32 replies to this topic

[CaptainSlug]

Just your average Big Blast, but I expanded the air tank by drilling a hole

then used a 1/4 brass pipe nipple, 3/4 pipe parts, and JB weld 2-part epoxy.

I already have a lathed posts for both basic arrows, and one for the proprietary Big Blast missiles.
Next I will be working on a barrel for firing Nerf Ballistic Balls.

Ranges
Basic Arrows: 70 feet
BBBB Missiles: 60 feet (need to machine the post a little more as it's a tad snug at the moment)
Micro Stefans from 12-inch barrel: 160+ feet
very difficult to measure such long distances near my house at the moment, won't be used to fire micros anyways

Edited by CaptainSlug, 13 October 2008 - 01:05 PM.

[sputnik]

Hot damn.

[Blue]

Is this something I could do with a dremel and some pvc with an end cap? How hard is it to do?

[Kid Flash]

Those are insane ranges... Did you plug the pump?

edit:
For the ball barrel get some 1 and 1/2 I believe it is and some reducers to hook it on. Shouldn't need a long barrel for it...

Edited by Kid Flash, 13 October 2008 - 01:18 PM.

[CaptainSlug]

Those are insane ranges... Did you plug the pump?

Not yet. The tank expansion only results in an extra 1-1/2 pump strokes.

Is this something I could do with a dremel and some pvc with an end cap? How hard is it to do?

I used a power drill and a flat-blade wood-boring drill bit to drill a 1/2" hole in the big blast internals and one of the 3/4" pipe caps, then screwed the two together with a 1/4 brass pipe nipple after applying a very generous amount of JB Weld 2-part epoxy. I let the parts cure for 12 hours, then simply trimmed the blaster shell down.

To keep the internals from sliding around I used hot glue to glue a small ring of 1-1/4 pipe to the outside of the pump tube.

I was planning on replacing one of the legs of the "tripod" with a specially contoured PVC tee joint. What do you think of the idea?

That would be much more difficult to get a good joint between the parts you are trying to attach to each other.
You could always just extend the blast chamber out to the side of the blaster.

Edited by CaptainSlug, 14 October 2008 - 05:44 PM.

[Galaxy613]

70ft with Arrows? They might be war-capable ammo then...

[Ambience 327]

That would depend on accuracy as well. Also, it would be difficult to carry a significant number of arrows or missiles to use something like that as a primary. If it were used as a scenario element (i.e. only arrows/missiles can damage the objective/target/bunker/tank/guy with the gold shirt) then it might be worth thinking about.

I'm curious as to Captain Slug's intentions. Are you doing this just to expand your knowledge, horizons and experience, or do you see a practical use for a weapon that fires these ammo types other than what I mentioned above?

[CaptainSlug]

I'm curious as to Captain Slug's intentions. Are you doing this just to expand your knowledge, horizons and experience, or do you see a practical use for a weapon that fires these ammo types other than what I mentioned above?

I don't really have any intended use for this particular project. It's just an experiment based on the dare Baghead issued me: find a way to shoot a Nerf Ballistic Ball 100 feet in an affordable and easy to reproduce way.
To fire larger ammunition you need a great deal of volume and a high flow rate, and the Big Blast already has most of that equation while being cheap, lightweight, and easy to modify.

Edited by CaptainSlug, 13 October 2008 - 01:57 PM.

[Ambience 327]

More power to you then sir. Your contributions to the NIC are already legendary, so anything you learn from this will no doubt be a blessing to us all. (Assuming you don't have to explain it all repeatedly to newbs over PM's!)

Modding for the sake of modding is great. Modding for the sake of a dare/challenge, even better.

I, for one, am quite anxious to see that nerf ball hit the 100' mark.

[Lt Stefan]

That's a really cool idea. I believe, to help with the 100 ft, take a nail, poke a hole in the ball to the center, and put a bb or two in the hole and push it to the center. It should help it go farther.

