TM MP5 NGRS

[Xepo]

Hi guys,

 

Some time ago I decided to upgrade my TM MP5 NGRS with a stronger spring. It shoots around 0.8J out of the box, but where I'm from we can shoot up to 1.2J; I watched the Eagle6 upgrades on Youtube and decided that just replacing the spring would be fine for now. Not sure which strength I would need I ordered an M100, M110 and M120. Before I began, I watched this video a gazillion times to know the internals; 

 

That's when the nightmare started haha. I took it apart and replaced the spring with an M120. Putting it all back was a bit of a fiddle but went ok. After putting it in dry fire mode (pressing the charging handle three times and a blue LED in the magwell starts flashing) the gun starts to behave erratic. 

 

When in semi-auto, it sometimes fires, sometimes it won't compress the spring entirely, sometimes it just errors out (blue LED becomes RED and the gun is unresponsive). So I figured that the spring was just too strong. I replaced it with an M110. Same exact problem. M100 then? Same problem. Finally I put the original spring back, but the result is the same. I'm obviously doing something wrong. At one point I though I had the gun working again, but when picking it up the next day, it won't shoot.

 

Things I've paid extra attention to / tried variations of:

- Spring strength (original, m100, m110, m120)

- Tappet plate is intact

- Tappet plate return spring is ok and in place

- Temporarily removed the blowback function (to see if it created too much resistance of some sorts)

- Fully charged battery

- Made sure that the piston grooves align

- The gears catch the piston

- The gears and piston have all their teeth

- On the bottom of the grip is a screw to push the motor into the gears; I've had it at all kinds of tensions, resulting in a free-spin, no-move or a shot (but only when the stars align)

 

Hoping someone had the same issue and could give me some pointers. It's hopefully something really dumb... if extra info is needed please let me know!

 

Thanks

[sjhirst]

Sorry, I cant help you with that problem, but there is a tm mp5 mgrs section in the guns, gear and loadouts subforum. Might be worth posting in there as well?