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Tuesday, May 31, 2016

Status

A number of readers have noticed that posts have slowed down on DZ. I haven't put up much of anything past my last action cam stuff a month or so ago.

Don't worry.

Nothing is wrong. I am just a bit busy. I still play regularly. I just played 2 HvZ events this weekend, but lately I get home from games and don't have the energy to blog about them, just stick some usual reddit/facebrick banter in here and there. Same with superstock builds, all of those are in cryo right now. I might not even bother with the Nerf Hyperfire for now, probably just the Rival Khaos, long story.

But before we get to what is going on, let's look at what is coming up for the near future.

For a while now I have been showing up in discussions of open class equipment (high velocity, stored energy) on reddit and facebrick, and been dropping mentions here and there of something called "Prometheus".

Prometheus is an ongoing development project of mine for a "kit bash" (discrete component) automatic pneumatic primary. Like many other cases, I don't just want to make my own version of the latest cool new thing, I want to jump ahead of the game, and this is no exception. I have been looking to everything that is wrong with the "current generation" openclass guns like the Red Baron, FAAG, Uglystick, and all their kin.


What I noted on facebrick:

Reciprocating barrel, pull type ram, coaxial action spring, Humphrey Products QE-3 main and 31P 3way trigger, shooting for 300fps@150psi, Upper and front top cover are 1.5" aluminum square tubing, lower is built up as in that homemade magfed flywheel thing from years ago, mounts at front with a hook and rear with screw. Internals all locate and mount on the 3 trunnions and nothing else, the trunnions and the barrel lug are the only critical dimension parts in the whole thing. Barrel is .527x5/8 aluminum tubing and breech cover and guide sleeve are 1/2" PVC schedule 40 which fits perfectly on the tubing I have. Dump chamber will stickout the side of the receiver to get it out of the way. 2" stroke and set up for short darts and Artifact mags, ram is an off the shelf cylinder probably a 9/16" bore double action like the parker one I have, with the cap side left open, or maybe a bigger one for bolt force balancing since the action spring needs accounting for there.



The basic concept is the closed bolt ram/exhaust valve engine which has been around nerf and spudguns for years. Since that post, I have changed things:

Main valve is to be a SQE-2 Humphrey, which will be much more manageable than the clunky QE-3 and yet will flow well enough for any legal nerf application (better than the majority of paintball marker valves), particularly given the operating pressure.

I have built the dump chamber, which is primarily 3/8" steel pipe, and is itself the line connecting the ram to the valve. There are no flexible lines. The chamber as-assembled will locate the valve in the receiver and itself be placed by the front ram threads. I forgot to photograph it. Volume is about 2 ci which should be about right for 150psi operation. The potential pipe tumor on the side is being reduced to a mere bulge with a cover over it.

The ram has been changed to 3/4" bore which will give me a bit more bolt closing force to allow for better barrel tuning. The 3/4" ram also relocates some dump chamber volume into the ram for slimmer profile and offers larger 1/8" NPT ports, which mean that (given proper fittings and some mild porting work) unlike the smaller cylinders with miniscule 10-32 miniature-pneumatic fittings, the air in that volume is not becoming wasted energy on throttling losses (an issue apparent to me in i.e. the Red Baron's extensive tiny hose runs between ram and dump chamber).

The grip frame concept still holds, the 31P is still going in there, and everything else.

Mandatory mention that Google Sketchup sucks, don't bother hating on my mockups, I hate it too. I am slipping toward yet another hand fitted prototype, as I have a history of, because of the lack of working CAD. Anyone know of a good 3D noncommercial CAD package?

Okay, now as to what is going on right now.

It isn't nerf. Well, wait. It is actually nerf equipment. I drive it to every game.

1993 Suzuki Sidekick LWB 4wd:


The 4 speed Aisin transmission that is in mine is not in a good state. 23 years of deferred maintenance before my ownership of this rig has taken a toll. So I have been putting together a 5 speed for it. Countershaft section finished:




Mainshaft parts all cleaned and inspected. Still waiting on a few to arrive.

The core I started with came out of a 1997 Geo Tracker (which is a rebadged Suzuki Sidekick) and supposedly worked OK. Well, one look and I wasn't about to put it in my car. The trashed input shaft and wasted bearings were apparent from the outside. Removed shifter, saw a bunch of metal particulate, uh-oh. Tore it down, found a munchy looking 5-R slider and reverse gear. Both getting replaced. Other gears all good.


I'm about a weekend away from having it assembled. It doesn't help that a supplier sent me an input shaft with a chip out of it from poor packing (shipping damage) and is now unreachable (never buy from American Powertrain Warehouse) so I am most likely out $62 and have to wait on a new one from another source. All changeover parts (wild geese, unobtanium Suzuki hardware) for the truck have been chased down to the last 2 dowel pins. Ahead of me is swap day, and this sort of stuff putting freshly worked-on equipment in service is always stressful as hell, but it will be a relief afterward. Thing's been going downhill for years and the thought of it cratering completely has been a constant burden.

All along has been the matter of my employment, slowing things down, nerf and otherwise. My primary hobby workshop is in a different city. I work late nights at a hard job all week, get nothing done while off work, and then have 2 free days to take another chip out of a project, then repeat. Oh and I just finished moving to a new apartment. So cut me some slack. Some of you guys on reddit who have given me heat about lack of new nerf content just joined r/nerf within the last 2 months, particularly you, you know who you are, you have attracted my unwanted attention. How about you take a look at my history before you make accusations like that; and on top of that, not to be elitist myself but you routinely take for granted stuff I helped lay the groundwork for. You have shown up, posted stuff that flat out entered the community because of me, and then flamed me for having the same answer. I am not sure if you are just too green to realize people have years of backstory in the nerf world or just egotistical and want to pick a fight, but get a grip, you little shit. I'm not your enemy.

