SpudFiles

any other ways to mix and vent besides fans and pumps? i read somewhere that putting bbs in the chamber will help mix.

Anything that can agitate the fuel/oxygen will work,such as a chain put between two points that is hung loose and is shaken works.But for venting it wouldn't do anything.

Ok well since you said mix and vent, I'm assuming you're talking about a combustion. I'm also assuming that you're talking about putting bb's in the combustion chamber and then shake the whole thing up to mix the fuel and air by way of the bb's moving around in the chamber. Honestly I do think it'd mix your fuel air mixture, but you're not gonna be able to use it to vent the spent gasses because you gotta open the system up to air and you're gonna dump your bb's out. All in all it is just entirely too impractical. If you want to build an advanced combustion go to office depot and spend $10 USD and get yourself an 80mm fan which once you zips the corners down a little bit will fir nicely in a 4" chamber. Install a ball valve on the back that you can open after each shot and click the fan on, wait about 10 seconds and click it off. Anyway short answer to your question is that it's just impractical to fill your chamber with bb's since you're gonna lose em when you open the gun to vent.

well i am not to worried about venting because i got a good set of lungs. but for mixing i need something for my mini.

Then go for it!They have a BB in spray cans for a reason,to mix the contents and thats all you want to do.

rna_duelers wrote:Then go for it!They have a BB in spray cans for a reason,to mix the contents and thats all you want to do.

They have the BB in the spray paint cans because you have to mix PAINT and the propulsioin agent! In this case, he's trying to better mix his propellent(gas form) and the Air! The whole reason that the ball is there is to move the paint, and unless he's hoping about shooting paint out of his cannon, then the BB idea is not needed. Like others have recommended, just go and buy a darn 80mm fan! That is all. Have a good day!

i dont think a 80mm fan will fit in a 1.5in chamber.

Kind of hard to get an 80mm fan into the chamber of a mini. Hard to get a 40mm fan into a mini.

You might be able to get the vibrator motor from a cell phone in. Maybe like this one;
Tiny motor with an offset weighted shaft, designed as vibrator for cellphone or pager applications. Operates on 1.5 - 4.5 Vdc. 5 x 6 mm rubber casing covers motor and is easily removable. Dimensions of motor with casing removed: 4mm diameter x 8mm long. CAT# DCM-320 $1.25 each

Depending on how small the mini is, BBs may help. Keeping the BBs in the chamber when you vent shouldn't be to hard since you probably vent by just removing the end cap and blowing into the chamber.

You can use a motor out of a little toy car or some such and model a fan to suit. The problem with this is that these fans have brushes that can expose your flammable mixture to premature ignition- simply cover all the vent holes in the motor with silicone or similar to negate that problem.
People have tried to initiate firing with these fans with not much success so it should be quite safe.
Good luck.

jimmy101 wrote:Kind of hard to get an 80mm fan into the chamber of a mini. Hard to get a 40mm fan into a mini.

But they come a lot smaller. This is the smallest fan I've ever seen, just 17 by 17mm, and 8mm deep - which is almost impossibly small. If you rounded off the corners a little bit, you could get it into 3/4" pipe no sweat.
I find it really hard to believe that there are fans so small I could fit them down HEAL's barrel, but there you are - it adds whole new possibilities for minis. I'm almost tempted to make the world's smallest advanced combustion using my special metering system I designed for metering small chambers accurately.

There are also 25mm and 30mm square ones as well.

Ragnarok wrote:

jimmy101 wrote:Kind of hard to get an 80mm fan into the chamber of a mini. Hard to get a 40mm fan into a mini.

But they come a lot smaller. This is the smallest fan I've ever seen, just 17 by 17mm, and 8mm deep - which is almost impossibly small. If you rounded off the corners a little bit, you could get it into 3/4" pipe no sweat.
I find it really hard to believe that there are fans so small I could fit them down HEAL's barrel, but there you are - it adds whole new possibilities for minis. I'm almost tempted to make the world's smallest advanced combustion using my special metering system I designed for metering small chambers accurately.

There are also 25mm and 30mm square ones as well.

Haven't you cleared that junk off you bed yet Rag!!

Ragnarok wrote:

jimmy101 wrote:Kind of hard to get an 80mm fan into the chamber of a mini. Hard to get a 40mm fan into a mini.

But they come a lot smaller. This is the smallest fan I've ever seen, just 17 by 17mm, and 8mm deep - which is almost impossibly small. If you rounded off the corners a little bit, you could get it into 3/4" pipe no sweat.
I find it really hard to believe that there are fans so small I could fit them down HEAL's barrel, but there you are - it adds whole new possibilities for minis. I'm almost tempted to make the world's smallest advanced combustion using my special metering system I designed for metering small chambers accurately.

There are also 25mm and 30mm square ones as well.

Ragnarok: A bit hung over from too much partying last night?

You quote my post, then describe a 17mm x 17mm x 8mm fan. In my post I linked to a 4mm diameter x 8mm motor which will probably work as a fan without any modiification (you wouldn't even have to add a fan blade). My motor is less than 1/4 the size of yours.

Wait a minute, that doesn't sound very manly ...

Hmm... I feel the presense of a pachyderm yet again

Don't worry, you can both have motor size issues compared to this massive beast.


You would have to fiddle the cell phone motor a bit and get some blades on there to get a decent movement of air going, an offset weight on the shaft is going to give dubious performance.

Ragnarok you want to share with us your " special metering system with us?" Tha is what I am trying to do is make an advanced mini just because you don't see a whole bunch of them.