[Kid Flash]

Would it be at all possible to get a picture of the front... I just bought a big blast (it had to be months old because it was soooooooo dusty and the pump was deadly dry so I had to lubricate it) and popped it open and Im wondering if you kept the screw below the air tank and if you just cut along the walls behind the air tank. Thanks

[Blasphemy]

I was wondering why you would build any of the barrels to fire such exotic ammunition as arrows when you've said many times in the past that in your opinion the only war-practical type of ammunition is the micro stefan. But than I saw that you were dared by Baghead, and I could understand that not doing this would be a blow to your pride.

Speaking of Big Blast experiments, this is one I never got to work out all the bugs in:

It is a good idea, but I've had problems find the right sized o-rings and modifying the pump head to accommodate a larger o-ring. I may get back to it some time, but right now it is on the back burner.

Awesome expansion though, if I were you I would've done it by using a section of large OD pipe and placing it around the existing airtank with quite a few more holes drilled in the pre-existing airtank and maybe some kind of jerry-worked pipe fittings which would connect the two pieces loosely with plumber's goop and JB Weld to seal, but that's just my opinion. Whatever works, I suppose.

EDIT: And, I'm not trying to hijack your thread with my pump mod, if that's what it looks like. I just posted it because it is something you might want to try to cut down on the number of pumps you need.

Edited by Blasphemy, 13 October 2008 - 04:16 PM.

[Draconis]

70ft with Arrows? They might be war-capable ammo then...

I think that 70-75 feet is a distance limit set by the arrow design itself. No matter what, I have been unable to actually push a Nerf/Lanard arrow beyond this mark without destroying the back end (too much pressure). The Signal Launcher missiles I can get a little further, but only 10 feet or so. And not consistently.

I'm very interested in long range balls, and I plan on doing some additional work with another $2 Titan I just purchased. I am wondering if we should be trying a longer, looser (slightly) barrel, rather than the short barrel with the tightening ring like Carbon and myself have used with relative success. I'm just thinking that the Spud gun boys might have that correct. I know, it's unlikely....

[analogkid]

Its gonna be tough to get the ballistic ball to go 100'. Not impossible, but tough. Working against you are the weight of the ball(very light), and that air resistance is roughly velocity^2, so you have to make it fire a lot harder to gain the desired range. Good luck though, very anxious to see the results.

Edited by analogkid, 13 October 2008 - 05:35 PM.

[CaptainSlug]

I think that 70-75 feet is a distance limit set by the arrow design itself. No matter what, I have been unable to actually push a Nerf/Lanard arrow beyond this mark without destroying the back end (too much pressure).

Well you're pretty much inhibited by having a specific post length that you cannot exceed.

For firing the Nerf Balls I'm going to be trying 1-3/4" ID Polyester tube.

[BendyStraw]

I have an idea that might increase range.
I know that when you play ping-pong, putting a top spin on a ball that's clockwise (or counterclockwise, I forgot exactly. I'm doing ping pong motions in the air trying to figure it out. Searching the net will be faster. ) relative to the direction the ball's going will make it have a topspin that makes it float more through the air.
A barrel that fires ballistic balls could simulate the effect by roughening a long strip on the... top? bottom? of the barrel, so that the balls are rolling and spinning in one direction on the way out. If you have too much topspin, they are simply going to just fly upwards. But if you have just the right amount, they will start to fall, but then topspin kicks in and they would likely float up a little again, resulting in increased range. The only problem is that that kind of topspin would likely slow the ball down.

If it works for ping pong balls, do you think it might work for nerf balls? They are both pretty light and have high air resistance.

Edited by BendyStraw, 14 October 2008 - 09:48 AM.

[MoonMaster]

BendyStraw, I believe you just described hop-up.

[BendyStraw]

BendyStraw, I believe you just described hop-up.

Heh, I've never played airsoft, so I had to search for hop-up on google to see what you were talking about. Looks like Paintball and Airsoft work on that exact same principle. There's no reason why hop-up might not work. The scale, of course, would definitely be different. Makes me want to try this.

