# slingshot crossbow



## luke brisco (Jun 25, 2011)

Hi,

Im thinking of making a slingshot crossbow like the one Joerg Sprave made based around a medieval european crossbow i have made a CAD model of it but i'm just wondering if the lathe at the front will be strong enough at 22mm by 40mm at its narrowest point to hold thera band gold at a draw length of about 75cm (it will be made out of normal timber from B&Q) 
any help or advice is greatly appreciated, because I dont realy want to cock it and get a broken piece of the lathe in the face.

View attachment crossbow.bmp


Thanks, Luke


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## JoergS (Dec 17, 2009)

If you use multiplex and don't exceed 90 kg of a draw, it will hold. My version only has 18 mm multiplex.

An important factor is how you attach the rods (fork arms). I use M6 screws that run through the entire length of the rods, with washers. That works.

Jörg


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## shawnr5 (Feb 16, 2011)

Looks good. I need to get more multiplex. I used all of my 18mm making slingshots for the Boy Scouts and used all of my 12mm making the Angry Birds slingshot for my wife. I also used all of my purpleheart and zebrawood. I really need to make a pilgrimage into town to go to Timber and Woodcraft.


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## luke brisco (Jun 25, 2011)

JoergS said:


> If you use multiplex and don't exceed 90 kg of a draw, it will hold. My version only has 18 mm multiplex.
> 
> An important factor is how you attach the rods (fork arms). I use M6 screws that run through the entire length of the rods, with washers. That works.
> 
> Jörg


thanks for the advice and your medieval crossbow looks brilliant and im looking forward to seeing your next creations

also what type of multiplex do you recomend I'm not sure whether to go for structural plywood or exterior plywood

http://www.wickes.co.uk/exterior-wbp-plywood/invt/110037/

http://www.wickes.co.uk/structural-spruce-plywood/invt/110036/


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## Rapier (May 28, 2011)

Umm safety glasses might be a good idea. I never see Joseg without them when trying his crazy inventions. Good luck with it


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## Rapier (May 28, 2011)

Rapier said:


> Umm safety glasses might be a good idea. I never see Joseg without them when trying his crazy inventions. Good luck with it


Joerg even


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## pyromaniac1918 (Jul 21, 2011)

Hey
I'm also making another slingshot crossbow as well but with a butt stock and a pistol grip.

How does your trigger mechanism work by the way because I'm having trouble with mine.


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## Rapier (May 28, 2011)

pyromaniac1918 said:


> Hey
> I'm also making another slingshot crossbow as well but with a butt stock and a pistol grip.
> 
> How does your trigger mechanism work by the way because I'm having trouble with mine.


Check out Jeorg Sprave's you tube channel and find his vids about his crossbow. It's an AWESOME thing with 20mm or 22mm spear gun rubber and shoots massive lead balls that would take a zombies head right off. You should be able to work out how the trigger works as he describes it a bit in the vid.

Good luck


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## slingshoot (Jul 15, 2011)

Is multiplex more resistant than other kinds of wood? I am thinking of use oak for the fork. What do you think?

Thank you.


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