Classic RT issues continue!

[Kajo]

All,

Just got back from another day of paintball yesterday. The second day using my new (used) classic RT. Unfortunately, I couldn't get the thing to shoot a single ball at a time because of the OVER reacting trigger and had to use a rental. I mean I was literally pulling and shooting off a string of 3 or 4. Of course with no level 10 it turned into a blender real fast.

If you remember my thread from last time I had a leak coming from the banjo bolt. So between then and my day yesterday I disassembled the marker, cleaned, replaced the banjo o-rings and reassembled.

What is making this thing RT like crazy?

Thanks!

[pbjunky99]

how much of a gap do you have between your trigger and sear rod? There should be a space between them.

[1stTarget]

Input pressure. My RT loves a certain pressure on supply side, with the regulator adjusted just right. 1100 psi input, 260 fps. Rt of one on pull, one on release. Tuning is fast if have adjustable reg. Once sweet spot is found, it is great. Turn down just a little it is only semi, tune too high it is a auto.

[Kajo]

In reference to gap I'm assuming I should check this with the gun aired up?

Also - both times i used preset tanks. They were different brands. I don't have my own air tank so I just rent one at the field.

[Ando]

In reference to gap I'm assuming I should check this with the gun aired up?
yes


Also - both times i used preset tanks. They were different brands. I don't have my own air tank so I just rent one at the field.
That might be it in a nut shell. No 2 regs are the same. Especially different brands.

Ck the 2 top on/off orings. Well, depending on your valve, you might just have one in there but just make sure it/they aren't messed up or missing all together. Just replace it/them to completely rule the on/off out. One last thing would be measuring the on/off pin. A stock mech pin should be in the neighborhood of .750" and a stock Emag pin should be in the neighborhood of .712". I set my mech pins in around the .730" mark, makes for a nice RT effect when I need it.

[Kajo]

Shouldn't the internal reg in the gun take the pressure down to something usable?

I'll grab a vernier from work tomorrow and measure my on/off pin. I'd rather keep it longer if it means I won't be RT'ing all the time. I play rec and I don't really need all that firepower, especially if I can't control it or if it is inconsistant.

[wimag]

we spoke on saturday.

Check your bolt spring. Check the bolt lip and sear where it catches the bolt so see if it is rounded off. I run a .750 on/off pin in all my RT's

I have had this happen numerous times and it came down to on of ones listed. Do the bolt spring.
Who knows...once you get a level ten in there it may fix it.

[kcombs9]

Shouldn't the internal reg in the gun take the pressure down to something usable?


Yes but that is not what is in question, you can use a tank that is set from 800 psi up to 1100 psi. and still shoot at 280 fps. but the gun reacts different to the pressures.

the higher the pressure the MORE RT effect you get.

but seeing as you use field preset tanks I would be suppressed if they are set any higher then 800-850psi. as most guns don't run on anything higher then that.

check your sear and bolt make sure they are in good shape, take some pic for us to see, if either or both are worn down you could just have a case of the sear and bolt going into full auto cause they don't connect properly and stop the cycle

[athomas]

Yes, it definately could be a worn sear tip. That would make for an overly reactive valve.

[Kajo]

Ok guys,

Thanks for the help (AGAIN!). I will check the sear and bolt spring. It's just weird that I could get single shots out of the gun three weeks ago but when I went to gas it up this time I couldn't get anything other than 4 to 6. Maybe the sear was not quite worn out and I finally sent it over the edge.

I will report back.

[athomas]

Did you change all the orings in the valve as you mentioned you were going to do? Any oring leak that allows air to flow into the valve can contribute to reactivity.

[Kajo]

All,

Just got done disassembling the entire marker. It is now in pieces on my work desk. I will reassemble tomorrow.

For the most part the o-rings looked like they were new and in pretty good shape. The one issue I did see was that the middle banjo o-ring was nearly cut through. I JUST replaced them Friday night before Saturday's paintball day so I'm going to assume that I cut the thing putting the Banjo bolt in or taking it out. My banjo bolt goes in and out relatively easily if I lube it and DO NOT gas the gun up. However, after gassing the gun up and degassing it's a real pain to get the banjo bolt out. I always need a pliers.

