Rapidfire, ULT w NO shims

[cadams]

Hi All,

I broke the on/off pin in my stock XValve on/off assembly. So I bought a ULT upgrade and now I can't pull the trigger without rapid fire of shots. I have 0 shims in the ULT and it still rapid fires.

My setup: XValve, ULT, Lvl 10 installed on a classic rail and body. I have 3 trigger frames; I've tried all of them and I have the same result. The 3 trigger frames I have used are classic, proline, and hyperframe (20 bps board).

The hyperframe seems to run away least. but it still does. Any suggestions?

[211]

Whats your input pressure?

[cadams]

800, non-adjustable

[Hilltop Customs]

what do you mean by runaway? If you pull the trigger hard and keep it held in is it firing more than 1 shot? If thats the case its probably the top o-ring in the ULT.

[athomas]

It sounds like a bad top oring.

[cadams]

By runaway I mean it fires a rapid succession of shots for as long as I hold the trigger down. The shots are so fast, that I can't shoot 1 shot if had to. With the quickest trigger pull, I get at least 2 shots.

Its not the top ULT o Ring (the tiny one at the top that the pin slides through, yes?). 1st, the ULT is brand new out of the box. 2nd, I already replaced it with the spare that came in the kit. No effect.

The only thing that has changed between the working setup, andthis now non-working setup, is the ULT upgrade.

[Hilltop Customs]

yep, that is caused by the top oring in the on/off assembly not sealing. By the top o-ring we dont mean the black tiny one that goes around the thin part of the pin, but the larger white one that seals with the "head" of the pin. With the 2 body parts of the ULT assembled the o-ring is still visible on the part of the on/off that goes into the valve first.

If that oring is not there/damaged it allows air to constnatly flow through the on/off, which will cause the bolt to bounce back and forth between the spring pressure and the air pressure since nothing is stopping the air flow into the powertube.

[SchoolU101]

I think that's the one he already replaced.

How much friction is the o-ring putting on the pin? Does it seem sticky? Either way, add oil.

[Hilltop Customs]

idk he said pin slides through. The pin doesnt really slide through the top o-ring in just kindof bump seals against it when the trigger is pulled.

If the tiny black o-ring is bad you will hear a leak coming from the bottom of the valve/triggerframe. If the top o ring is missing/bad you will get rapid fire/bolt not fully resetting.

[michbich]

What's the length of the pin?

[cadams]

correct, I already replaced that one. The white one where the ULT meets the Xvalave, NOT the black one sandwiched inside the ULT. The one that was installed in the ULT brand new comparred to the spare one that I used to replace it; same issues, no difference between the 2 O rings. I guess its possible that both O rings are bad, but neither has ever been used, unlikely, but anything is possible I guess.

I am not supposed be using that double O ring setup from the old on/off too am I? I tried out of desperation (my thinking is along the same lines of all of you, leak where the on/off meets the Xvalve) but the ULT sticks out way too far and won't fit into the body.

My suspicion now is that the problem lies with the fact that I'm using the old 68 classic body and rail and maybe the thickness of the rail and body is too much. Where maybe theres too much distance between the sear and the ULT pin.

To clarrify my setup; I've owned an Automag for years. Started with a 68 Classic with Expansion chamber. I upgraded to the XValve and switch from CO2 to Air and used that setup, XValve on 68 classic, for years. Then I added a proline trigger and got this same problem, actually, so I went back to the stock 68 trigger. Then I got a hyperframe, and it worked fine. Then one day, during play, my trigger frame screw came loose, the body, rail, valve, all separated and resulted in my stock on/off pin getting decapitated. I didn't see the stock XValve on/off in the online catalog so I got the ULT to replace it. Its brand new, and I cannot get it to work no matter which trigger frame I use now. Maybe this adds some insight into the problem?

[cadams]

I don't have the pin in front of me, but its the standard ULT pin that comes with the kit. I have not shaved or modified it in any way.

I have considered shaving it though. The rapid fire problem increases as I add shims so length of the pin may be key. But how would I shave anything off that thing? its so fragile.

[Hilltop Customs]

Your right the double orings used with the original on/off are not used with the ult.

adding shims has a similar effect to shortening the pin, so shortening the pin wont help. Since that oring is in the top, it sounds almost as if your pin is too short. Like michbich said is there any way you could measure it?

Also check the exterior o-ring on the top of the ULT(the one that contacts the valve), if it has any slices, it could be causing the problem too.

[cadams]

0.74 inches.

