daven Posted January 30 Share Posted January 30 dusted down the old mp5, charged battery, wont fire. just get a click. the motor spins although i can grip and hold it with my hand. the bevel gear can be moved reasonably easily with a pokey tool. fully assembled with a multi meter in series with the fuse it'll pull over 10amps. the battery reads 9.2v on an 8.4 nuprol 1.6Ah before i pull it right apart, can i rule out the battery with those figures? it's a t&m mp5 from about 2002 and afaik the gearbox has never been apart, was running fine when i last used it (a couple of years ago maybe). many thanks Rogerborg 1 Link to comment Share on other sites More sharing options...
Sewdhull Posted January 30 Share Posted January 30 I don't think you can rule out the battery. When stalled the battery should be pulling as many amps as it ever can and 10A is no where near enough under load, my motor needed 5A just to start turning... You say the motor spins. Is this out of the gearbox? Is the commutator coppery or black. There are switch contacts and the copper parts on the selector plate which can corrode over time and use. Either you have too many high resistance parts in the wiring, or the battery current capacity is insufficient. You might want to give it a bit of a service anyway after 22 years... EDcase, Dan Robinson and Rogerborg 3 Link to comment Share on other sites More sharing options...
EDcase Posted January 30 Share Posted January 30 (edited) I'd suspect the battery as well. Especially if its the same age as the MP5 You shouldn't be able to hold the motor pinion As Sewdhull said, its probably worth doing a service anyway. Reshim etc... Edited January 30 by EDcase Link to comment Share on other sites More sharing options...
Supporters Rogerborg Posted January 30 Supporters Share Posted January 30 Me three. I've popped stock fuses (20A? 25A?) with stalled motors, and now upgrade by deleting them and applying electromechanical sympathy. Batteries - particularly NiMh - can look good by producing voltage without being able to supply enough current, so I'd agree with trying another one, i.e. a 7.4V lipo rather than spending more money on last-last-generation technology. The other thing you can try, short of a gearbox stripdown, is shoving a long ball-end Allen key or similar up the nozzle, feel where the piston is, and see if you can get the it moving a bit. I've used that to push a stalled / locked up piston back past the release point. Be aware that it'll then want to come forwards rather assertively. Link to comment Share on other sites More sharing options...
daven Posted January 31 Author Share Posted January 31 the stock fuse is 15A, i'll go get another battery. cheers chaps. Link to comment Share on other sites More sharing options...
daven Posted November 1 Author Share Posted November 1 im just gunna close this up, thanks for those that replied, ive finally ordered a new battery,not before i took the c*** apart, a few things went PING! i thought HTF am i getting this back together and gaining a new respect for airsoft techs, that fiddly shit mah dayz. a mate told me how i was measuring it wrong, put the meter in parallel and saw the volts drop to 1.... yeah..ok... so yeah new battery on the way. cheers! (an yeah somehow i got it all back together ) Link to comment Share on other sites More sharing options...
Moderators Jez_Armstrong Posted November 2 Moderators Share Posted November 2 So it works now? Link to comment Share on other sites More sharing options...
daven Posted November 6 Author Share Posted November 6 On 02/11/2024 at 10:07, Jez_Armstrong said: So it works now? well.... put the battery oh... nada... ok i'll charge it.. put the fully charged battery on.... no bueno. hold the trigger... fuse pops. motherf.... so i strip it all apart... again... getting half ok at this now. still cant see any reason for it not to move, i reassembled it without the piston and spring (i'd appreciate it if someone could tell me how to release the metal tab that appears to hold the spring in) and clack clack whirring of gears... so... i dunno. anyways, i remember this guy... what he said had always stuck in my head On 30/01/2024 at 18:14, EDcase said: its probably worth doing a service anyway. whilst i have no idea how to judge if it needs shimming it's barely done a thousand bbs i reckon but the lube could be getting a bit sticky, so i cleaned it all up and read you need two different types of lube so i used butter and old engine oil. i've just reassembled it, pulled the trigger.... fuck me dead and bury me pregnant .. it works! i guess it was just the old sticky lube. it's probably only firing 3fps but its a start. Link to comment Share on other sites More sharing options...
EDcase Posted November 6 Share Posted November 6 Congrats. Well on the way to becoming a tech 😜👍 daven 1 Link to comment Share on other sites More sharing options...
Moderators Jez_Armstrong Posted November 7 Moderators Share Posted November 7 12 hours ago, daven said: well.... put the battery oh... nada... ok i'll charge it.. put the fully charged battery on.... no bueno. hold the trigger... fuse pops. motherf.... so i strip it all apart... again... getting half ok at this now. still cant see any reason for it not to move, i reassembled it without the piston and spring (i'd appreciate it if someone could tell me how to release the metal tab that appears to hold the spring in) and clack clack whirring of gears... so... i dunno. anyways, i remember this guy... what he said had always stuck in my head whilst i have no idea how to judge if it needs shimming it's barely done a thousand bbs i reckon but the lube could be getting a bit sticky, so i cleaned it all up and read you need two different types of lube so i used butter and old engine oil. i've just reassembled it, pulled the trigger.... fuck me dead and bury me pregnant .. it works! i guess it was just the old sticky lube. it's probably only firing 3fps but its a start. Well I was going to offer a free service if you cover postage each way 🤷 Tackle, Colin Allen and daven 1 2 Link to comment Share on other sites More sharing options...
Moderators Tackle Posted November 7 Moderators Share Posted November 7 Lozart and daven 2 Link to comment Share on other sites More sharing options...
daven Posted November 7 Author Share Posted November 7 6 hours ago, Jez_Armstrong said: Well I was going to offer a free service if you cover postage each way 🤷 that's pretty decent of you, thank you. i'm onto feeding issues now. they seem to get jammed the loading side of the hop up. Link to comment Share on other sites More sharing options...
daven Posted November 7 Author Share Posted November 7 after another round of this (as you can see, i dont have any feeding problems) and a little rubber retainer fucking off into another dimension... i found the problem. if you had n00b assembly error, you were correct. i had failed to correctly seat the slidey thing into the skirt of the slidey nozzle which backups the confusion i had that i couldnt depress the nozzle which i was sure i'd seen that positive airsoft fellow do on the youtube. thank you all again for your help Link to comment Share on other sites More sharing options...
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