23 replies to this topic

[Glint]

Alright, so I recently picked up a Blastfire at a local thrift store (lucky, lucky me) and PETG barreled it. I'm just having a bit of trouble putting it back together properly.




I'm having the trouble with this lil' thing right here:





I don't know where/how to place it on the rod. Here's a sketch:


Blue = little ridge inside. It's not hollow.


I've tried a couple things and none seem to really work well. Here's the closest thing and what I think it should be like:


Red = torsion spring


But the problem with that it that the spring doesn't have anything to push/rest against, so it just goes up and down with the little tooth orange thing unless I hold it up against the top of the shell (which ) can't do when it's closed).

So could someone please show/tell me how this is supposed to be?


UPDATE:

After taking a glance down the plunger tube I found this:




I don't know if you can see that, but there's a little rubber nipple-type thing at the end of the plunger tube that seems to have ripped off a little at the end. I don't know if that's a problem or not. It seems like it pushes down the OPRV when you fully push the pump down (which I haven't plugged). It still feels like it's working somewhat, but when I pump the gun with the white tooth-like piece extended (with the insides only, not put together) it doesn't actually pumped. This had happened a bit before I had opened it up and it was stock, but I had it working fine and shooting before I opened it up. now it's just as if the white piece isn't extended out and it's just letting the air pump through everything (for those of you who knows how a Blastfire works)

Is this a problem, or should I just leave it? Also, why wouldn't the pump be properly working even when the white piece is extended?

Edited by Glint, 04 May 2009 - 06:25 PM.

[CaptainSlug]

You need to flip the torsion spring 180 degrees so it pushes on the slide. The tooth needs to be forced to rotate clockwise, not counter-clockwise.

Edited by CaptainSlug, 04 May 2009 - 06:47 PM.

[Glint]

Ah. So like this?:

[CaptainSlug]

Like this, torsioned to force the tooth into the white rod.

Edited by CaptainSlug, 04 May 2009 - 07:16 PM.

[Glint]

Ah, alright; thanks Slug. Never woulda guessed that.

Anyone have any ideas on my pump problem?

[CaptainSlug]

Anyone have any ideas on my pump problem?

The check valve is likely dried out and not functioning. You can simply add a replacement one inline with the tubing. Either make your own, or use on of the $4 barbed ones from Mcmaster.

[Glint]

Okay. Here’s what happens when I put it back together. I pull the top white toothed thing back and then pump. When I pump it's as if air is just passing through and going somewhere. On the other hand when I don't pull the white toothed thing back I can pump, but the white thing kinda pops backwards a bit and then air goes straight to the bottom barrel (first one to shoot) when I pump.

When I just have the insides in my hands and I pump with the white toothed part in, it sounds like the OPRV kicks in after only one pump or so. When I hit the button to "Blast" it shoots out a bit, but not it's full air capacity. Sometimes the white toothed aprt just shoots out of the end alltogether. When the white thing is out it sounds like air just passes through again (like when it was together).

Just thought that might add a new perspective.

So you're saying I should cut off this white thing from the pump:



And install a new check valve in it's place?

Edited by Glint, 04 May 2009 - 08:21 PM.

[CaptainSlug]

So you're saying I should cut off this white thing from the pump:
And install a new check valve in it's place?

What? No I didn't tell you to cut anything. You can just put one of these

or any other check valve inline with the tubing from the pump.

If you have an unreliable check valve you can always just add a second one.

[Glint]

Oh, okat. I was thinking replace the check valve, but adding another one behind it/further up makes more sense.

Where at the McMaster site is the one picture you specified? There's like a kbjillion "Check Valves" at McMaster and I don't know which one I need/want.

[CaptainSlug]

Part# 7757K13

[pongityping]

I'm not sure if I'm seeing this correctly, but it looks like the nipple thing is stuck in one of the check valve holes. If it is, I had that problem with one of my at2k pumps. Just pry it out with a dowel, or pen, or something so it no longer is stuck in the check valve hole. Remember to spray some silicone in it too. Or, just buy a new one like Slug suggested.

[Glint]

Slug: Alright. Thanks so much for all your help.

pongityping: The nipple isn't stuck in one of the holes, although I can see how you saw that from that picture. Part of the top is ripped off and just laying there (stuck, won't fall out), and the remaning nipple part is just really crooked and kinda messed up and angled.

[Zorns Lemma]

Cut the tubing a few inches after the pump and blow into it. If you can, that means air is going the wrong way through the pump and it's a check valve issue.

If you can't, the problem is somewhere else.

You can put the tubing back together via barbed fittings (compression fittings don't work as well on the soft tubing in most air guns) or shoving the open ends into a small piece of 1/4x3/8 tubing and gooping it all together.

