Howdy, I’m not FIRST or FRC or anything, I stumbled across this forum while on my endeavor to make a t shirt launcher for my girlfriend’s dance studio. She does recitals and parades and we thought it would be a cool addition and good for pr, but dont have 700 dollars to buy a micro mini launcher https://thestore.gameops.com/Micro_Mini_T_Shirt_Launcher_p/wm-micromini.htm
Heres what I’m hoping to achieve:
20-80ft range, single barrel (no revolver launchers like ones I’ve seen), and most importantly safe (no pvc/abs) launcher.
I’m comprehending most of the concept except:
•What is used to regulate pressure down from first stage to second stage (which leads into the solenoid firing mechanism).
•The electronic stuff for making the millisecond pulse to increase the power and lower the psi needed.
•how to calculate what psi is needed for launching based on the valve sizes and barrel width/length.
If anyone could send me a schematic that they used or a detailed picture/ video link of how theirs works I would be very appreciative.
This would be known as a regulator. McMaster-Carr has a selection, as do a number of other places.
Not sure what you mean by this–if you’re referring to the act of firing the shirt (open valve, release air, close valve), that’s known as a solenoid valve. There are several types, and you’ll need something that can control the valve as well (a microcontroller).
On your third question… I honestly don’t know for sure. It does depend on how the shirts are rolled, though–some ways work better than others. Depending on your math level, you may be able to follow this general path: From the range, find the muzzle velocity (hint: during the flight, the only forces acting on the shirt are gravity and drag). Then you need a force-distance-time relationship for the barrel that factors in fill rate of the air–that’s where things get nasty. (Basically… you need enough force acting on the shirt along the length of the barrel to overcome friction and get the shirt to muzzle velocity, but the force exerted by the air is a function of the barrel diameter [to get the area] and where the shirt is in the barrel (for the volume, to get the psi acting on the shirt at any point in time).)
The most important thing in getting enough air in fast enough to launch a shirt is to use a sufficiently large solenoid valve. 3/4" is a minimum, 1" is better. Use a metal-body valve. Plastic sprinkler valves are not rated for air; they don’t have a greater tendency to fail on air than on water, but when they do, they produce shrapnel because air at a given pressure is storing a LOT more energy than water at that pressure.
I meant as in electronics/coding required to make the millisecond pulse to actuate the solenoid quickly enough as to use air more effectively ie, less psi.
Shortly after writing this I found out we can really only use it for parades so it wouldnt be used much which is sad haha. To the back burner it goes until maybe next year. Thank you for the help.