Running into an issue: my gun is , ever so often, double or triple firing. not double feeding. just burst fire on semi.
Checked the cutoff lever. seems good.
Used to shoot aka hard gels but when i tried cheap gels it started doing it. also noticed that i’m loosing compression around the cylinder head. Do you think it’s related? my guts tell me yes. loosing compression in the cylinder decreases piston resistance and my very torquey motor and heavy metal gears would be prone to overspinning. I’m i on the right track?
also, since i need to do it anyway, any good online shop that has an upgraded cylinderhead/nozzle that ships internationally? is an airsoft cylinder head different from a gel blaster cylinder head? (not talking about the nozzle)
Thanks
Oh and i deduced that my cylinder head is toast because i’m running an m100 spring on the stock plastic head
Sounds like it is “overspinning”. Can occur when there is not enough pressure on the cut off lever spring or the cut off lever is not free moving enough; or not enough resistance from the main spring compared to the motor torque/speed and gear train.
The cylinder head seal is likely barely related, also I have used m120 on stock plastic cylinder heads so should be fine provided the tube is sealed to the plastic. Airsoft heads are only compatible if the cylinder head tube is 5.4-5.5mm diameter. If it is that LDT, CYMA are closer related to it and you can use airsoft cylinder heads.
It is common for gel blasters to be 6.4-6.5mm tubes. If that is the case it is more related to Jin Ming, Jingji, JG, RX, gel ball style cylinder head. A lot of companies tend to use this in gel ball.
Basically, if the head has a “shelf” and can only be pushed so far into the cylinder Jin Ming are likely the best choice. If it doesnt and the head can be pushed straight through the cylinder then JingJi/SLR head is probably the choice.
Best way to resolve this without parts is to change the cylinder head o-ring to a slightly wider one. Failing that remove the o-ring, Put some PTFE tape around where the o-ring sits, then put the o-ring back on. You want enough to be able to just squeeze the cylinder head in the cylinder. It isn’t ideal but I have had to do it plenty of times due to lack of aftermarket parts and available o-rings.
Your cylinder head looks like a JinMing one, but can’t tell for sure from your photos.
Onto one of my favourite issues, the overspin. You can find a small spring for the cutoff lever that is slightly larger or smaller than the one currently installed, and twist it into each other. Essentially doubling up the springs. Check it still fits in the space and doesn’t catch. Springs from a lighter or pen can be just the item sometimes.
This will only resolve the issue if the problem is purely the cutoff lever not activating in time.
If the overspin is being caused by the gears and motor being too fast though, you will have to use a larger spring, or more torque based slower motor.
One way that usually works is to go up a spring size and remove two teeth from the pickup side of you sector gear. Make sure to keep the gear as round and smooth as possible where the teeth are removed, and take care not to hit the new first tooth. You can clip it and it isn’t the end of the world but best not too.
You do not need to remove teeth from the piston rack.
Long as your piston head still clears the port it should not change fps much. If it does increase it beyond what it was, I would consider removing another tooth, again provided the piston head still travels past the cylinder port.
I agree with Roksolid that it’s not likely to be your cylinder head.
Chinese manufacturing standards being what they are, there have been plenty of times I’ve bought aftermarket alloy cylinder head /nozzle packages and the cylinder head’s ended up in the spare parts drawer because it doesn’t fit the shell. The location holes have either been drilled undersize or mislocated and won’t line up with the lugs.
So then you run with the OEM plastic unit and upgrade nozzle… never had a problem doing that, provided it seals well. It’s a static part and upgrading to an o ring nozzle does more for performance than swapping out the cylinder head anyway.
You’ll sort your double tap issue, I’m sure… you’re onto it.
thanks for the heads up. Used PTFE on the cylinder. should hold up now. forgot to mention that is had almost no compression but a change of oring on the piston took care of that
Anyway about double firing: i think i found the culprit
bench testing is promising but i still need to shoot a few gels to be sure. but there is a general election here right now, spirits are quite hot and it’s not a good time to be mistaken holding what looks like an assault rifle in your yard
Oh and i got quite efficient in opening the gun now.
