29 replies to this topic

[Tsunami]

Whether it's a nitefinder, crossbow, or anything, what replacement springs do you use to add a l;ot of range to your gun? Where would I buy them? Thanks

[blister]

For Nitefinders, I use SP-9713 Handyman Springs from Homedepot.

[Ronster]

http://www.bravocomp.....ne action.htm

[CaptainSlug]

Whether it's a nitefinder, crossbow, or anything, what replacement springs do you use to add a l;ot of range to your gun? Where would I buy them? Thanks

You could search for gun specific threads where springs are mentioned to find the answer. Generally for every gun that it will fit in I use the AR-15 spring Ronster just posted a link to then cut it to the length needed.

[Cennipe]

Could you use really strong magnets, with same poles facing eachother and glued in place for a spring, like a small super magnet.

such as this

or this

They are really light, less then a gram each, and they are really strong, the second one holding over 18 pounds.

Edited by Cennipe, 29 May 2007 - 05:47 PM.

[Cennipe]

They are REALLY light, and they are strong, over 15 pounds each. I might see if I could try it. You know the toys, SuperMags, ya, I put some in a straw and launched them by putting opposite polls together. CaptainSlug, Carbon, Groove, what is your oppions if this would work?

[Gengar003]

That's a sweet idea!

I actually looked into powerful permanent magnets a few years back as potential parts of a railgun...

Check out this page: http://www.kjmagneti...ucts.asp?cat=10

Some of those suckers, about the size of a penny, have 40+ pounds of pull.

Of course, they'll also shatter themselves if you let them snap together, and can cut skin/crush bones depending on their strength, so they're not for everyone

[CaptainSlug]

CaptainSlug, Carbon, Groove, what is your oppions if this would work?

Distance reduces the pull strength, unlike with springs where compression or extension distance scales up the applied load.
I'm not optimistic.

Edited by CaptainSlug, 30 May 2007 - 04:15 PM.

[Ixius]

I would think that while the pull strength of two magnets decreases over distance, it may be useful in guns such as the nite finder or those with a similar plunger shaft length. I mean, with 18 pounds of pull (40 on some), over small distances it shouldn't be a problem.

But that's just my reasoning.

[hoshiadam]

I think a stack of ring magnets (on a non-magnetic post), with alternating poles, might work. Essentially replacing the spring with magnets that repel each other as they get closer. Probably more expensive than springs though, and I'm not sure of the benefits of it overall.

Adam

[Shralla]

I've heard that most people use the ACE #49 spring as a replacement for NF springs, but I can't find such a thing on the ACE website. Is it there, and I'm just missing something?

[Foam Total War]

Could you use really strong magnets, with same poles facing eachother and glued in place for a spring, like a small super magnet.

such as this

or this

They are really light, less then a gram each, and they are really strong, the second one holding over 18 pounds.

That is an awesome idea! For people who don't want a spring replacement, they can just get magnets to add some range. Nice idea, man.

-Foam

[Yazzeh]

CaptainSlug, Carbon, Groove, what is your oppions if this would work?

Distance reduces the pull strength, unlike with springs where compression or extension distance scales up the applied load.
I'm not optimistic.

Even so (with the kind of power these magnets have, that wouldn't be a big deal over a span of 5 inches), you can simply add another magnet at the back of the plunger, which is repelling the magnet on the plunger itself. That way, you have the immediate full force of the repulsion as well as the immediate attraction of the other magnet. The whole thing'd be so powerful it might just break itself if it were made of plastic! Haha. I think this is a good avenue for a home-made.

[Prometheus]

You would need a cushioned plunger head, because the force of impact could be enough to realign the magnetic domains. Also, magnetic fields are inversely proportional to the distance squared, so this would need to have super slim and super strong magnets. I'm thinking that for the cost and effectiveness of this (over $20 in magnets) you might as well have used the spring, which is far more reliable. Great thinking, but not a feasible idea.

[Yazzeh]

You would need a cushioned plunger head, because the force of impact could be enough to realign the magnetic domains. Also, magnetic fields are inversely proportional to the distance squared, so this would need to have super slim and super strong magnets. I'm thinking that for the cost and effectiveness of this (over $20 in magnets) you might as well have used the spring, which is far more reliable. Great thinking, but not a feasible idea.

I don't know, a 3 mm thick magnet with 18 lbs of pull strength for $1.08 seems pretty decent to me. Not as cheap as a spring (since you'd be using two or three of these) but it wouldn't be a bad idea. I agree with cushioning the plunger. Also, leaving an actual gap between the two attracting magnets so that they couldn't touch even if there was no cushion. Benefits of using magnets instead of springs... well, you get more power out of magnets, depending on the magnet used. Uhh, yeah, that's all I can think of.

Edited by Yazzeh, 30 May 2007 - 06:51 PM.

