Who makes Artillery ??

[AuxArcher]

Ducan, my little machine is a work in progress....and I can fairly easily rebore the spring holes to 1 3/4" at this point, as I have enough room. Are you pretty certain about those dimensions? Having more power will be nice

Errr...but, I have to consider the frame dimensions then, eh? perhaps I should stay with the spring diameter I had planned, and make another machine later. What think you?

[Gaius Julius Caesar]

I reckon it would be wise to stay as you are and bulid another with the propotions to match the larger springs........safety first :wink:

[D B Campbell]

... safety first :wink:

I'll second that!

[LUCIUS ALFENUS AVITIANUS]

I think the modioli are 45 mm but exterior. Look at the x-ray picture published in

http://www.archaeologie-krefeld.de/Bild ... orsion.pdf

There is a graphic scale, and using it , seems that the white coloured cercles (the metal parts) have a diameter of 45 mm. But that diameter is, in my opinion, the exterior.

I have made 4 modioli with a 45 mm inner diameter and are clearly bigger than the used by the yet made Xanten reconstructions.

If you put 4 modioli with a 45 inner diameter inside the upper an lower 21 cms tables, there are clearly oversized.

Dane, you can't adapt such diference of diameter. If you have beginn with 3,5 you can finish it with that. There are modioli of such little proportions. You will haven't the "Xanten· manuballista", but you will have a well proportionated manuballista.

I think 5 years its a reasonably time to publish that find. There is a lot of interest in know the sizes, so what do you think to send some kind of request of that to the museum, suported by the RAT administration? It's possible?

[AuxArcher]

I do agree with you guys. A moment of temporary madness,

I'm sticking to my plans, and the ratios I utilized in sizing the entire machine. And I do seem to recall feeling 45mm is the outside diameter, as well.

Guys, if I ever get a free 3 hour block, I will have my bolt slot routed in, and perhaps a bit more done - i hope this weekend that happens, so I can post more pictures.

[AuxArcher]

I agree with this statement. I know I would be terribly appreciative, and so would so many of us.

Dane

I think 5 years its a reasonably time to publish that find. There is a lot of interest in know the sizes, so what do you think to send some kind of request of that to the museum, suported by the RAT administration? It's possible?[/quote]

[P. Clodius Secundus]

Here are a couple of rather poor photos (sorry guys ) of my initial attempts at fabricating budget carchesium parts. I've got some better shots of the nearly completed mock-up/test rig, but they are at home and I'm at work. Today I cut and ground the teeth on the right side cog and started making a drum retaining pawl for that side as well. I'm not sure if the Romans would have bothered including a drum latch on both sides, but I figure the added complexity is worthwile for safety reasons alone. the tricky part will be connecting them in such a fashion that they work independently when winding, but can be disengaged together. If I had thought of it earlier I could have aligned the two gears before welding them on the shaft so that the pawls could have just been welded to one common axle. Add that to the lessons learned column. To make the ratchets I start out with a black iron pipe flange and drill four more holes between the existing ones. Then I cut straight in from the edge to the center of each hole. Next I cut diagonally from those cuts to the top of the nearest hole. The result looks like a very nasty eight-toothed saw blade. I use a flapper type grinding wheel to curve the back of each tooth and a file and emery paper to clean up the rest. I'm not sure how well they'll work under a load but they sure look like the real deal and the price is low enough that I can afford to experiment. The first ones I tried were 1/2" flanges, but for my machine I'm going with 1". I originally planned on using a large and small (lever and drum) cog on the left and another small one on the right for the other lever. It would work, but I dedcided to apply the K.I.S.S. principle to reduce the possible modes of failure. The hardest part has been figuring how to make it so that it can be disassembled without griding and re-welding. I know there'll be lots of that going on. Someone suggeste that I could have the finished pieces bronzed. Wouldn't that be cheating? Let me know what you think.

[Gaius Julius Caesar]

Interesting pieces Randi!

[Gaius Julius Caesar]

!I'm not sure if the Romans would have bothered including a drum latch on both sides, but I figure the added complexity is worthwile "

To equalize the stresses?

[P. Clodius Secundus]

I'm home from work now so here a few newer carchesium pics.

[M. Demetrius]

Someone suggeste that I could have the finished pieces bronzed. Wouldn't that be cheating? Let me know what you think.

I'm not sure that there is anything that would be cheating. But one thing that can be done fairly inexpensively is to heat the steel and rub it with a brass brush. This gives a quasi-reasonable represenation of bronze, or at least non-steel, and likewise helps some with rust preventative.

Just a thought.

[AuxArcher]

Randi, great work as always (I had a preview of this work, and am impressed now as then). As for bronzing, the Romans used iron components in many of their machines, so maybe plain steel would be fine.

[AuxArcher]

If anyone is still following this thread, here is a shot as she looks now. Please note that I mocked up the springs and bow arms, simply to double check some areas. They decidely won't be cardboard tubes, twine, and salvaged arrow shafting.

[Titvs Statilivs Castvs]

Looks great! Who are you going to shoot?






(Nice dog.)

[D B Campbell]

Somehow I missed your posts last month, Randi. I'm glad to see that you're making progress.

... carchesium pics.

You confused me with talk of the carchesium, which is the name usually given to the component that Marsden calls the "universal joint". That's the must-have tilt-and-swivel mechanism on the stand of a regular catapult (and also found on cranes).

But, as you've obviously discovered, Vitruvius seems to use this word for the drum of the winch. I wonder if this is perhaps a mistake in the manuscript tradition. (Goodness knows, there are enough problems in this manuscript already!) It would be peculiar for the same word to be applied to a component that moves in two planes (the tilt-and-swivel joint), and to a component that simply turns (the winch drum). Hmmm. :?