Zidar's Crossbow

Welcome Zidar, will try to help. By the way you English is fine. I know what it is like to work with limited resources. I like Barnett's stock design, to help you with proportions start with a trigger (the actual trigger you pull) to butt distance of around 13 1/2 to 14 inches. Most overall lengths are including stirrup. The power stroke is measured from where the string sits at rest to where it is held by the string catch or latch. Before actually starting on the stock you need to work out how you are going to mount the limbs, so you can figure the distance to the trigger.

Good luck, Todd

Welcome Zidar.  Good English!

Length doesn't really matter until you decide whether you want a pistol or a rifle style stock (which we call the tiller).  Depending on how the bow (we call it a prod) is mounted, you need some length of stock in front of the prod.

The Width is probably the width of the prod from tip to tip.  Power Stroke is the distance from the string to the string-catch.  The trigger is usually some distance farther away from the prod than that.  

Very interesting compound design you came up with, as well as the multiple laminate prod.  I'm impressed.

A-C is a matter of aesthetics  -- Trigger guards come in a wide range of shapes and sizes.
B-C depends on your body - arm length in particular.  However 18" (45 CM) is a good place to start.  You can make a simple tester with a stick and some nails set at 45, 46, 47, 48 CM and see what distance feels most comfortable for you.

I feel 18" is much too long, like I said earlier line B should be 13 1/2" to 14" or 34 cm to 35.5 cm.

Todd

line B should be 13 1/2" to 14" or 34 cm to 35.5 cm

Excellent, this is what I was looking for. New drawings, this time with dimensions (inch and mm). Note that total length will probably be different then this one (690 mm).



Does this size of the crossbow look good?

The key to shooting any weapon,is comfort.Y
ou want a weapon that is comfortable to shoot.I am a person of average height,and the most comfortable butt-end to trigger measurement(dimension B)for me,is 14 and a half ins.What I would suggest,is acquire some scrap planks or plywood,make a rough cutout on the short side of the dimension I have given,and the nail strips onto the butt until you reach a butt to trigger length that feels comfortable to you.People come in all shapes and sizes,and have shooting styles that will depend on whether or not they have been trained to shoot,or have arrived at a shooting style by themselves.
                          Once you have arrived at a butt to trigger length that that suits you,the rest of the dimensions will be determined by the Fistmele(old fashioned term that means the distance between the string and the bow when it's strung,usually the width of your fist,in the case of a solid bow)the position of the nut,and the length of draw for the bow,plus any fancy bits you want to add on.

How could I have forgotten that? My height is 180 cm.

Zidar wrote:

Considering that I've never held a real crossbow or rifle of any kind in my hands, my main source of information is internet/Google.  

 

Welcome, Zidar! I'm going to argue with you on that point. That weapon may not be perfect, but it looks perfectly real to me. I don't think I've ever seen anything quite like it, and while there are obviously some things that could have been better, I'm pretty impressed with your prod design. I don't think I would use turnbuckles on the string quite like you've done there, but I have been thinking about turnbuckles a lot lately as a quick, easy, and inexpensive way to mount a prod to a stock. Don't undervalue your own experience and intuition!

I think you're off to a great start, basing your design on something commercially available that you like. I wish I had that kind of sense with my first few builds- I started out in fantasy land and had to drag myself back to reality! Don't be surprised if you want to make some changes once you are holding the roughed-out stock in your hands, though, in the end your own comfort and ergonomics trump anybody else's idea of what your stock or tiller looks like.
One piece of advice, I wouldn't even start actual work on the stock/tiller until you've nailed down exactly what your prod is going to be and how it will be mounted.

Good luck, can't wait to see what you come up with!
Gnome

"I don't think I would use turnbuckles on the string quite like you've done there..."

I need to formally retract that comment. The more I thought about it, it seemed like a simple solution for an experimental build I've been working on. Thanks for the idea, Zidar!
Gnome

^ It's a stupid idea. If you tighten the string too much, the prod may lose its elasticity/power after some period of time.

When I try a long weapon for size I place the butt (C) at the bend of my elbow, my forearm horizontal and palm up, and my finger hooked on the trigger.