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| BC Pneumatics |
 Posted: 05/09/2008 22:22 PM Post subject: |
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Donating Moderator
Joined: 18 Jan 2005
Posts: 1085
2349.99 Spud Bux
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You've got me all wrong David, this is the stuff I love to see, I was just pointing out it probably isn't your best bet for performance:cost ratio.
In my personal opinion a backpack leaf blower based BBMG would take the cake for coolest BBMG here.
I myself have thought of the idea before, but ditched it due to my lack of cash to buy anything better than the bottom of the line electric blower I have. A stunning 65mph or something 
(These considerations took place when I was probably 14, so the project has long been considered 'abandoned'.) |
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| Drop that Sound |
| Posted: 05/09/2008 22:25 PM Post subject: |
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Private First Class
Joined: 22 Jan 2008
Posts: 30
74.85 Spud Bux
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Is the blower gas or electric? Wouldnt it just cause the fan/turbines to drag and burn up the motor?
I dunn'o man maybe a turbo shaft attachment of some kind with a cyclic feeder. In other word a mini gun type with more barrels for more flow. I would suggest holding your hand over the blower and try to run it.
Good luck man!
-Drop |
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| magnum9987 |
| Posted: 05/09/2008 23:13 PM Post subject: |
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2nd Lieutenant
Joined: 07 May 2008
Posts: 229
0.74 Spud Bux
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| couldn't the cover of the air fan be removed, and instead a solid cover be added. then the vortex block does around the covered fan. A path just beyond the leaf blower fan blades would create a slip stream not unlike you see in a whirl pool. With the air coming in from near the source of ammo, the ammo is sucked in vacuum style, and centrifugal (spelling?) force carries the bb down the barrel. The problem is making the fan powerful enough to make the device above average performance. |
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| rna_duelers |
| Posted: 05/10/2008 1:51 AM Post subject: |
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Major General
Joined: 26 Sep 2005
Posts: 1615
3047.84 Spud Bux
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| It could be done in theory and achieve a realtive high fps,just look at a turbo charger on a vehicle they can be made to achieve upwards of 70psi of pressure in very high volumes although they do work at high speeds upwards of 100,000 rotation per minute.It could be done,but being feasable and practicle at the same time?It's out of the question. |
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| CpTn_lAw |
| Posted: 05/10/2008 5:24 AM Post subject: |
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Colonel
Joined: 11 Sep 2005
Posts: 501
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| small turbocharger actually rotate in excess of 200,000 rpm...mine has a max. rpm of 211,000..... |
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| psycix |
| Posted: 05/10/2008 6:40 AM Post subject: |
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Major General
Joined: 25 Jun 2007
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The idea is good, but I think it wont work very well.
Leaf blowers got flow, but no pressure.
What we need for spudguns, is mostly pressure. |
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| SPG |
| Posted: 05/10/2008 8:08 AM Post subject: |
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2nd Lieutenant
Joined: 09 Feb 2006
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Hang on though, haven't we already established that the pressure in a vortx or cloud is really quite low, and that what they relied on was flow? I thought JSR had done stuff on this, all that stuff about hop-ups and barrel chokes to build pressure?
And surely if you reduce the size of the nozzle on a leaf-lower you're going to increase the speed of the air flowing through it? I'm sure there's some lovely maths which would tell you just what these increases would be for any two given nozzle areas (would it be velocity squared perhaps?)
Anyway, if anyone has a leaf blower it should be a simple enough experiment to try. |
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| POLAND_SPUD |
| Posted: 05/10/2008 9:05 AM Post subject: |
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Colonel
Joined: 13 Oct 2007
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there are hardly any compressors using this way of pumping air... becasue this gives a lot of flow and very low pressure...
as someone said before - for the same price you can buy an used compressor that would serve you much better |
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| magnum9987 |
| Posted: 05/10/2008 10:40 AM Post subject: |
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2nd Lieutenant
Joined: 07 May 2008
Posts: 229
0.74 Spud Bux
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| Well, a lawn mower with its relatively heavy blade, achieves only 2600-rpm. If the fan on a leaf blower where to replace the blade, the rpm would increase. THe question is will the increase in rpm be substantial. |
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| STHORNE |
| Posted: 05/10/2008 10:51 AM Post subject: |
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Master of Spuds
Joined: 14 Feb 2007
Posts: 1160
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Found this on ebay
It's a really good deal on a miniature 12V 250 psi air compressor...
only $13 TOTAL!!! |
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| magnum9987 |
| Posted: 05/10/2008 11:02 AM Post subject: |
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2nd Lieutenant
Joined: 07 May 2008
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| i dont believe in ebay. jk |
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| STHORNE |
| Posted: 05/10/2008 11:07 AM Post subject: |
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Master of Spuds
Joined: 14 Feb 2007
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| magnum9987 wrote: | | i dont believe in ebay. jk |
lol, so what do you think? 
You could just make your own compression tank from (nsf-pw) pvc and hook this up to it as a motor. Then you will have a bigger "compressor" for a fraction of the price 
I'm actually thinking about buying it myself if you're (or anybody else) not interested... |
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| Imortal87 |
| Posted: 05/10/2008 11:11 AM Post subject: |
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Private First Class
Joined: 10 Nov 2007
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Unfortunately a leaf blower even funneled down isn't going to create much more pressure than what it started with. Using the fan in a blower just wont create any more than a few psi, compressors use a piston to seal off and drive air into a chamber to be stored and used later. I tryed using a blower in much the same way a long time ago to shoot pea gravel and it got us nowhere.  we had more fun feeding the gravel directly into the turbine and letting it fling the small stones. For the weight of a decently powerful leaf blower you could probably get 3 or four air tanks 14" long and 2" dia. PVC. Which is what DavidVaini and I are currently using to power our gun. Not to mention the price difference.
You can even get a cheap compressor and thorw it all in a back back with a car battery.
See STHORNE's last. |
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| SPG |
| Posted: 05/10/2008 11:12 AM Post subject: |
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2nd Lieutenant
Joined: 09 Feb 2006
Posts: 236
500.93 Spud Bux
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I have one of those compressors and:
a) it'll never get beyond 125psi
b) it takes five minutes to pump one 28" bicycle tyre up to 125psi
so I'd say it's not going to be much good in a BBMG.
I take it no-one else is rising to the comment I made about low pressures inside vortex chambers. Ahhh if only JSR wasn't occupied with the mamacitas. |
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| magnum9987 |
| Posted: 05/10/2008 12:14 PM Post subject: |
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2nd Lieutenant
Joined: 07 May 2008
Posts: 229
0.74 Spud Bux
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| Like i said earlier, it is less predictable to measure the strength of the slipstream that will actually propel my system. Rather than pressure all it needs is centrifugal force and air behind it provided by the fan. It is a proven principle, Don't ALL tornados basically do the same thing though less predictable? But the question is how effective will it be. |
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