55 replies to this topic

[Liang Jieming]

Hehehe ok thanks. It's also one big learning process for me too.

BTW, my test of max range with my model this weekend isn't going to be accurate since I'm not using composite bows similar to what a real ChuangZiNu would use.

Assuming a perfectly scalable equivalent javelin represented by a short bamboo stick would represent a direct proportional reduction in projectile weight and flight characteristics, we are left with only the dimensions of the ChuangZiNu itself.

Here's my preliminary calculations.

Estimation of overall length of a life sized ChuangZiNu (bow tip to winch) = 4m

Overall length of my model ChuangZiNu = 0.17m

So, to (inaccurately) scale a max range of 1000m with the real ChuangziNu, we need to achieve a max range with the model of approximately 170/4000 x 1000 = 42.5 metres

I seriously doubt I can reach that kind of range. Maybe if I change the bows to steel I may.

I'll try anyway.

[mk_cn]

hope it can reach 20m

[Liang Jieming]

No good. The maximum I could get with 45 degree arc was 9-11m which would translate to just about 210-260m which is only typical Roman Ballista ranges. Its probably due to the bows not being of proper material. Let me sleep on this and see how I can make better bows and then I'll do a retrial to see if I can get at least your stated 20m range.

[mk_cn]

No good.  The maximum I could get with 45 degree arc was 9-11m which would translate to just about 210-260m which is only typical Roman Ballista ranges.  Its probably due to the bows not being of proper material.  Let me sleep on this and see how I can make better bows and then I'll do a retrial to see if I can get at least your stated 20m range.

thank your for your effort, maybe material is the key.
do you think the ancient Chinese crafts or processes have been lost for many years, so maybe we cannot restore a crossbow as powerful as before.

[Liang Jieming]

Yeah, material is the key. I don't have the bows done well enough or properly enough. Chinese traditional bows are composite bows in three primary materials, the tensile sinew, central core bamboo and wood in the compression face. There is one traditional bow maker left in China, in Beijing. I'm quite sure he could still make large enough bows in the traditional way to mount onto a Chuangzi to make the San Gong Chuang Zi Nu!

I intend to purchase one of these traditional bows. Possibly in my next trip to Beijing I'll pick up one.

[mk_cn]

a rich man

[Liang Jieming]

a rich man

Nah, just one with a passion.

BTW, Kenneth is back from his trip to Xian. He has a lot of new info on the Siege Crossbow. According to him, he was told that Song dynasty acruballistas had ranges up to almost 2km! I find this a little hard to believe but there has apparently been a test done on excavated tomb acruballistas (reconstructed I assume) which reached ranges of 900m. I'm still trying to verify this. Hopefully I can find the source and quote details later.

[mk_cn]

Nah, just one with a passion. 

BTW, Kenneth is back from his trip to Xian.  He has a lot of new info on the Siege Crossbow.  According to him, he was told that Song dynasty acruballistas had ranges up to almost 2km!  I find this a little hard to believe but there has apparently been a test done on excavated tomb acruballistas (reconstructed I assume) which reached ranges of 900m.  I'm still trying to verify this.  Hopefully I can find the source and quote details later.

whoops, 2km... , i will try to ask some friends from Xian to verify if there was a test before.

[Liang Jieming]

Yeah but I haven't found the references to verify the 2km distance yet though. Hopefully Kenneth settles down and starts posting his comments on this soon.

[General_Zhaoyun]

Yeah but I haven't found the references to verify the 2km distance yet though. Hopefully Kenneth settles down and starts posting his comments on this soon.

Have you already solved the '2km distance' mystery?