Paleblue Posted August 27, 2012 Report Share Posted August 27, 2012 So here's the situation. I have an E1 V6 that only locks up when I full auto and then by chance stop right when the piston is pulled all the way back. After that, the only way to reset the gearbox is to take off the motor cage and hit the AR latch. Pulling the trigger does nothing and makes the FET I installed very hot. The strange thing is, when I full auto, the gearbox will not lock UNTIL I stop and the piston happens to stop near the back end of the gearbox. I have the following mods and upgrades: Cut Spring (poormaned to about ~300, it did not penetrate the side of the can) Stock Bevel and Spur Plastic Piston Head Stock Bushings Stock Pinion Short Stroked Piston (2 teeth) Sector with two teeth removed Correct AOE SHS High Speed Motor P-Channel FET China 9.6 1600 mAH Battery Guarder nozzle and tappet Deans Shimmed I have done some unit testing to narrow down the list of possible faulty parts. Tested full teeth piston and full teeth sector gear - locked more often Faulty SHS pinion (differently shaped teeth) - less locking as a result I don't believe it is a mechanical problem because the gun will cycle as long as the gearbox is reset and the trigger constantly pulled back. And the spring isn't too stiff because a .2 will not penetrate the side of a can. This leads me to conclude that I have an electrical problem. I believe that the SHS motor draws too much power, which my battery cannot provide. As a result, the motor doesn't have the juice to pull back the spring at the spring's most compressed position. I don't have a more powerful battery to test, and there is no way that a more powerful Nimh battery will fit in the small space of a P90, so at this point I am leaning towards Lipos. Also, with a high discharge Lipo in tandem with the SHS high speed, my gearbox could rip itself apart. I'd rather not replace the SHS, so I'm at an impasse. I would really appreciate some second opinions. Link to post Share on other sites
LordElpus Posted August 27, 2012 Report Share Posted August 27, 2012 A high discharge lipo WILL NOT rip your gun apart if the gearbox is working properly a the gun will only demand what it needs to run at 100% If the gun does indeed eat it's own gears, it's because something is wrong inside the box. If a gearbox locks up regularly, it is most likely one of 4 problems. * Motor is too weak/failed and doesn't have the power to pull the spring all the way back, * Fault in wiring, trigger mech/mosfet. At peak load (piston all the way back) the mosfet is cutting out so the motor stops * Battery can't supply enough Amps to run the gun at peak load. Swapping the motor for one out of another gun will check the first. Remove the mosfet and run the gearbox again, does it still lock? Use Multimeter to check resistance of the wiring Use Multimeter in circuit to check power drain. Attach the + meter cable to battery + and - meter cable to gun +. At 300fps it shouldn't be much over 20A but you will need access to a battery or bench power supply capable of supply over 25A for this test Link to post Share on other sites
Kevlaa Posted September 7, 2012 Report Share Posted September 7, 2012 Did you find out what the problem is? I'm have similar problems with mine? Link to post Share on other sites
jal3 Posted September 8, 2012 Report Share Posted September 8, 2012 Try simulating the sectorgear running over the piston rack and see what happens. Link to post Share on other sites
Paleblue Posted September 9, 2012 Author Report Share Posted September 9, 2012 I ran additional tests, and measured that the SHS high speed motor was drawing a whopping 28+ amps. So now I plan to first locate a powerful battery and see if it still locks up. Then, I'll remove the FET to see if the gearbox locks. TLDR: Still locking, need more testing. EDIT: Try simulating the sectorgear running over the piston rack and see what happens. I did, and I also tested a full teeth sector gear and a full teeth piston with the first teeth removed to correct for AOE, and the locking was worse. So my short stroking job was proficient. Link to post Share on other sites
LordElpus Posted September 9, 2012 Report Share Posted September 9, 2012 28amps? something is not right there, try another motor. Link to post Share on other sites
jal3 Posted September 9, 2012 Report Share Posted September 9, 2012 Show us a picture of your sectorgear and piston rack. Link to post Share on other sites
richwuk Posted September 9, 2012 Report Share Posted September 9, 2012 I've had troubles in the past with locking up relating to motor height adjustment. Try adjusting the motor closer to the gearbox. Link to post Share on other sites
Kevlaa Posted September 9, 2012 Report Share Posted September 9, 2012 I've just had my box apart to try and get to the bottom of this! After swapping the motor, reshimmed the gears, lubricated and fitted an new AR spring and latch but to no avail. I did notice that the tappet plate is worn quite abit, would this cause a lock up? Link to post Share on other sites
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