[Qui'lan Fett]

rork, on Nov 10 2008, 10:58 PM, said:

NO springer is going to be able to push a stefan much over 150', and that's pushing it hard. The rule of thumb is that springers top out at around 100', airguns at around 200'. Of course, there are exceptions that prove the rule (Plusbows, Pump shotties, etc.), but foam darts are singularly ill-suited to being fired very long distances; they're just not aerodynamic enough, and they shed energy fast. ~Rork

It is not that they are so unaerodynamic, but that little physics law that says that if you drop a rock and throw another rock flat, they will both hit the ground at the same time. On earth, you have to take into account air resistance, and a small amount of rise from Bernoulli's principle, but for the most part, the dart only has as long as it takes for it to fall to the ground to travel it's whole rage. Because of aerodynamics, air resistance, and inertia, it is very hard to get the dart going fast enough to get it to travel more than 150 feet before gravity has its way.

[Foam_Shooter]

nerfboi: It costs < $20. The PC is the same about 13" including the bushing in it.

Meaker: I used a +Bow spring.

[Draconis]

I still need to make one of these for balls! It's been on my back burner for a while now too.

[nerfboi]

Maybe you should try to make this one fire balls. Defiantly has the size.

[MercenaryXero]

And I thought I was all done with my homemades for the year...

Heh. I'm definitely considering making one.

[Carbon]

nerfboi, on Nov 11 2008, 02:31 PM, said:

Maybe you should try to make this one fire balls. Defiantly has the size.

It definitely does. I'd be really interested to see what a +bow spring could do in a ballgun.

[Foam_Shooter]

I'll try making it fire ball.

Carbon: Do you think that you could explain how you made yours shoot balls.

[Carbon]

Foam_Shooter, on Nov 11 2008, 03:43 PM, said:

I'll try making it fire ball.

Carbon: Do you think that you could explain how you made yours shoot balls.

A summary is worthwhile, because the process was spread out over a few pages. Here’s a few of the points that I found:

Ballguns typically use a retaining ring to keep the ball in the barrel until enough pressure builds up. I used a 1.25” sanitary coupling as the retaining ring, because it had a nice ridge in the middle. I shaved/sanded it down until the ball could pop through with air pressure (that’s all trial an error). And since airflow needs to be high, I just shoved the retaining ring into the end of the pressure chamber, with a few turns of tape to keep it tight.

The interesting discovery was that dead space is helpful in a ballgun, because it gives extra volume for pressure to build before forcing out the ball. Large volumes of low pressure air seems to be key. So, that's where the inline clip came in...it fired better with it than without it.

This post has been edited by Carbon: 11 November 2008 - 01:54 PM

[Just Some Bob]

I could use some data on the balls themselves. What are you using, and where can I get some which I can expect to be the same?

I have a 1.25" sch40 PVC coupler to compare with, and I have balls from the ERTL shotgun (1.7" - too big) which I had believed to be the same as Nerf, and from the Lanard Ball Blaster (1.3" - too small). I also have some "whiffle" style practice golf balls (1.6"), and they seem about right.

I also was thinking that threaded couplers might give the ability to make changeable "washer" type orifices for the resistance feature.

[Carbon]

Just Some Bob, on Nov 11 2008, 04:42 PM, said:

I could use some data on the balls themselves. What are you using, and where can I get some which I can expect to be the same?

Foam practice golf balls from Kmart. Six for $4, or 50 for $20....not sure about the size.

[Draconis]

Carbon, on Nov 11 2008, 04:31 PM, said:

Just Some Bob, on Nov 11 2008, 04:42 PM, said:

I could use some data on the balls themselves. What are you using, and where can I get some which I can expect to be the same?

Foam practice golf balls from Kmart. Six for $4, or 50 for $20....not sure about the size.

Honestly, I would stick with K-Mart, too. Though the majority of what I have now are practice golf balls from Target. Available 12 for $5 or so. The drawback is that they are noticeably smaller than Nerf balls, and have the dimples. At first, the dimple sound like built in awesomeness, but alas, they allow air leakage around the sealing rings. They are also so much smaller that they don't really work with Reactors, and get substantially shorter ranges with my motorized Ballzooka. The K-Mart balls are between the Target balls and Nerf balls in size.

[Wes7143]

There was some talk a little while back in this thread about using rubber washers for the 2" plunger tube, and the difficulties of it. Here is one solution:

Recently, I have been making one of Rork's SnapBows. It is working good, and now I'm just waiting for the springs from McMaster to arrive. I purchased Every last thing on his list and ended up with quite a few things I didn't need, one of which being a 2" PVC tube. While I was building the snap, my dad fiddled around with it in an attempt to make a Nerf cannon. Here's how he did the plunger head



It's a 1 1/4" cap that he put on the laythe and cut grooves into for the O-rings. It works astonishingly well, and when we were messing around with it, I pushed the back of the plunger rod. The cap we had put in the front had not been drilled yet, and shot off! It made a fairly large crater in the wall. My dad plans on using extention springs, rather compression springs to power his.

Just a different way,

-Wes

[rork]

You people, with your lathes and fancy shoes and hoity-toity ways...

[Wes7143]

rork, on Nov 11 2008, 08:55 PM, said:

You people, with your lathes and fancy shoes and hoity-toity ways...

Don't worry Rork, the SnapBow I made still uses the same rubber washer method as yours. And yes, my shoes are fancy because I lathed the insides to fit my feet perfectly! [/sarcasm]

Actually using the lathe is a good alternative if your local hardware store does not offer rubber washers big enough to make a seal in 2", although I'm not sure where you would go to use a lathe. Perhaps your school's building classroom has a lathe?

[rork]

I'll get around to getting one eventually. Until then, I will wallow in my spite and (On Topic) use O'rings from Mcmaster.