I'm an author and illustrator in the fantasy genre, and I am working on a book series currently that requires some designs for repeating crossbows with a simple and effective lever or crank action that could be mounted on the back of a very large animal, say the size of a rhino, that could be operated by a single rider.
That was a mouthful...
I've done rudimentary first sketches which led me to understand that I didn't know enough about crossbows to fake it reliably, started doing research, and began to love crossbows.
But I realized that I need to find some crossbow enthusiasts to help me out a bit with terminology and the dynamics of such a thing; I want it believable, since I will be illustrating it in the books. Then I stumbled across this site while doing research.
It's a long-term project, so I promise I won't be a pest on the site. javascript:emoticonp('')
You can see some of my artwork here: http://www.toddlockwood.com/
Anyone interested in corresponding with me on designs would have my gratitude, and might be challenged to help invent something fun.
Take a look at Ralph Payne-Gallwey's "The Crossbow, Medieval and Modern" also published as "The Book of the Crossbow" There's a pattern for a Chinese lever-action repeating crossbow. These date back several hundred years at the least. Most weren't terribly powerful, but they were generally fitted with 10 or 20 shot box magazines on top. I have made several. They're not terribly accurate, but will reliably deliver one shot a second. Geezer
And I did find drawings of that machine just today. They're impressive in their simplicity.
Here's the question, then: if you had an unlimited budget and could design that bow to be murderous, how would you change it? What if it needed to pierce the hide of a rhino, say, and still be easy to reload/loose? What would be your first considerations?
The Chinese repeater has the advantages of being simple, robust and Really Fast Shooting. What would make it better? A more efficient lock/release would mean less string-wear and more accurate shooting... fitting the slider with roller-bearings to keep it tight, yet running smoothly on the lower stock would improve accuracy. If you want more power, you'll need a longer lever-arm, or some sort of more efficient coupling, say like the Spanish 'gafa' cocking lever, that should afford improved mechanical advantage without too much increase in weight and complexity. A more efficient bow-stave (prod) would be helpful... perhaps a horn-sinew composite... either Eastern or European, would give you more punch than either a wooden self-bow or even a steel bow. Steel bows can be made stronger, but the composite bows will give more power for the weight of draw. Of course if your alien culture has some sort of naturally occurring carbon-fiber (like the N'avi of Pandora) that could help a lot. A longer draw-length would increase power as well, though that will make your repeater wider, hence a bit unwieldy. The fact is, you only get as much energy OUT of a bow as you put into it. Any quick-loading repeater will require substantial energy to span. Perhaps if you had a lever-action lock that could be pumped back several times to bring it to full-draw.... rather like a car-jack, that would give you more power (at the cost of slower loading). At some point, the whole concept of repeating crossbow becomes moot, as your 'repeater' gets heavier and more complex. It might be easier to simply have a strong crossbow that your Bantha-rider could rest in a swivel of some sort, without the auto-loading. Or have a loader riding behind, to hand you ready bows as the situation demands. As far as shooting at Rhinos.... you would need a portable ballista to get the sort of energy you'd need to reliably take down a rhino. Renaissance armies went over to gunpowder for a reason. You can get ooodles more power from expanding gasses in a tight-bore than you can conveniently do with any sort of bow, or even bundles of sinew/hair twisted into a catapult skein. If you want a light artillery piece... admittedly not a quick-loader, for shooting from Bantha-back, I recommend you look at the Roman 'Cheiroballista' light field artillery piece. Heron's 'Bellopoeica' (Greek treatise on catapults) featured a crank-operated catapult with some sort of gravity-fed magazine for city walls. It wouldn't be very portable, but might load a bit faster than a standard machine. For more info on Greek/Roman artillery, look for "Greek and Roman Artillery" by Marsden. Either Oxford or Cambridge University press, I don't recall which, @ 1968. Payne-Gallwey has some stuff on Catapults as well, but Marsden is MUCH more authoritative. Geezer
Interesting site and your artwork ... well ... Fantastic!
I agree with Geezer, you might need a pretty powerful crossbow to take on animals of this size....though modern crossbows/bows already shoot "through" animals and they aren't really big(see Excalibur's Equinox, Exomax crossbows; Hunting elephants with crossbows, etc)
Unless of course you want to use shovels instead of arrows then you are looking at a two man team cranking things to load it....hey if it's a tank you want, it's a tank you're gona to get.
....fantasy wise > I'd make it a really overbuilt compound system...perhaps even reverse draw like Scorpyd
or even better - a REB(Reverse Energy Bow).
