Quote:
Originally Posted by Kyle Butzerin
So I ask my questions,
Are there valves that will release the stored air we need to propel the shirt through a 4" barrel without modification? If so, what can you suggest?
Should we go with the air storage I have in the model, or something else? Should we charge it up with a ViAir? or a better Compressor?
Are there any good ideas to lift the barrel? We are wanting to use the Lead Screw method that our 2013 team went to St. Louis, but we are open to new ideas.
Thanks!
RoboEagles FRC 4579
|
A bigger barrel means more air faster to propel a projectile. We use a 2.5" barrel and have been happy with that, a 3" would be nice for XL and XXL t-shirts though. There are valves that are capable and a few have been tossed around forever on CD, look to fast acting 3/4"-1" solenoids for this. We used a really cool hose from Parker Hannifin that requires no fittings and is available in those sizes with fittings being the biggest cost.
After running the FRC compressor to charge our cannon the first year of it's existence, I will never do it again. We have times at pep assemblies where we have five shirts to shoot in ten seconds, and the little viair just isn't up to the task. We use a 5# CO2 cylinder because it's cheap, we have a discount to make it cheaper, and it is a lower amount of stored energy than a SCUBA tank. The only issues we see from this is that with liquid CO2, you can freeze your system forcing you to wait a minute if you fire rapidly.
Your storage looks to be PVC, but I can't tell from the drawing exactly. Be ready to be attacked for that, and with good reason. Go find the videos of plastic tanks exploding for why. There are tons of safe high volume tanks available with large ports, you'll just have to look outside of normal FRC vendors to find them. We got ours from Home Depot with a 1" port.
For lifting the barrel, go with what you like. We change ours by hand because we have only changed it a handful of times since we built it. Ours uses a CNC Plasma cut angle gauge and wingnuts to lock it in place. We had designed a motorized version, but the only time we lower it is when it's in the trailer or if we are test firing and don't want the height.
Everyone will go over a lot of details on high pressure systems and safety and a lot more. Design safe and stay safe. We use no more than 30 PSI and typically run at 12-15 PSI for shots from our track to the top of the bleachers at our football stadium, it's around 200 feet or so. Ask yourself if you need to shoot further, then ask yourself why...