02-16-2022, 09:08 AM | #1 |
Join Date: Jun 2013
|
Gear Rifles - design assistance requested
This is an idea I had (or, rather, shamelessly stole from this thread), for a "rifle" that stored its motive power in a clockwork battery. A good option for how it turns energy stored in said battery into propelling a bullet into some monster's skull, however, has always eluded me.
Until now. Thanks to the Forgotten Weapons interview with the cofounder of ArcLabs about their GR-1 Anvil Gauss Rifle, I realized I could use a mechanism that pulled the bullet, rather than pushing it, down the barrel. This is what I've come up with. I'll note this is meant for DF, so strict realism is not necessary, although some nods to it would be welcome. Aesthetically, the weapon would look more-or-less like a typical TL 4-5 musket/rifle, but with an ovoid barrel rather than a circular one (or a rectangle rather than a square, or an elongated hexagon rather than a regular hexagon). Internally, there is a winged "cup" at the back of the barrel, with a hole in top (matching up with one in the barrel; the latter would have a movable cover) for putting the bullet in. Threaded through the wings is a chain on each side, which wraps around and links to itself (going through the elongated portion of the barrel). When the weapon is fired, gears spin to move this chain, in turn accelerating the cup (and bullet within). When the cup reaches the end of the barrel, it strikes a brake (probably made of soft leather, or cork wood), which has a hole in the center for the bullet to pass through - this stops the cup (which slips from the chain on impact, so that the gears can continue turning for a bit rather than coming to a jarring stop; basically, the chain fits it snugly enough that it can be accelerated fairly quickly, but not enough to hold on at the sudden stop at the end). To reload, you flip a safety switch to disengage the gears from the battery, pull the cup back into loading position (it has a tab on it that comes up through a slit in the top of the barrel, and serves as rear sights; for long barrels, it typically has a lanyard attached so you can just grab and yank that back), drop a bullet in, then attach a hand crank, wind the mechanism, detach the hand crank, and finally flip the safety switch back to shooting position while shouldering the weapon. However, that requires a sufficiently-long reload process that it may reduce the weapons to "one shot per battle," which is very much not what I want. Absent Fast-Draw, and ignoring the time to actually wind the mechanism, I'm thinking you could flip the safety and pull the cup back into position as a single Ready; draw a bullet from your pouch as a Ready; remove the cover, drop the ball into the cup, and replace the cover as a Ready; draw the handcrank as a Ready; attached the handcrank as a Ready; detach the handcrank as a Ready; stow the handcrank as a Ready (you could skip this step if you have it on a lanyard, simply dropping it as a free action); and take a final Ready to, well, Ready the weapon and flip the safety. That's 8 seconds! What options would I have to speed this up? Having the crank permanently attached would cut time in half, but absolutely ruins the aesthetics of the weapon, so I'd rather avoid that. Might it be feasible to have a folding crank, such that the weapon doesn't have a big bulky thing off to the side normally, but you can pop it out, crank it, and put it back in (with the crank's position serving as the saftey - pulling it out switches the battery to be connected to the winding mechanism, putting it back in switches the battery to be connected to the gears). Or should I allow the battery to store multiple shots, so that reloading during combat only consists of pulling the cup back into position and dropping a bullet in? For cranking and damage, my inclination is to define battery capacity in terms of pounds, have a character charge it by BL lb with each Ready (either 1.5xBL or 2xBL with an All Out Ready), and have the damage be equal to thr at the ST for which the battery's capacity matches its BL. That is, a battery that can store 80 lb would take a character with ST 10 around four seconds to charge (three or two seconds if going All Out) and deal damage equal to thr at ST 20 (2d-1). Does that sound feasible? Note if you dislike setting battery capacity in terms of pounds, you could instead use Joules - for 5xBL Joules, 7xBL Joules, and 10xBL Joules, respectively (of course, damage probably is unlikely to match up at all using Doug's spreadsheet, but that's fine - this is for Dungeon Fantasy, not Tactical Shooting). I could go on, but ultimately, these are my current questions (repeating some from above):
Any assistance would be greatly appreciated. Hopefully this time I've avoided my chronic issue of "information overload in the first post."