I checked the bolt spring against the one in my spare parts kit. Unless the one in the kit is used (a possibility) it feels ok. Both springs compressed similarly under my "calibrated" fingers. Not sure how else to tell if the spring is failing.

I took a vernier to my on/off pin and got .7415" so I do not think the length of the pin is an issue. If anything I should be RT'ing less.

Pictures of the sear are at the google picasa link, sorry if they are a little hard to make out. It's damn tricky to take a photo of the wear. Having no other sear to establish a baseline I really cannot say much about it. The edge where the bolt catches seems to be reasonably good. The on/off portion is rounded.

https://picasaweb.google.com/106337693851443932562/AutomagRTSear?authkey=Gv1sRgCJKAnbXT5JmwZA&feat=directlink

[athomas]

The sear doesn't look bad, although it is hard to tell with the pictures a bit out of focus.

A worn bolt spring will make the marker have bolt stick, but it won't make it go full auto.

The on-off pin length is fine. It shouldn't have uncontrollable reactivity with that length.

Full auto causes:

1) worn sear tip, which allows the bolt to slip off the holding surface when air fills the chamber.
2) short on-off pin, which allows air to charge the front chamber before the sear catches the bolt.
3) bad oring(s) in the regulator section of the valve, which allows air to flow into the front chamber even though the on-off is closed.

[Kajo]

Guys,

I am still at a loss for what to do about the extreme reactivity.

Per athomas my sear and on/off pin are ok.

The o-rings look pretty fresh. I guess I can just order a parts kit, replace them all and hope for the best. I'm a little leery about throwing a lvl 10 in without getting the gun functional in lvl 7. I know I am going to have issues to address with the lvl 10 and I don't want to bring any other variables into the equation.

Anyone in Milwaukee have access to parts/air and want to help me out (that's good with mags)? :) I have no problem spending money on parts for the thing but I'd like to know what parts I have to swap before I start buying everything available on the AGD site.

[rawbutter]

You, sir, seem to have yourself a puzzler. At least you're smart enough to hold off on the Level 10. Order yourself a parts kit instead (even if it doesn't fix the problem, it's good to have one on hand for the future), replace all the o-rings, and see what happens.

Also worth replacing is the bumper (the big, blue flat washer-like thing that sits between the valve and the bolt... it looks like this).
http://store.airgundesignsusa.com/images/product/19.jpg

The bumper acts as a cushion to keep the bolt from bouncing back when retracting. If yours is worn, it won't absorb that impact as well, so the bolt may be bouncing a few times before settling. This is unlikely (bumpers are supposed to last forever), but still... they do die occasionally. Best to be thorough.

The good news is that a bumper should come in your RT parts kit, so at least you don't have to buy it separately.

If all that doesn't fix it... I don't know. Your sear DOES look fine to me. Your on/off pin is within specs... If replacing all the o-rings and bumper doesn't do the trick, you may need to send it off somewhere.

Good luck. :cheers:

[Kajo]

Well guys,

I just went ahead and ordered a new RT parts kit as well as a level 10. I'll get the gun working (hopefully) with the parts kit and then move on to installing the level 10.

[Kajo]

The rebuild kit and LVL 10 FINALLY came in. I tore the whole mag down and started trying to match up o-rings but I'm having a tough time deciding what size goes where. Some seem really close to the same size and given the stretched condition of the old o-rings it is difficult.

Is there a complete list of all the o-rings in the classic automag RT? Location in the gun, quantity, and sizes?

Also - the level 10 kit has 4 carriers but two of them seem to be duplicates. Two have two grooves and the others have none (or 1, I forgot).

Last question - I took apart the regulator valve pin assembly. There is a brass bushing between the spring pack and the o-ring stack. The bushing has a side with a "fit" or lip and the other side appears to be ground flat. I put the "fit" side towards the o-ring stack or facing the barrel side of the gun when assembled. Is this correct?

[Shirow]

Guys,

I am still at a loss for what to do about the extreme reactivity.

Per athomas my sear and on/off pin are ok.

The o-rings look pretty fresh. I guess I can just order a parts kit, replace them all and hope for the best. I'm a little leery about throwing a lvl 10 in without getting the gun functional in lvl 7. I know I am going to have issues to address with the lvl 10 and I don't want to bring any other variables into the equation.

