I know it's not a crossbow...(Ballistas, Catapults, etc.)

First topic message reminder :

..but has anyone thought about making a scorpio or a full sized ballista? http://www.legionxxiv.org/catapulta/
I think I am going to start making a mini model of one for fun, hopefully leading to a larger one. It would be cool to design one based on modern materials just to see how much it could be improved upon.

Yer kidding? I put the ballista on my lawn for 48 hours, as you can see in the pics, but no police ever stopped by, although an elderly gentleman got off his bicycle and walked around it, while I watched smiling from the window. How that police rumor started is way beyond me. Me and my assistants and friends routinely fired the ballista on Saturdays at Anoka High School. If you think having a siege engine is illegal on your front lawn, try this one fer size...



And yes, it works and is legal.

No this happened in southern Minnesota, the city of St. James I believe. Would have been about 6-7 years ago give or take.
That is cool that you can use that at the High School.

OT- Yeah I would love to have an MG 42 mounted on the house. That looks like lots of fun as well.

Wow, I am stunned at the power that thing puts out. Very nice work. Thanks for the links everyone, I will go through more thoroughly when I have the chance. To be honest I doubt I will ever get to build anything at that scale.

DARIVS ARCHITECTVS wrote:I host Iriarte's info on a subpage on my website. Aitor is a friend of mine. Pay SPECIAL attention to his method of connecting the half-spring frames to the upper and lower transverse members. A few wooden wedges, and he solves a problem that other siege engine archaeologists could not. Pure genius... that which only can come from an Engineer, not and Academic.

I assume you're talking about the wedge system in his cheiroballistra? If so I agree that it's a beautiful solution.

Btw. has Iriarte published anything on ballistas since 2003 ("The Inswinger theory")?

Without Academics, we would not have those nice Greek and Latin translations. Without us Engineers, no one would have a working siege engine replica.

Let us not forget the carpenters and blacksmiths who actually made the various parts, nor the limitations (and advantages) of the methods and tools they used. Some solutions that are possible today with modern power tools were not possible then. Most academic reconstructions seem to ignore these and treat ballistas as some kind of three-dimensional geometric objects.

I have not heard of any new developments since Aitor converted his cheiroballistra to an "in-swinger" for experimentation. I should probably write him a quick email to see what he's been up to.

Lets have a little refresher here.

A little while back I met a guy online who built a fantastic ballista. I think you guys may have mentioned him in this toppic already, but I just know him as Warhammer1 and have been reading his blog occasionally. Very interesting build and even more interesting are the results he's getting with his machine.

I've uploaded a few videos I got from his site to you tube to allow embedding them on the forum. Chem this guy out, rocking cinder blocks, propane tanks, and stacks of plywood...


Fuckin amazing!...if you ask me.

Ivo,

Do you have a link to his site?

I can't tell from the video; what is the "energy storage mechanism" for this machine?

Mac

I had the page bookmarked on my old computer, but after it broke I was looking for his site and can't find it for some reason...all that comes up is his other blog...which is still great though.

http://warhammer1.wordpress.com/scorpyd-ballista-completed/

I sent him an invite, hopefully he will stop by and tell us a bit about what he's been up to these days...really interesting fella I must say and crazy as hell...just like most of us.

Ivo

Hello Ivo - I finally broke down and got a webcam and some software. I have a few vids of me shooting the "Scorpio" hand held. The large machine in the above photo's are from Nicks blog which I help with occasionally in the performance dept.
I dont know how to post to youtube yet, but can send a few vids by email if you pm me your email addresses. Im putting new slingshot arms and getting some heavy pull latex tubing for a torsion assisted inswinger slingshot.
I'll get a ballista bow video out soon I get it back.
BTW - The woodland flipper I've managed to get limited manufacturing rights for it as its patented, and hope to offer my own version - a little more power perhaps and a more conventional shooting position.
Nicks blog site for the full sized ballista is www.wattsunique.com and Im working on a new video blog site.
W.

Hi Warhammer1, really cool of you to join man!

The in-swinger ballista concept is a wicked one indeed. I've been giving it some thought...I can't say that everything is laid out in my head as well as I would like it, but I think I can at least contribute to possibly improving the limbs(levers)

If you checked out Igora's bow powered in-swinger ballista, he suggested using a flat strip as a lever. >>> Igora's Ballista Perv.

This kinda makes sense:

• Less air resistance.
  
• Improved rigidity along the x-axis
  
• and...perhaps Less weight. >>>BTW What are the dimensions of the Firefly ballista's levers? how much do they weigh?
  

