12 replies to this topic

[CaptainSlug]

I don't want to take over snakerbot's thread so let's move this here.

Support for Constant-Force Spring pair (21lb total draw).

Support for ESLT extension spring.

Support for any 11-inch compression spring.

The plunger rod is pushed backwards into the plunger tube by the foregrip.

Redirect piece attaches to the backside of the grip frame.

Redirect piece is a pipe coupler, pipe plug, and a polycarbonate disc to act as a stop for the plunger head. The barrel output is a 5/8" hole with a 1/2 CPVC stub glued into it.

Trigger is the same as a plusbow Rev.3, just backwards and on the opposite side of the grip frame piece.

[TheNerfZilla]

With so much weight suspended out front by those rods, are you worried about the rods flexing or bending at all? I would worry about the long-term durability of a system like that.

Other than that, this is is awesome, I can't wait to see the results.

[CaptainSlug]

Maybe, we'll see. The back-up option is to switch to 1/4-20 threaded rod (less than a dollar per foot) and spacer stock.

[Meaker VI]

Myself, I'm not sure I see the need to avoid slots completely. The 1-1/4" PVC 'frame' with through-cut stopped slots as in the PSCR is quick and easy to machine with common tools (I used a framing hand saw and it took like 5 minutes). I'd be worried about torsion on those rods breaking the frame pieces, and the frame pieces built to avoid slots would take longer to make than a through slot. The only improvement I can imagine on the PSCR system is an all the way through slot, and all that would require is anchoring the 1-1/4" PVC to a couple of 1" PVC stubs at either end.
 

I'd like more detail on the redirect though, that is really cool.

[Snoop Doggy doge]

This is what I'd be down for funding? lol 

I see this as more of ESLT and Plusbow combined, also is that a o ring holding a seal in? I'm assuming that there is a rod pushing the plunger head back and caught on the rod, instead of a sear in the back that's for a floating plunger head. 

[CaptainSlug]

The plunger is basically just backwards from a usual springer. The rod is used to push it against the spring instead of pull against it and they're attached together (unlike the PCSR). The back of the plunger head only has a spring alignment piece.

 

The o-ring is the seal against the plunger rod.

 

Here's an exploded view of the redirect.

 

If you want to use this in a PCSR all you do is make an identical plug that lacks the o-ring seat, then screw the two together face-to-face. Or better still wedge a frame piece inbetween them and mount a grip to it.

 

I'll slap together a slotted pipe concept of this blaster tonight or tomorrow.

 

Here's the draft. I managed to design it without slots.

If you're not color blind, you're about to be...

Edited by CaptainSlug, 20 July 2016 - 09:53 PM.
New images

[DjOnslaught]

Since the plunger system is backwards, does that make it a reverse plunger? Over all the system looks like what the mega centurion should have functioned like.

Still heavily interested in this blaster.

[Zorns Lemma]

Since the plunger system is backwards, does that make it a reverse plunger? Over all the system looks like what the mega centurion should have functioned like.

 

No

[DjOnslaught]

 
No

Well the function seems the same just a different mechanism for it, the tube moves to compress the spring instead of the plunger rod...
Maybe I just misread it though

[xXD3V1LXx]

In a reverse plunger the airflow is directed into the plunger rod which is facing backwards. The breach is the plunger rod where the seal is formed at the end. The plunger tude is then what holds the spring load so when you press the trigger instead of the plunger rod moving up the plunger tube does. Now the problem with reverse plungers is since it is using an oring it does not allow for the use of a larger plunger tube this was a problem with the older models. Now the pnly reason the mega centurion is using one in my mind because hasbro doesn't want it hurting small children as it is pretty powerful for a stock blaster already.

[Meaker VI]

Well the function seems the same just a different mechanism for it, the tube moves to compress the spring instead of the plunger rod...
Maybe I just misread it though

The PT is not moving, hence, not a reverse-plunger system.

[CaptainSlug]

Making a Reverse Plunger Tube blaster not suck would require nesting the barrel into the plunger itself. Then having a compression spring ride on the outside of the barrel. Otherwise you end up with the same problem that stock blasters with reverse plunger tubes have, which is lots of dead space. And therefore way lower potential peak pressure.

 

I futzed with a design a while ago, but it's such a miserable setup and even if you could rear-load one you would be at rick of suction-loading the dart into the plunger tube. So I never bothered making a prototype.

 

Anywho, I will decide after Apoc which of the two designs in this thread I will tackle first. The Trishula or the PCSR. Here's what the PCSR ended up looking like after it was revised to use snakerbot's redirect.

[Meaker VI]

I vote for PSCR, if that means anything. It's a solid format and your model looks simpler than Trishula.