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Thread: MW 2013+ Ruleset Additions and Changes Discussion

  1. #141

    Re: MW 2013+ Ruleset Additions and Changes Discussion

    I think that's a great start! Some immediate things that come to mind:
    I think the numbers you came up with are OK, except turn down the depth penetration allowed to 0.2mm, and specify that pressure in any part of the system may never exceed the limit (50 psi?) for more than 0.5 seconds in addition to never exceeding (even temporarily) 80 psi.
    If I can get 0.2mm into a sheet of polycarb with a pellet, it doesn't take many pellets to smash through the protection for the target panels if I'm dead on. I'd go for "not visibly mar" although that might be a little too soft...

  2. #142
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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    Depends on the system used. Airsoft bbs are likely to shatter before PC gets damaged unless under a LOT of force.

    I would definitely set the pressure and FPS maxes based on current AEGs, so as to not DQ currently in use weapons.

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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    Grrr. How I hate charter. Ever increasing fees for an increasingly crappy selection of channels, the shift to all digital requires rental of boxes despite the TVs all having digital receivers (work fine for most of the digital channels already available, but others in the package were scrambled and now everything else will be scrambled), and the actual change-over cut my internet connection for an hour or so just when I wanted to post this.


    jwatte
    I was thinking that the kinetic energy and material limits on the projectile would require a very thin and hard (sharp point, fiber-resin composite) plastic at the velocity limit to actually make much of a dent and would likely lodge in any void it might create (either the entire projectile or just a part of it that survives the impact). A prohibition against any significant marring of the surface is the spirit of the rule, and I was mostly pulling that number out of my bum thinking that a 0.5mm divot would be easy to identify during a quick visual inspection without compromising too much of the polycarbonate's protective capacity.

    ArduTank
    Propulsion #3 was intended to grandfather in commercial AEGs and custom spring-loaded pistons since there is no storage of pressurized fluid. For AEGs, there is a small volume of pressurized air produced and utilized in a fraction of a second, and pressure is self-limited by the limited friction/inertia of the airsoft BB in the barrel. Still mostly pulled the values out of my bum, so if anyone has any better approximations of the peak pressures within an AEG piston/barrel, please speak up.



    I also should have been a bit more accurate in stating projectile material limits. A foam is just a liquid or solid with regular voids within its structure, so can be made from 'rubber' or 'plastic' or any other material. Both 'rubber' and 'plastic' are polymers, so saying the projectile must be some combination of either is a bit nonsensical. Urethane foams and vulcanized rubbers are both thermoset polymers, so limiting projectiles to only thermoplastic polymers doesn't quite work. So, another try at satiating my hatred of imprecise and ambiguous language, especially in rules and regulations...
    1a) Commercially manufactured 6 [mm] solid plastic airsoft BBs in the 0.12~0.40 [g] mass range are the default projectile due to easy acquisition in most jurisdictions, acceptable safety characteristics, fairly uniform material properties in each mass rating, reliable dimensional tolerances, and inexpensive construction of a robot mounted firing system. 0.20 [g] or 0.25 [g] are two very common mass ratings providing decent accuracy and mechanical strength without requiring high power AEG or gas firing systems.
    1b) Custom projectiles may be made only from some combination of polymers with hardness no greater than Shore 80D (roughly equivalent to Rockwell R100 and Rockwell M30), in either foam or void-free solid form, and should not be intended to shatter upon impact or otherwise produce any hazardous dust or obstructive residues. Non-exhaustive list of prohibited projectile materials: metals, liquids, hard and fragile crystalline ceramics/minerals/carbons (e.g. ceramic balls, stones, graphite balls), fiber-resin composites (e.g. fiberglass, kevlar, or carbon-fiber composites), materials that spontaneously change phase at room temperature (e.g. water ice, solid carbon-dioxide), materials that bond to objects at impact such that mechanical and/or chemical treatment is required to remove it (e.g. paints, adhesives, semi-molten polycaprolactone, low-wax chocolate).
    Would be interesting to try making airsoft-sized pellets of dry ice on demand. Grind it down into 1~4mm pieces and compress it into a mold before loading it into the barrel of an AEG. There would be no clean-up necessary, but it shatters upon impact and having lots of it sublimate to gaseous CO2 in an enclosed space is not wise...
    Please pardon the pedantry... and the profanity... and the convoluted speech pattern...
    "You have failed me, Brain!"
    bleh

  4. Re: MW 2013+ Ruleset Additions and Changes Discussion

    While I share your hatred for vague or ambiguous language in the rules, there is the downside that any rule that cannot be tested against a standard reference is effectively useless.

    Will there be test equipment at the event to test compliance with every one of the points you make?
    ---
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  5. #145

    Re: MW 2013+ Ruleset Additions and Changes Discussion

    Regarding cable TV: When it comes to Charter, they should be able to rent you Cable Cards that let your TV or computer or other device decode their scrambled channels. If I remember correctly, this is required by cable regulations.