Edited by BendyStraw, 14 October 2008 - 02:36 PM.

[CaptainSlug]

I don't really have the luxury of being able to add friction to the barrel. The projectile is not going to be traveling far enough or fast enough for spin to really help in any significant way.

[BendyStraw]

I don't really have the luxury of being able to add friction to the barrel. The projectile is not going to be traveling far enough or fast enough for spin to really help in any significant way.

Sure, you can't exactly roughen an entire barrel length, but to do hop-up, airsoft apparently does it using a little device like this:
http://www.scairsoft...php?topic=517.0
This actually doesn't use friction at all to make them spin. This device changes the way in which the air hits the pellet.

While you're right that ballistic balls will probably not spin any significant amount, I think its worth a try. I have a big blast. This would be a fun project. I'll post a topic with my results if I get around to trying this.

[CaptainSlug]

This actually doesn't use friction at all to make them spin. This device changes the way in which the air hits the pellet.

Incorrect. It adds resistance to the travel of one side of the BB being fired, thus inducing spin.
I might tinker with spin later, assuming I get results that indicate that it would be beneficial somehow.

The only type of spin I can induce without adding friction inside the barrel would be if I were to put the barrel on a rotary union and use a motor to spin it prior to firing. But axial spin wouldn't do anything except improve trajectory consistency.

But whatever, you'll all trying to think too far ahead. I still have to determine the best barrel dimensions.

Edited by CaptainSlug, 14 October 2008 - 03:02 PM.

[Kid Flash]

I used a power drill and a flat-blade wood-boring drill bit to drill a 1/2" hole in the big blast internals and one of the 3/4" pipe caps, then screwed the two together with a 1/4" brass pipe nipple after applying a very generous amount of JB Weld 2-part epoxy. I let the parts cure for 12 hours, then simply trimmed the blaster shell down.

I just got all the materials or so I thought... The first post says you used 1/4 inch brass parts but the hole you made was 1/2 inch in this post... How did you screw them together?

[BendyStraw]

This actually doesn't use friction at all to make them spin. This device changes the way in which the air hits the pellet.

Incorrect. It adds resistance to the travel of one side of the BB being fired, thus inducing spin.
I might tinker with spin later, assuming I get results that indicate that it would be beneficial somehow.

The only type of spin I can induce without adding friction inside the barrel would be if I were to put the barrel on a rotary union and use a motor to spin it prior to firing. But axial spin wouldn't do anything except improve trajectory consistency.

But whatever, you'll all trying to think too far ahead. I still have to determine the best barrel dimensions.

Yeah, you're right. The little rubber nub gets it spinning through friction and it continues that way down the barrel.

Are you going to use Nerf Ballistic balls? I've seen foam driving range balls that might also work, and are smaller.

[CaptainSlug]

That's nice guys, we'll cross that bridge when we get to it. I'd rather do practical tests in a logical order rather than wasting a bunch of time debating them on a theoretical level.

Just Some Bob, you didn't even seem to read the part of my post you quoted.

I used a power drill and a flat-blade wood-boring drill bit to drill a 1/2" hole in the big blast internals and one of the 3/4" pipe caps, then screwed the two together with a 1/4" brass pipe nipple after applying a very generous amount of JB Weld 2-part epoxy. I let the parts cure for 12 hours, then simply trimmed the blaster shell down.

I just got all the materials or so I thought... The first post says you used 1/4 inch brass parts but the hole you made was 1/2 inch in this post... How did you screw them together?

You added a " symbol in my post where there was none.
1/4 pipe size brass pipe nipples are a tad over 1/2" in diameter. If you want more thread engagement then you have to drill the hole a little smaller than 1/2" in diameter.

Nominal Pipe sizes do not in any way indicate fractional measurement sizes.
It's a conspiracy of confusion authored by Plumbers trying to secure their profession, or something.

Edited by CaptainSlug, 14 October 2008 - 04:44 PM.