Chakram upper surface profile
 

... or chakra, or quoit.

Payne-Gallwey, in his talk at the Royal Institution of Britain meeting, 1908 (reprinted in A. G. Credland, "Sir Ralph Payne-Gallwey Bt. and the Study of Medieval and Ancient Projectile Weapons", Arms & Armour 8(1), 46-88 (2011)) describes the chakram:

"It is made of the finest sword-steel, and is usually eight inches in diameter, including its inch-wide rim. It is a sixteenth of an inch thick and eight ounces in weight. [...] The upper surface of the quoit, or the surface that is held uppermost when the quoit is thrown, is slightly convex. The under side is flat."

Thinking that it might be interesting to make a replica (maybe a safe non-steel replica for playing with), and that "slightly convex" is very general, I ask: what is the profile of the upper surface in more detail? Is it very stereotyped, or does it vary a lot from chakram to chakram? Since it's an aerodynamic weapon, the details of the profile might affect the performance a lot.

Payne-Gallwey on the performance of the chakram:
"I have often thrown one of these quoits over 200 yards, its height above the ground, for two-thirds of its flight, not exceeding 4 or 5 feet. This shows what a deadly weapon it must have been in warfare when used by the native soldier, who could doubtless cast it with much more force and precision than I can."

Intriguing weapons. I was lucky enough to pick one up a while back and might provide some insight.
This one is the same type and sporting the same mark as shown on top of page 314 in Robert Hales' new book. It is convex on both sides, like a sword. Made of great steel and rings like a bell as they say… It is a little larger, about 9.5 in and although I have not thrown it, it feels great to hold.
I look forward to hearing more about your project…

I don't have anything to add here at this point, but I just wanted to thank you guys for the detail in adding references in these posts! These are most interesting weapons and material is pretty obscure, so its great to have a benchmark for researching further and discussion.
Much appreciated and thank you so much!!

Jim

Hi Timo,

A subject close to my heart as you can imagine.

From the examples I have handled and have in my collection, I can tell you the earlier specimens DO have an 'Airfoil' or 'Convex' profile. The chakrum itself has an almost very narrow 'diamond' section profile, but a close inspection does reveal a slight 'aerfoil'.

In examples which I believe are later, the 'Airfoil' is more pronounced. I cant tell you which is better, I have never wanted to throw old chakrum around, although I cannot imagine it would damage them if thrown in open ground. Perhaps I will give it a go one day!

The British historian Mike Loades made a documentary under the series 'Weapons Masters' which some of you may have already seen. A very interesting and useful introduction to the Chakrum and aerodynamics of the object, I think it's a definite watch for you Timo.

Here is the link, although others in the States have told me it is not viewable there, perhaps it will work this time. If you cannot view it, let me know and I will see if there is another way to access the programme.

https://www.youtube.com/watch?v=sev9LmC_d_4

Good luck in your quest, and if you have any other questions feel free to ask.

Sincerely,
Runjeet

Great info Runjeet! Unfortunately the link still doesn't work for us in the States.... :(

Thanks for letting me know Jose. I will look into this, and see if I can come up with a solution. Hopefully Timo can view it thought?

Regards
Runjeet

For those situations were your location keeps you from accessing certain internet addresses you can use "Hola", I just watched the video (very interesting) using it. https://hola.org/

Great tip Eric, thanks.

Apparently the documentary is also streaming on Netflix.

Thanks,
Runjeet

Works for me; many thanks! (Now I need to have time while in front of a computer with working sound, or fix the sound on mine.)

For comparison, my Chakrum
 

Hello,

Here is a small picture of my chakram. It measures 9 ⅜ inches in diameter. The ring is beveled in a diamond cross section to generate aerodynamic lift. In shape, it very much resembles the modern "Aerobie" toy which was reportedly modeled on the charm. The patina of my example is mottled gray with light pitting. The composition is radial patterned steel, pattern welded for strength and not for esthetic effect. In other words, a weapon intended for use and not simply show.

Interestingly, steel versus brass chakra have different throwing distances. A steel one such as this has an effective range of 40 to 50 meters. A brass chakrum, due to lower mass, could be thrown in excess of 100 meters.

Here is a link to my website with further information:

Chakkar Sada Chakrum

Best Regards,

Dave A.

Why are brass ones lighter? Are they smaller, thinner, or hollow on the bottom surface? (Brass being denser than steel, there must be a smaller volume of metal compared to steel ones.) Are the brass ones non-weapons?

(Maybe the best thing to do is to get an Aerobie and copy it in steel.)

Here is a different version, same uploader, which might be more easily viewable for some: https://www.youtube.com/watch?v=sDNw2slOK3Y