Anyone in Milwaukee have access to parts/air and want to help me out (that's good with mags)? :) I have no problem spending money on parts for the thing but I'd like to know what parts I have to swap before I start buying everything available on the AGD site.

Kajo,

I'm not an expert but I'd be willing to help you out. I'll be at Breakaway next weekend and I have a couple of tanks so I can fill them both up for some after-game experimentation.

I think we can probably sit down and figure it out, just PM me if you want to work on it sometime - I'm in West Allis.

[athomas]

Also - the level 10 kit has 4 carriers but two of them seem to be duplicates. Two have two grooves and the others have none (or 1, I forgot).The carriers have grooves and dots or just grooves or nothing at all. A carrier with no dots or grooves, represents size 0. Each dot represents 0.5. Each groove represents a 1. Thus, a carrier with a single groove and dots would be a size 1.5.

[rawbutter]

The level ten carriers are a pain. Like athomas said, it's all about the lines and dots. Only problem is that the dots can be hard to see if you're not looking for them.

As for a diagram of the o-rings, I think this is the best thing out there.
http://www.airgundesignsusa.com/downloads/retroexploded1.pdf
This is for a RT pro valve, but I think the only difference is that the classic RT valve has the banjo bolt. Otherwise, everything should be the same.

[Pneumagger]

is it like... rediculous 30bps full auto?

I once had some bad reg-pin seals and the marker was rediculously fast... over 30bps. Basically, what happens is that the air flows through the on/off so while the sear hook is released the bolt bounces back and forth like a furious paint blender.

I would check:
1) Reg seat orings and holder
2) Reg Valve pin assembly and two orings
3) On/Off top oring

[Kajo]

Ok,

Ordered a ninja 68/4500 tank instead of using a POS rental of questionable quality. I also think I have everything in the correct spot rebuild wise. I'm still a little confused about the different sizes and compositions of o-rings but everything appears to fit "snug" which is what the ring is for anyway.

I'm going to take it to the range and try and dial it in Saturday morning before my scenario game Sunday. If this thing doesn't work I'll have to use my friend's electric spyder... the horror!

Rawbutter - Can't thank you enough for that diagram, it's exactly what I wanted. I was combing through threads all over trying to find something like it.

Pneumagger - No symptoms like you describe. The trigger is just so sensitive that it's tough to fire one ball at a time but it doesn't go full auto when you hold it down.


is it like... rediculous 30bps full auto?

I once had some bad reg-pin seals and the marker was rediculously fast... over 30bps. Basically, what happens is that the air flows through the on/off so while the sear hook is released the bolt bounces back and forth like a furious paint blender.

I would check:
1) Reg seat orings and holder
2) Reg Valve pin assembly and two orings
3) On/Off top oring

[Kajo]

SUCCESS!! Finally!

After tearing apart every little piece in the gun, cleaning, and replacing with items from the rebuild kit I finally had some success. Against my own better judgement I went ahead and stuck the level 10 in without trouble shooting the issue I was having before.

I put my brand new ninja tank on with 3000 psi (first fill) and nothing happened when I screwed the on/off down. My first reaction was aww man here we go again. I set the gun down and walked away to take a look at the level 10 instructions. Well, 30 seconds later I heard the gas start to vent from the marker. I took a look and it was pouring out of the 8k burst disc. GREAT! I figured my brand new tank was hosed. The guy at the field said I could be building pressure between the gun and the tank and maybe that was why it ruptured. I replaced the burst disc and filled the tank again. This time I screwed the velocity adjuster in quite a bit... VOILA, success! The trigger pin kicked forward and I could fire the gun.

Per the level 10 install instructions I fit the carrier that seemed to provide a "snug" fit along with 2 shims. I had no leaks from anywhere. I cycled the marker 200 or 300 times without paint anticipating that the carrier would start to leak as the o-ring broke in. Nothing. I then put paint in and fired another 300 rounds. No leaks and no chops. This thing was a blender before and I had NO chops with the old paint I was running through it. I decided not to screw around trying to fine tune the level 10. Realistically, I'm not sure what else I could do. If it starts to leak when I play all day Sunday I guess I will drop down a carrier size.