I also would like to add that doubling the strips with spacers in between might be a good idea...a sheet/plate frame of sort.



...the lever in the picture is from a different project, so it doesn't fully apply to our ballista discussion...yet still has a few details that I wanted to mention)

Perhaps the levers will weight a tad bit more, but rigidity will improve along other axis as opposed to just flat plate version. The tip being a wheel instead of a knock is another good thought.



Since with an idler wheel there will be less string-to-nock friction as the string angle changes...this might be another performance improving factor, though I'm not sure whether it will be improvement in speed or accuracy since the assembly may add some weight to the tip depending on the materials. Perhaps you had a chance to speak with Robin Allen about one of his experimental crossbows with similar tips?

https://thearbalistguild.forumotion.com/t55-crossbow-creations-by-robin-allen#292

---

If you have some pictures to post... that's awesome! Check out this video I made on how to do it here. >>> Posting Pictures

As for videos, you can send them to me and I will upload them to youtube for you....the rest is easy ...when writing a post - there is a film "strip button" at the top, click it and post the URL of the video into the field that pops up. PM Sent.

Good Day,

Ivo

Nice looking arms. Nick likes long arms as well, and the new ones he's building will be a couple of lbs lighter than the last. I like the shorter arm design for my purposes. Its late but there should be a vid I sent by email. Will stop by again soon.
His new arms should be ready for testing in another two or three weeks. Maybe sooner if he's got an itch to fire here up again. He broke them big old log arms with his new winch and long ass handles.

Me on the receiving end, couple more under construction

---

The in-swing type ballista is know in the community as a Hatra ballista.

I'm also working on a torsion skein ballist with the skeins housed in wooden cylinders

Well I'll be damned

Don't you trust his aim me' Lord?

This is nuts.

This might just explain the firm belief in your ability to stop a table saw blade with your bare hands. Awesome head-shot though - props to the operator...and of course you, the volunteer target.


Ivo


PS: You can embed a video from youtube pretty easy here, there is a "filmstrip" button where you can paste the video URL and it will automatically add the code making the video play in the post.

---

Warhammer1,

Got your e-mail. Get those license stamps and roll it in here...that thing is bad-ass!!! And if you can, please send an invite to Nick for me, a guy who hunts propane tanks and cinder blocks is too good to be left behind.

Thanks. Sending it off this week for inspection and testing. At NIcks site, just drop a comment there inviting him over to the party. He is pretty busy tho and doesnt answer much anymore. He doesnt even bother to post on Romanarmytalk.com now.
Gonna try to get a strong band for my slingshot and then destroy some cinder blocks and bricks for a neat vid. Will be getting an old Jennings Devastator (railess design) to convert to ballista. Got a DTM375 that needs a new look as well.
Hoping to get a rail and trigger to slap on the pistol version.

Had to hand my ballista over to someone else to finish. It was test fired, pretty snappy with an improvised bowstring. Polished up the trigger for smoother release, polished the nocks on the prod. I don't like the way the winch is set up but I'll change it when I have a better idea for mounting it. Stock needs to be shortened about 3". Second stock is in the same workshop, skein carriers for 3rd ballista has been farmed out.

Spent yesterday getting a ballista up and running. We were getting 50 yards out of it. We need to make a longer string and increase the draw length. Might add a helper spring behind the prod so we can get 80 yards out of it. We built a stand resembling those on a roman scorpion, but it should have been about 4" shorter. I'll post some pictures when I figure out my scanner.

Sounds great can't wait to see pictures.

Tried to upload photos but I didn't get it right, Help.

Hey, looking good.

Thanks for going through the trouble with that scanner and posting the pictures, I'll fix them in a second.

---

Ok with pictures fixed, now I can go on rambling about how awesome this thing is.

Definitely want to hear more specs on this machine. \

• Prod weight Dimensions, Source, ...
  
• The Improvised string?
  
• The trigger ... as I understand is basically a one axel mechanism? ...in a
  sense that the claw retaining the string and the lever release is one
  part?
  
• What are the projectiles made of?
  

Ivo

PS: A cheap digital camera goes a long way...also I recommend you try
Photobucket.com as a picture host. It's much better suited for sharing
albums(as in slideshows) and pictures on forums...not to mention, with
Photobucket you can upload and share videos just as easy as you would
pictures.

