CPS 2700 Trigger Crack

[SEAL]

My 2700 developed a small crack in the trigger about a year ago. After MOAB, I decided I'd better reinforce it, so it wouldn't end up like my 2500 (the trigger on which cracked at that war). So I opened up (drilling out like 3 screws in the process...ugh) the blaster, and epoxied carbon fiber strips to the sides and glued up the crack. Worked great at Soakemore, then at Downpour (the war where almost all my guns had problems) the thing cracked wide open even with the reinforcement. As you can imagine this pissed me off. So just a few minutes ago, I opened the thing up to see what the heck happened. Here's what I found:

CPS2700TriggerCrack1.JPG (1.72 MiB) Viewed 2428 times

So you can see the crack a little better:

CPS2700TriggerCrack2.JPG (1.63 MiB) Viewed 2428 times

It looks like the plastic somehow broke loose of the strips; I guess from all the hard trigger pulling. I supposed I'll have to glue a piece of metal or something to the underside. Any suggestions?

Sorry for the oversized pictures! I don't have time to do anything about them; I have to go study for a test. *Runs away from computer with a cartoon "WHOOSH" sound*

[HBWW]

I've had this problem with my own 2700, and it's something that will happen to all of them by design. (Many Larami CPS triggers were specifically designed to break quickly, including the 2700.) Anyway, I always use the sheet metal and epoxy repair, which is very commonly posted.

Here are some pictures. This one is from a 2100 using Gorilla Glue, but the idea is the same. I wouldn't recommend Gorilla Glue now at all.
http://i.imgur.com/nnq7ynv.jpg
http://imageshack.us/photo/my-images/23 ... smlki3.jpg

The idea is to get a good surface bond with as much surface area contact as practically possible. I started by grinding down the ridges on my 2700's trigger to accommodate the sheet metal cutouts. Unfortunately, I made a few parts too large and ended up having to use the dremel to get things to fit in the case. The largest problem is that the trigger no longer aligns and wiggles when pulling, but this isn't that bad when the blaster is pressurized.

DX managed to get a good 2100 trigger fix with only epoxy, but I swear by my method and would never just use epoxy by itself without the reinforcement.

Welcome to the World of Shittacular CPS Triggers. You'll get used to it eventually, but it's something you'll deal with on other blasters like the 2100 MK II or the CPS 2000/2500. I can't help but ponder the process of which Larami used to decide which blasters would have properly designed triggers and which ones would be deliberately designed to break quickly.

If it weren't for the fact that we aren't planning much rivalry (if any) this weekend, I'd have considered leaving this post out. =p The 2700's capacity is ridiculous and super-helpful for those factory rounds, although I personally would prefer something lighter at this point.

[SSCBen]

I would strongly suggest against using carbon fiber and reiterate CA99's suggestion of metal and epoxy. Carbon fiber is designed to be strong mainly in one direction, whereas metal is strong in all directions. If your load is not along one direction (and here it's definitely not) then carbon fiber is a poor choice. Plus, you can easily get more surface area with metal.

[HBWW]

An important detail I didn't mention is that some repairs only use one metal strip on the bottom of the crack as seen here: http://www.sscentral.org/repairs/snapped_trigger.html

From my experiences, this simply does not work very effectively, as the epoxy eventually slips and disconnects due to the concentrated stress. With the method shown in my post above (using two identical sheet metal cuts, one on each side), the stress gets distributed better on a direction that's less able to bend the sheet metal. The problem with my 2100 repair is that it lacks surface area contact with the trigger, and my newer repairs/reinforcements don't have that problem. The solution is to simply cut out a larger piece of sheet metal that covers more of the trigger. In a few cases, you may be able to grind the casing down in favor of a larger trigger with more sheet metal coverage.

Tools/materials list, just to be clear:
- Snips (cutting sheet metal)
- Thin sheet metal (found some around the house, not sure where to find it)
- Epoxy (I use Devcon Plastic Welder; you want something good for both plastics and metal)
- Sandpaper (prepare surfaces for epoxying)
- Dremel (grind out excess casing/trigger that prevents it from fitting back to the case)

[GJIV]

Just think logically, where the maximum stress will be. There you have to put materials and so to stabilize these stress concentrations.

here you have the maximum stress directly where the kink is, so where the trigger-part for your finger is attached to the rest.

You can put in some metal here, just as done at ssc, you can also put some cyanacrylat glue on the pull-side ( front side) and then put over some rubberband, to get a laminate material. This works a little bit like a composite material. glue, rubber band, glue. Have a try, I did repair every trigger and every hole in any pressure chambers(Air-Chambers, no CPS....)

good luck

[marauder]

This doesn't help you this weekend, but I would strongly recommend you getting a new trigger manufactured out of metal in the future. Dux has a contact who has a machine shop and is going to start manufacturing 2000/2500 triggers for us. I am going to talk to him about making some parts for other guns eventually. It won't be the cheapest option, but I believe it will be the most durable option, which is most important to me.

[SEAL]

Thanks for all the advice. Hopefully I have sheet metal laying around somewhere. I'll let you know how it turns out.

marauder: That would be awesome. My dad actually works with CNC machines at his job; they can make almost anything out of metal. Maybe I should ask him about it...

[marauder]

I know it cracked again at the war. Have you been able to work on it at all?

[SEAL]

Haven't done anything to it yet; I'm planning to get rid of the old trigger plate and make the metal strip longer. As it is now, it works fine if I pull the metal strip, but it's too short to use effectively.