Smallchicken
Mechanical
- Jun 12, 2006
- 1
Help a guy that likes to tinker. Bet I have you guys smiling before you finnish reading this..
Need to rule in or out the use of Spool Valves for a main valve OR a triggering/control valve to open a quick exhaust or diaphragm valve with the 4-6 CV needed for this application.
Currently using a 200 psi 5 CV, 150 psi, quick exhaust valve modifed to work as a piston valve. Vents the air to atmosphere to open the QE. Works like a charm for SIMULATED blowing up of paintball tanks, bridges, buildings, bunkers, helicopters, and amphibious landing craft, etc.
The projectile is a 2" diameter foam football with fins called a Nerf Vortex Pocket Rocket. Muzzle Velocity is limited by the field's insurance companies to 230 fps.
So the performance issue is NOT more velocity but a quest for smaller, lighter, more compact, and faster rate of fire for our pneumatic "Bazookas". Safety is always the first consideration.
I have already built an rotating magazine autoloading bazooka. Weighs 6 pounds as a prototype for concept testing. The first in the paintball community that I know of. Autoloading cannons exist but are large, heavy mechanisms that have to be hauled around in motorized tanks/vehicles. I have YET to engage one with anything approaching a rate of fire exceeding 1 round per 4-5 seconds. They seem to be having the same issues I'm listing here.
For your amusement, here is a link to some pictures of the painball tanks in use.
Now I need to increase the rate of fire and minaturized it even more to reduce weight and overall bulk of the bazooka.
I would be the terror of the tank community if I could achieve 1 RPS firing rate. Of course, faster would be better up to a point where you can empty your magazine before you can target it properly. But those Nerf Rockets frequently don't fly straight and you need to get additional rounds off at that tank before the turret gunner lines you up with his 13 RPS machine gun and welts you up with paintballs. You pay a price to hunt tanks.
The limiting factor to overall SIZE is the operating pressure and the static air chamber volume behind the quick exhaust discharge valve. Currently 150 psi using a 100 ci air chamber. Theoretically, by increasing the operating pressure we decrease the static volume required.
But main valve opening speed is a significant factor because of our desire to have as short a barrel as possible - currently, 18" long.
Neither a quick exhaust or a diaphragm valve gets completely open before the Nerf has left the barrel.. It only uses the top 150 psi down to 80 psi to actually get the Nerf up to speed and out of the barrel. Since the triggering is a complete dump of the air chamber, considerable air volume and psi is wasted.
Hence, my hope to use electronic valving and try to CLOSE that valve in time to save some of that wasted air AND to decrease the RECHARGE time and thus increase the potential rate of fire.
The air chamber recharge time would be decreased and potentially increase the Rate of Fire. Plus increase the air efficiency of the cannon's air supply. Typically 68 ci x 3000 psi paintball air supply tanks. Their outputs are regtulated to not more than 1500 psi and usually 850-1000 psi. So I have to regulate that down to 150 psi with a secondary regulator.(More weight, space, and expense) That secondary regulator also significantly lowers the recharge rate to about 3 seconds.
So to achieve 1 RPS with 150 psi operating pressures I will need multiple regulators and possibly multiple air supplies to feed them at max rates. (More weight, space, expense)
The ideal maximum operating pressure would be 1,800 psi which is the safety burst disk rating for an unregulated, liquid CO2 paintball tank. If I remember my Boyle Laws the air chamber would be in the 18 cubic inch range for 1800 psi operating pressure.
If that is possible, the secondary regulator could be eliminated and potentially any standard paintball air tank could be safely used.
I get 9 Nerf shots per air supply fill. So increased efficiency would be very useful.
Already have built a 556 chip occilator to control the electronics for the valve's duty cycle off and on times. (From an earlier project)
Of course, another limiting factor is these run off DC batteries you can carry. I would be tickled with a 20-30 shot battery life per charge. So 110 volt AC items are ruled out. 12 -24 volts DC would be ideal.
I have located 750+ psi diaphragm valve bodies but the electronic solenoids are limited to 150 psi.
Simularly higher pressure rated quick exhaust valves with the same 150 psi limitation of the electric solenoid valves that operate them.
But it was suggested by an engineer at a Quick Exhaust manufacturer, that an electronic actuated spool type valve would solve many of my issues compared to direct acting solenoid valves. Lower power consumption and less actuating force required.
POSSIBLY a larger one could have sufficient CV and opening speeds to replace the Quick Exhaust valve. Spool valves are used in hydralic application so they can run easily at operating pressures of 1800 Psi. The CV could be smaller as well. Have no clue how fast they can cycle off and on.
Smiling yet? Tis a bit of an engineering challenge trading off all those factors and performance criteria..
So am I going the right direction using a electronically actuated spool valve for a QE or Diaphragm valve trigger?
Is it POSSIBLE to use a electronically activated spool valve as the main valve using 1800-2000 psi operating pressures in this application?