__________________
GURPS Overhaul |
02-16-2022, 10:54 AM | #3 |
Join Date: Nov 2015
|
Re: Gear Rifles - design assistance requested
So my take on this from a physicist's perspective, while not being completely realistic is it sounds very fun and cool. My answers would be:
1. I'd say you should store multiple shots per crank session (maybe 4-6) then have a lengthy winding session. Additionally, you could see a slight reduction in power per additional shot as the gears wind down. 2. I think your cranking set sounds like a good balance between realism and game balance. 3. I think you've got them a bit too light. All this mechanism is going to be far heavier than real guns. I'd say a minimum should be double a comparative TL4 gun. 4. Barrel length I feel is your trickiest and potentially least realistic point. A longer barrel is going to have far more friction with this system than a bullet so I don't think things scaling like a real gun is appropriate. At best you might break even with losses and gains. The most realistic method might be what you suggest with the length being related to the strength of the gun, but I would say if anything the stronger the gun, the shorter the range should be due to friction losses. And it might be interesting effects on usability. 5. Rifling again would be very tricky. Your ideas though are a pretty cool way of giving some rational explanation. I think the wax jacket is most realistic. The trade off of range for accuracy seems most feasible. 6. Caliber seems good the way you've described. Flechette darts might be good too as an option. |
02-16-2022, 10:57 AM | #4 | |
Join Date: Jun 2013
|
Re: Gear Rifles - design assistance requested
Quote:
However, the description I first read about it gave me another idea for imparting spin to a projectile. I've heard before that vibrations can cause screws to, well, unscrew themselves - here's a video, ignore the (I think accidentally, but my volume is off) salacious title, they just use a vibrating toothbrush and electric shaver. I'm pretty certain that's an aspect of their threads, but would it be feasible that a vibrating gear rifle - say, because the gears aren't quite properly well-aligned - could impart spin to the projectile? I could see this being an accidental discovery in the early days of replicating the gear rifles found in the dungeon*, where it turned out that getting proper alignment to reduce vibration actually reduced accuracy. So, designers have the choice between better accuracy but lower efficiency (vibration is going to eat up some of your energy), or lower accuracy but better efficiency, getting the sort of accuracy-vs-damage trade-off I'd prefer. But I don't know if that's even remotely realistic. *Oubliette is roughly TL 2-3 generally, but has found - and successfully replicated - TL 4+ technology in the dungeons that tend to randomly pop up all over the place.
__________________
GURPS Overhaul |
|
02-16-2022, 10:57 AM | #5 |
Night Watchman
Join Date: Oct 2010
Location: Cambridge, UK
|
Re: Gear Rifles - design assistance requested
I'd suggest having a weapon that takes minutes to wind up, but powers an endless chain (like a chainsaw) that runs for 4-6 seconds.
You drop your cups onto that when you pull the trigger and they get flung downrange. You need a magazine in the weapon, to make this work. That gives you RoF 1 if your magazine is operated automatically, or RoF 1/2 if it behaves more like a bolt-action rifle.
__________________
The Path of Cunning. Indexes: DFRPG Characters, Advantage of the Week, Disadvantage of the Week, Skill of the Week, Techniques. |
02-16-2022, 11:27 AM | #6 | |||||||
Join Date: Jun 2013
|
Re: Gear Rifles - design assistance requested
Quote:
Damage slowly going down matches the behavior of the TL 5 air rifle in HT, IIRC. I'd have to decide if I want that for DF - I'm honestly leaning toward "no" ("It's your last shot... and it does half damage" seems like adding insult to injury). Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
__________________
GURPS Overhaul |
|||||||
02-16-2022, 12:14 PM | #7 |
Join Date: Feb 2005
Location: Berkeley, CA
|
Re: Gear Rifles - design assistance requested
You know, the way the gauss rifle works is that you've got a primary electrical energy store (high storage, but not enough power to directly propel the bullet) that charges a secondary energy store (low storage, but high burst power). The equivalent of this for clockwork would be to use clockwork to charge a device of another type, such as a bow, sling, or spring.
|
02-16-2022, 12:30 PM | #8 | |
Join Date: Jun 2013
|
Re: Gear Rifles - design assistance requested
Quote:
__________________
GURPS Overhaul Last edited by Varyon; 02-16-2022 at 12:35 PM. |
|
02-16-2022, 12:48 PM | #9 | |
Join Date: Feb 2005
Location: Berkeley, CA
|
Re: Gear Rifles - design assistance requested
Quote:
|
|
02-16-2022, 01:11 PM | #10 | |
Join Date: Jun 2013
|
Re: Gear Rifles - design assistance requested
Quote:
What sort of material/technology did you have in mind? It may be something they could get access to via the dungeons, and potentially have other uses (for example, I'm considering the advanced knowledge of clockwork and gears allowing for decently-accurate timepieces and low-tech velocipedes, despite such not showing up as loot in the dungeon). I'll note I'm not aiming for scientific rigor, rather more "that makes sense, and would be pretty neat."
__________________
GURPS Overhaul |
|
Tags |
artificer, dungeon fantasy |
|
|