Some pictures, if it helps

http://i23.photobucket.com/albums/b375/cadams7407/paintball/XValve.jpg

http://i23.photobucket.com/albums/b375/cadams7407/paintball/ULT3.jpg

http://i23.photobucket.com/albums/b375/cadams7407/paintball/ULT2.jpg

http://i23.photobucket.com/albums/b375/cadams7407/paintball/ULT1.jpg

[SchoolU101]

It's supposed to be 0.75". I would think that 0.74" would be close enough though...

[SchoolU101]

idk he said pin slides through. The pin doesnt really slide through the top o-ring in just kindof bump seals against it when the trigger is pulled.


Mine slides through it. Is it supposed to just push the o-ring up?

[Hilltop Customs]

no its supposed to be able to slide through it, just when you pull the trigger it moves up just far enough to seal....not really going through very far. I guess I said that wrong, sorry.

[cadams]

I can push my pin through the top oring too. I gather that when aired up, it doesn't go up through the o ring, but it doesn't take much force to slide that pin through the top O ring.

0.740, measured with calipers. 0.75, our difference is less than the size of a ULT shim

[Hilltop Customs]

the only other thing i can think of is body/valve not properly seating onto the rail. Unless the on/off side of the sear was shaved down at some point. Bolt wear on the sear wouldnt cause it, because if the trigger was fully depressed it should still seal on that oring.

im out of ideas :confused:

[Spider-TW]

Have you checked your rail where the valve and reg sit? If there is a burr on it from your previous 'event', it could add 'thickness' to your rail/valve fit. Also, try tightening the rear frame screw a little more than hand tight, if you have the new style screw. This brings up another point; the old style rear frame screws were a little too long for the xvalve sometimes, make sure the valve is tightening up on the rail, not just the screw. Or add a washer under the head of the rear frame screw if it is too long.

[cadams]

Have you checked your rail where the valve and reg sit? If there is a burr on it from your previous 'event', it could add 'thickness' to your rail/valve fit. Also, try tightening the rear frame screw a little more than hand tight, if you have the new style screw. This brings up another point; the old style rear frame screws were a little too long for the xvalve sometimes, make sure the valve is tightening up on the rail, not just the screw. Or add a washer under the head of the rear frame screw if it is too long.

I have the original rear screw that came with the 68 Classic, and I do recall that while the valve is secure, it can wiggle a tiny bit. I'll add a washer and tighen the fit a little bit.

Additionally, if I were able to somehow increase the height of the sear, where it contacts the ULT pin, do you think that would help? I have the original sear that came with the hyperframe and it has a different shape. It sits way too high in the frame now, but maybe some modification of that sear will allow me to close the gap between the ULT and sear, that is if any of you think it will help?

[cadams]

well, I added a washer and it helped. It only double fires now, using the hyperframe. I'll swap out for the proline after work (I really want to get the proline working, but I'll make my peace with any of the frames that end up working). But maybe by adjusting the hyperframe settings I can eliminate the double fires.

[Spider-TW]

Check that the rail is smooth under the valve too.

If the back of the sear is damaged, the bolt catch may be worn also. Hyperframes have been noted to increase bolt/sear wear. Check that the sear tip is sharp and flat (not curved at the tip).

[cadams]

I only used the hyperframe for a day. Well, actually half a day. I had just installed it when the stupid 'event' happened. The sear has a nice sharp ball catch and the sear doesn't appear damaged, no bends or anything.

I have my original sear still. Its a little worn but it was still working when I replaced it; I'm gonna have one of the guys in the shop at work see if they can add a little thickness to the on/off contact point on the spare sear.

[angrysasquatch]

Maybe try adding like 3 washers under the back screw, it might still be doing the same thing.

[Hilltop Customs]

Maybe try adding like 3 washers under the back screw, it might still be doing the same thing.

Yea get that valve tightened down on there. You could also buy a shorter 10-32 cap head screw or grind down the field strip screw instead of having a bunch of washers on there.

[cadams]

1 washer seemed to get the valve very tight. I tried 2 and 3 washers as well, but didn't improve over and beyond 1 washer.

Without washers, the wiggle is very subtle, and had not caused any trouble with the stock on/off. Understandably, the ON/off pin has changed so thats why I've had this problem. But the valve is as tight as its going to get.

Is it safe to assume that the 68 classic body and rail are thicker than some of the more recent makes? ULE, E, etc.?

