16 replies to this topic

[3DBBQ]

http://nt3000.googlepages.com/test

looking the new material

[CustomSnake202]

From the looks of it, it didn't work unfortunately. It looks like a solid concept though. What kind of spray are you using to create the foam? I've never seen anything like that in a can. Also, I was wondering where you get those rolls of yellow foam, because they look like perfect dart material.

[sporkboyofjustice]

It looks like expanding foam insulation that they have at hardware stores. Home Depot carries the Great Stuff brand.

[pat 1st Lt]

Yes. This has been tried before, with about equal success. It's a very solid concept, but's its been tested a lot (At least a lot of people have thought about doing it: I'm not sure how many have actually done it). I'm sure it will be done again in the future, with probably the same results.

I really wish that expanding foam insulation would cure well in PVC pipes, but the fact remains that it doesn't. The expanding foam doesn't dry well in a PVC pipe, since the way it cures is by transpiration, and the SA of the foam in a PVC is almost nothing.

Also, the foam, while it does 'expand', does not FILL the tube. Even though it may expand so much that it over-flows the tube, that does not, NOT mean that the foam is fillingthe tube without any gaps. The foam by it's nature makes bubbles and air-pockets when it cures. Imagine those bubbles as giant holes in your Stefans: nothing possibly good.

As I said, it is a very sound concept, but it does not translate smoothly to actual production.


What would probably work, as it wouldn't require as much SA to cure, and wouldn't have bubbles if done correctly, is some kind of ultra-litghweight clay, or some sculpting material. The only problem is that I don't think there is a material that is light enough to do this with, as clay would be much too heavy to use as dart material.




Sincereley,
Pat

Edited by {SF3G}pat 2nd Lt., 05 July 2006 - 05:18 PM.

[LastManAlive]

Wax paper seemed to work better, but The Good Stuff foam is too briddle for use of a dart. It would break up in the pockets or much less the barrel.

Edited by LastManAlive, 05 July 2006 - 10:16 PM.

[Enigma1313]

What would probably work, as it wouldn't require as much SA to cure, and wouldn't have bubbles if done correctly, is some kind of ultra-litghweight clay, or some sculpting material. The only problem is that I don't think there is a material that is light enough to do this with, as clay would be much too heavy to use as dart material.

Hmm...this got me thinking...it might be a bit resistant...but how about that Crayola Model Magic stuff? I've fooled around with it, and its light, airtight, and clay-like...perhaps its worth a try.

Edited by Enigma1313, 05 July 2006 - 10:46 PM.

[CustomSnake202]

Wouldn't any type of clay break on significant impact? Plus it would hurt like chartreuse if you got hit by it.

[taz22]

thats the same kind if dart i'v designd on the boltsniper forum. i'v build one dart from that stuff (hand crafted in shape, because i hadn't a can at home). they shoot very good.
i think i like the paper thing idee. because how will you be able to put wax in those tubes?

greats

[3DBBQ]

Any kind of paper can seperate the bullets, even glow in the dark paper

The bubble problem is solved:
http://nt3000.googlepages.com/air.jpg

It would suit better with longer PVC
The only advantage puDart has is that it's low-cost and can be made into any size
The problem now is that
doing so won't save any time
My idea at that time is to find a faster way to produce bullets
Is there a way to produce bullets massively?
The ultra-lightweight clay isn't really heavy, but it's too expensive

Translation: Kourge

[sam]

Thats pretty sweet. How do they preform? Are they durable?
To make darts faster you could make a board with pieces of PVC (cut to the length you want your darts) on top of a sheet of wood or some other flat material. The drill holes in the board and glue the PVC pieces on top of the holes. The holes are their so that you can push the darts out easily. Hopefully you understood that.

Hopefully the picture make a little more sense. The gray is PVC, the Yellow is the wood or other flat material, and the black are the holes.

On an off-topic note, could you post some information on the Walloper?

Edited by sam, 06 July 2006 - 11:44 AM.

[taita cakes]

Translation: Kourge

Ahhh, it all makes sense now.

If anyone has any really important questions they feel need to be translated to Chinese for 3DBBQ, keep it short, visit http://www.firemonge...php?showtopic=7 that page, and speak to Kourge.

[blinkycc13]

I think sam's idea would work well. If you don't understand, the finished product of his idea is just a bunch of little tube (PVC) with an open and and a partly-closed-with-small-hole end. The small hole should let you push the darts out and it should solve the problem of air bubbles.

[sam]

Actually I met for the board to be used to speed ud the production of regular darts, but it might work with the expandable foam also.

[bigpinecone]

I have an idea!!

Just fill the tube with expanding foam from the bottom, and have a sealed weight on top. Leave the weight on it until it dries and when it's dry, glue piece of fbr with a weight to the front, and you have a dart!
I haven't a clue if this will work, just an idea

[pat 1st Lt]

What's the weight for? Is it to compress the air bubbles? Because if it is, I'm sorry to be a pessimist, but it won't work.


The weight would push the foam out of the bottom (That little hole) before it ever pushed the air bubbles out. And if you get rid of the hole, the you're effectively made a container to hold the foam in status. The way the foam cures is by transpiration. For this to take place, there has to be an air exchange going on. This air exchange causes bubbles by it's very nature. Either it cures and there are bubbles, or there are no bubbles, but it isn't dry. And since no one wants to fire a dart made of goo that will fall apart during flight, we can't have no bubbles.

I'm sorry, but expanding insulation foam is not the material for this concept.

If you put a weight on the foam that is heavy enough to squish air bubbles that form, then it will also be heavy enough to exert enough pressure on the foam at the bottom of the tube to keep it from curing.


There may be some other type of foam out there, or some other foam-like material that cures differently, but standard sprayable insulation foam does not work in the way we all would like it to.

I swear, when I head off to college, I'll try and find some suitable materials in Chemistry. But as of now, I'm out of ideas for this concept.


Sorry if anything in my post sounded mean... it's just that I desperately want this concept to work, and I'm angry that it doesn't. I've tried this a million different ways, and ruined a pair of pants with that foam to try to get this to work, and as far as I can tell, it won't unless we REALLY start to overcomplicate it, which refutes the point of this concept: just spray some foam into a mold and *Presto* you've got a bunch of darts.

If anyone has any ideas on differnet materials we could use, I'm sure we'd all love to hear them!


-Pat

[bigpinecone]

I see you point, and nothing sounded mean at all, i just come up with lots of random ideas and post them. The other reason that i have so many ideas is that i build robots.
As of typing this, i got an idea . A nerf sentry gun
I'll get to working on it as soon as i can, because i still have school
I'll probably have it dont by the end of the week.

[General Cole]

What are you going to built it out of? Before I really knew what FBR was I thought it was expanding foam. (yes I was a super noob). I tried so many things, including making a pipe with lots of little holes and if there wasn't a foam curly fry coming out every hole it had an air pocket. Expanding foam will never make darts.