    A while back, I realized that my Tivo had died, and that it had died six months before I realized it was dead, because it turns out I had stopped watching TV, using Netflix and Crunchy Roll and Youtube instead. So, after being annoyed at Tivo-the-company for keeping charging me for service and not letting me know my box wasn't calling in, I cancelled all "TV programs" and such. Life is better now :-)

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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    Quote Originally Posted by Xevel View Post
    While I share your hatred for vague or ambiguous language in the rules, there is the downside that any rule that cannot be tested against a standard reference is effectively useless.

    Will there be test equipment at the event to test compliance with every one of the points you make?
    1) The 1.6 mm thick, rear-supported polycarbonate plate test would be an easy standard, and Shore D80 was pulled from my bum because most unmodified polycarbonate plate is harder than Shore D80.

    2) Almost all polyethylene; most polypropylene, silicone, neoprene, and urethane; many ABS, polyester, and PVC; and some polycarbonate, acrylic, and styrene are softer than Shore 80D. Documentation of the materials used would probably be adequate for most cases and digital Shore D Durometers go for ~$60. Attempting to cut through a projectile would be another option to get a good idea of the material hardness. If a decent quality, non-serrated, steel blade cannot make much of a scratch in the surface, then it is definitely pushing the hardness limit (Shore D uses a 30 degree cone point ground from hardened steel rod [usually 0.055 inch diameter for full test range] and a 10 lbf driving force; Shore D80 would be the cone penetrating only 0.02 inch after 15 seconds of applied force).

    3) Anyone serious about designing a new multi-material projectile or higher velocity firing system should be able to drop another ~$100 for a gun chronograph to check the velocity and ~$30 for a small scale to measure its mass. Physically verifying pressure limits inside the firing system can be a bit more complicated, but pump ratings and spring forces, piston area, and projectile retention force can be used to roughly estimate it.

    4) How many people will actually be trying to make complex custom projectiles at this time? How much would testing cost relative to the cost of the rest of the mech?


    jwatte
    CableCARD is mostly dead as there are very few TVs that actually have the slot required for it, and I do not have, nor particularly desire to purchase/rent, a TiVo or other DVR that might have a CableCARD slot. The CableCARD replacement, 'AllVid', was rather nice sounding, but it seems to have died in its FCC crib. It was supposedly the location of Stone Mountain between us and most Atlanta TV towers that prevented us getting any decent analog OTA 20 years ago, but might be worth testing a digital OTA receiver since there is not much on non-local channels except reruns and movies we could get through Netflix, Hulu, and other internet services. The big problem is that the ACC government essentially gave Charter a monopoly within its jurisdiction which cut out all the other existing cable companies whose competition helped keep rates lower (we repeatedly changed providers over many years based on who was offering the best price per service before the charter monopoly). Even if we drop TV service, we are still essentially stuck with Charter, AT&T, or maybe Comcast, for internet (there are a few other companies, but only satellite, DSL, or dial-up).
    Please pardon the pedantry... and the profanity... and the convoluted speech pattern...
    "You have failed me, Brain!"
    bleh

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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    If this goes through, I'll be trying to make a cloud gun, as they are simple and cheap.

    the .12g airsoft pellets I have must push the Shore D80 hardness limit then, because a sharp utility knife blade makes almost no visible mark.

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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    Quote Originally Posted by ArduTank View Post
    If this goes through, I'll be trying to make a cloud gun, as they are simple and cheap.

    the .12g airsoft pellets I have must push the Shore D80 hardness limit then, because a sharp utility knife blade makes almost no visible mark.
    I was able to make slices at least 1mm deep into a .12g with a pair of scissors (~50 degree triangular edge), but cutting through it would have required better securing the BB to prevent it slipping (my clumsiness is dangerous enough without adding sharp objects to the mix). Pretty sure most 0.12~0.3g non-biodegradable airsoft BBs are ABS, and even if they are harder than Shore D80 they are easily grandfathered in because of their known safety with AEGs.

    Another option might be a vortex gun. And a pump powered version of this is an option for the collection of empty fluoxetine/buspirone bottles on my desk, although the pen inner diameter is ~6.5mm so it will be rather inaccurate.
    Please pardon the pedantry... and the profanity... and the convoluted speech pattern...
    "You have failed me, Brain!"
    bleh

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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    I may look into that.

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    Re: MW 2013+ Ruleset Additions and Changes Discussion

    I'll likely end up doing some damage tests on a simple cloud gun (only machined part is the barrel; it doesn't have to be a machined part) with varying pressures on cardboard, foamcore board, abs, and 1/16th" steel. Maybe throw in the casing of an HS-311 (their cases are weaker than the AX-12's) for good measure.

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