Chakram upper surface profile

Timo Nieminen · 20th June 2014, 06:17 AM

... 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."

20th June 2014, 06:17 AM	#1
Timo Nieminen Member Join Date: Mar 2012 Posts: 422	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."