13 replies to this topic

[nerfnerd88]

EDIT: The mod pics weren't helping at all.


I have made the decision to make a bold move by letting everyone on Nerfhaven see how the tank extension mod for the airtech guns is not true. I messed around with the gu-gauge and tried exactly what the mod said to do to extend the tank. For those of you who don't know how the gu-gauge works. It is like a small balloon that seals the airtank from the liquid. When air is pumped into the gun the balloon inflates pushing the liquid up.



There are 3 main problems I found with these mods.

1. If you cut off the top of the gauge, poor out the liquid and put pvc around it, you still have that "balloon" seal preventing any air from getting up into the extended tank.
2. If you remove the "balloon" so air can reach the extended tank you loose the seal between the two parts and the tank wont hold any air.
3. The final problem is if you cut a hole in the "balloon" and do extend the tank you dont increase the range at all. I added an additional 3 inches of tank to it and it increased my ranges at the most by 3ft. Which could just have easily happened just by the weather.

Nerf isn't real war. With the AT family, never squeeze the trigger. Always firmly pull it.

Prove me wrong.

Edited by nerfnerd88, 13 December 2008 - 09:55 PM.

[Puppylayer]

Pretty excellent, props.
However, I cannot see the consistency of performance when subconciously squeezing the trigger...
Also, what ranges do you get now?

P.S.- Titan!? are you kidding me? that, under some circumstances, could be larger than th AT2k itself. But hey, "you got to do what you wanna doooo
As long as everythin ya doo is cool with everyone else"

"SP parody of HSM"

[Wes7143]

You've got a red dot scope where you cannot see it. That makes a lot of sense...

We do have evidence that the tank extention works, but Mods don't always work for everybody.

This is great for anybody who has never modded a 2K, though.

[TantumBull]

This is retarded. The hot glue mod is one of the most obvious mods for the AT and SM families ever. Also, those nubs you cut out don't matter, the air is gone before your finger can pull the trigger back that far. Also I don't trust you're "disprovement" of the extension mod at all. Did you test the 2K, and then immediately put in the extension and test again? If you did ANY modifications at all in between then your results have the potential to be false. Also, I hope you used the same blaster for testing, because every gun performs slightly differently. Also, was it close to the same temperature and windage when you did your second testing trial? Did you seal everything propoperly. I hope you used a different amount of pumps with the gauge extension, because you would need the blaster to have the same PSI during each series of tests. Did you use the exact same darts? Did you put longer barrels on when doing tests with the extended tank to make use of the extra air? You didn't even post fucking results. Did you even use a god damn tape measure?!

I suggest that 13-year-olds people in general should know the basics of the scientific method before making claims as to the effectiveness of other's mods. Fail

Edited by TantumBull, 13 December 2008 - 12:18 AM.

[nerfnerd88]

I see how many of you think that the tank extension works, but how? Someone who did it, tell me in detail exactly how you did it? If you look at the facts it is impossible to do without another missing step. Someone please tell me.

And secondly it does matter how fast you pull the trigger on an air gun such as these. Try this to your Airtech and you will see that your range is dramatically increased when you suddenly rip the trigger back, instead of squeezing it.

Ranges are around the 110'

I'm not Fucking 13 years old. I'm taking AP Physics. Bitch.

Edited by nerfnerd88, 12 December 2008 - 11:28 PM.

[imaseoulman]

Settle down children, settle down.

As I previously stated in the goo gauge tank extension thread, I don't see how it can improve range; mainly because the flow rate is too limited.

Again, in this thread, I will state my disbelief. It is for the same reason. Pulling back the trigger further won't make any difference in flow rate. The air can only flow as fast as the narrowest opening allows it. Let's assume that this narrowest opening is the valve opening itself. Being a circle, it has an area of pi*r^2. If the opening is 3/8" in diameter, then the area of the opening is about .11 square inches.

Now, here is where critical thinking becomes important. To ensure that the limiting factor for air flow (the narrowest point) is the valve opening, we must make sure that we are pulling back the valve head (gasket/seal/thingy) far enough that the air can rush around it and to the valve at least as fast as it can leave the valve. Ignoring turbulence, we can assume then, that the imaginary cylinder, with a base the size of the valve opening and a height of the distance between the valve opening and the valve head, must have a surface area (excluding the bases) equal to or greater than the surface area of the valve opening. Essentially, what I'm saying is, the valve head needs to be pulled back far enough so that the air can easily flow around it and out the valve opening.

So how far is that? Well, as I stated above, the minimum would be equal to the area of the valve opening. So, the formula for area of a cylinder (excluding the bases) is pi*d*h (circumference of base times height). We know that d is the same for this cylinder and the valve opening and so we can solve for h in terms of d. So, pi*d*h=pi*r^2 (r=1/2d) so h=1/4d.

So, in our case (where we are assuming the diameter of the valve opening is 3/8"), we would have to pull back the valve head 3/32". Again, that's ignoring turbulence, but even if we triple that distance, it's still only 9/32" which is just about 1/4". So, tearing out those two pins will do nothing because of the size of the valve opening is the limiting factor. And, even if you did enlarge the valve opening, the limiting factor would be barrel width, which is about 1/2", so you'd have to pull back your valve head 1/8" (or less if your valve is actually larger than 1/2").