Also, the white toothed thing is a ratcheting trigger. As it slides down the tube, it opens and then seals different air ports to the tanks. See Venom's attempt at a homemade backpressure trigger or the hornet trigger for a similar design. If you pull it out all the way, then air will just leak out the hole that the trigger is supposed to seal into.

Edit:

I've thought of a much easier diagnostic. Pull out the internals, hold the white part in with your thumb, pump once or twice, and then pull the pump out of the tube. If you hear air leaking out the pump tube, then it's a check valve issue.

Edited by Zorn's Lemma, 05 May 2009 - 06:42 PM.

[Glint]

Zorn.:

When I meant "all the way out" I meant like putting it in the shell and pulling back as far as it could go (like when you pull it back with the shell together) and then testing. Not actually pulling it as far back as I could.

But I did what you suggested. The problem is the ratcheting trigger never actually sits as far in as it can when it's in the gun. It sits a bit back and out of the air tank. But I did ask you said. When the ratcheting trigger is fully in and I pump, it's weird because it's like the OPRV kicks in after like only 2 pumps (sometimes the ratcheting trigger just pops out anyways). When I pull the pump out there's no leakage through where it's check valve is.
But as I said before, I don't think this is a solid test because the ratcheting trigger is never fully in when the gun is together.

So I tested with the ratcheting trigger as far in as it could go with the one shell half, holding it in place. The gun isn't really supposed to be pumped like that, because when the gun's together you're supposed to pull the ratcheting trigger back and then pump, so it was pressing hard against my finger. It's weird what happens though, and I can't really give a solid answer because it varies like every time.
Usually I pump it once, then the next pump it's as if the OPRV kicks in.
At this point the ratcheting trigger is pushing really hard against my finger and if I let it go the slightest bit air rushes out it's end.
I can keep pumping and kicking in the OPRV to my heart's content now, but once I let go of the ratcheting trigger all the air rushes out.

Here, maybe some videos might explain a little better:
(Then again, maybe not, because it's tough to do things right, especially in a video, but hopefully they'll explain well enough. I'll try and explain what I did in them)

Number one
In this one I pushed the ratcheting trigger in as far as possible with just the internals and pumped. It shot out after a few pumps.

Number Two
In this one I held the ratcheting trigger in and pumped with the just the internals. I could pump all day and nothing, as if no air's actually being forced. Then I held the ratcheting trigger out a bit (as if it was in the shell) and pumped (messed it up the first time and let it go a bit). The OPRV kicks in and the ratcheting trigger could let all the air out if I moved it just a little bit.
Sometimes when I do this it just leaks straight out where the ratcheting trigger is.

Number 3
In this one I'm pumping with it attached to the shell. The first thing I do is self explanatory. Then I hold the ratcheting trigger in and pump. The OPRV kicks in after like 2 pumps, and when I let it go it shoots out. Then I try and pull the pump out after pumping but accidentally let go of the ratcheting trigger. Then I bring the gun up to the camera so you can hear and let go of the ratcheting trigger. All the air rushes out.

If I didn't make anything clear or if you ahve any more questions about it's functioning, please feel free to pester me with them. I want to get this working. Or if you'd like me to try something again or explain it clearer I'll do my best the second time.

[Zorns Lemma]

When the trigger is all the way in, it's actually past where the outlet for air from the pump is, which is why 1) it's really easy to pump and 2) nothing happens. You're just pumping against atmospheric pressure; there's no tank that the air is directed towards.

When the trigger is just pulled out slightly, you're directing air to the first tank. I don't know about tank volume vs pump volume on the blastfire, but I'm guessing that 2-3 pumps is normal for filling up a single tank before OPRV kicks in.

The best news so far though? You don't need to replace your check valve.

As far as I can tell, there actually isn't anything wrong with your blastfire from the diagnostic tests you did. Reviewing your past observations I come to this:

When I pump it's as if air is just passing through and going somewhere. On the other hand when I don't pull the white toothed thing back I can pump, but the white thing kinda pops backwards a bit and then air goes straight to the bottom barrel (first one to shoot) when I pump.

This is perfectly normal behavior. Unless you meant nowhere instead of somewhere. In which case we have a problem.

I suggest pulling the trigger almost all the way out, and then holding it in place. Then pump. If air is leaking out the trigger, push it slightly farther in. You want the o-rings to be before the first hole that goes to the tubing to the tanks though. I suspect that all your tanks will fill. If the tanks do fill, start pushing the trigger in. Your tanks should start firing. Either way, take a video so I can see what happens.

