Tony.S Posted May 7, 2018 Share Posted May 7, 2018 Hi guys, I need some help with a problem I have. The gun is an LCT AS Val, I have an SHS high torque motor, 11.1v Lipo and a pico aab mosfet. I did all the upgrades myself and had no problem before I changed the motor and did a little rewiring. As soon as I connect power to the gun, it fires in full auto without stopping, and I have to remove the battery or a wire in the mosfet to fix it. If I use the old standard motor for the Val, the gun works perfectly as intended. Sadly, I did not check the motor before changing the wiring so I couldn't narrow it down any further. I did have a similar issue a while back due to the mosfet wire shorting, but I have sinced changed the wiring. If any more information is required, I'd be happy to add it. Thanks in advance! Link to comment Share on other sites More sharing options...
Iceni Posted May 8, 2018 Share Posted May 8, 2018 First thing to do would be unplug the trigger connections on the fet and plug in a battery. It'll show you if the trigger is in an always on state. If it powers up and shoots the Fet has blown and is allowing voltage leak past the gate. If it doesn't it might indicate the trigger is stuck on. You can bridge the mosfet trigger connector with a small flat screwdriver, If it shoots and stops when you remove the screwdriver the trigger is at fault. It'll either be touching contacts or a stuck on dolly. Link to comment Share on other sites More sharing options...
Tony.S Posted May 8, 2018 Author Share Posted May 8, 2018 Thanks for the reply, I will try the first thing you said tomorrow as it's too late to be shooting haha. I have played around with it a lot and from what you're saying, it seems the trigger is at fault, I don't see the trolley getting stuck and I checked the whole trigger system a few weeks ago and haven't touched it since though, but I tried bridging the connections and it did as you said. The only thing I don't understand is why it works perfectly with the old motor but the new one just fires constantly without pulling the trigger. Could there be a problem with the motor? I dont have another gun to test it on so I'm a little stuck. Link to comment Share on other sites More sharing options...
Iceni Posted May 8, 2018 Share Posted May 8, 2018 There could be a problem with the motor. SHS high speeds have an issue with the end caps where the screws can cause shorts if they don't have insulating washers. If you decided to connect the motor with ring connectors then that would cause the problem. FC and RC on that image. I don't know how the Mosfet is internally wired and if a motor short could bridge the trigger loop. For V3 boxes I normally solder wires directly to the motor and run them up to the connections to the fet. You can remove the motor without the problems of the V2 so soldered connections on the tangs removes a point of failure with connectors dropping off. Link to comment Share on other sites More sharing options...
Supporters Sitting Duck Posted May 8, 2018 Supporters Share Posted May 8, 2018 True - G&G, SHS & some others use that "lock ring" where m2.5 bolts screw into without insulating washers you create a short on both poles - not good Just test the bare motor on say 7.4v and be done with though tbh using 11.1v & AB you will get some carbon building up you can always cut the signal wire to mosfet and test with a separate loose posi wire if all works you got short from sloppy trigger switch soldering (just a faint hair like whisper of solder will be enough to bridge the circuit closed) Of mosfet is borked - but I avoid AB as heat & carbon build up using 11.1v on A SHS HT you gotta be on say 30rps which is a bit quick personally I aim for 20-25rps and just avoid needing AB for overspin (13:1 & decent 7.4v, m110/120 SS a couple of teeth but to each their own) soz for jumping in - just saying about AB on 11.1v Link to comment Share on other sites More sharing options...
Tony.S Posted May 8, 2018 Author Share Posted May 8, 2018 I have narrowed it down to the motor, thankyou. I still can't find out a fix though. I used the FIS connectors but dont see any issue with the connections shorting. Could I get a little more info on how it might be shorting inside the motor, I'm not too experienced with it and will probably watch some videos before having a go at taking it apart myself. And yes, 30 rps is a little high, but it seems to be closer to 25, and I'm only using it for trigger response anyway for my local indoor site. The wiring is done exactly like this, but without a fuse. Link to comment Share on other sites More sharing options...
Iceni Posted May 8, 2018 Share Posted May 8, 2018 The short will be because of the screws in most cases. There should be a plastic or fibre washer between the screw and the silver plate so the plate is insulated. Lol It would help if I could spell! Insulation washer! Link to comment Share on other sites More sharing options...
Tony.S Posted May 8, 2018 Author Share Posted May 8, 2018 Thankyou! It worked!!! I'm so relieved right now haha thought I'd have to buy a new motor, the screws did have a plastic cap, but I unscrewed them slighly and it's working perfectly. Again thankyou aha Link to comment Share on other sites More sharing options...
Iceni Posted May 8, 2018 Share Posted May 8, 2018 2 hours ago, Tony.S said: Thankyou! It worked!!! I'm so relieved right now haha thought I'd have to buy a new motor, the screws did have a plastic cap, but I unscrewed them slighly and it's working perfectly. Again thankyou aha It's probably the Length of the screw that has caused it then, I'd grab some small plastic washers and just add a couple to each screw just to bring them out a touch so it doesn't happen in game.https://www.ebay.co.uk/itm/2-5mm-NYLON-PLASTIC-WASHER-SPACER-TO-SUIT-M2-5-BOLTS-SCREWS-NEW-PACK-x-20-/260843448579 Link to comment Share on other sites More sharing options...
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