9 replies to this topic

[ST9000]

materials:
-a self determined length of 1/2 in. cpvc or acrylic
-a length of fishing line determined by multiplying the length of your barrel by 8 (i.e. a 1 foot barrel needs 8 ft of line)
-electrical tape

tools:
-dremel with cutting wheel
-pipe cutters (optional)
- some thing to cut the e-tape and fishing line with

Note: this does NOT work well for "blowguns"


step one: cut your desired length of cpvc or acrylic ( i will be using cpvc ) i cut roughly 8 1/2 i




step 2: take your dremel and make 4 little slots on each end of the barrel. note:make sure that the slots on one end are lined up with the slots on the other end) like this



step 3 : thread your fishing line through the tube and pull about 2 inches over and through one of the slots, then wrap it in 2 wraps electrical tape like so



step 4: pull the line through the next notch over on the other side so the line on the inside makes a 1/4 turn (sorry i couldn't take a good picture of it)

step 5 pull the line straightup the outside of the barrel to the same notch on the other side and and pull the line through the barrel and repeat step 4, keep doing everything said in this step until all of the slots are filled and ther are 4 lines inside of the barrell then proceed to step 6

step 6; tape the end of the line to the outside of the barrel the end result should look like this (i recommend wraping the entire thing in e-tape to protect the fishing line

[thedom21]

I may have to try this and do some accuracy tests. I have access to a high speed camera as well......

[Ozymandias]

3DBBQ's version

What you could do, however, is some sort of comparative test video.

And now we wait for Doom...

[andtheherois]

This is an interesting concept that has been tested by many people, however without any picture/video evidence that this actually improves accuracy, there's no point in doing this.

With all due respect, I don't have the time, patience, or money to test every claim like this. You're the one making the claim. Back your claim up with the test data you would have to take to make the claim.

Edit: I've been told that 3DBBQ's darts are unweighted. This would allow rifling to improve stability and in turn improve accuracy, so the claims are believable. My points below about improving the weight distribution such that the dart's center of gravity is in the front of the dart and increasing muzzle velocity and dart inertia still stand. Rifling is pointless when the weight distribution is good.

The two easiest ways to increase accuracy for Nerf darts are to increase the muzzle velocity and the dart inertia (mass). Safety concerns prevent these two from increasing too much. There is a practical limit to accuracy. Until a gun and dart combination reach that limit, I see no reason to futz with things that probably won't do anything.

Rifling to improve accuracy seems to be one of the "holy grails" of Nerf and it will remain so because it can't work. At best it would improve a dart's stability, which typically is already excellent due to the weight distribution as I've mentioned. At worst it will reduce stability, tear the dart, and contribute to leaks.

Edited by andtheherois, 04 January 2012 - 08:32 PM.

[cmeej]

This is an interesting concept that has been tested by many people, however without any picture/video evidence that this actually improves accuracy, there's no point in doing this.

Hero, there is purpose to this if you are using JSPB darts.

[ST9000]

This is an interesting concept that has been tested by many people, however without any picture/video evidence that this actually improves accuracy, there's no point in doing this.

i use 1/4 inch slingshot darts and when i tested it the barrel without rifling made the darts fly 1-1 1/2 feet off target but the rifling improved this to about 7 inches around the target. note: i did all of my testing with a couplered big blast

[roboman]

i use 1/4 inch slingshot darts and when i tested it the barrel without rifling made the darts fly 1-1 1/2 feet off target but the rifling improved this to about 7 inches around the target. note: i did all of my testing with a couplered big blast

That's great and all, but it raises a number of questions.
How far were you standing from the target?
How big was the target?
How did you measure how far your darts were hitting from the center of the target?
Do you have pictures of your darts, so people can evaluate their quality?
Did you use the same darts for both tests?
How many trials did you run?
How did you ensure that the barrel was straight?
How do you know that the improvement in accuracy is not due to chance alone?
Did you mount the blaster in any sort of fixture, so that it aimed at the same spot every time?

I could go on. You need to provide some more details, along with pictures of your setup, if your data is to be even remotely believable. Simply stating that your "rifling" technique improved the accuracy of your blaster is not enough.

[Zorns Lemma]

i use 1/4 inch slingshot darts and when i tested it the barrel without rifling made the darts fly 1-1 1/2 feet off target but the rifling improved this to about 7 inches around the target. note: i did all of my testing with a couplered big blast

You need to post your setup and data. Preferably with accompanying video of the testing process.

Most likely your results are a sample of user error and confirmation bias, and under repeatable conditions are not statistically significant.

[Doom]

i use 1/4 inch slingshot darts and when i tested it the barrel without rifling made the darts fly 1-1 1/2 feet off target but the rifling improved this to about 7 inches around the target. note: i did all of my testing with a couplered big blast

Roboman and Zorn are right. You can claim whatever you want, but to get people to believe something that seems to be physically impossible we'll need the details of your test setup and experiment including the raw test data.

I have shown before that data posted by proponents of rifling doesn't show that rifling improves accuracy or precision. And I have a few suggestions about testing rifling.

[Aeromech]

Roboman and Zorn are right. You can claim whatever you want, but to get people to believe something that seems to be physically impossible we'll need the details of your test setup and experiment including the raw test data.

I have shown before that data posted by proponents of rifling doesn't show that rifling improves accuracy or precision. And I have a few suggestions about testing rifling.

ST9000, Doom mentioned the subjectivity of these rifling tests in the links he provided. With the setup described in this thread, was the blaster bolted to a table/ secured in a vice, or did you just point and shoot to acquire your data? Also, was your air pressure approximately constant for each shot?

Also, other items to be taken from this:
-The main variable under scrutiny is the accuracy of the darts, but would the additional friction created by this fishing line setup also reduce range due to added friction?
-Finally, what would the lifespan of a stefan be with this setup? In other words, will this shred slugs?

Edited by Aeromech, 07 January 2012 - 02:18 AM.