[Glint]

When I pump it's as if air is just passing through and going somewhere. On the other hand when I don't pull the white toothed thing back I can pump, but the white thing kinda pops backwards a bit and then air goes straight to the bottom barrel (first one to shoot) when I pump.

This is perfectly normal behavior. Unless you meant nowhere instead of somewhere. In which case we have a problem.

I suggest pulling the trigger almost all the way out, and then holding it in place. Then pump. If air is leaking out the trigger, push it slightly farther in. You want the o-rings to be before the first hole that goes to the tubing to the tanks though. I suspect that all your tanks will fill. If the tanks do fill, start pushing the trigger in. Your tanks should start firing. Either way, take a video so I can see what happens.

What I meant by somewhere is not where it's supposed to go; not filling the tanks. It's going through the pump but it just passes through somewhere else up near the tank.

Testing Video
I took that video. It's kinda self explanatory. I start with the ratcheting trigger out and slowly inch it back in. Every time I can just keep pumping through and through.

At the end when I pump I can hear the air going through one of the barrels (pretty sure the bottom one). At the beginning of this one you can hear it passing through the barrel:
Video 2

If I tested doing something wrong then please tell me and I'll fix it and try again.

Edited by Glint, 06 May 2009 - 03:26 PM.

[DrSpaceman]

This may seem off-topic but what did you use to put those barrels on?

[Glint]

This may seem off-topic but what did you use to put those barrels on?

Epoxy.

Exactly this, except with PETG.

Edited by Glint, 06 May 2009 - 03:49 PM.

[Zorns Lemma]

I'm pretty sure one of your tanks is busted.

You have a leak somewhere, and it's not the trigger, given that your trigger shoots out. It's not the tubing, because I can see those are all stock connections. So it's most likely the tank.

Judging by the connections, in a stock Blastfire, it shoots bottom-up right (as opposed to the hornet, which shoots top-down)?

The only test I can think of is to pull the trigger mostly out, probably .5" from maximum draw. Hold it in there, and pump. Assuming you didn't get unlucky and have the sealing washers on the trigger right over a valve, the other 4 tanks should pressurize.

Or, you could cut the tubing to the last tank, throw some hot glue into the tubing as a temporary stopper, and pump. It should pressurize fine until the hot glue shoots out. If you don't have the connectors or larger ID tubing to rejoin tubing, I'd go with the first option.

[DrSpaceman]

I've throughly been reading the write-up and Cxwq states that you cannot damage the valves in the tanks or your gun will not work.

My hypothesis: You damaged the valve in the first tank and because of that air leaks out.

Edited by DrSpaceman, 06 May 2009 - 04:47 PM.

[Glint]

I'm pretty sure one of your tanks is busted.

You have a leak somewhere, and it's not the trigger, given that your trigger shoots out. It's not the tubing, because I can see those are all stock connections. So it's most likely the tank.

Judging by the connections, in a stock Blastfire, it shoots bottom-up right (as opposed to the hornet, which shoots top-down)?

The only test I can think of is to pull the trigger mostly out, probably .5" from maximum draw. Hold it in there, and pump. Assuming you didn't get unlucky and have the sealing washers on the trigger right over a valve, the other 4 tanks should pressurize.

Or, you could cut the tubing to the last tank, throw some hot glue into the tubing as a temporary stopper, and pump. It should pressurize fine until the hot glue shoots out. If you don't have the connectors or larger ID tubing to rejoin tubing, I'd go with the first option.

Oooh... alright.
Yes a Blastfire shoots bottom-up.

So what you're saying is that I basically have to cancel out the first tank, thus putting the gun down to only 4 shots?

[Zorns Lemma]

So what you're saying is that I basically have to cancel out the first tank, thus putting the gun down to only 4 shots?

Temporarily. See if only using 4 shots works. If it does, either keep it that way, or try to fix the 5th shot. If you can't fix the tank, you can always cut around it and replace it with a Salvo or Triple-Strike tank (or even a Hornet).

[Glint]

So what you're saying is that I basically have to cancel out the first tank, thus putting the gun down to only 4 shots?

Temporarily. See if only using 4 shots works. If it does, either keep it that way, or try to fix the 5th shot. If you can't fix the tank, you can always cut around it and replace it with a Salvo or Triple-Strike tank (or even a Hornet).

Okay. How would I go about trying to fix the tank?

But nontheless, thanks for all your help, both Zorn and Slug. Greatly appreciated.

[Zorns Lemma]

Most backpressure tanks suffer poor sealing on occasion. People have had mixed results with mineral oil and warm water down the barrel to soften/lubricate the poppet that seals the tank.

If you damaged the valve when taking out the ARs however, there's minimal chance of salvage, apart from cutting open the tank, replacing the poppet, and then sealing it back together with some chemical glues.