Dwell time does affect velocity. Paintball velocity adjustment is accomplished by two methods. One is adjustment of the operating pressure (via a regulator) and the other is adjustment of dwell. Paintball markers advertized as "Low pressure operation" achieve reasonable muzzle velocities by high flow rates through their valves and long dwell (valve open) time. I would agree that having the valve open for a full second would be a waste, but this is only because the projectile should be long down range by then and no longer affected by your propellant.
From: rctankcombat@googlegroups.com [mailto:rctankcom...@googlegroups.com] On Behalf Of Mike Måne Sent: Monday, June 08, 2009 10:52 AM To: rctankcombat@googlegroups.com Subject: [TANKS] Re: Canon design, gas pressure and the likes I don't know if I can help very much, but what I do know is that the time the valve is open does not effect velocity. If the valve is open for a tenth of a second or a whole second, it will not effect the paintball's speed as long as the pressure is the same. And about the compressor, if you were to use that, will the pump have to constantly run? If not, as the gun is fired, the pressure would reduce and the compressor would have to fill up so that the reservoir provides enough pressure. Will this be computerized or metered somehow? -Mike M 2009/6/6 Modena <b...@holnet.net> As has been discussed previously markers down-under are a problem, this means we need to home-make a "marker". This isn't all bad as it gives a chance to make things fit nicely as required into whatever turret/chassis you may be working on. I'm looking at either going the on-board compressor route like Chris Barthelson has done (see T030), or going with a HPA bottle. So I have a couple of questions which people with experience in pulling markers apart should be able to answer. This is all my understanding from limited reading on the subject, some, most or all may be wrong! A C02 system runs at about 600-800psi, HPA runs at about 3000psi, In either case I believe you need about 120psi to actually fire a paintball with a reservoir-like setup, but on a real marker w/C02 is it just using the 600psi and only opening the valve for a tiny amount of time? I'm guessing HPA would be similar, with the regulator bringing it down to a pressure similar to that of C02. I guess what I need to know is, what pressure, volume and length of time do I need to shoot gas in order to fire the ball? E.g. do we use 600psi for a smaller amount of time, or 120psi and a larger volume? Chris B has provided me with some good test data based on his 120psi compressor setup, but with C02 or regulated HPA I'm hoping to be able to get some pressure/volume data or advice out of commercial marker use? Ben -- -Mike Måne @ http://moonrcprojects.googlepages.com --~--~---------~--~----~------------~-------~--~----~ You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat-unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat -~----------~----~----~----~------~----~------~--~---
