15 replies to this topic

[fishingdude2044]

First off, I do not know if this belongs in the modifications section but anyways.

I am doing a science fair project on if the length of a barrel affects the distance a foam dart can fly (in this case a stefan). I need some "research" so does anybody have knowledge on what barrel lengths have worked the best for you? Any and all help or "research" Is greatly appreciated.

Plus some background information is that I will be using a Nitefinder with AR removal, cpvc coupler'd , and bands added (it's in the Modification pictures thread, page 108 if i'm not mistaken) for all of the tests.

Thanks,

FD2044

[Banshee]

Why don't you do your homework yourself and use the whole site for your own research. Use CPVC, its cheap and easy to cut. Coupler your gun and do the rest yourself. What do you expect us to do? Spoon feed you your science fair project?

[Mr BadWrench]

whats with that stupid quote anyways?

[Banshee]

I would use about an 8-12 inch barrel for best range but I would use a 14 inch barrel for incredible accuracy.

Out of a NF? 14 inches is a bit excessive, no?

[fishingdude2044]

At Banshee:

I'm using cpvc, I've couplered my Nf. Damn can you learn to read what I posted? I put the mods I performed on my NF. I just wanted some personal experience from some of the members okay?



At Mr BadWrench:

I just thought the quote was funny.



At fadinglight4:

Thank you for posting something related to my topic that is useful in my project



For anyone else before you post, I need some personal experience with cpvc and the lengths. I need like an interview so anyone who would like to help me please pm me,

Thanks for your time,

FD2044

[Blasphemy]

You do know longer barrel=/=better accuracy all the time. Just as the range can dip with too long a barrel so can accuracy, especially because if your range is less the velocity of your dart will be less and therefore typically affected more by outside forces (i.e. gravity, air resistance, etc.).

EDIT: By the way, 8 to 12 inches is way to long for an NF, you will NOT get optimal range out of that, the longest you ever want to have your NF barrel being is around 6 inches. Generally 4-6 inches is the best length to get optimal range and accuracy out of an NF.

Edited by Blasphemy, 22 October 2008 - 08:49 PM.

[fishingdude2044]

I would use about an 8-12 inch barrel for best range but I would use a 14 inch barrel for incredible accuracy.

Yeah 14 inches sounds a bit long but, I'm using these lengths: 2",4",6",8",10",12", and 14" of 1/2" cpvc for my project and I'm shooting 20 stefans out of each length of cpvc.

[Daniel Beaver]

Yeah 14 inches sounds a bit long but, I'm using these lengths: 2",4",6",8",10",12", and 14" of 1/2" cpvc for my project and I'm shooting 20 stefans out of each length of cpvc.

I think smaller increments would be better - 1" or even 1/2". CPVC is cheap.

Make sure your stefans are as consistent as possible, since that could be a major source of variability. Find a way to mount your gun on something so that you can fire it from the exact same position every time. If you have a bench vice, drag it outside and set it on one side of your lawn and then clamp the NiteFinder (Ideally you want it at shoulder level, but consistent positioning is more important). Grab a clipboard or a notebook, lay down a measuring tape (a rope with marks works too), and start shooting. It is very important that you perform at least two runs from each barrel; i.e., instead of shooting 20 all at once, shoot 10 at a time from each barrel, and then repeat the experiment again. This will reveal any drift in your data from factors you cannot control (darts getting shredded, temperature changing, etc.).

Read the articles here. cxwq's Darts and Barrels article is great, and may be a good source to use. Take some measurements of the plunger tube and figure out how big of a volume of air the NF puts out (that info is probably floating around somewhere here). That should give you an idea of what the "ideal" barrel length should be. The actual best will probably be different - which is why an experiment is a good idea.

[Foam Total War]

I don't know about you, but for my science fair we have to get sources from books or archived magazine articles from .org or .gov sites only. Not to discredit anyone at the Haven, but I don't think asking a large group of people (mostly teenagers) on the internet is very scientific. I suggest you do some research about air volume. Also, I think someone posted a mathematic formula for barrel length efficiency somewhere way back in the homemades section. That said, good luck with your project!

Edited by Foam: Total War, 23 October 2008 - 04:35 PM.

[TantumBull]

I don't know about you, but for my science fair we have to get sources from books or archived magazine articles from .org or .gov sites only.

That's complete bullshit. There are plenty of good, infomative, and reliable .com websites.

[Blasphemy]

Umm... not to insult you, Foam: Total War, but I don't think you're being very reasonable trying to discredit us as a reliable source for information on this topic. We do this specifically as a hobby, and we're pretty much his biggest source of information on this SPECIFIC TOPIC, and most of us are very credible because we've had a good amount of time doing this. There's not really anything published on this specific topic in books or on .gov or .org websites. You can look at all the friggin' information on air volume that you want, but last I checked those books don't include reasonable conclusions as to what works best in a particular situation to get the best performance out of a Nerf blaster.

Yes, read up on air volume, air displacement, velocity, and projectiles, it should help you a lot. But, there are so many other variables that you can't try and keep it to what the books and formulas say SHOULD work through your hypotheses, to get the best performance he needs to experiment and get input from others based on their experience. Besides, experimenting and gathering data are part of the scientific method.

Edited by Blasphemy, 23 October 2008 - 10:19 PM.

[Lynx]

4 to 1 is the most efficient plunger to barrel or barrel to plunger ratio. (its in a snap write-up)

Use brass, it's uniform in most everything.

Edited by Lynx, 23 October 2008 - 10:19 PM.

[imaseoulman]

A reccomendation for your project. Let's say that after your initial round of tests you show that 4" and 6" performed very well. On a scale of 2-14", sure they're close together, but on a scale of 3.5" to 6" there extreme ends. It would make sense to do a second round of tests with smaller increments (like 1/2") Testing from 3.5" to 6.5". Again, you're likely to find a more narrow length range that performs better. If you wanted to, you could then divide that range into 1/4" lengths for the "perfect" barrel length for your blaster and darts.

Also, when recording the distances the darts travelled, do not simply record an average for each barrel length. Record the distance each of twenty darts travelled for each barrel length. This will give you the data you need to appropriately analyze it

[Carbon]

4 to 1 is the most efficient plunger to barrel or barrel to plunger ratio. (its in a snap write-up)

I in turn got that value from Boltsniper. Check out his writeup on the FAR to have some science dropped on you (complete with formulas).

[fishingdude2044]

Wow thanks everyone! Great suggestions/advice, I will look at it today and figure out the specifics for my project. thanks,

FD2044