Pop four of these around the rider's seat and have him perform a rowing boat motion - spanning and unloading the weapons in groups...top row ...bottom row...top... bottom.....or build the animals anatomy around this system and have it do the same by performing sort of a "yoga move" - shifting series of protruding bones/thorns to span/shoot etc... while the rider is just chilling in the lawn chair on it's back and pulling on the leash to correct the trajectory.
***
Of course if you wish for a fast "cheetah" or "bat" like creature with a shady rider like a ninja or a wraith(J. R. R. Tolkien could have made them so much sicker if he gave them crossbows )...well if that is so then this topic is all yours >>>Link <<< I've missed one really nice lever-action crossbow and also found one new one, so I'll be adding them to the list a little later in the day.
Post your sketches mate! Don't worry about functionality...it will come.
Yes: I found that link Googling "lever-action crossbow," and I devoured every word, picture and video of it. It's what led me to this site.
Great stuff!
I'm becoming a crossbow fan, big-time.
And thanks, KiwiJim! I joke with a friend of mine about Thomas Kinkaide, who calls himself the "painter of light," doing these saccharine landscapes full of flowers and retarded houses and such. (Oops ... did I just cross a threshold regarding terms of use of the website?)
Anyway, the joke is that i aspire to be the "painter of dark."
ToLo wrote: I'm becoming a crossbow fan, big-time.
Now if you're ready... Please step into my Office.
3D Warehouse- Model Download(Sketchup)
I used to doodle back in high school a bit too ...only now I have much less time. What you see above is a basic concept of what I mentioned earlier(rider spans a set of bows with a rowing motion)...It certainly "looks" like it works, now if we were to build a prototype, this could in fact be a real cool toy.
kiwijim wrote:Carpe Noctum!
ars est celare artem
fantasy wise > the levers were drawn very basic and only to show how they would function...now when I say "ars est celare artem" I really mean it ...these levers can be so much more, they can be used to house bladed weapons which in their turn can be combination weapons > gun blades, sword rifles, axe shotguns, compressed gas daggers, etc.
Another example of "hidden art" that could be difficult to illustrate without making a comic book goes hand in hand with compressed gas daggers , picture the same thing only this time -------> with arrows.
ToLo wrote:
... I want it believable,...
Crossbow don't really need to be HUGE, they can be quite compact and still deliver kinetic energy equal to KE of a bullet fired from a handgun...small powerful limbs(preferably parallel), efficient cams, and long draw length are some of the key features...then again it's up to you mate.
Guess that's it for today. Want more...let us know more about this project of yours.
Okay: I have to spill a little bit here: space for rider and machinery is limited by the real estate left over after considering the native movements of the animal in flight. Yes, in flight, because it is a dragon, as you might have suspected. So the area available to the rider and machinery is limited to a space in front of the rider and above, a long, narrow space behind (along the spine of the mount) and little else. I can easily imagine a crossbow that is cocked quickly and easily by a "shrug" or trained forearm movement of the mount, freeing the rider to simply choose targets and loose. That does, however, render a "rowing" motion problematic.
Sketches will come, I promise. But probably not suddenly. Right now I'm doing the work that pays the bills, while I shop the story around in search of a publisher ...
I'm thinking the rider is responsible for shooting and for swapping out multi-shot magazines, but the dragon cocking the bow solves a lot of problems (and makes the machinery that much cooler!). The only trouble with having the mount do the cocking is that he will engage in dragon-on-dragon combat occasionally, and then he's going to need his claws. But if the same system can be backed up by the rider's legs, it's not terribly more complicated. The rider is strapped in anyway, on general principals. With a tall back on the saddle he could brace and push with his legs.
Well wings change everything ...I was still working on the ground unit...much much easier If we consider the few factors listed below and take advantage of the twin levers the ground unit is pretty much complete with the only change probably in the riders positioning putting him slightly lower and thus making the levers more comfortable to use...and well making better use of the levers, by adding a few more features.
I currently don't own any dragons, so I pictured this weapon mounted on "my" back instead (well I was born in the year of the dragon, so it's as good as it gets )
One important thing that I've come to understand is that there "has" to be at least two weapons, one on each side. This is the top most priority because getting shot in the back of the head is the last thing on the list. Long neck is also a problem as accidentally placing a shot in the cheek is not a selling factor, especially when we want it to be compatible with as many models of "dragon" as possible.
