| Author |
Message
|
| judgment_arms |
Posted: 07/18/2008 12:52 PM Post subject: |
|
|
 The Judge

Joined: 17 Oct 2006 Posts: 1243 1456.17 Spud Bux
|
| socoj2 wrote: | Rotational issue with paintballs. I worked up some math this past month for shooting down the barrels of rotating tubes. ITs just not feasible. If you Are shooting down a 1.5" barrel so the ball doesnt clip the side and break. The fastest you can make it shoot is 20 balls per second. Granted this assumes barrles on a 2" diameter pattern and 1.5" in diameter.
|
I don’t see how it matters how fast the barrels spin…
Obviously you’re doing to wrong…
The barrel, breach, valve, hammer, etc all rotate together.
For example let’s say we have an 8 barreled Gatling gun:
Simplest way to make one would be to take 8 CCI Phantoms and replace the pump handle with standard issue Gatling gun cam mechanism to re-cock and fire each unit.
As for the feed something like a Q-loader or a Warp feed would be necessary to keep up, all the barrel units would be fed from the 12 o’ clock position and fire from the 6 o’ clock position.
Gas would be fed through a custom swivel/distributor.
Done. |
|
| Back to top |
|
 |
|
|
 |
| socoj2 |
Posted: 07/18/2008 15:04 PM Post subject: |
|
|
Master Sergeant

Joined: 29 Jun 2007 Posts: 170 403.45 Spud Bux
|
well let me see if i can explain...
You have a ball going in a -----> manner
Now you are rotating stuff in a ^ manner
Depending on how high your RPMS are this could be a VERY high ammount of force. and if you are doing like 150 RPM if you are shooting through just a paintball barrel the ball is going to be 1.54" from where you shot it.
IS Thrust force vs Radial. NOrmall a paintball has no Radial Force but itsdoes have thrust if you are trying to shoot down a barrel you are adding radial force on the ball.
Last edited by socoj2 on 07/18/2008 15:15 PM; edited 1 time in total |
|
| Back to top |
|
 |
| MaxuS the 2nd |
Posted: 07/18/2008 15:08 PM Post subject: |
|
|
 Colonel

Joined: 19 Jan 2008 Posts: 653 827.94 Spud Bux
|
| I had a design set out for an airsoft minigun, but the thing that made me shelve the plan was that it needed a high speed, high pressure swivel fitting that I havn't managed to find anywhere. |
|
| Back to top |
|
 |
| judgment_arms |
Posted: 07/18/2008 15:31 PM Post subject: |
|
|
 The Judge

Joined: 17 Oct 2006 Posts: 1243 1456.17 Spud Bux
|
| socoj2 wrote: | well let me see if i can explain...
You have a ball going in a -----> manner
Now you are rotating stuff in a ^ manner
Depending on how high your RPMS are this could be a VERY high ammount of force. and if you are doing like 150 RPM if you are shooting through just a paintball barrel the ball is going to be 1.54" from where you shot it.
IS Thrust force vs Radial. NOrmall a paintball has no Radial Force but itsdoes have thrust if you are trying to shoot down a barrel you are adding radial force on the ball. |
Ah…
I get it, so if the actual firing happened at 6 o’ clock then the ball could be leaving at a position as far along as 9 o’ clock…
Still it should be fairly consistent, if the ball is traveling down the barrel at the same speed and the barrels are spinning at the same speed then all the balls should leave the gun at the same position, right?
Or are you suggesting some for of external ballistics force my be imparted that would cause the ball to be unstable in flight resulting in accuracy (or lack there of) that’d make a stock Tippmann 98c barrel look like a Stiffi? |
|
| Back to top |
|
 |
| ALIHISGREAT |
Posted: 07/19/2008 4:51 AM Post subject: |
|
|
 Eternal Noob