Sunday, May 22, 2016

Misadventures with an Apollo (and PSA: those gears break pretty easily)

This post is the unfortunate result of a late-at night whim for a quick and easy mod project, and is more of a collection of miscellaneous notes and a don't-do-this guide than a mod guide - if you're looking for an Apollo mod guide, Mag212 has a pretty good one on Youtube, although there are some potential "gotchas" that he doesn't mention that I suspect lead to a gear breaking in mine. (If you'd just like to hear about that, go ahead and skip to the end.) I had an Apollo lying around, which I initially bought as part of a project to asses the effectiveness of Rival rounds. It hasn't done much since then, and it isn't the sort of blaster that I'd usually use - but it might make a decent sidearm, especially for a non-dart loadout. My line of thinking was "I'm probably going to sell this or give it away, so I may as well make a holster and mod it first."

This is a standard duck tape holster with epoxy rim re-enforcement, silver duck tape on the outside, and aluminium tape around the rim. The rigid panel at the back (not visible from this angle) was made from some disposable chopsticks, and the velcro strap comes from some scavenged scraps. The tab that you see on the end of one of the velcro strips was made by folding the end over and gluing a short section of the velcro to itself.

If you want to copy this holster, you'll want to sand off the nub on the front of the bottom of your Apollo's trigger guard - this makes drawing and re-inserting the Apollo much easier. Also, the Apollo's upper tac rain has a slope on the back, and it's slightly easier to holster if the tac rail is turned around so that this slope is on the front. This piece is designed so that it can only go in one way around, presumably to prevent accidental backwards insertion during assembly, but it only takes a little bit of careful cutting to overcome this.

The holster was a quick and easy build and, overall, it turned out very well - which makes what happened when I turned my attention to the inside of the blaster all the more frustrating. 

I tried to make this Apollo quieter by padding the plunger head. This is a piece of padding that is supposed to go under the feet of furniture, cut to shape with an Xacto knife after being stuck in place, and with the stray fibers at the edge burned away with a lighter. Subjectively, this seems to make the blaster a little bit quitter - but it's still darn loud. The thickness of the padding that I used is slightly less than the length of the four nubs that protrude from the front of the plunger head, so this allowed the plunger rod to travel slightly further. I didn't think that this was going to be a problem at the time, but this might have contributed to a gear breaking.

This air restrictor is a little odd. It seems to be designed to push the ball forwards by a small distance, where the barrel is just slightly narrower such that it seals around the ball. I don't think that this is a necessary for the blaster to fire - it only takes a very small waft of air to push the ball forwards and form a seal, so the ball will only leak a little air if it isn't pushed forwards before firing - but this might have a small impact on performance. Secondly, and perhaps more importantly, this air restrictor doesn't actually do much to restrict air. The plate at the back of the AR is full of holes and too small to completely cover the hole at the front of the plunger tube. Overall, I'm not sure what effect an AR removal has on an Apollo's performance, but I suspect that it improves things a little. I'll leave that for someone with access to a chronograph to test.

I removed the air restrictor, because otherwise the plate at the back of the AR would transmit the brunt of the now-flat plunger head's impact to the webbing that normally supports the AR, and I didn't want that webbing to break.

The extension spring on the trigger is easy to accidentally overextend - but it isn't a big problem if it is, as it can be replaced with an elastic band.

There are several locks under the priming bar of the Apollo. The rearmost of these prevents the blaster from starting to prime the blaster unless the plunger rod is in its foremost position. This lock looks like it might do a little to absorb some of the brunt of the impact of the plunger head. Carving down the middle tooth on the top of the lock may therefore be preferable to removing it entirely, and that's what I did.

The rack on the plunger rod that interfaces with the geartrain sits on a sled, that slides within the plunger rod. If the blaster is re-assembled with this sled in the wrong position, the blaster may be unable to prime (if it's not in contact with the geartrain), or unable to prime far enough to catch (if it's a little too far forwards) - or, worse, the blaster might end up in a situation where the geartrain takes the brunt of the impact of the plunger (if it's too far back). This is the biggest "gotcha" that I found inside the Apollo. I suspect that this could have been how I broke one of my Apollo's gears. The fact that the plunger rod could travel a little further forwards before being stopped by the front of the plunger tube could also have been a contributing factor.

After reassembling the blaster and test-firing it a few times, part of one of the teeth of the third gear from the back chipped off. Part of the tooth remained, with the result being that the gearbox would run smoothly while not under tension, but the gears would jam if under tension - meaning that it took a while to realize that a gear actually was broken!

There are a few lessons to be learned here:
  • From a modder's perspective, blasters that prime using gears suck. (We knew this already.)
  • If a blaster that primes using gears acts funny in some way that doesn't seem like a broken gear, it might mean that you have a chipped gear.
  • Padding the plunger head of an Apollo doesn't help (much), and can cause other problems if the padding isn't thick enough.
  • Take care to ensure that the sled with the rack inside an Apollo's plunger rod is properly positioned during reassembly. In particular, if it ends up too far back, the geartrain will take the brunt of the plunger's impact during firing. Keep in mind that the geartrain will be driven slightly when the piece with the priming handle is inserted into the gearbox. You might want to keep the left half of the gearbox's shell off, so that you can temporarily remove one of the gears - the gear with the flat top comes out easily - and manually adjust the position of the aforementioned sled after inserting the piece with the priming handle and before closing the gearbox.
This is probably just the sunk cost fallacy, but right now I'm sorely tempted to get another Apollo just so that I can throw its non-broken guts into this blaster and have something to go with the holster that I made - with the alternatives being to either scrap the blaster or throw on a little decoration and keep it as a wallpiece.