So, mathematially, your mod just doesn't seem to work. If there was an increase in range it was likely due to something else you did.

Being in AP Physics, you can probably understand that you got a little over excited and that physics proves the futility of your mod.

[TantumBull]

And secondly it does matter how fast you pull the trigger on an air gun such as these. Try this to your Airtech and you will see that your range is dramatically increased when you suddenly rip the trigger back, instead of squeezing it.

Are you fucking retarded? Did you even READ my post? I never said air release isn't important and pulling the trigger fast isn't important.

Also, those nubs you cut out don't matter, the air is gone before your finger can pull the trigger back that far.

Did I anywhere say that a fast trigger pull isn't important? Did I? No, what I said is that by the time you pull the trigger to THAT point, the air will have already exited the tank.

You also still aren't answering my questions. If you did all or most of the things that I asked about in my last post, then you are correct, then the extension mod wouldn't work. Unless you suck at modding, you probably did the mod right, you just didn't use the mod to its full potential, and that is why you either got similar ranges or lost range. If you're not pumping more, then there will be less pressure because of the tank extension, which equals slower air release and less range. Secondly, without longer barrels, the extension mod won't help because the air that was stored in the extended goo gauge comes slightly after the air from the original tank, meaning that you need longer barrels for that second blast of air to come in contact with the dart.

Edited by TantumBull, 13 December 2008 - 12:17 AM.

[analogkid]

I see how many of you think that the tank extension works, but how? Someone who did it, tell me in detail exactly how you did it? If you look at the facts it is impossible to do without another missing step. Someone please tell me.

And secondly it does matter how fast you pull the trigger on an air gun such as these. Try this to your Airtech and you will see that your range is dramatically increased when you suddenly rip the trigger back, instead of squeezing it.

Ranges are around the 110'

I'm not Fucking 13 years old. I'm taking AP Physics. Bitch.

1)For a tank extention to work properly, you need to use a longer barrel. The extention stores more air at the same PSI, so when it is released, there is a higher volume of air displacing the dart. If the air does not have enough time to expand from its compressed state, it will push the dart out of the barrel before all of the air has expanded, and the rest of the expanding air will exausted out of the end of the barrel.

2)It certainly does matter. I know that the dominate paradigm in Nerf modification is to glue the spring. However, the spring is actually acting as an assist. If you leave it unglued, then squeeze the trigger, the energy will be stored in the spring until there is enough energy to open the valve. Then the valve will spring open quickly.

3) I'm taking IB Physics.

EDIT: Thanks for the addendum imaseoulman. I forgot to mention that.

Edited by analogkid, 13 December 2008 - 11:24 AM.

[imaseoulman]

1)For a tank extention to work properly, you need to use a longer barrel. The extention stores more air at the same PSI, so when it is released, there is a higher volume of air displacing the dart. If the air does not have enough time to expand from its compressed state, it will push the dart out of the barrel before all of the air has expanded, and the rest of the expanding air will exausted out of the end of the barrel.

And this only works if the air gets to the dart fast enough. If the flow rate from the tank expansion to the orginal tank is so poor (as in the goo gauge modification) then the dart will still leave the barrel before the air from the tank extension has a chance to accelerate it.

[TantumBull]

2)It certainly does matter. I know that the dominate paradigm in Nerf modification is to glue the spring. However, the spring is actually acting as an assist. If you leave it unglued, then squeeze the trigger, the energy will be stored in the spring until there is enough energy to open the valve. Then the valve will spring open quickly.

Wow, I never thought of that. Thank you. Like a lot. Time to go pick hot glue out of my at3k spring...

[imaseoulman]

The problem with the spring though, is that there is sometimes so much pressure in the tank that you cannot open the valve because the spring just compresses. You can fix this with a stronger spring, but moving the spring up does not allow the valve to close properly. I also don't think range is significantly hurt by leaving it unplugged. I've experimented with both and found no statistical difference, but there may be a slight one (3% maybe?)

[imaseoulman]

The problem I brought up isn't usually a problem with AT2K's. I've only had it happen to me with one AT2K and I have modded somewhere around thirty. It is, however, a common problem with SM1500's, which is the reason the mod was developed in the first place. It was done simply to ensure that the blaster could still fire (we didn't just start gluing springs for fun). If you plug a pump on an SM1500 and don't do the hot glue/bic pen mod, you'll probably have a 50% chance that the blaster occassionally won't fire when you want it to.

Edited by imaseoulman, 13 December 2008 - 02:12 PM.

[Lynx]

Last physical science I took was chemistry since next year, I'm taking AP Chem. (now in AP Bio). But I still know this

This whole argument is silly since the trigger pull and the size of the valve opening is what matters since the pressure and volume are the same unless you do an expansion of the tank.

The trigger pull needs to be fast enough to not let the amount of air pass through the valve so the dart just falls out of the barrel or the dart is most of the way out of the barrel and gets hit by uber turbulence.

The valve opening needs to be large enough so that the air passing through is not just leaking out of a small hole (tiny valve) and that it's not being wasted (XXXL valve).

Also, don't argue over threads. It just looks bad.

[imaseoulman]

Childish arguing may look bad, but often constructive discussion can lead to more people having a better understanding. In the process of that discussion, people are likely to disagree, and that's okay.