I was thinking
A two distant sear engagement points.
B making the transfer port further back on the frame than where the 2 rams have their near collision.
C 2 different cocking levers, or 1 to make it super complex, but 2 would be fine by me.
Im sure there are 10 more, please share. tia

Crosman developing a dual rammed gun and you got the drop on it?
Spit it out, I won't say anything, I promise.

S.W.A.G. it!

so its eeither a bullpup pcp, a dual ram , or an electronic prod is my best guess.

In every dual-piston gun I know of, the two pistons are mechnically linked to force them to move in unison. This is true of both diverging piston (like the Dianas) and converging piston (JWs) designs.

So you can probably start with that pretty large complication. The good news is that at then least you need only one sear and one cocking linkage.

Small favors.

Steve

once you have the 2 opposing pistons within 1mm of each other, then u start securing the rear end of them. knowing that 1 mm is the buffer space.. the the initial tp is drilled in the comp tube right above this and ideally run right into the barrrel.both triggers can be fired at same time with simple connecting rods and a pivot rack pinion type linkage.. as for the cocking , i havent come up with a mind visual for how they would both cock off one lever/

...then the opposing pistons, even if released at the same instant, will experience different driving forces, accelerate at different rates, travel at different speeds, and therefore can be expected to come together at a spot where (regrettably) the transfer port isn't.

That is, unless they're mechanically coupled.

Steve

Ok good point , well taken , the damb gun might barely fire in this case, How do we make the 2 pistons codependent withought having em facing the same dirrection>??tia

Steve

go dance and sing in the rain, you just might
get an epiphany. Couldn't hurt right?


S.W.A.G. it!

just something to stir the brain cells, saw a engine at the portland Ind. engine show a few years back. two piston, two cam, two cranks and ONE cylinder, all horizonaly opposed and timed with chains!! there was one spark plug in the cylinder and the pistons came to TDC with about a inch in between. set there and ran like a top. Dave.

that takes some serious planning and engineering aptitude....

so that they see the same pressure. Would that be enough?

would equalize pressure and speed perfectly/.

...of the prevalence of pre-charged sealed rams. But on second thought, you're right and I was wrong - that's not much of an objection. It might make final assembly tricky, but it'd actually be a terrific feature to have a little external plumbing since it would make it possible to incorporate a Schrader valve to allow adjustment and recharge of the rams. Yours is a good idea.

And equalized pressure might well be enough to synchronize a pair of converging pistons, since the other variables - like piston dimensions and mass - should be accurately controllable.

Just so long as the piston latches could be made to release at "exactly" the same time. That is to say, within a few micro-seconds of each other.

Steve

not to mention the added benefits steve mentioned.as for the 2 sears my rack pinion go kart steering idea would be simple and effective i feel.

Not exactly a "simple springer" anymore, though....

but the rack and pinion is simpler and only adds about half a lb to the design..Now can we figure out how to cock both pistons with one lever.

...because the

1. "flight time" of a springer piston is around 0.010 seconds,
2. stroke length is usually of the order of 4"
3. the distance a constanly accelerating thingie travels is proportional to the square of the time it's been accelerating
4. we need linear accuracy of piston convergence (guessing) of about 1/20" = 1/80th of the total stroke.

That means the tolerance in the timing of piston release is 0.01/80/2 = 62 micro-seconds.

That's tricky for any mechanical device.

Steve

maybe the solenoids is the better idea, but you have said previosly that lock time on those is a crapshoot, and thats also been proven on mythbusters when those rigs are impossible to time.

Ps I did somne reading and as it turns out becuase people are crazy, the bigger question is how did doc complete all the time circuits in 1885. I figure its simple , no he didnt have microprocessors but he likly was able to duplicate all his schematics with good old fashion wires, hence he neeeded an entire train to accomodate all the wiring.

Steve

so basically making an imitation JW economical is out the window,..

...it looks vewy vewy twicky.



Steve

either need to linked again somehow , or they need to have a crash point in the middle.

While the link I provided speaks to hydraulic, I believe working with gas would be more difficult because it is easily compressed.
http://www.dynexhydraulics.com/split.htm

people seem to have little difficulty building a co2 or pcp rifle from scratch. show me a few people who have built a spring gun. I don't mean take a pile of parts and assemble but some one who has actually built a spring gun. like make your own parts then assemble./ then to make one with a double ram?

any one ever try to shoot both barrels of a double barrel shotgun at once....extreemly hard to do cause once one barrel fires the recoil drives the gun back and takes pressure off the second trigger. john

building a springer is likely more complex than all other designs,