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mini combustion

Posted: Sat Jun 12, 2010 8:13 pm
by ilovefire
this is a mini i made in a couple of hours its kinda ghetto but i was just wondering is a chamber fan would make a mini of this size any better/easier to use it may not be that powerful but i think the fan works quite well on this mini.

Edit: here are some pics of the improved version, i think its much better

barrel: 6mmx140mm
chamber: 15mmx80mm
fuel: propane butane mix
ignition: pizero
gun length: 250mm
ammo: BBs

[youtube][/youtube]

[youtube][/youtube]

Posted: Sat Jun 12, 2010 8:21 pm
by Ranger
Neat :P I dont think a chamber fan would have much effect (affect?) on such a small gun.

Posted: Sat Jun 12, 2010 8:31 pm
by ilovefire
Ranger wrote:Neat :P I dont think a chamber fan would have much effect (affect?) on such a small gun.
hmmm maybe i might make another without the fan and compare the two to see if your right, if you are it was still a fun little project.

Posted: Sat Jun 12, 2010 8:34 pm
by theBOOM
Very nice combustion I'm just wondering how you managed a fan almost the size of your chamber in there???

Edit: where did you scavange it from?

Posted: Sat Jun 12, 2010 8:38 pm
by Ranger
:oops: The way I read it I thought you were asking if a chamber fan would help. I didnt watch the vid. :oops: Oh well :roll: Its still a cool cannon (gun, Pea shooter :D )

Posted: Sat Jun 12, 2010 9:06 pm
by ilovefire
theBOOM wrote:Very nice combustion I'm just wondering how you managed a fan almost the size of your chamber in there???

Edit: where did you scavange it from?
i got the motor from an old cd player, i made the blades from some very thin aluminum and just cut the mount out of some plastic then glued them all together
Ranger wrote::oops: The way I read it I thought you were asking if a chamber fan would help. I didnt watch the vid. :oops: Oh well :roll: Its still a cool cannon (gun, Pea shooter :D )
sorry now that i look back at it i can see your confusion, i will go edit it.

Posted: Sat Jun 12, 2010 9:32 pm
by theBOOM
Nice thinking, but I was wondering how you actually mounted it onto the combustion chamber.

Posted: Sun Jun 13, 2010 1:56 am
by deathbyDWV
Yeah a fan prolly won't effect (affect) :? the preformance with this small of aa gun. It is neat though... :)

Posted: Sun Jun 13, 2010 2:57 am
by ilovefire
theBOOM wrote:Nice thinking, but I was wondering how you actually mounted it onto the combustion chamber.
oh ok sorry, if you look at the picture of the fan you can see the black U shaped peace of plastic which fits tightly in the camber but so it can still slide, then i put some glue on the inside of the U then slid it in the chamber then you put the fan in and center it, solder some wires on made a small hole in the chamber put the wires through then slid the fan in. hope that answers your question.

Posted: Sat Jul 03, 2010 6:13 pm
by Zeus
I didn't see the video (low internet download limit), so I don't know if you
are using fuel metering, but if not it would make quite a difference.

Compared to most minis here, it's very tidy. The 9V battery clip interests
me though. I've never seen one witha switch integrated with the clip.

If it does what you want, you don't need to change anything about it.

Regards

Lachlan

Posted: Sat Jul 03, 2010 7:42 pm
by ilovefire
Zeus wrote:I didn't see the video (low internet download limit), so I don't know if you
are using fuel metering, but if not it would make quite a difference.

Compared to most minis here, it's very tidy. The 9V battery clip interests
me though. I've never seen one witha switch integrated with the clip.

If it does what you want, you don't need to change anything about it.

Regards

Lachlan
no its just a spray and pray sort of thing although i dont usually have to do much praying
the battery clip was from a dead 9v battery that i modified to have the button
and thank you for your kind input.

Posted: Sat Jul 03, 2010 7:57 pm
by Zeus
Well, metering is very easy to do. If you can find out the volume of the
chamber (pi(r*r)*l).

Going by my sums, you'd need to inject about 0.45 mLs into your
chamber. That is easily done with a measuring syringe.

If you use butane, hold the chamber with the barrel pointing up, if
you use propane, point the barrel at the floor. Make sure that you
load the barrel first.

I see that you used a mix of propane and butane, can I ask why?

Posted: Sat Jul 03, 2010 9:11 pm
by theBOOM
It easy to do it with the valve from lighters, the one the butane comes out of, rip that from the lighter, go get a butane refill tank for lighters, push the small valve you salvaged from the lighter onto the tip of the syringe body and simply press the syringe down on the valve ontop of the refill bottle, your syringe eshould fill with butane.

Atleast that's how I do it.

Posted: Sun Jul 04, 2010 7:38 pm
by ilovefire
Zeus wrote: I see that you used a mix of propane and butane, can I ask why?
thank you and i used the mix of propane and butane because my brother found a part used can from a gas gun at work and gave it to me and i found that it was better then just using butane
theBOOM wrote:It easy to do it with the valve from lighters, the one the butane comes out of, rip that from the lighter, go get a butane refill tank for lighters, push the small valve you salvaged from the lighter onto the tip of the syringe body and simply press the syringe down on the valve ontop of the refill bottle, your syringe eshould fill with butane.
theBOOM wrote:
thank you i will have to try that

Posted: Sun Jul 04, 2010 8:55 pm
by inonickname
The plastic braces/supports/whatever are a very good touch, and it looks very nice. Whether or not the fan does much on this scale is debatable. For a while, I had trouble getting my advanced mini to fire with a metered mix. I think a shorter, fatter chamber works better than a skinny, long one.

But keep the fan, it's a nice touch.

By the way, when you're using the quote tags:

The first tag is correct. For the second on don't use the same, simply use "/quote" (in the square brackets).