With the animal spanning the crossbows it would certainly look cooler, but it would still most likely be a simple "lever" or as kiwijim has suggested "pulley" system...just bigger and if fixed permanently - limiting animals motion > Imagine permanently being attached to an exoskeleton suit that was used to compress a powerful spring on your back and you would be required to perform series of complex motions in it...it's going to be a real work out. When I suggested it(animal spanning the bows) I was thinking of a practically stationary ground unit for artillery like applications that would either have protruding spikes for levers or a free(or extra) set of limbs to swing/pull these huge levers/ropes. A solution most likely lies in a system that would be permanently attached, but would have to be joined at a certain point to complete and ready the mechanism for spanning.
Still I like the simplicity of crossbows mounted on shoulders/shoulder blades and rider spanning them with the pivoting twin levers at his sides which he would also use to control the animal(yeh...no magic in my head ) as well as aim and shoot the crossbows...we'll see what else we can come up with in the next few days...should have some more pics soon.
PS: Here is a little theory...
Did you think about putting the rider some place else...say, the animals chest - hang gliding position? Guess it wouldn't go too well with the riders safety during the collision of animals in flight or ground fighting. Thought I'd mention it ... might just spring some more ideas.
Last edited by Ivo on Tue May 18, 2010 11:44 am; edited 2 times in total
So Geezer told me I better get on here, (still working on that fancy Danish bow, and forgetting to stick my head up for air) and check out the dragon thread. I did. And, he and I started talking... and we decided (in our own little worlds) that the female dragons would, of course, be the ones who carried the men who used crossbows. They could cock the bows in flight, being, of course, more flexible than male dragons, and so much quicker and agile in flight. And, to further that, that it was the male dragons, (with female riders) who did the dragon to dragon combat. Because, you see, female riders work better with the male dragons, there is less squabbling over dominance. More cooperation. So, the male riders, with the large, powerful bows, and the agile dragons, do all the shooting, and the female riders, with the large, powerful dragons, do all the aerial combat. This is what comes when a large powerful male and a small agile female, make crossbows together in the same shop!
Ok, back to the Danish bow.. the stock is done, and has a beautiful finish! Photos soon.. we are waiting on a 175 prod, and, a made to order gafa, so I can complete it and send it off to the lucky owner...
... Though it doesn't allow for the vagaries of which animal will choose to bond with which human, and vice-versa. And as with any critter, some females will be large and robust, some males will be small and timid, and you have to slot them into the order of things where they fit best.
Still trying to work up the resolve to rewrite the previous [nuked] post ...
Hi Guys, Thought I might add my $0.02 again. Firstly I think the crossbow should be mounted facing behind the dragon. This is for two reasons. 1)To defend against attackes from the rear (from other dragons). I imagine the rider would use it like the rear mounted machine gun in a WW2 Spitfire. 2)The crossbow does not need to face foward. There are few weapons more formidible than the front of a dragon. A crossbow will not add much. Also, if the crossbow was foward mounted there is a risk of hitting the dragon in the wings, neck or head.
Im imagining a swivel mounted crossbow behind the riders saddle and just behind the wings. At the base of each wing would be a small harness. With each wing flap the harnesses would move backwards and fowards. This will provide the power for spanning and releasing the crossbow- in the same style as a chinese repeating crossbow. When needed the rider could spin around in his saddle (or he could have second passenger to shot the crossbow- someone light like a halfling), engage the harnesses to the crossbow and start firing - a shot for every wing flap. Dragon wings must be incredibly strong to lift their body weight, so Im thinking a draw weight of 1500# and a power stroke of 30"- (1,500 x 30= 45,000!!!!)thats some serious striking power!!! Bolts would be unfletched javelins with massive broadheads for stability and killing power; and they would be loaded into magazines- just like the chinese repeater.
Does that make sense? Sometimes I start to ramble.......
Rearward facing rider: bad artistically, bad for the rider as they're flying toward an objective, and you're taking the position that the best defense is a good defense, rather than the accepted opposite (the best defense is a good offense). Better to shoot them down before they get to you than expect to engage them mano-a-mano, and watch your ass while your mount and most-important-buddy is getting his ass kicked up front (and maybe shot by an opponent with a forward facing bow).
I've considered using wings as the power behind the spanner/architecture, but most large flyers spend more time gliding that flapping, using updrafts and such. Whatever movement spans the bow can't be subordinated to involuntary or regulated movement. At the least, it has to be something that isn't subordinated to flying movements or "Scrapping" requirements, which is why I find myself leaning toward having the rider span the bow with his legs at need. His (or her) legs are the only set of muscles that aren't required to do something else absolutely essential.