I bought the plans fromwww.ballistaplans.com
The plans for the play bolt tips are herehttp://www.thesiegeshop.com/Pool_Noodle_Assm.html

The prod is from a truck spring shop. I used a leaf spring .323 X 2.5 X 60" At this point I threw in my own modifications. I had the spring shop roll in a recurve.
The original plans had the nocks on the prod centered on the ends of the spring. To me it looked like there was too much string pressure on the top of the stock and too much mass at the limb tips so I did a pyramid like taper from about 15" from limb tips and reducing limb tips by 1/3 the width.
It is 28" from center of nut loop, ( 1/4" steel, upgraded from .080 in plans) to back of prod hole. With the linkages figured in it works out to about 24 1/4" draw length. Don't know power stroke, and it is going to be changed.
Ivo's observations on the trigger are correct. I should put another bend in the handle so it rises above the nut loop when the string is winched back. Next one I make should be about 2" longer
The string is an endless loop string. 40 strands of Dacron B50, triple served, assorted serving materials. It is 56" long, should have made it longer, maybe 1 1/2" longer because of the recurve.
I also think the nut loop to back of prop should be 2" longer with the recurve prod. I want to add a 18" backer spring to the prod.
The stock is pine or spruce. The front end is cut off to form a long sloping ledge. Hopefully it will keep the bolt from being knocked off by an "enemy fighter" trying to spoil our shot. I would like to get it carved and painted to resemble a dragon.
The boat winch only sort of works. I think I need to make a cheek piece on the left side, and a platform that brings the top of the winch spool even with the groove for the winch rope in the back of the stock. A sleeve over the drum of the winch would make it take up rope faster.
I also need to add a handle to increase control while winching / aiming / firing.
My co-builder is working on a video of it. We will post soonest.
The projectile shafts are 160 psi siloflex or equivilent, and the link for how to make the tips is at the start of this post.

another machine from same plans

Samuli!!

Didnt know that was you here under a diff handle! After coming across it the other day I wanted to write you and thank you for doing the wiki stuff.

I sent Ivo a video of an earlier manuballista build that was getting 175fps with about 50lbs pull on a scorpyd platform. If you'd like to see it I'd be happy to send you a vid. I just finished a new ballista build with a new arm length to axle to axle ratio.

On my blog somewhere I believe I still might have math calculations concerning limbtip speed to string speed you might find interesting as it might help any theories you have.

Im still out on a limb with my crazy ratio's and even Nick is skeptical. So now my design allows one to use either a compounding or non compounding design with one simple quick change of string attachement points. Takes about ten or twenty seconds. It automatically doubles the available power by eliminating the mech advantage the pulley system provides, while the still remain in place.

I've also made it so one can adjust the mech advantage in increments from zero to a two to one mech. advantage such as the Woodland Survival Flipper employs.

How is your book coming along? I hope to write one someday and share my performance findings. Chiefly Nick has been the only one using some of my ideas and findings.

My newest build with really short arms might give him a nudge, but I will first have to prove it. So, I have a bevy of custom arrows weighing in from 244 grains all the way up to 1280.

I have stopped contributing to RAT as my work is not so popular there LOL.

While I have mathematics and mathematians sometimes helpful in design verification, they are loathe to accept new theory or evidence if the math does not agree.

The benefit of results driven work is that the performance is duplicatable upon demand. Chronies dont lie!

BTW - thanks for the wiki link to my blog. Its an honor to be included with Nicks work and machine. With the new arm positioning, we believe the new and proposed design to be the most accurate interpretation of the Orsova find but is yet to be verified by testing and the chrony!

If you read the comments there, I post as Captn Harpoon a lot. I took the nickname as I was trying to convince Nick to up the bolt weight, size and length from 2800 grain durabolts to 7500 - 10,000

He said they werent arrows and accused me of being part of a japanese whaling fleet haha.

With any luck Firefly will soon be tossing around 20,000 grains, or something about four to five feet long. I believe Firefly is up to the job and the weight more to her liking.

If nicks machine resembles my designs or my machines resemble nicks machine its because we share the same tech. to a certain degree. I am unsure of nicks reluctance to finish up the new arms, so he is due for a video of my new build and performance.

He is a hard fella to convince and I have to work within the confines of his build guidelines, namely period correct technology wise and correct to the Orsova frame find.

Warhammer1

basileus wrote:Hi guys,

Please check out the Wiki I founded mostly for my own manuballista (in Greek cheiroballistra) project:

• http://ballista.wikia.com
  

Currently all of the content in that Wiki is written by me, but I'm hoping that'll change eventually. Unfortunately the lack of any decent communication channels (e.g. proper forums or mailing lists) within the Wiki project makes collaboration very difficult. I may end up moving the Wiki to another host just because of this.

