32 replies to this topic

[Ice Nine]

Today, during math, I was thinking about homemades. I was thinking about how they're powered, which I concluded is air (duh). We have a few different ways of getting the air that pushes the dart, like spring and pump. Some people have used combustion and CO2.

But what about other kinds of chemical reactions, like acids + bases?

So when I got home, I sketched out a design for a chemical reaction powered pistol. In this case, the reactors are vinegar and baking soda, which I could easily obtain. I built one really simple design, but didn't glue it, and used too much of each kind of reactent, and it leaked air.

But the second version is drying in front of me.

Any ideas, questions, or comments? I'll post pictures and ranges and results when its dry.

[WEASEL]

I must say that vineger and baking soda do not produce much preassure but whatever.

[Bobert]

You could try using nitroglyceren and water, although I would run for my life on the test fire (just kidding! Dont do this!)

[Talio]

How about zinc and hydrochloric acid?

[Ice Nine]

I must say that vineger and baking soda do not produce much preassure but whatever.

You'd be suprised. I only need about three spoonfuls of each to shoot a cork, stuffed tightly in a 12 oz. bottle, to shoot the cork 30 feet in the air.

I figured that a little more vineagar and a little more baking soda, combined with a smaller area, will create a lot of pressure, enough to send the dart at least 50 feet.

[THIRST]

Vinegar and Baking soda!? Thats halarious. Not a bad idea though. I made several homemade designs planned for vinegar and baking soda a few weeks ago, and it ended up being semi-auto, except you would have to reload a dart every time...Its a cool idea. I feel lazy, so I doubt Ill do it, but Good luck!

THIRST

Looks like great minds think alike

[Vintage]

Ok, this is an idea for you:
Make a homemade that has an airtank. Have a open ball valve at one end. Whatever valve that shoots at the other. Pour baking soda and vinegar into the ball valve then shut it. Fire the shot.

It could be useful if you can readily carry vinegar and baking soda around with you.

~Vintage

[Ice Nine]

Got the pictures. The second one is the next design. The gray shaded stuff is PVC Sch. 80. I'm sure you can figure out the other things.


[/img]

Darn. The pictures are too big. Again.

[Vintage]

So, you pour the ingredients down the barrel, shut the ball valve, wait, then open it to fire?

Maybe you could keep a reservoir of vinegar in the tank, so you just have to pour a measured amount of baking soda down the barrel.

~Vintage

[Ice Nine]

Yeah, that was the entire purpose of the second design. The ball valves regulate the mixing of the chemicals in the "mixing chamber," while I can only put in a little and conserve the rest for many more weak shots, or mix it all and have a powerful one.

I load the vinegar and baking soda into the first one by:
1.) Load baking soda.
2.) Close ball valve.
3.) Fill barrel with vinegar.
4.) Open valve and allow the vinegar to go into the mixing area.
5.) Shake.
6.) Load dart.
7.) Open valve to fire.

Lather, rinse, repeat.

[BoltMasterZero]

Here's a similar idea I came up with not too long ago.


You open up the valve on the far right allowing Vinegar and Baking Soda to mix, the once pressurized open up the valve near the male adapter shooting the gun. I realized that there might not be sufficient pressure to propel the dart so it kind of stoped here, I never got around to building it.

[taita cakes]

... smooth ...
two seperate compartments, i like the idea ...

[cxwq]

I realized that there might not be sufficient pressure to propel the dart so it kind of stoped here, I never got around to building it.

Or it could be way too much pressure. The problem with the chemical reaction approach is that you never know.

I realize that this isn't likely to be a problem with baking soda and vinegar, but you really need to be careful with chemical propulsion so that you don't accidentally go over your PSI limit and blow PVC shards all over the place.

Aside from that, it's an interesting though not entirely practical approach.

[BoltMasterZero]

Aside from that, it's an interesting though not entirely practical approach.

I realized that so I stopped. That and I didn't have sufficient funds to buy all the valves and PVC. I was kind of broke.

[UpGraD3]

I remember one day while I was at Nerfonline browsing through the forums clicking on the topics that did work (I was using NerfWorlds museum) I think I saw something about someone using dry ice.

[Vintage]

Ya know Ice Nine? You are going to have one messy shot! Your barrel is going to be so greased with vinegar, that your foam is going to take alot of it with the shot.

That will be one very unhappy target! A very big room clearing event.

I think, you need to somehow isolate the gas from the remnants of vinegar and baking soda before you fire the gun. Or you will have a either a poof of powder, or a stinky victim.

~Vintage

[ompa]

Well... If you made it like a bucket with the barrel out the side at the upper portion of the barrel, most of the chemicals would stay at the bottom... at least it would reduce the stuff squirted out. Also, the pressure would still be present so there shouldn't be too much of a loss in performance, although making a bucket would mean more vinegar and baking soda to create enough gas to fill the thing.

~ompa

[Techno-Dann]

Why don't you just use a smaller tank, put a valve between it and the barrel, and hook a pump up to the tank? No mess, and it'll probably shoot further than some vinegar/baking soda gun. Plus, the fuel's free, and you'll get way better ROF.

[Vintage]

Why don't you stay out of a topic in which you have nothing to contribute?

Yes, airtanks are the easiest and quickest way to go, but chemical reactions are fun. No one has fun hooking up a bike pump to a valve stem for each shot. Especially just for having some fun shooting around the backyard. Vinegar and baking soda won't be too efficient or fast, but it sure will be a blast!

~Vintage

[THIRST]

Techno, Did you ever hear him say once that this gun would be engineered for practical use? Hoemmades are meant to be fun, and I have yet to see over 3 homemades that are actually practical and useable. Using a chemical reaction to prepel a dart is a very fun project. Why make it generic with an airtank?

Think.

THIRST

[Ice Nine]

Okay, I got all the results, but they may be a little skewed because I had to shoot it uphill.

On average, with about 5 (heaping) tablespoons of each, I got 51 feet and 5 inches. I did a mean of 10, and I used the same dart everytime, along with the same kind of vinegar (white) and same baking soda. I'm sure that I lost some distance because the best way to do it was take off the barrel, open the valve, pour in the vinegar, close the valve, put the barrel back on, put the baking soda in the barrel, open the valve, shove the baking soda down it, close the valve, insert dart, shake to get all the reactents workin', and fire. I think I lost distance because I had to leave the ball valve open for a little longer then I wanted to, so I could get all of the baking soda into the tank.

I'm sure that with the gun BoltMasterZero posted designs for (and a few of my changes), I can get a good RoF, with fairly good range.

[Vintage]

Ok, Ice Nine, I think I might have just found a fault in the design. I remember reading in my chemistry course, that chemical reactions always have limitations set by their surroundings. Things that affect reactions are the amount of reactants, heat, pressure, and mixing. I think that pressure is adversely affecting the reaction.

I think that once the reaction reaches a certain pressure in the tank, it will stop the reaction process. That would mean that the tank will never be pressurized more than a set psi. No matter how much baking soda and vinegar you put in it, it won't raise the pressure much.

Just a hunch I have that might explain the range of 50 feet.

~Vintage

[Alexthebeast]

Yes, it's called a mole Ratio.

[BoltMasterZero]

On average, with about 5 (heaping) tablespoons of each, I got 51 feet and 5 inches.

Oh, I didn't know it would do that well... Now I must do my idea! Your ranges inspire me. I shall make it semi auto too! I just have to stop being lazy.....

[taita cakes]

just imagine the future, cartridges filled with segmented backing soda and vinegar, that are combined by snapping the cartridge much like the frozen tubes...

EGAD! I said something intelligent