjam that..urg.. also the spur gear was warped..looked like an old vinyl record that was left inside a car parked all day under the sun on a 42*c summer day.

anything i could replace from that nightmare of a gearbox i did, some stuff had to be modified and or fabricated and now his ACR runs perfectly.

if i ever decide to get one for myself, i think it would be to make a GBBR.. as the first thing i would do is toss out that POS gearbox.