is there anything like this out there? is there a need?

[ultralight]

i know the answer to the second quesdtion is a resounding NO!
anyway...

i got to thinking about it, and in an intimidatior/imp/borg/defiant/b2kx/ego a ram hits a poppet and releases air into a port under the bolt. it takes a bit of force to open that poppet.

couldn't you use a sort of spool operation to work a stacked tube design? instead of venting the air out the front you vent the air up through the bolt which is linked to the ram/spool as in an intimidator. basically you're just permanently linking the poppet pin to the ram, removing the poppet spring, and lowering overall pressure so you don't need an lpr.

as i said before, i know there's no need, but does it already exist?

here's a very poorly done paint sketch of what i'm talking about:
[IMG][/IMG]

[FinchMan]

i don't think i've seen any guns quiet like that, I think i've seen one design but it was just another doodle.

i have seen something that may improve your design. (or at least an improvement to your poor paint skectch )

try making it a ballanced valve by encorperating air assist...

http://www.lucky-paintball.com/getlucky/viewtopic.php?t=431

maybe you could make it have a small burst chamber and forward seal so it's a true spool valve.

...maybe i'll draw up a design later....



*later*


I made the valve into a ballanced spool valve (not quite ballanced in that pic, but oh well). And i made it use an burst chamber to limit the air too, so you don't need to worry about dwell as much.

also, the way you made the ram wont work because the connecting rod for the bolt goes through a slot in the lower chamber. Probably would just use a ram from an impulse or something: http://www.zdspb.com/media/tech/animations/impulse.gif

here's a question though, is it better/more effiecient to use a level stream of constant air (like from a poppet valve) or to use a burst chamber where the air flow is limited and drops off after the initial pop (reall spool valve)?
I think that poppets may be more efficient because thats just what vikings and borgs use, and they're known to be very efficient. ... but the stock shocker bolt is less efficient than the "H.E" bolt that gives it a sealed burst chamber.

[slade]

pressures, hon... that wont work.

your HP air is exerting force on the spool that seals the air off from the bolt. your LPR is, of course, set at a low pressure, and while you potentially could compensate with surface area (to make the force exerted by the lpr greater than that of the hpr), its still not a great design. the HPA will be holding the spool back while the LPR is pushing it forward. you should be able to redesign that.

the second does look better conceptually.

[usagi_tetsu]

I believe SP is using a spool valve in their Nerve. It has a ram controlled by a solenoid just like my favorite Tribals (a decidedly poppet-valved design), but that's where the similarities end. The ram faces the back of the marker and butts up against the spool valve. Take a look at the diagrams in the owner's manual over on smartparts.com, I may be wrong, but I'm pretty sure it's a spool valve in there. If so, I think the reason the ram faces away and is not attached to the spool valve operator is that the ram has to move an inch total, while the spool only has to move a bare fraction of an inch.

Good idea, connecting it all up like that, by the way, mock up a model and do some testing. Who knows, you may have the newest thing to sell to next decade's version of the "agg" kiddie.

[ultralight]

slade, there is no lpr. it all uses the same air pressure (~150psi) like an ion.

finchman, thanks, that looks much nicer.

is it just me or does this thing look like it has the potential to be very small and light? smaller and lighter than an intimidator anyway.

[Lenny]

Wait, didn't the shoebox shockers use somethinglike this? Where a solenoid powered both the bolt and the valve? Hmm... I may be wrong though...

[slade]

slade, there is no lpr. it all uses the same air pressure (~150psi) like an ion.

finchman, thanks, that looks much nicer.

is it just me or does this thing look like it has the potential to be very small and light? smaller and lighter than an intimidator anyway.

okay, then assume you are running 150-200 psi through the noid. if the valve is .25" in diameter and the ram .5", then the bolt moves forward with 22-29 pounds of force, and returns with 29 - 39 pounds of force. you could lower that by changing the surface area of the bore, but the thing is, no matter what, the force returning is going to be greater because of the design of the valve.

[ultralight]

okay, then assume you are running 150-200 psi through the noid. if the valve is .25" in diameter and the ram .5", then the bolt moves forward with 22-29 pounds of force, and returns with 29 - 39 pounds of force. you could lower that by changing the surface area of the bore, but the thing is, no matter what, the force returning is going to be greater because of the design of the valve.

can you please show me your math? if the valve side of the piston is smaller then it should theoretically push with less force at the same pressure than the larger ram side of the piston.

here are my quick calculations:

.25" daimeter valve side of piston (v)

.5" diameter ram side of piston (r)

surface area of v = .049 [.25*(pi*(r*r))] (av)

surface area of r = .196 [.5*(pi*(r*r))] (ap)


av * 150psi = 7.35lb
av * 200psi = 9.8lb

at 150-200psi a .25 diameter piston should produce 7.35-9.8lb of force

ap * 150psi = 29.4lb
ap * 200psi = 39.2lb

at 150-200psi a .5 diameter piston should produce 29.4-39.2lb of force

according to the .25"/.5" figures, the valve side could stand to be larger in order to be closer in pressure to the ram side to reduce kick and wear. or you could reduce the size of the ram side, it would probably take a little of both.

i'm not great at math and i don't pretend to be, so please tell me if i messed up somewhere.