Which raises the question: how much power is needed to pierce a rhinoceros hide? Elephant? Then add a layer of hardened leather armor?
Also, is there a way to harness and STORE kinetic energy, like the flapping of dragons' wings, in a way that can be transfered later to the spanning device, ala a coil spring or the like?
Digging this conversation, regardless; it's like observing decades of combat experience played out and analyzed ...
Tolo, If you want power, accuracey and rapid rate of fire you may be best with an archer with a middle eastern horse bow , say with 140# draw weight at #30" of draw. That would be a good way to pick off distant targets. If you want some kind of mechanism that looks cool, then use a foward facing crossbow, the leg power of the rider would provide no more(and probably less) than the power of a horse bow with a long draw and heavy draw weight . To get the power up, use the dragons strength. You could harness the neck . At least when you combined that power with a chinese repeater system, the dragon could fire the mechanism at the riders command, simply by dropping it's head. This would also take it's head and neck out of the line of fire. But if you want something that looks really cool, then just make something up. If you something that works, use dragon mounted archers with horsebows (dragon bows). But really, why do dragons need crossbows. When I played AD&D ( about 20 years ago) they could cast powerfull spells and fear. regards james
"If you want power, accuracey and rapid rate of fire you may be best with an archer with a middle eastern horse bow , say with 140# draw weight at #30" of draw. That would be a good way to pick off distant targets."
Saving that for my heroine! Though 140# is probably more than she could handle. Maybe
The logic is that she's a great shot, so she goes that route. The less gifted use crossbows that deliver a high rate of fire.
"When I played AD&D ( about 20 years ago) they could cast powerfull spells and fear."
These are just animals, with claws and teeth, and no magic. There ARE other dragons with those attributes, but they're rare and mostly not ridden at all. The meat of the story will revolve around our riders who ride these animals, with kick-ass equipment.
I like the idea of harnessing the dragon's neck. One thing I want is for it to look believable enough for a group like, say, this one to look at it and say, "Hunh! Well, that's cool!" And not "Hunh, well that's retarded." Without crossing a line into "That looks like it would work well, but it looks retarded..."
I'm allowing myself all the benefits of modern bow architecture, on the assumption that they've been doing this for a looooong time, so they've become good at it (they don't have internal combustion engines, electric motors, or gunpowder, but they have modern production techniques apart from that, so that parts are made identically and can be swapped out and repaired). So compound-bow tech is kosher.
Lightly and Geezer, you have my applause, it would certainly simplify our situation and give a more romantic storyline . On the other hand I think it is best we stick with designing "saddle with built in spanning mech crossbows" while ToLo throws new challenges at us.
I actually don't like the idea of animal spanning the crossbows with dragons being the animal choice. Such a design choice would easily look cool, but it would just as easily cross the line and and progress into "it looks cool and looks like it would work, but it's not going to" because with the wide range of movement involved in flight, overdoing a spanning motion is very easy and that would mean exceeding the limits of the mechanism and breaking it...
The rule goes >>> "The less complex the mechanism, the more reliable it is" So less D&D and More D&B!
Kiwijim, it looks like we are on the same though pattern here.
Rear is in fact open to attack and some sort of protection is needed there...I think we can cover both protection and attack of the rear without the use of aimed weapons...I propose that on each side there are multiple rows of small-medium canisters with some nice brutal nets (with hooks every few inches)....no aiming - just eject and watch the nets expand creating a wall of death in front of your enemy.
And the thing with armor that would be kinda cool is to make it adjust as the rider moves to span the bows. What I noticed from my drawing is that the rider is wide open to all kinds of attacks...left, right, front, back, top...with the only shielded area being below him(the animal he is riding)...the design is simple yet REALLY COOL inspired by a combination of traditional crossbow shield (Pavise) and convertible cars. Given the rider will have to do some serious spanning he/she will be required to operate a spanning device (I stand with levers*) he/she will practically expand from a crouching position to a standing position....with space being an issue and riders vulnerability being at it's highest while spanning I believe the shielding system should adjust accordingly to provide maximum protection to the rider during the entire spanning procedure.