[athomas]

Is it safe to assume that the 68 classic body and rail are thicker than some of the more recent makes? ULE, E, etc.?No, but the PIM (where the grip frame screws into the body) can be a bit different. Your body may not be sitting down tight on the rail due to the PIM bottoming out. If it is bottoming out, file it down a bit.

[Hilltop Customs]

check for deformation of the body where the on/off passes through, both on the inside and the outside.

[cadams]

Hey All,

1st just want to thank everyone for their input so far. Its been a great help.

The body and rail are smooth and generally ok. The frame screw is holding the body snug and tight, and with 2 washers under the feild strip screw, the valve is locked in tight.

I have finally had time to really explore the problem. I'm getting rapid firing, I think, because the sear is not catching the bolt properly. After I pull the trigger, the sear does not return quite all the way.

I ran my tank down to just below 800 psi so I've stopped for the night. Instead of rapid firing I'm getting mostly bolt stick now. Will get a refill in the AM and try some more. But my best guess is that the on/off pin is too short and is not pushing the sear down far enough after the shot.

I had tried dropping a few shims into the on/off hole on the valve, then installing the ULT on top of them. My thinking is that this will drop the whole on/off assembly and, while it doesn't lengthen the pin, wouldn't this help close the gap between the sear and the pin? Well, I added 3 shims by this method and noticed no difference. I can't add too many more of the whole ULT will protrude from the valve. But am I on the right track, or just tired?

I'm low on air so I'll refill and try again. But its starting to look like I'm sol because the pin is too short.

Anyone got a nice long pin for the stock Xvalve on/off or a RT on/off with a longer pin that they wanna sell?

[Spider-TW]

I have the original rear screw that came with the 68 Classic, and I do recall that while the valve is secure, it can wiggle a tiny bit. I'll add a washer and tighen the fit a little bit.

Additionally, if I were able to somehow increase the height of the sear, where it contacts the ULT pin, do you think that would help? I have the original sear that came with the hyperframe and it has a different shape. It sits way too high in the frame now, but maybe some modification of that sear will allow me to close the gap between the ULT and sear, that is if any of you think it will help?
What happened to the sear that came with the x-valve?

You could try epoxying a small piece of brass on to the tip of the sear where it hits the on/off pin. I don't know long it would last though. :confused:

Or try a couple pieces of brass shim under each side of the sear pin in the rail.

I have a classic body that I had hell getting a Doc's barrel adapter installed in. It was about .998 bore and the adapter was .999. Getting all that stainless to fit was tough. Doc said that was the smallest bore he had heard of (4xxx serial number). Your body may just be thick.

[cadams]

I'm presently using the Xvalve sear.

One of the guys in the shop at work offered to weld more material on the sear and then grind it down. He thinks it should be pretty durable, its just alot of trial and error grinding it back down to the proper height.

I think when I do that, given that I'll have an excessivly long sear on/off contact point, that I'll put half a dozen shims in the ULT before I start grinding down the sear to fit.

[Hilltop Customs]

Hey All,

1st just want to thank everyone for their input so far. Its been a great help.

The body and rail are smooth and generally ok. The frame screw is holding the body snug and tight, and with 2 washers under the feild strip screw, the valve is locked in tight.

I have finally had time to really explore the problem. I'm getting rapid firing, I think, because the sear is not catching the bolt properly. After I pull the trigger, the sear does not return quite all the way.

I ran my tank down to just below 800 psi so I've stopped for the night. Instead of rapid firing I'm getting mostly bolt stick now. Will get a refill in the AM and try some more. But my best guess is that the on/off pin is too short and is not pushing the sear down far enough after the shot.

I had tried dropping a few shims into the on/off hole on the valve, then installing the ULT on top of them. My thinking is that this will drop the whole on/off assembly and, while it doesn't lengthen the pin, wouldn't this help close the gap between the sear and the pin? Well, I added 3 shims by this method and noticed no difference. I can't add too many more of the whole ULT will protrude from the valve. But am I on the right track, or just tired?

I'm low on air so I'll refill and try again. But its starting to look like I'm sol because the pin is too short.

Anyone got a nice long pin for the stock Xvalve on/off or a RT on/off with a longer pin that they wanna sell?

Are you still having the problem of holding the trigger in and the marker going full auto?

When you gas up the on/off gets pushed out against the inside of the body, so adding spacers above the on/off will have no effect. Putting spacers in between the ULT halves spaces the top up higher, which adjusts the timing between the bolt being caught and the on/off allowing the dump chamber to pressurize.

[Spider-TW]

I thought this was already covered, but...

Do you still have a little gap (not a big one) between the back of the trigger and the trigger rod?