Tappet plate and Sector gear problem

[insidus]

Hi all,

 

(on behalf of a friend)

 

He has bought a valken tactical battle machine mod-ec (to be precise) which was running a little hot (375 fps) so he bought an M100 spring and we changed it. It took us a while to get the gearbox back together again as the anti-reverse latch was being a b....

 

However, when the gun is fired, the piston pulls back as normal and so does the nozzle but it will then get stuck and stayed pulled back; it will not return, the spring will not release and we have to take apart the gearbox again. The spring for the tappet plate is connected properly, and you can push the nozzle in and it returns like it should. When we open the gear box, it looks like the tappet plate (the part that protrudes down and connects with the sector gear) is on top of the sector gear and stuck. We have made sure that the tappet plate is installed correctly and in its grove but it keeps happening (at least 4 times now).

 

We have tried the gearbox without installing the tappet plate and it functions normally (the piston pulls back and the spring is released correctly), but with the tappet plate installed it gets stuck and lodged. Nothing looks broken, and it looks exactly like this (though this is someone elses): http://i86.photobucket.com/albums/k120/DarkRepressor/gearbix.png

 

Any help would be greatly appreciated as we have a game on the 12th!

 

Thanks,

[Sitting Duck]

how much did you disturb when opening up the gearbox ???

 

If the box exploded as it often does when you first open up a box then gears/shims could go everywhere

these little shims are to space the gears correctly to each other and the other components should operate smoothly

(cut-off lever and tappet plate springs to mind - ha "springs" ha - uhm ergh I'll get me coat...)

 

now what "may" have happened is sector gear might be shimmed a little tight to rub against tappet or force it to bind in box

but most likely there could be a burr on that high precision inside casing near where tappet spring is

 

BUT to be truthfully honest - almost anything could be causing the thing to jam/lock up

you need to examine the stuff really closely and ensure say the tappet plate glides back n forth in a silky smooth action

place it in the normal left side - no tappet spring, slide back n forth to check for any points it may catch on

repeat in the right side or gearbox lid - sometimes the fin can snag around spur gear's bushing/bearing area

 

It isn't hard but likely something like shimming might have got disturbed, or the trigger spring might have come off, replaced incorrectly or shifted over to maybe sit in the tappet plate's travel and catch as it goes back n forth

You could of caught the tappet plate itself - unlikely but any form of burr on tappet plate or its runners in box will affect how smoothly it operates

 

I would suggest some thorough research on gearbox assembly/reassembly and once a little familiar then open her up to check the operation of everything but trying to disturb as little as possible as shimming may not be perfect but probably better than many new comer's first attempts of shimming

 

something somewhere is binding, must be quite bad to stop tappet plate/nozzle returning though as spring should be ensuring it flies back just before piston fires.....

nozzle is often starting to retract once more though as you fire in semi - many panic seeing nozzle not returning flush with box but it has and by time piston starts to retract the tappet plate has already pulled the nozzle back about 80% already getting set to load & chamber a bb

 

but really impossible to guess/predict exactly wtf might have taken place if you can't even show us a picture of the box in question