solenoid in paintbal marker

[athomas]

Originally posted by Methylphenidate
dude
the solenoid in my friends timmy can take 85psi safely and that runs on a nine volt
if you were to throw a battery like the one on an emag.
which i beleive is 18, correct me if im wrong. but the way you are describing it the tolerance of 85 psi would then be increased because a greater charge going to the solenoid increases its tolerance to pressure.

The Timmy uses a different system than you are talking about. The timmy uses a solenoid to control a ram. The pressure is 85 psi but it has no large volume capability. The size of the port in the solenoid is very tiny. Therefore the actual pressure exerted on the solenoid that has to be controlled is very small and it requires a lot less power. The flow of air to the ball in the Timmy is based on the operating pressure (~250psi) and the amount of time the bolt is forward (dwell). The air port in the bolt is very large, even at 250 psi, for the ball to be accelerated to 300fps.

An solenoid air valve is rated based on pressure and volume it can handle. The Timmy solenoid is probably rated around 9v. Putting 18v on it would probably just burn it up because it would souble the current flow through it. It would be more powerful for the brief moment before it failed though.

Lets say you are delivering a full blast of air to the ball from a solenoid controlled air valve that is holding back only 100psi (that's a pretty low pressure gun). Now, to provide adequate air flow we need a solenoid opening of 3/8" in diameter. The pressure exerted on the plunger of the solenoid would be 11.05 lbs. Therefore, to allow for adjustment and adequate tolerance error, we will need a solenoid capable of at least 16.5lbs. That's one big solenoid valve. To put it in perspective, the emag solenoid is designed for 4lbs of pull and may or may not work at 7-8 lbs. The problem would be compounded if the operating pressure had to be 200psi instead of 100psi.

[Joni]

200 PSI

And iv'e never heard of a marker having input pressure below 200 psi. (Please, no smart remarks about "low-pressure" at 70 psi. Thats the pressure on the ram that drives the hammer and bolt, not the input pressure). I guess this idea would be possible if you made the entire frame to a soleonid, an mounted 3-4 E-mag batteried =)

[pbjosh]

Lets make a couple things clear-

The Solenoidvalve you see in just about every marker is actually a small solenoid 'Pilot' valve that actuates a larger '4-way' type of valve.

Every tweeked with the 4-way on a cocker? It only needs that much force.

When that 4-way is switched the output goes to a ram (in most cases) and that output energy goes into moving the hammer, and that energy goes into opening a valve.

All with just a small amount of energy usage from your battery. To tweek the sear in a marker, something that is already balanced to release easy, it generally take a much larger solenoid, and a cap, to even have enough energy to drop a sear. And that means a larger battery, and even then a shorter battery life.

To MOVE a hammer or bolt would require a much larger battery, and even if you had the valve setup to release really smooth you would need a battery, most likely, the size of an RC Car 7 cell, and even then, you might only get a few thousand shots.

Is it worth it? A battery pack the weight of your tank just so you can do the work of a solenoid valve and a 5v battery source?

I do not need to answer this one for you, by know you might have figured it out.

Josh

[Slimm Jimm]

so your saying it's pointless to do just a solenoid opening a valve. okay.

could you instead use a solenoid to close a valve, and have the air pressure itself open the other end by releasing some sort of catch (like a sear)and then reclose from a spring once all the pressure is gone?