General Questions

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cypressfalls Robert
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Re: General Questions

Post by cypressfalls Robert » November 23rd, 2009, 4:04 pm

"e. Liquids (except for water)......"
According to this rule the only liquid that we can use is water. So would carbonated water would be okay to use? :ugeek:

Also, I have tried to "use the heat from the resistance in an electrical wire to melt a mono-filament line in two" but have no idea on how to accomplish this...any ideas? :?

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Re: General Questions

Post by Dark Sabre » November 23rd, 2009, 5:34 pm

The wiki actually has some info on the monofiliment wire bonus. They are trying to get you to use Nichrome Wire, for which there is some info here: Nichrome wire Wiki.

I never got around to adding photo/video demos of NiCr wire in action, but the gist is that you hook up a short length to your battery and it gets red hot (I've lit matches and candles, burned through string, watched my helpers burn themselves, and melted fishing line). The only challenge for you will probably be in getting enough current to make the nichrome "work".

If you are using little alkaline batteries, you will need to put several in parallel for it to work. You will also probably need to use a pretty short length (maybe in the <1" range, I've never done it with little alkalines). In the missions of yesteryear, I've used nichrome in longer lengths with these types of batteries:
ImageImage
^ they are the size of two of the normal "latern" style batteries side by side. 6V each. You probably don't need a battery that big, but I've never tried anything smaller.

If you pick too short of a length, the wire will heat up too much and break, which is inconvenient since it has to be replaced every run. If you pick too long a length, it won't heat up at all. You just need to find the middle ground.

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Re: General Questions

Post by Paradox21 » November 23rd, 2009, 6:41 pm

I hooked up about an inch of nichrome to 4 D batteries. It goes through fishing line almost instantly. I just went to goodwill and bought the cheapest toaster I could find and cannibalized it. You don't need much wire.
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Re: General Questions

Post by cypressfalls Robert » November 23rd, 2009, 8:49 pm

I'll try the nichrome wire; i already took out some wire from a toaster. thanks for the help.

and do you(everyone) have any thoughts about the carbonated water?

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Re: General Questions

Post by Flavorflav » November 24th, 2009, 10:07 am

Dark Sabre wrote: If you are using little alkaline batteries, you will need to put several in parallel for it to work. You will also probably need to use a pretty short length (maybe in the <1" range, I've never done it with little alkalines). In the missions of yesteryear, I've used nichrome in longer lengths with these types of batteries:
ImageImage
^ they are the size of two of the normal "latern" style batteries side by side. 6V each. .
Do you mean these are 12 volt batteries? If they are 6V, I would like to find some. Do you know what are they called?

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Re: General Questions

Post by gh » November 24th, 2009, 9:34 pm

Pencil lead works well as a resistive heating element too; they come in convenient sizes but are a little harder to hook up to. If you aim for lower resistance (shorter and fatter), breakage won't really be a problem.
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Re: General Questions

Post by Dark Sabre » November 25th, 2009, 6:11 am

Flavorflav wrote:
Dark Sabre wrote: If you are using little alkaline batteries, you will need to put several in parallel for it to work. You will also probably need to use a pretty short length (maybe in the <1" range, I've never done it with little alkalines). In the missions of yesteryear, I've used nichrome in longer lengths with these types of batteries:
ImageImage
^ they are the size of two of the normal "latern" style batteries side by side. 6V each. .
Do you mean these are 12 volt batteries? If they are 6V, I would like to find some. Do you know what are they called?
They are 6V batteries and they are a type of lantern battery. I don't know a specific name for them and I've never seen what they are actually used in either.

I didn't buy the ones I have; they were handed down to me...so I don't really have any personal recommendations on where to buy them. I don't think I've even seen them in a physical store before.

I found the images just googling "latern battery". Clicking on the results gave me these pages:
http://www.batterymart.com/p-energizer- ... ttery.html
http://www.electronicsnmore.com/product ... ts_id/6458
I have 2 of the Energizer ones. If the produce specs on those are to be trusted, the Energizer one there has 52Ah to the Duracell's 27Ah. The prices reflect that. Under the same load, twice the Ah should mean a battery that lasts twice as long. My teams used the two I had (in series, since those years allowed 12V) for a number of years. For non-recharagable batteries, that strikes me as fairly impressive.

One of these should definitely be a cost savings over AAA/AA/C/D batteries.
You can calculate it out for other size alkalines if you want, but I think one of the Energizer 52Ah batteries (for ~$26 from that one store?) would be $45 in Energizer C-cells from Walmart. Plus you have to buy holders for 24 C-cells :lol:

I'll see if I can find anything else out about the batteries I have when I'm home over Thanksgiving.

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Re: General Questions

Post by cypressfalls Robert » November 25th, 2009, 10:41 pm

is it okay to soder the nichrome wire to copper wire?

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Re: General Questions

Post by Dark Sabre » November 26th, 2009, 5:40 am

I always just held it in tension with mounted alligator clips.

I mean, you are not going to blow anything up. Assuming they solder together, they might still come unsoldered when the NiCr is powered, though that might not happen if the copper wire is thick enough to act as a heatsink. I dunno...try and see :lol:

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Re: General Questions

Post by fleet130 » November 26th, 2009, 8:26 am

Ordinary solder does not bond to ni-chrome wire. In my experience, it's better twist the wires together (not an easy thing to do) to make a good mechanical connection or to use alligator clips or similar or some sort of screw-terminal arrangement. For "mid-air" connections you can use a #4 or #6 screw (size is not important) with 2 washers and a nut to clamp the wires together. In any case the constant terminal expansion/contraction tends to cause the connections to loosen over time. It's wise to check their security before each use.
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