Friday, March 21, 2014

Rapid Upgrades and Rambles.

This last few days saw a lot of Rapidstrike tweaking.

Following the testing of the OMW Swarmfire spring, it was clear my RapidSwarm (my current stock class and HvZ workhorse) had to have it. Also, a fellow member of the squad proposed a hybrid type of grip design for a proper Swarmfire trigger/foregrip on these and requested that he finally get the recommended Swarmfire upgrade. Finally, I finally got the Rapid2 back. Finally. It had been loaned, along with a battery pack, to a player last game - so this was my first opportunity to install its new custom battery pack in the correct location.

Up first was the RapidSwarm.

Here is where design for service comes in handy. The entire front assembly, including the barrel shroud, inner barrel, flywheel cage, front sight and Swarmfire receiver are a lift-out module. No annoying workshop worthy procedure here.

Note that the mechanical modularity is inherent when you do the Swarmfire install properly. What isn't inherent is that this entire section of the wiring harness unplugs.

That is a wise decision for RS builders. It only takes a minimum of 3 pins (for front-wired or Swarmfire equipped guns) or 2 (rear-wired and non-underslung equipped) of power connectors of your choice to do the basic common builds. The magwell area has adequate room to place these connectors and secure the wire.

CT-0268 also had me install the VFG/trigger unit (mentioned below) on the original RapidSwarm's twin, but he elected to omit the connectors at build time to save pocket change worth of parts, resulting in a tedious Swarmfire upgrade and grip install.

And here's a nice visible example of flywheel buildup after a recent test of elite darts. A lot of nerfers know this rubbery stuff that accumulates on flywheels from high-speed, high-temperature contact with dart tips and foam.

But what continues to baffle me is that the default assumption is that this phenomenon is somehow a problem.

Flywheel buildup is a normal and functional part of high-end flywheel gun operation. Dart damage will drop off and velocities will increase significantly after a new clean flywheel set has developed its buildup layer.

Note that the buildup self-aligns to the assembly of the gun: cage to magwell alignment, flywheel axial position on the motor shafts... It's a lot more accurate than you are (without machine tools and overkill measurement methods). In fact, it almost forms a concave surface in this example, and at the very least, will correct for any taper of stock flywheels that is a usual suspect for accuracy problems.

So don't worry about it. Don't clean your flywheels. Don't apply stuff to them either. One, the gap is probably correct from the factory. Two, mark my words about Delrin objects rotating at high speed being a bad place for anything adhesive. It will shred. When? Who knows. Probably when you are about to get tagged.

The best way to get flywheels gripping better and running truer is to go to the range and burn ammo.
So, the spring was dumped into the Swarmfire, which was cleaned and lubed as always (anyone who tells you that putting "nerf" before "gun" somehow magically exempts you from maintenance requirements has never cleaned an HvZ gun and seen all the shit they collect!) and performed as expected. But we have had enough images of Swarmfire guts, you know what working on Swarmfires looks like.

I also modified a Swarmy cylinder retainer with a steel grip loop to allow quick cylinder dropping in the field (the idea is to tie the retainer to the gun with a piece of paracord or something so that the retainer can't get lost). That will not be implemented in combat. Not yet. Why? It's real dumb... I can't think of a sound way to carry the damn cylinders. They are an awkward device, and they have darts protruding that you don't want to dislodge or mangle. This calls for a specific piece of tac gear, a Swarmfire cylinder bandolier or a MOLLE Swarmfire cylinder pouch/clip or something.

So here's the VFG/trigger pack that CT-0268 devised, based on a Retaliator-type Nerf VFG (a common and often unwanted accessory) minus the junk railgrabber it comes with. The combination of a vertical grip with a trigger is odd. Reminiscent of an RPG launcher, perhaps. I would not have come up with that, and I recommended a real pistol grip, but it works.

His got a "stock" dual-contact switch salvaged from something Nerf, along with a Stampede magwell interlock button, which resembles a grip switch button when installed.