You are probably most interested in these articles, which I hope will eventually end up into "real" articles in scientific publications:

• http://ballista.wikia.com/wiki/Cheiroballistra
  
• http://ballista.wikia.com/wiki/Inswinger_and_outswinger_controversy
  
• http://ballista.wikia.com/wiki/Personal_torsion_weapons
  

The problem I've noted with academic research related to the manuballista (and ancient artillery in general) is that the academics tend to be, well, academics, meaning they're fluent in ancient Greek and Latin, but lack experience in practical issues. For example, their reconstructions may be perfectly doable with modern machinery, but not with tools of the era (antiquity). This tends to lead to unrealistic reconstructions. Second thing thing the academics seem to struggle with is performance of these machines, which is so poor that nobody in the antiquity would have used them. Anyways, I'm hoping that my work as an academic and as a craftsman/hobbyist will eventually help fill the voids I've described.

Now, fortunately some non-academics have managed to get impressive results from these machines:

• http://wattsunique.com/blog/
  

Actually Nick's blog was the reason I again (after a pause) became interested of the torsion weapons. As an example, his machine has spit out war-weight bolts at 400fps.

As you can see, I'm pretty deep in this manuballista stuff, so feel free to ask anything .

-basileus

Hey baileus.

In the inswinger outswinger wiki page, you post that the arm constantly is under acceleration when in actuallity it slows down almost imperceptedly.

On the Hatra design (original find) the arms were at rest postion at a 12 oclock position and full draw is 120. If you have followed my RAT postings on the subject I described a "lull" that occurs when arms horizontally opposed.

Later a mathematician plotted limb tip speed to string speed, thus proving up my theory.

On the Orsova design(with overdraw past the 12 oclock rest postion), there is actually two spots where that "lull" should occur - namely the normal 12 oclock rest position. I havent found a mathematician to work that out for me.

When using either as a rock flinger with a heavier weight it should not result in a sine wave in the string, but if too light a projectile is used from a 120 degree rotation release point, the string halves will accelerate toward each other and at the point where the string is normally slackest (90 degrees from rest) the strings will have enough energy and momentum to actually cross over each other during this "lull" and then have to straighten out as acceleration of limb and string begins again.

Here the strings direction changes from being at its widest, to its closest, and then moving apart again.

With Nicks new extended rotation (22% jump in speed) the strings direction must again change direction where it is joined to the lever or limb. Only the middle of the string continues to accelerate as vertical acceleration has ended completely at the 12 oclock position and only a horizontal movement is available. Once past 12 oclock the the direction of the levers has actually reversed and headed back towards the user.

IMHO, this should also result in funky business, but we will have to wait for the new arms on Nicks machine. He has also now got a 1200 frame per minute video cam. so we should be able to see things more clearly, and exactly what does happen.

Of course its very easy to see on my low powered machines, but I like to have a second confirmation before publicly posting actual results or claims.

So far I believe I am the only "ballista freak" doing extensive research and testing using much shorter arms expressed as a ratio of arm or lever length to axle to axle length.
While some figure I use the compounding design to change limb tip to string speed (which it does), it is far more productive controlling the angle of pull on the string which is all important.

Keep up the good work. I wonder if what reseaching is similar to the comparison of two bows both having the same overall length, but one having long limbs and a short riser versus the other having short limbs and a long riser. I believe the latter performs better but only up to a certain point. No doubt there is one layout that is most effiecent and going too much either way performance starts to drop off.

Todd

thanks Todd. Here is a link to anyone interested in either inswinging design - the Hatra or Orsova. The link points to math calculations for normal length arms, and my findings.
http://warhammer1.wordpress.com/nu-inswinger-data-to-digest/

I've always been a contrary critter, and always insist on swimming upstream when the rest go with the flow.

I have always found that a failed design will teach you more, if nothing else through process of elimination. Success requires many such failures and is too be expected.

One day I hope others will pick up where I leave off, and help them poor scholarly types build something that works as its supposed to. Nick of course excluded.

BTW - nu arm pics on his blog. www.wattsunique.com and I cant wait for the full power testing which should still take some time and a lot of work on NIcks part.

Since I use the same spring and power level in all builds, any performance must come from the engineering. While the range of the ballistas in this threads links have a max range of 200-300 feet with light bolts, that is my range in fps. The very lightest load for my machine is a 250 grain arrow which works out to over five grains per lb of pull, and the heaviest arrow is 1280 grains or some ridiculous amount for the power used.

Anyhow, hope you enjoy the read and findings .

[Admin Edit by Request]

Warhammer1's Inswinger on the Scorpyd platform.




Warhammer1's Inswinger Pistol Crossbow (aka Ghetto Blaster )