Here is how I see it > 1. The back shield should slightly extend above the neck and head 2. Forearms operating the animal/crossbow controls/levers should have shields extending on the sides(protecting riders arms, ribs) and pivoting with the back shield to protect the rider as he/she stretches and lies down while pulling the levers, the arm shields(side shields) in all should be making up 2/3 of the front shield. 3. "Main" front shield will be composed of two shields(one riding on top of another) with the top shields attached to the arm shield and pivoting/sliding adjusting to the riders position as he stretches to span the bows. 4.There should be another set of "static" shields protecting the primary axle on which lever is anchored, this set of shields will also protect the riders thighs.
I'm still debating with myself whether this "suit" should be a part of the spanning mechanism or if it should be a part of the riders armor that he/she would put on before getting on the animal, but it definitely will have to connect to the levers and lock to the sliding top of the "main" front armor. This combination cockpit like structure should still allow the display of the simple and effective spanning system in operation, yet at the same time will create a feel of complexity with multiple armor plates moving in unison with the rider spanning the bows.
Bottom Line... cool thing about it is >>> This approach will give the entire assembly a feel of those skeleton watches, yet will not make the spanning mechanism more complex than it should be.
*Levers + Spanning with legs...
Now that I think about it - a lever can in fact be combined with simple leg spanning Proposed by ToLo. Kiwijim you are messing with peoples minds here. "Im thinking a draw weight of 1500# and a power stroke of 30"- (1,500 x 30= 45,000!!!!)thats some serious striking power!!!"
I think a more realistic picture is in the FD curves of various limb profiles(no cams>trad archery)....practically all start out at lower draw weight and slowly increase as the bow is drawn and final draw weight is reached...I think it works the other way around similarly > The arrow is accelerated along the track receiving the energy stored in the limbs, receiving less and less energy per inch of travel as it accelerates. Long story short>>> the first half of the draw is going to be lighter than the final draw weight and thus can be spanned a certain distance by legs and lock it...further spanning is done with levers.
I can push around 900lb at 45° angle with legs about five times. Unless you regularly exercise weightlifting, don't try it...you will blow your back on the first try...been there done that ....This seems about right with the 1500lb draw weight presented by kiwijim so I can easily picture a battle hardened maniac with thirst for destruction loading these crazy crossbows dozens of times before he/she calls it a day.
Sorry for the speech...also no pics yet, just writing as I think...surprisingly the keyboard didn't melt.
Yer killing me with your comment about the spring loaded net canisters, because I have them already, only I was putting them beneath a dragon, to be released onto other targets, whether it's an animal or military unit on the ground or another dragon. But I hadn't actually considered installing them on the back of the saddle. Yet I have a scene written already in which the heroine, having been partially netted, manages to gather the net and throw it behind herself to take out a pursuer.
In other words, stop reading my mind! I mean... I like how you think!
I'm failing to see the armor you're describing in my mind's eye. Some shielding is obviously essential. The dragons wear some armor to protect chest and neck and the wing joints. I have a sketch of that (though I'm not in love with it yet for various reasons).
Here are the three bits of mechanism I've written in so far (none of it in stone);
The topbows (as I've been calling them) that we have been discussing here. They need to be able to lay down suppressing fire, among other duties,. but it has to be serious enough to threaten armored dragons.
A lance mechanism in which the rider feeds a disposable wooden lance into a carriage, then windlasses it over the dragon's shoulder --the point, which was facing aft, now flips up and over to point forward as the dragon takes it and does the actual steering. The butt of the lance sets into a stop built into the armor. They take out big animals on the ground with heavy (xbow) artillery mounted on howdahs on their backs. The lance will pierce, shatter, and release from the carriage. Rider carries a number of lances and spare carriages in the event one is damaged.
The netters, who follow behind to drop nets over the occupants of said howdah, or supporting ground troops, or other dragons. Between net and hooks in net, being dragged at speed by a dragon in flight is not a fun ride. The net canisters are fed into position by a similar carriage/windlass system so that there's no danger of accidentally snagging the mount. The weakest point in the dragon teams are the wings and the riders, and a net from above is good for eliminating both.
Netters and lancers need personal protection, but don't have room for topbows. There will be less lancers than netters, and possibly less netters than topbows in any unit.
because with the wide range of movement involved in flight, overdoing a spanning motion is very easy and that would mean exceeding the limits of the mechanism and breaking it...
That's why I was leaning toward the rider spanning the bow, and proposed that he do it with his legs. Originally I had imagined a lever-action of some sort -- the rowing motion combines both, but in my mind's eye looks a little ridiculous...but that doesn't mean that there isn't a solution in there. I'm not sure how to return the system to a reset condition with the riders feet sitting on the pegs or pedals or whatever, though. Perhaps a rotating system--not rotating as in a wheel, but as in after any shot, what was at the bottom is now at the top, with what was at the top now at the bottom, to swap again. But now that I picture that, all that leg action is wearing me out, and I can't see a way that the legs and mechanism don't end up in each other's way. Maybe it's better to just brace with the legs after all.
