Hi mryy .. after watching the vid of the home made spring gun I had some thoughts about how something like it might give you some real-world data about forces and energy required to cycle the gun, or something like it in your wheel (this could be a hypothetical thought experiment).
Imagine the bloke anchoring the gun vertically for a bench test. He hand cocks it and tips the release mech. It shoots the ball bearing (bb) straight upwards. He measures the vertical height gain over a number of tests and averages them. Then he climbs a step ladder and drops the same bb from the average height previously gained. Miraculously it falls straight downwards gaining KE and enters the barrel without so much as touching the sides, and contacts the spring mech depressing it (doing Work).
I'm gonna guess it compresses the spring mech and sometimes cocks it and sometimes not. So he climbs another rung on the ladder and repeats the drop test runs. This time the bb always cocks the spring.
Then he climbs down and goes to work with pencil and paper. He calculates how much GPE the bb gained when the gun is shot. He also calculates how much GPE is lost by the bb (gain in KE - not counting frictional losses of air drag and contact losses of sound and heat) from his ladder drop test. They appear to be fairly similar.
He designs a 4 : 1 ratio pivoted lever beneath the gun. He attaches a string to the end of the short side and runs it downwards and around a small anchored pulley and back up to the cocking mech so that when the string is pulled sufficiently hard it cocks the mech. At the other end of the lever at 4 times the distance from pivot he attaches a mass. He adjusts the mass (amount) until it can rotate the lever downwards and cock the spring gun. He notes the mass of the bb and the mass of the 'cocking' mass which gives him another ratio (disregarding lever mass).
Then he leans the gun over and repeats the experiments at various degrees of lean. This time he runs the bb down a half pipe into the gun barrel etc. He takes some notes and makes some calculations. This is to approximate the red flying weight being shot upwards from about 6.0 o'cl to land around 1.0 or 2.0 o'cl. He doesn't consider for the moment the dynamic situation where he'd actually have to 'advance' the shot (aim higher) to arrive at 2.0 ocl as the wheel turns etc. This gives him how much force is required to cock the gun when the gun is leaned over [gravity force acts vertically and the resultant vertical vector is the one he is interested in (see forces in a ball running down a straight incline - vector analysis)].
Then he starts to imagine his spring gun and cocking lever arrangement in his wheel and begines to ask himself some questions. When and where does the cocking mass (yellow mass) actually cock the mech. OK - got that. Now he can draw it up and plot the positions of the yellow masses as they revolve with the wheel in various positions and calculate their torque contribution. He does the same for the red flying masses. Then he can calculate and plot the system COG/COM and its position thru various incremental degrees of rotation to see where it moves to etc. And find out if its possible for the positive-torque generated to overcome back-torque and cock the gun etc.
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All I'm doing here with this thought experiment is start to lay out the possible steps I might go to to get valid data and information to progress the idea in the real-world or sim-world.
Best -f