I was not to be one-upped, though. Sure, I did that work, but I wanted to go one step farther and upgrade to a microswitch and a proper ergonomic trigger.

I fabricated the trigger from PVC sheet, installed a steel pin for the trigger pivot and used the usual full size microswitch, with no lever actuator. The result is extremely crisp and has a very short pull. Just the ticket for my snappy new 90-100fps Swarmy and its higher amp draw...
 Here you can see the trigger/switch arrangement and how short the stroke is on that.

 And the trigger removed.

 And the trigger itself.

Ah yes. You should ALWAYS have a trigger guard.

Negligent discharges of these Swarmfires have been a major problem with the old side trigger system. Initially, CT-0268's gun did not have a guard on the new grip assembly, but a few days later it was clear I was not crazy to suggest a guard. I fabricated a guard on the spot with some PVC sheet heated over a stove burner and bent. Slammed it on with Devcon. Problem solved.

My install got the exact same guard from the start.
Now, in my case, there was a certain problem with the change to the foregrip trigger: I am a habitual mag gripper when I handle rifles, ever since the Stampede era, and find I can get the fastest sidewise engagement of a sudden target (such as a dodging zombie) by mag gripping my rifles. Keeps the mass (of the support hand and arm) pulled in tighter, less inertia to swing around. Thus I tend to shun VFGs and foregrips in general. My old side trigger rig could not go, it had to remain for snap reaction use, since I will not be using that VFG continuously.

So, it got a separate safety, solving the problem of Swarmy NDs and not being able to chuck the gun into a car trunk without it going off.

So here it is.

Up next: That stick battery install into the Rapid2.

This stock had already been prepped for a stick battery as covered a while back and I had also made the pack for it, a slightly shorter while back. It is a 2S, using the Sanyo UR18650SAX cell as all of my budget packs have.

(A note on the state of the big Li-ion changeover: It is a huge success, the packs are all troopers. I cannot understate how awesome being able to check state-of-charge with a voltmeter is. I also cannot understate how awesome the low self-discharge is. In the time since last game and following Worldfire events and other nonsense, many nickel packs of mine self-discharged, built up voltage depression and went out of balance, and had to be slow charged and cycled to get back in the game. Meanwhile, the 2S Li-ion from the loaned Rapid2 didn't even need a charge!)

All it took was a quick wrap with some sock material to provide some impact protection and stop rattling, and you would never know it's there. Light and unobtrusive.

"Where the hell is the battery for that thing?" 

Take that, Trustfire Brigade! Can't get a junk AA holder into here now, can we...

Unfortunately, with this choice of battery location and the particular way I implemented the stock, the RS has to split to access it, and that includes charging.

A spare female Deans and a balance tap extension tucked inside a tool-free access cover on the receiver would solve that VERY nicely. You don't want to charge lipos while they are installed in something, but these packs aren't lipos, and are about as safe as 3.7V chemistry Li-ion charging gets.

When I get around to it, I guess.

With the current motors in this unit and occasional use there is no big problem with battery life.

So on another note... Anyone remember this beast?

The Cyclone DMR.

That wss a time in my HvZ career where I had run several games with my trusty Swarmpede, and proven the rifle/Swarmfire deal was my stunning tool of choice... but I wanted to give a more civilized weapon a try. This was it: long-barreled, iron-sighted, semi-automatic, equipped with monstrous high-end motors and a flywheel configuration that works to defy the conventional logic of barrel length and flywheel accuracy, and it remains the sweetest handling nerf gun I am aware of.

Recently I brought it out to advertising and got some clean shots on zombies that my Rapidstrikes could never hope to match.

There is something to be said for that whole concept.

Don't get me wrong, I'm not going to full-scale-game this gun any time soon. But it still is just as good at what it does as I designed it to be, even today.

At least after I clean the sticky trigger.

Damn gremlins.

1 comment:

  1. Highly accurate Stryfe you say.
    Looks like I have some digging to do to find your posts on them.