I like the idea of a coil spring with enough tension in it to span the bow five or eight times for some rapid fire shooting, but the mechanism for that would be extreme ... and yet, the sort of thing a dragon could wind and forget for a few minutes. Two coils, side by side, with two bows side by side, could be wound up while they approach the battle.
It might be more of a "span-assist" that allows the rider to span the bow easily and quickly with a simple lever (probably getting a little harder with each pull) until he has to either span it himself or get the dragon to wind it up again.
Now it's getting complicated again. But I'm picturing a crossbow that can go crack-ker-rack-ker-rack-ker-rack ... How cool would that be. And a spring self-destructing? Spectacular!
I haven't put the shifting armor on paper yet, the reason for the hold up is my visit to the library...just kidding...no time for that. I did read up a bit on the topic of fighter pilot training and this is why...
While attempting to design of the shifting armor cockpit I filtered all the important details to one that I could put down as a starting point of my research. > Position of the pilot's body.
In my first drawing with the rider squatting or even the traditionally accepted "gladiator" styled rider sitting up straight as if riding a horse...both might look cool, but would they work in reality?
As we know the coolest things are functional things, so I tried to imagine what flying a live creature would feel like. A roller coaster I thought to myself, well that's close to 100+ mph (160+ km/h)...also worth adding is the constant change of direction with the flapping of wings and evasive maneuvers dodging arrows launched from the ground and nets thrown from above...and have arrived at one of the sickest sports of today.
The forces pilots undergo during each and every maneuver are enormous, probably nothing like the fighter pilots at their wicked 9 G's, but still the G's are going to be there.
Levers are not looking good ...
There is more info online explaining isometric exercises which these pilots perform to keep their head on their shoulders...similar exercises are performed by regular pilots to reduce chances of hypertension as well as just people fighting their blood pressure on the ground.
Aaaaand we're back to using muscles to stay conscious.
Now if we go back to the roller coaster portion of this ride being over 100mph I begin to remember how cool my high school physics teachers were. The class that day was based on the vivid impressions of students coming back with their impressions of the six-flags trip and how cool was Nitro.
Watch the video and then read on further
So we're riding dragons that fly close to 130mph ei? Well what we see in that video isn't even 80mph! There are other roller coasters out there that are designed to safely accelerate it's passengers to 90-100mph, but these are mostly drop rides that don't even last 3 seconds...on the other hand there were a few rides built were actually considered "roller coasters" going at 90-100mph and this is where I was first told about the reason why pilots during WWII were tucked into small cocoon like cockpit with their knees tucked much closer to their chest than we usually see pilots do. Interestingly this was done to keep the whole blood pressure/G forces issue at bay without the use of special equipment that took time and money to build or simply didn't exist at the time.
So the rider/pilot will not be leaning forward(as was illustrated by me in the beginning ), but actually leaning a bit back preferably with his legs slightly bent at knees to get them closer to the chest. Armor - I'm rethinking it. The levers - I'm now thinking if they can now be used for anything else other than controls(though still drawing out the set I initially imagined).
The lances are a fun idea, but please think what a collision at 100+mph is going to feel like...shatter and splinter unpredictably in all directions...and that's in the chest/neck area if I'm not mistaken? Why not just employ an atlatl with the tail being used for leverage? I really like this video for the info in it, but the anarchistic humor is not my thing though.
Imagine a dart cradle/quiver mounted on the dragons chest with the ability to feed darts to the tip of the tail and have the dragon suddenly redirect and fly up doing a very tight back flip with the tail hurling the dart at the enemy...or perhaps a top mounted system where a rider would feed a dart on the spine of the tail and the dragon would do a slightly twisted roll(shoulder first, tail last) and hurl the dart that way?
About the spring spanning assist...well I'm not too found of the big heavy spring having to wind up...sorry, but that is just not "cool" ...perhaps a hydraulic system? I mean it looks bad ass to say the least ans yet it pretty simple(I'm guessing )...The problem with the big spring is tha it HAS to be compressed...WORK has to be done to do that...a hydraulic or pneumatic system can be easily eased down to it's beginning position(not compressed like a spring ) these two are not really my profile and I did already use up my library time for today, so I'll need to do some reading on that a little later.