Joined: 25 Aug 2007 Posts: 1313 1009.27 Spud Bux
|
| i think the best potion is to use a smart parts ion fed by a QLOADER then you just need to work out the timings on the barrels..... (easier said than done!) |
|
| Back to top |
|
 |
| Ragnarok |
Posted: 07/19/2008 5:55 AM Post subject: |
|
|
 Lord of Karma

Joined: 19 Dec 2006 Posts: 2629 7172.77 Spud Bux
|
| ALIHISGREAT wrote: | | Easier said than done! |
Just about everything is.
However, working out timings on the barrels wouldn't actually be too hard - run some numbers for approximate results, then a little trial and error to sort it all out.
I've worked a lot of it out myself, although I never seem to have the spare cash to make the prototypes. |
|
| Back to top |
|
 |
| judgment_arms |
Posted: 07/19/2008 6:53 AM Post subject: |
|
|
 The Judge

Joined: 17 Oct 2006 Posts: 1243 1456.17 Spud Bux
|
There is no timing on a true Gatling weapon.
Or at least not between barrel and breach...
Q-loader only holds 100 rounds, that’s why I said Warp; as I recall a Warp can feed at 54 BPS. |
|
| Back to top |
|
 |
| ALIHISGREAT |
Posted: 07/19/2008 7:00 AM Post subject: |
|
|
 Eternal Noob

Joined: 25 Aug 2007 Posts: 1313 1009.27 Spud Bux
|
the problem with trail and error is that it would be very messy.... working out the acceleration of the paintball would help as you could work out how far it would travel how quickly.....
(just a side note.... the gun would need to be very consistent to avoid breakages.... maybe multiple regulators would help?)
the best way is probably to use a custom board to make sure the gun fires in time with the barrels... (again easier said than done! as then you have the problem of actually making the board....)
so in conclusion i would get in touch with the creators of other paintball miniguns to get some tips....
| Quote: | Q-loader only holds 100 rounds, that’s why I said Warp; as I recall a Warp can feed at 54 BPS.
|
ooops i thought it was 200..... the other option is to make a custom feed similar to a warp feed that uses internals from a commercail hopper such as a halo.... and use it to feed from a bag/hopper underneath like this gun... http://www.pbnation.co.uk/m249-minimi-p-7.html |
|
| Back to top |
|
 |
| Ragnarok |
Posted: 07/19/2008 7:50 AM Post subject: |
|
|
 Lord of Karma

Joined: 19 Dec 2006 Posts: 2629 7172.77 Spud Bux
|
Damn this accursed thread...
I've had yet another idea. I can't escape the ruddy things. |
|
| Back to top |
|
 |
| ramses |
Posted: 07/21/2008 9:39 AM Post subject: |
|
|
Staff Sergeant

Joined: 29 May 2008 Posts: 123 91.43 Spud Bux
|
| socoj2 wrote: | well let me see if i can explain...
You have a ball going in a -----> manner
Now you are rotating stuff in a ^ manner
Depending on how high your RPMS are this could be a VERY high ammount of force. and if you are doing like 150 RPM if you are shooting through just a paintball barrel the ball is going to be 1.54" from where you shot it.
IS Thrust force vs Radial. NOrmall a paintball has no Radial Force but itsdoes have thrust if you are trying to shoot down a barrel you are adding radial force on the ball. |
That is interesting. to explain it better, it would be as if you attached a paintball to a string, swung the string over your head until 150rpm and let go. The effect would be less, but you get the idea. If the rpms were variable, you couldn't even control when you let go of the string. sometimes it could be moving up, other times to the left... Real guns may not have this problem because the projectile is moving over 1500fps rather than the 300fps likely for paintball. I am only going into algebra II, but someone in higher math should be able to calculate how bad accuracy would be. ex 1 ft to the side in 10 ft forward. |
|
| Back to top |
|
 |
| magnum9987 |
Posted: 07/21/2008 10:17 AM Post subject: |
|
|
 1st Lieutenant

