Shooting machine and a heavy Turkish flight bow

[mikekeswick]

I've made shooting machine for my heaviest Turkish flight bow because it is too heavy for me to shoot in full control with the light arrows. I also have a new batch of flight arrows made up and ready to go. I've got high hopes for this new rig and will post the results as soon as we get a nice day with no wind.
Bow is 90# + and my arrows are all from 190 grains to around 250 grains. 6 piece Tonkin cane and some pitch pine and deal. There has got to be a 400 yard + shot is here somewhere!
I'm working on making a light string for it at the moment but the string is very high and I'm a bit scared going light with the linen I have as it seems a bit brittle, breaking at 7 - 8# per strand. Maybe it is a bit dry?

[avcase]

Very cool!

Where are you doing the shooting?  You can always lightly dampen a linen string with a damp cloth and pluck the string a couple of times to shake off any excess moisture. Only a couple grains of water can radically increase the strength of linen.

As an alternative, you can use reeled silk.  Silk is much less sensitive to humidity and variation in tension distributed across the strands. On the other hand, a linen string has to be made perfect, but the performance will be much better.

I look forward to your results. 400+ yards is a pretty elite club for Primitive flight equipment.

Alan

[BowEd]

I would say so too.90#'s shooting a 200 grain arrow.That's almost a dry fire.I can see why your concerned about the string holding up.If there's anyone who can do it you can Mike.Wish you success with it.
I'll try to get a pic of the shoooting machine Gary made over here.

[mikekeswick]

Here is the rough and ready mk1 version. I threw it together to make sure the idea was going to work
I might be going down to my friends farm to shoot it this afternoon, it is windy today though. Thanks for the info about dampening the linen strings. What strength would you be aiming for in a string for this bow Alan?
I'd be interested to see it Ed. A photo would be great.

 

[BowEd]

Awesome!!!OK Mike.I like that mk1.Garys' gone up north fishing in Canada at the moment.I'd think with a shooting machine that it's got to be securely fixed to the ground too while shooting.The bow looks awesome!!!
Gary made one to see the difference in speed between a trigger release and finger release.Don't know how heavy duty it is.Think it's on a saw horse type set up.

[avcase]

I start with a total strength of string that is four times the draw weight of the bow. So this would be 4x90=360 pounds. I'd expect a quality fully served linen string with reinforced loops will have a total mass of about 90 grains. 

I can gone down to 3 times the draw weight of the bow for a reeled silk string, but the strength-to-weight and stiffness-to-weight of silk is not as good as linen, so the performance suffers.

Alan

[mikekeswick]

Thanks Alan, 4x strength it is then. I'll see what I can come up with and see what the weight comes out at.
I haven't been able to get out and shooting this thing yet as the fields I use are full of grass for hay. They are being cut in the next week or so. I made an overdraw device for the machine and I can now shoot 24 inch arrows at a 28 inch draw.

[Del the cat]

Let's have a pic showing your trigger arrangement and a long shot pretty please
It will provide some vicarious satisfaction 
Del

[mikekeswick]

No problem Del. I'll try and get one today. The trigger is a compound trigger activated by a series of levers that move when they hit a stop on the rail. I need to tie a D-loop onto the string to get a true straight pull on the small nocks and make a few changes but it works fairly well. I have also added an overdraw so can now shoot the 24 inch arrows at 28.
I've just got permission to use some perfect fields, much better than my old place. I've now got about 1000yards The grass is being cut in the next week or so and hopefully we will have some nice weather by then.

[Del the cat]

Ta,
Lucky man, I have trouble getting permission to shoot anywhere suitable near me. Air traffic control at Stansted Airport keep chucking me out
Del

[Aaron H]

Very cool Mike, bow and machine both look great

[Selfbowman]

I like it mike. See ya in August. Arvin

[Badger]

  I bought a compound trigger for my machine that uses a thumb trigger that pushes instead of pulls. Makes the triggering a lot easier

[mikekeswick]

  I bought a compound trigger for my machine that uses a thumb trigger that pushes instead of pulls. Makes the triggering a lot easier

Haha yes my friend told me about those when he saw what I had made....doh! I just used what I had lying about.

[mikekeswick]

So I finally got around to letting a few fly.
The wind wasn't ideal, about 20 mph from over my shoulder and I had a trigger malfunction so only got to shoot half of my arrows. I noticed that the bow was only drawn to 27 inches when I had finished, it can go to 28 1/2. String was a 16 strand B50.
Best shot 470 ish yards.
I 'm guessing but maybe with ideal conditions and a good linen string, full draw etc this bow might push 550 - 600yds.
I have a lot of new hornbows slowly progressing and am making some very heavy Turkish flight bows to try and get close to the legendary distances of old Adam has been getting close and that is fuel for the fire!
I also have a new order of Tonkin cane coming to make more sectional boo arrows a la Alan Cases methods. Thanks for that build-a-long Alan.