Any Product or Vendor suggestions? Links please..
Tanks a LOTs
Dale
Need to rule in or out the use of Spool Valves for a main valve OR a triggering/control valve to open a quick exhaust or diaphragm valve with the 4-6 CV needed for this application.
Currently using a 200 psi 5 CV, 150 psi, quick exhaust valve modifed to work as a piston valve. Vents the air to atmosphere to open the QE. Works like a charm for SIMULATED blowing up of paintball tanks, bridges, buildings, bunkers, helicopters, and amphibious landing craft, etc.
The projectile is a 2" diameter foam football with fins called a Nerf Vortex Pocket Rocket. Muzzle Velocity is limited by the field's insurance companies to 230 fps.
So the performance issue is NOT more velocity but a quest for smaller, lighter, more compact, and faster rate of fire for our pneumatic "Bazookas". Safety is always the first consideration.
I have already built an rotating magazine autoloading bazooka. Weighs 6 pounds as a prototype for concept testing. The first in the paintball community that I know of. Autoloading cannons exist but are large, heavy mechanisms that have to be hauled around in motorized tanks/vehicles. I have YET to engage one with anything approaching a rate of fire exceeding 1 round per 4-5 seconds. They seem to be having the same issues I'm listing here.
For your amusement, here is a link to some pictures of the painball tanks in use.
Now I need to increase the rate of fire and minaturized it even more to reduce weight and overall bulk of the bazooka.
I would be the terror of the tank community if I could achieve 1 RPS firing rate. Of course, faster would be better up to a point where you can empty your magazine before you can target it properly. But those Nerf Rockets frequently don't fly straight and you need to get additional rounds off at that tank before the turret gunner lines you up with his 13 RPS machine gun and welts you up with paintballs. You pay a price to hunt tanks.
The limiting factor to overall SIZE is the operating pressure and the static air chamber volume behind the quick exhaust discharge valve. Currently 150 psi using a 100 ci air chamber. Theoretically, by increasing the operating pressure we decrease the static volume required.
But main valve opening speed is a significant factor because of our desire to have as short a barrel as possible - currently, 18" long.
Neither a quick exhaust or a diaphragm valve gets completely open before the Nerf has left the barrel.. It only uses the top 150 psi down to 80 psi to actually get the Nerf up to speed and out of the barrel. Since the triggering is a complete dump of the air chamber, considerable air volume and psi is wasted.
Hence, my hope to use electronic valving and try to CLOSE that valve in time to save some of that wasted air AND to decrease the RECHARGE time and thus increase the potential rate of fire.
The air chamber recharge time would be decreased and potentially increase the Rate of Fire. Plus increase the air efficiency of the cannon's air supply. Typically 68 ci x 3000 psi paintball air supply tanks. Their outputs are regtulated to not more than 1500 psi and usually 850-1000 psi. So I have to regulate that down to 150 psi with a secondary regulator.(More weight, space, and expense) That secondary regulator also significantly lowers the recharge rate to about 3 seconds.
So to achieve 1 RPS with 150 psi operating pressures I will need multiple regulators and possibly multiple air supplies to feed them at max rates. (More weight, space, expense)
The ideal maximum operating pressure would be 1,800 psi which is the safety burst disk rating for an unregulated, liquid CO2 paintball tank. If I remember my Boyle Laws the air chamber would be in the 18 cubic inch range for 1800 psi operating pressure.
If that is possible, the secondary regulator could be eliminated and potentially any standard paintball air tank could be safely used.
I get 9 Nerf shots per air supply fill. So increased efficiency would be very useful.
Already have built a 556 chip occilator to control the electronics for the valve's duty cycle off and on times. (From an earlier project)
Of course, another limiting factor is these run off DC batteries you can carry. I would be tickled with a 20-30 shot battery life per charge. So 110 volt AC items are ruled out. 12 -24 volts DC would be ideal.
I have located 750+ psi diaphragm valve bodies but the electronic solenoids are limited to 150 psi.
Simularly higher pressure rated quick exhaust valves with the same 150 psi limitation of the electric solenoid valves that operate them.
But it was suggested by an engineer at a Quick Exhaust manufacturer, that an electronic actuated spool type valve would solve many of my issues compared to direct acting solenoid valves. Lower power consumption and less actuating force required.
POSSIBLY a larger one could have sufficient CV and opening speeds to replace the Quick Exhaust valve. Spool valves are used in hydralic application so they can run easily at operating pressures of 1800 Psi. The CV could be smaller as well. Have no clue how fast they can cycle off and on.
Smiling yet? Tis a bit of an engineering challenge trading off all those factors and performance criteria..
So am I going the right direction using a electronically actuated spool valve for a QE or Diaphragm valve trigger?
Is it POSSIBLE to use a electronically activated spool valve as the main valve using 1800-2000 psi operating pressures in this application?
Any Product or Vendor suggestions? Links please..
Tanks a LOTs
Dale