Bolt stick. Springs or sears?

[ArmyEngineer]

Hey guys,
I've been having some bolt stick with both of my e-mags lately. Both had the gold springs installed, but I switched one over to a silver and it seems to have fixed the problem. (Both golds extend 3/16" past the end of the bolt.) Red is too strong. Lvl 10 carriers are properly sized on both valves.

The bolt stick I was experiencing was mainly apparent when the bolts were blocked up to a quarter inch into travel. If I blocked them further out, they were more likely to make it back. Pulling the trigger in e-mode after the stick would allow the bolt to slide all the way back into position. Are my springs just shot, or could this issue be due to the sears being out of adjustment? Manually resetting the bolts was taking a little more muscle than I expected. There is roughly a 1/16" gap between the trigger and trigger rod at the shortest distance. My calipers are at work at the moment, and I can't remember the exact rod/plunger lengths. I will have to check them tomorrow. Just wondered if that was a culprit.

Just out of curiosity, what are the symptoms of too short/long a trigger rod and plunger as far as the performance of the marker goes? (Damage to the frame and solenoid/ferrite aside.)

[Abizdafuzz]

I have had this issue of sticking before and for me I just had to make sure the field strip thumb screw was not to tight. If you tighten it down to much it will cause a bind in the bolt.

[Ando]

If the spring fixed it, I'd call it a day. If you want to, you could lengthen your plunger .005 and a time and see if that works.

[ArmyEngineer]

Ahh. Thanks Ando. You're the man! I will give it a try. I'll be sure to post my measurements before I change anything though.

I tried all different torques on the frame and thumb screw. I finally gave up on that idea. I took everything back to snug/hand tight. Good advice though!

[211]

if the LVL X wont reset after stopping, then try adding a shim or 2

[ArmyEngineer]

if the LVL X wont reset after stopping, then try adding a shim or 2

Hey man. I don't think this is a shim issue. I already tried that as well. I went up to 3 and back down to 0 with no apparent change in stick. Those shims are like 10 mils, correct? All they do is push the powertube tip out a little further giving you a minuscule lengthening of high pressure time behind the bolt/vent? Meaning the vent is activated a tiny bit later? Is that the correct way to think about it?If so, they would seem nearly useless. Wouldn't the position of the valve be more significant since there is some wiggle room in the rail bushing/frame hole. I am trying to wrap my head around everything. Bear with me.

[fishmishin]

Sounds to me that you already have the bolt stick issue figured out. I normally use the silver spring and trim it down to were I need it to get the lvl x to function properly. I remember reading one of athomas's posts in the beginning of last year that he doesn't even run the shims in his powertube normally. He said it was more about having the spring correct than having the shims at all. He seems to have some of the best advice around, no offense to anyone else of course, and that is what I ran with. It has worked out well for me in the last year as I very rarely break paint with my lvl x, and I normally shoot the most brittle tournament grade paint I can get my hands on.

[athomas]

Shims only adjust how far the bolt needs to travel before it can vent air. They push the carrier and oring farther back on the bolt stem so that the hole in the bolt stem passes the carrier oring sooner. This allows the bolt to vent air sooner so that it can reset if it stops on something in the breach. Most of the time, the distance is already very short and if there is a breach blockage, the bolt will move far enough to vent air anyway. Most setups can't use anymore than 2 or 3 shims without leaking. That means that if the bolt moves at least 20 to 30 mils, the bolt can release air and reset. Thats a pretty small movement. You would have to have a solid breach blockage right against the face of the bolt to stop that amount of movement.

In the event that the gun fires, or if it "chuffs" or vents air in any way. then shims will not make any difference in it resetting.

If you are experiencing bolt stick issues, then it is most likely a carrier size issue or a leaking on-off top oring. The small urethane oring behind the regulator seat oring can cause minor issues as well, but it rarely does.

If the plunger is out of spec, the plunger may not be pulling the sear far enough or with enough force. If this is the case, the sear could be rubbing on the bottom of the bolt which could inhibit its ability to cycle. This would explain why it resets when you fire it again in e-mode.

[fishmishin]

Ah, and the master has arrived /\/\

[ArmyEngineer]

Ah, and the master has arrived /\/\

Lol. Indeed he has! I think the new spring did it, but I am worried about wearing my sear down prematurely. Like athomas said, a poorly adjusted sear seems like it would explain being able to pull the trigger and reset the bolt. But I had to wait for some experienced input.

The plunger length seems like such a difficult thing to measure though, it makes me a little nervous. When I make the measurements, should I measure to the end of the clevis, or should I go on the inside of the clevis and take the top of the sear bar at 90 degrees? I'm tempted to take my entire marker to the metrology lab at work. Complete CAD of an e-mag anyone? lol

Athomas, I've thought about those shims a lot, probably too much, but the lvl10 magic made me curious. Right now I am thinking that the shims do not have any effect on the location of the vent hole with respect to the stem o-ring unless you really overdo it. LMK what you think. I am trying to learn exactly how and why everything works the way it does.

When the bolt is at rest, its stop position is solely determined by the thickness of the bumper. The only reason I say this is that if you remove the bumper, the bolt will slide a good bit further down the powertube before the inside of the bolt and the tip of the powertube meet or the back of the bolt hits the valve. If the shims were able to change the position of the vent hole, it seems like the bolt would have to stop on the end of the powertube tip with the bumper still in place. Unless you have too many shims, I don't think this is the case. I believe that the shims control the timing of the large dump by moving the tip forward or effectively lengthening the powertube. Here is critical the position I am talking about:


If that is the case, adding shims might give you a tiny boost in efficiency if the dump was occurring before the end of the bolt made it past the breach. Otherwise, they would seem almost completely useless.

???

[athomas]

When at rest, the bolt is forced forward against the sear. That is its resting position with air applied and the sear engaged. The bumper only acts as a shock absorber.

The carrier assembly is free floating in the powertube although it is limited in how far it can move. Without any shims installed it is pushed forward by the air pressure in the chamber and rests against the powertube tip. As you add shims, you move it farther back in the powertube. Since the bolt stem is at a fixed distance with respect to the powertube, moving the carrier assembly farther back in the powertube also moves it farther back on the bolt stem and closer to the vent hole, thus shortening the distance between the carrier oring and the vent hole.

For adjusting the plunger, I believe the measurements are from the plunger tip to the center of the clevis hole. This is typically how parts are measured. When I adjusted my plunger, I pushed the plunger to the bottom of my solenoid and then adjusted the plunger rod length so that the sear was clearing the bottom of the bolt.

[ArmyEngineer]

athomas I learn something new every day. I had no idea the carrier was free to move around in there. It all makes sense now.

I took a closer look at adjusting my first plunger, and it was not loctited into place. I could easily turn it with my hands. I'm still a little fuzzy on where the length is supposed to be taken. Lornecash's xmod guide makes lit look like he went from the top of the clevis. Taking it from the center of the clevis pin would make way more sense. Mine was off target anyhow. If no one else has any input (Tuna) I'll probably go from the center of the pin to the tip of the plunger and try her out.

Thanks again guys!

[athomas]

The solenoid exerts most of its power when the plunger is closer to the bottom. So, the solenoid needs to be adjusted so that when bottomed out it clears the bolt. If its too short, it doesn't have enough power to properly activate the sear. If its too long, the sear rubs the bolt. The indicated length provides the distance to work. Once you have the plunger adjusted, just check the sear clearance inside the body. It will give you a pretty good indication whether it is correct. The plunger rod should be loctited in place. It will vibrate loose and the plunger will move during use.