The gun reacted before almost out of control but now it doesn't seem like it's reacting at all. This doesn't bother me. I opted for the 750 - 850 psi ninja tank instead of the 1200 psi just in case I need to switch it to a different marker. I can live without the reactivity.

Thanks for all the help everyone. I'm glad I got this antique working again and I've got my fingers crossed that it doesn't let me down on Sunday. See you on the field.


Ok,

Ordered a ninja 68/4500 tank instead of using a POS rental of questionable quality. I also think I have everything in the correct spot rebuild wise. I'm still a little confused about the different sizes and compositions of o-rings but everything appears to fit "snug" which is what the ring is for anyway.

I'm going to take it to the range and try and dial it in Saturday morning before my scenario game Sunday. If this thing doesn't work I'll have to use my friend's electric spyder... the horror!

Rawbutter - Can't thank you enough for that diagram, it's exactly what I wanted. I was combing through threads all over trying to find something like it.

Pneumagger - No symptoms like you describe. The trigger is just so sensitive that it's tough to fire one ball at a time but it doesn't go full auto when you hold it down.

[rawbutter]

:clap:

Glad to hear it.

Don't be scared to start messing around once you get some playing time in. Now that you have a configuration that you know works, try making little changes (one at a time) to your Level 10 setup and anything else you've been wanting to play with. That way, if you make a change and something starts leaking, you can always go back to the known configuration that works.

[Kajo]

Well,

Seems as if I spoke too soon! :cuss:

Of course when I went to the field things didn't work quite as well as the day before when I was at the range. I have a small leak from somewhere in the rail (best guess). I loosened and tightened the banjo bolt while gassed up and the leak would stop for a second or change pitch but would never completely go away. Velocity was reasonably consistant so I just put up with the leak all day. It got pretty annoying though when you would run into someone new and they would tell you your gun is leaking, lol.

I met 211 at the field and he said to throw an o-ring on it between the banjo bolt field strip head and the grip frame. I'll give this a whirl and see if it does anything. Seriously though AGD, worst design ever with the bano bolt. If I had access to a mill I would consider milling a new field strip hole and running a permanent hardline somehow up through the banjo bolt hole. Anything has to be better than a bolt with 3 o-rings that needs a pretty precise alignment in the vertical direction to actually seal.

[Kajo]

Well I once again think I've cured the marker of leaks. It's sitting on the desk leak free. I'll see if it remains that way through a day of play next weekend.

I tried to take some recommended advice and put an o-ring at the base of the banjo bolt near the field strip end. This actually made the leak worse and tightening/loosening did nothing to help. In a last ditch effort I actually sandwiched another o-ring in the middle banjo bolt position. I was continuously cutting o-rings from what I believe was a blowout issue on o-ring 2 (middle one). Whenever I gassed the gun up and degassed I would pull out the banjo to either a severely pinched middle o-ring or one that was completely cut in half.

It makes it a little more difficult to assemble the marker but if it works and I don't have to buy a new rail I'll be happy. This is what I did to get the additional o-ring on:

1. Assemble the grip frame onto the body rail and set aside
2. Stick the valve/bolt/regulator assembly into the body and set aside
3. Put three rings on the banjo bolt and slip it into the body rail/grip frame assembly from step 1
4. Stick a fourth "middle" o-ring on over the portion of the banjo that is exposed through the body rail. You will have to slip the o-ring over the top most one on the banjo and snug it up flush with the machined hole
5. Push the valve assembly down into the body tube so the hole the banjo goes into is aligned properly
6. Put the two halves together, start squeezing them at the same time you are turning the banjo so you effectively pull the valve towards the body rail assembly. This seems difficult but I almost found it easier than slipping the banjo in with the valve already on the marker.
7. Snug the banjo side
8. Snug the front bolt side

No idea if this will work for anyone else but it makes some sense. If there is any slop between the body/rail you will end up with room for the middle banjo bolt to "blow out" into the void between frame and rail. With a fourth o-ring acting in compression you can hopefully hold the whole thing together. If it makes a difference I have what I believe to be an updated rail. Looking down from the top view the rail banjo hole is counterbored but does not have a taper. For what it's worth there is also some scoring in the bore but I attribute that to disassembly.

I degassed and re-gassed a bunch of times and it's been sitting for about 1.5 hours with no leaks. I've got my fingers crossed!