As many of you know, the rotation mechanism in my Vulcan, that's used to advance the chain, broke. As of right now, it's completely removed. And I sold my chains. You guys are now probably thinking, "well, that just ruined the main advantage of the Vulcan - the rate of fire." This is true. But I plan to change that.
My first idea (this is before the mech broke) was to make the chain a loop around the front of the gun (15 links fits perfectly for anyone who wants to try this; be careful on the last link's spacing, it's pertinent) and make the gear train push a dart from a hopper into the chain for an infinite feed.
But since, my overall idea for the Vulcan to feeding darts is a hopper feeding straight into the barrel. That's an entire project in itself, but I've had this idea for some time now. From what I understand, it's not original. It has been tried before. And in all honesty, a deodorant clip is basically an 8 round hopper.
So what's the most efficient hopper? The breeched hopper. Great. But, with 3-4 rounds per second, how are you going to move a breech that fast? Simple, attach it to the gear train - the plunger tube. But it needs to be closed before the gun fires. This poses a problem. Also, the Vulcan only has a pull of 1 3/4", so the stefans are going to have to be shorter.
Here's the solution, in a nice proof of concept.
The blue represents the plunger tube; the orange is the connector rod from the breech to the system. It is attached on a pivot that is spring pulled downwards. It would normally be a lot longer, and the hook on the plunger rod would be further back to allow for the plunger tube. But since thisis just a proof of concept, this small change allows a big size reduction.
The barrel is connected to the breech by a good powered spring. The white is a wedge.
Here you can see the plunger tube being pulled back. In the Vulcan this would be done by the motor. You can see the silver screw that catches the connector rod to pull back the breech.
Once the plunger is pulled back far enough, the wedge dislodges the breech. The plunger continues back far enough to lock in as normal. Note: in the Vulcan in full-auto, the plunger does not catch. This is why the return spring needs to be decently strong.
The spring closes the breech to be airtight.
The plunger shoots forward (as normal, the work is done by the plunger spring). When it reaches a certain point, it latches back together with the connector rod. It is now back where it started.
Now this is a lot of work, and calibration. But what do you think? There are a lot of fragile pieces, but they can be machined. This is very feasible. Yet very difficult. This is my proof of concept.
At this point, I will be trying to get a breechless system to work, but the problems with that are that it has to be airtight. This means the entire hopper, and the cover. And you don't want to make the cover small (which would be easier to make airtight), because that would increase refilling time.
Edited by Splitlip, 06 August 2008 - 06:54 PM.