Joined: 07 May 2008 Posts: 276 4.03 Spud Bux
|
Their are six barrels
Each has a opening to allow ammo in
As the barrel rotates it lets ammo in
Simultaneously, as it rotates, a seal covers the hole in which ammo entered
Then as the barrels continues to spin, it triggers the 12 ounce co2 bottle attached to each barrel
The same process is repeated on the bottom barrel.
This system has two hop up systems, so it can fire to rounds at a time, which means you don't necessarily need a high rpm system to get the same rate of fire. But it would be cool if you did!
Also I suggest you do some talking to some people on how to build one. Their is this guy on youtube who built the "M4 Minigun" He has built several gatling type guns and you could learn from him. |
|
| Back to top |
|
 |
| blind909 |
Posted: 07/21/2008 10:18 AM Post subject: |
|
|
 Colonel

Joined: 02 Aug 2007 Posts: 648 758.96 Spud Bux
|
Has anyone seen this, It might be able to be converted to Paintball, but the barrrels rotate, but only the middle one fires, it is either a cloud or a vortex.
CLICK HERE |
|
| Back to top |
|
 |
| iknowmy3tables |
Posted: 07/21/2008 10:30 AM Post subject: |
|
|
Brigadier General

Joined: 15 Dec 2006 Posts: 1133 2685.49 Spud Bux
|
| socoj2 wrote: | Rotational issue with paintballs. I worked up some math this past month for shooting down the barrels of rotating tubes. ITs just not feasible. If you Are shooting down a 1.5" barrel so the ball doesnt clip the side and break. The fastest you can make it shoot is 20 balls per second. Granted this assumes barrles on a 2" diameter pattern and 1.5" in diameter.
|
socoj2 mentioned a legitimate concern, but I feel he was alittle ignored
I believe what he is trying to say is that in feeding the balls can't load fast enough and will get cut up during feeding, the solution is that feeding can not happen a very limeted sharp perpendicular angle |
|
| Back to top |
|
 |
| socoj2 |
Posted: 07/21/2008 18:31 PM Post subject: |
|
|
Master Sergeant

Joined: 29 Jun 2007 Posts: 170 403.45 Spud Bux
|
No what i am saying has nothing to do with Feeding.
Think of looking at the paintball gun from the top down:
The barrel is parrellel to the Y axis.
It rotates on the Z axis.
Lets say you would like to fire a ball every 66.66 ms for a rate of fire at a paltry 15 balls per second.
you will need to make 2.833 revolutions in that 1 second. If your barrels are on a 4" diameter template that gives you a 12.566 circumference.
So you are going to be turning your a barrels at a rate of 35.5994 inches per second. or .0355994 inches per ms. Give 285 fps. it will take your ball 7 MS to travel 24" *if your thinking 14 or 16 barrels that would look like crap ;P*
Now in those 7 ms your barrel has a lateral velocity on its z axis of a .25" Not much you say?
after 10 feet it really starts to add up. Ie The ball is still traveling forward while The barrel is Rotating to the Right.
Real weapons ignore this because they travel so fast. The vulcan IS over 2800 FPS *almost 3 feet in 1MS*, So it is a fraction of a ms before it exits the barrel.
There isnt a question of whether the rotating mass could be built, that is a piece of Cake. The problem is getting accuracy with Rate of Fire. I could probably build something with 6 Guns and 4 loaders. But it would be A. Prohibitively expensive b. Complicated as hell.
There would be a LOT of customer machining and you would not want to carry it. |
|
| Back to top |
|
 |
| VH_man |
Posted: 07/21/2008 18:51 PM Post subject: |
|
|
 Swimmaman

Joined: 09 Dec 2006 Posts: 1532 168.49 Spud Bux
|
mabey you could hook up something that waits for the paintball to exit the barrel before it switches to the next barrell as to keep the minigun effect.............
either that or just go for function over form........ |
|
| Back to top |
|
 |
|
|