Nylon Gen 9 gearbox can't keep M130 spring


I think I pushed the limit putting an M130 in this particular Gen 9 nylon gearbox. Pushed the cylinder assembly past the head retainer and broke the fin off the tappet

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M130…that’s a lot of spring power for a nylon gearbox. Was it a single rate or dual rate spring?
The differences between the “M” rating and the “mm” rating is always a point of contention, with some people saying you can fit this ot that, no worries…
I am still an “L” plater, but I research everything before I make a decision and then buy based on my best knowledge and allow a fudge factor of + or minus 15. My original spring in the CYMA was 1.2mmx15cm, giving me an avg of 250-260 fps, After many questions to people, forum and stores, I came out with a dual rate M110. This combined with my barrel to cylinder ratio should turn in, I hope 300-330fps and not load the gearbox unduly. Only the bloody head and nozzle to go and front hand grip to come. I’ll let you know how it all goes when it comes to the assembly LoL.

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I’ve got an M110 in a metal box, and even that worries me lol. @Stirlo share the pics of the gearbox you destroyed last week :joy:

you may have had your super villain pants on that day.

absolutely no surprise you destroyed the box but i am a little about the tappet tail.

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Yeah mate, it had an SHS M100. The mm rating as in outside spring diameter ex, 1.2 or 1.3 is a little inconsistent with spring tension. You can have similar OD but different tension whether equal or unequal. With the SHS M type, I find they have a really high fps for the first week or two of use. After that they tend to drop fps and settles with consistency. You can see the difference on the length after a couple of weeks. What I was hoping for is work the spring out on one session and hopefully it will settle. Boy was I wrong. This is the second time I’ve caused catastrophic failure on nylon gearbox lol. The other ones Gen 8 where the piston jammed in the gearbox with funnily enough M130 spring. I think I learned my lesson :joy:

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110 on metal, I think you’ll be ok. I’ve got stuck an SHS M150 on my nylon CYMA DSG build. It’s short stroked and ported to 50% and still working. This might give you a peace of mind :wink:.

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Yeah bud, pushing the limit on nylon coz I’m all about cheap build plus I’m poor haha. Tappet must have broken off when the whole cylinder assembly pushed past the gearbox retainer pins. Still got the super villain pants to try on my P90 and SLR

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Slightly off topic
Which side of unequal springs goes into the spring retainer?

the side with the compressed coils. hope that makes sense?

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Thank you!

basically blew the cylinder head straight off of acr

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