[FinchMan]

here's another old thing i found a while back i just remembered.

http://www.mcarterbrown.com/cgi-bin/...play&num=25068

[slade]

can you please show me your math? if the valve side of the piston is smaller then it should theoretically push with less force at the same pressure than the larger ram side of the piston.

here are my quick calculations:

.25" daimeter valve side of piston (v)

.5" diameter ram side of piston (r)

surface area of v = .049 [.25*(pi*(r*r))] (av)

surface area of r = .196 [.5*(pi*(r*r))] (ap)


av * 150psi = 7.35lb
av * 200psi = 9.8lb

at 150-200psi a .25 diameter piston should produce 7.35-9.8lb of force

ap * 150psi = 29.4lb
ap * 200psi = 39.2lb

at 150-200psi a .5 diameter piston should produce 29.4-39.2lb of force

according to the .25"/.5" figures, the valve side could stand to be larger in order to be closer in pressure to the ram side to reduce kick and wear. or you could reduce the size of the ram side, it would probably take a little of both.

i'm not great at math and i don't pretend to be, so please tell me if i messed up somewhere.

umm, what? i think you completely missed my entire post. that was a calculation assuming the piston is .5" in diameter and the valve opening is .25". when the marker fires the bolt moves forward with the force on the piston minus the force on the valve, and the bolt moves backwards with the force on the piston plus the force on the valve (which, because of the design of the valve/piston, would equal the force calculated for the piston). my point was, no matter how you change the dimensions or pressures, the force when the bolt moves forward is going to be different than when it returns; there are better designs.

[ultralight]

umm, what? i think you completely missed my entire post. that was a calculation assuming the piston is .5" in diameter and the valve opening is .25". when the marker fires the bolt moves forward with the force on the piston minus the force on the valve, and the bolt moves backwards with the force on the piston plus the force on the valve (which, because of the design of the valve/piston, would equal the force calculated for the piston). my point was, no matter how you change the dimensions or pressures, the force when the bolt moves forward is going to be different than when it returns; there are better designs.

gotcha, i forgot to factor in the force of the air in the valve/dump chamber. in that case, instead of a double acting ram you could use the force of the air in the valve/dump chamber to return the piston. possibly using a spring assist in front of the ram like a mag bolt. if that's the case, then i think it's close to the operation of the new infinity legend marker being released in april.

[usagi_tetsu]

here's another old thing i found a while back i just remembered.

http://www.mcarterbrown.com/cgi-bin/...play&num=25068

The new one, that's all the rage with the AGG kiddiez, is called the MQ Valve.

[FinchMan]

The new one, that's all the rage with the AGG kiddiez, is called the MQ Valve.

yup, that valve's pretty awesome.

[benzy2]

umm, what? i think you completely missed my entire post. that was a calculation assuming the piston is .5" in diameter and the valve opening is .25". when the marker fires the bolt moves forward with the force on the piston minus the force on the valve, and the bolt moves backwards with the force on the piston plus the force on the valve (which, because of the design of the valve/piston, would equal the force calculated for the piston). my point was, no matter how you change the dimensions or pressures, the force when the bolt moves forward is going to be different than when it returns; there are better designs.

Isnt having the bolt move forward slower and backwards faster a good thing? I always thought having a slow (relatively) forward movement and a fast backward movement was what you wanted. It kept cycling speeds fairly high but at the same time was gentle on paint. Also if the valve was designed using the new air assist type of a valve with the dump chamber idea wouldnt the valve be almost balanced to the point that in all reality if no lpr was used and a piston with roughly the same size ratio to the valve was used that the piston would be more than capable of cycling fast enough and smooth enough in todays standards? If the design finch man made was used the only unbalanced part of the valve would be the diameter of the rod that transfers air to the back side of the valve. At the forward most part of the shot when the chamber is closed the differences in the face that seals the dump chamber and the face that seals the back of the valve may be enough that it is totally balanced. I would think a stacked tube spool valve marker would be a good idea and if it was made as a drop in kit for markers like timmies and such I would think it would sell like hot cakes.

[ultralight]

from what i've been hearing, hotcake sales are at an all time low. darn low carb diets.