[Carbon]

Interesting idea abou the magnets, but I'm with CS...not likely to work. Like Prometheus was saying, the force of attraction drops off exponentially with distance: you won't be gettign 18 lbs of pull when the plunger is pulled back. This brings in another problem: since the force of attraction isn't great, initial velocity of the plunger would be low. Compare this to a spring, where the force stored in the spring is greatest where you need it most: at the point of firing. Plunger acceleration is where it's at for range.

[Gengar003]

Oh, y'all've got it all backwards (literally)!

You'd not have magnets attract and pull the plunger together - you're absolutely right that that raises all sorts of issues, with magnets realigning, shattering (the neodymium super-strong ones will), etc.

You'd put them at the BACK of the plunger, and on the BACK of the plunger-head, so the repulsive force of the magnets accelerates the plunger. That way, you get the full pull (or push, in this case) of the magnets right off the bat.

You'd probably have to use something like this (60 lbs of pull each):

Around the plunger shaft inside the tube, and where that's not feasible, you could just arrange some of these (8 lbs of pull each):



lined up around the shaft, glued on.

This is a very tempting idea; I may have to actually buck up and try this.

Edited by Gengar003, 30 May 2007 - 07:36 PM.

[Yazzeh]

You'd put them at the BACK of the plunger, and on the BACK of the plunger-head, so the repulsive force of the magnets accelerates the plunger. That way, you get the full pull (or push, in this case) of the magnets right off the bat.

The problem with that is that once the magnets have finished repulsing (that is if the force doesn't reach to the other end of the tube) then the plunger will decellerate as it goes along it's path. Which is why I suggested using both repulsion and attraction with magnets that won't tear the casing apart.

Anyways, I like the idea. You should go for it and tell us the results.

[Carbon]

Interesting...but most "floating magnet" type of things I've seen show a distance between the magnets of 1/4" or so (i.e. no more pushing force). Considering that a plunger stroke is typically 3" or so, you're looking at a whole lot of magnets. But considering that while the inverse square law works against you going durther away, you'll get exponentially more power when you move closer together.

Yeah, I'm interested to see what you could do with this. But I'm glad I'm not paying for all the magnets. Keep us poseted.

[Cennipe]

Hey, Gengar, (or anyone else), do you think for my magnet spring, would this be to powerful for the crossfire, like, would it break the slide? It holds like 36 lbs.

Edited by Cennipe, 31 May 2007 - 07:42 PM.

[Shralla]

I've got a question. People say they use ACE #49 springs as NF replacements. However, I went to ACE today, and the only springs they had that were numbered like that were from some other company (not ACE) and #49 was an extension spring, not a compression spring.

Do all ACE stores carry said spring, or does it differ from store to store?

[CD-R]

I thought about the magnet thing when I was a newbie lurking on the forums. I think that it should work; however, In my experiences with high energy electronics and magnetics I have found that often the magnet will not move straight, but rather try to rotate and stick to the other magnet. So basically, when you release the plunger, instead of going straight down the tube due to repulsive forces, it could break the plunger shaft in half, spin around, and slam into the other magnet breaking both in half. Maybe you could play around with the polarization of the magnets to overcome this. For now, just give it a try. I think that it might work.

[Gengar003]

Hey, Gengar, (or anyone else), do you think for my magnet spring, would this be to powerful for the crossfire, like, would it break the slide? It holds like 36 lbs.

I dunno. Get one, try it, and let US know.

Or you could go find something in your house with a known weight (or more than one something), and begin attaching them to your crossfire slider until their weight can cock it. Then you'd know how much force it takes to cock it with a spring in there. You'd want to match or exceed that.

I thought about the magnet thing when I was a newbie lurking on the forums. I think that it should work; however, In my experiences with high energy electronics and magnetics I have found that often the magnet will not move straight, but rather try to rotate and stick to the other magnet. So basically, when you release the plunger, instead of going straight down the tube due to repulsive forces, it could break the plunger shaft in half, spin around, and slam into the other magnet breaking both in half. Maybe you could play around with the polarization of the magnets to overcome this. For now, just give it a try. I think that it might work.

If I were to do this, I'd get a bunch of little ones, and either make a "+" shape or a ring of magnets around both the back of the plunger head and the back of the plunger tube, alligned to repel. Hopefully, any errant forces would be canceled out in this way.

But in all honesty, if I've got magnets powerful enough to tear a Nerf gun apart... Well that'd be about as cool as a magnet-powered Nerf gun

Edited by Gengar003, 31 May 2007 - 08:59 PM.

[Cennipe]

The CrossFire cocks at 6-7 pounds, dart tag NF over 5 and uner 7.5, depending on how fast you draw. I think that 40 pounds is way to much, and when the magnets are compressed together, I think that they should be repelling at about 10 pounds, does that sound like it would break the gun?

PGSN--NSGB
PGSN--NSGB
PGSN--NSGB

P-PLUNGER
G-GLUE
S/N-MAGNET,S AND N REPRESENTING THE POLLS
B-BACK OF GUN
--PUSH OF MAGNETS

This would be when the gun is cocked. "--" I think should equal the draw weight, right?