Author Topic: Del's Primitive Crossbow  (Read 29462 times)

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Offline Del the cat

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    • Derek Hutchison Native Wood Self Bows
Del's Primitive Crossbow
« on: October 29, 2011, 02:15:01 pm »
31" ntn with some built in deflex Laburnum (from one that died in the garden a year or so back) backed with rawhide.
80# @ 12.5"
No metal in the construction. The bow curved upwards so the string doesn't press down hard on the stock, and there are a few nice touches like a sliver of Ivory to stop the bolt being push back too far.
A full build along is on my Bowyers Diary starting here. http://bowyersdiary.blogspot.com/2011/10/graingram-scales.html
I'll take it up the club to the Samhain festival tomorrow.
It certainly shoots clean and fast, no real kick, just a nice click & twhack.


I'll post the speed tomorrow, anyone care to guess >:D
The butt end looks a bit white as it isn't properly finished/varished yet.
Full draw shot ..

Just did some chrono tests. With the heavy bolt in the pic (it has a flat head nail in the butt end for added weight) it was only about 125 fps, but going to a V light bolt (50gn point) it shot upto 170fps. With such a short power stroke I s'pose the heavier bolt slows it down a lot.
I had a couple of dry fires as trigger groove needed a bit of fettling... dind't scare the cr*p out me at all O:).
BTW the string is 90 strands of linen thread. The binding for the prod is hemp twine soaked in a mixture of beeswax & linseed oil.
All fixed now :)
Del
« Last Edit: October 30, 2011, 05:08:30 pm by Del the cat »
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blackhawk

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Re: Del's Primitive Crossbow
« Reply #1 on: October 29, 2011, 02:28:41 pm »
Cool Del....more photos? How bout a full draw :)

Offline Del the cat

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Re: Del's Primitive Crossbow
« Reply #2 on: October 29, 2011, 02:55:09 pm »
I've just added full draw and I'm going to edit in the chrono results.
Del
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Offline ken75

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Re: Del's Primitive Crossbow
« Reply #3 on: October 29, 2011, 03:07:51 pm »
thats pretty cool there "cat daddy", i half expected to see a clothes pin on top  >:D

Offline Matt S.

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Re: Del's Primitive Crossbow
« Reply #4 on: October 29, 2011, 03:10:54 pm »
That's incredibly cool, I'll take a look at your build-along. I'd love to make a crossbow, so I'll be adding this to my bookmarks  :)

Offline crooketarrow

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Re: Del's Primitive Crossbow
« Reply #5 on: October 29, 2011, 03:45:17 pm »
  SWEETTTTTTT
DEAD IS DEAD NO MATTER HOW FAST YOUR ARROW GETS THERE
20 YEARS OF DOING 20 YEARS OF LEARNING 20 YEARS OF TEACHING

Offline Ifrit617

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Re: Del's Primitive Crossbow
« Reply #6 on: October 29, 2011, 05:31:35 pm »
That is awesome! I am curious though how much the bolts weigh?

Offline Del the cat

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Re: Del's Primitive Crossbow
« Reply #7 on: October 29, 2011, 06:10:10 pm »
That is awesome! I am curious though how much the bolts weigh?
The heavy bolt (11/32") in the picture is 440gn @ 125fps = 20.7 Joules of energy
A ight bolt (5/16")                                    150gn @ 170fps = 13.0 Joules of energy
The heavy bolt goes pretty slow, but being 4 times heavier ends up having much more energy.
It would be interestion to plot loads of different weights and see which actually gives most energy.
BTW the bolt has just 2 flights fixed at a slight angle to help it spin.
Del
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Offline ErictheViking

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Re: Del's Primitive Crossbow
« Reply #8 on: October 29, 2011, 07:54:54 pm »
Really cool Mr. Cat, that binding for the prod is sweet looking. whole thing is top shelf .
"He that but looketh on a plate of ham and eggs to lust after it hath already committed breakfast with it in his heart"  C.S. Lewis

Offline Ifrit617

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Re: Del's Primitive Crossbow
« Reply #9 on: October 29, 2011, 08:08:42 pm »
That is awesome! I am curious though how much the bolts weigh?
The heavy bolt (11/32") in the picture is 440gn @ 125fps = 20.7 Joules of energy
A ight bolt (5/16")                                    150gn @ 170fps = 13.0 Joules of energy
The heavy bolt goes pretty slow, but being 4 times heavier ends up having much more energy.
It would be interestion to plot loads of different weights and see which actually gives most energy.
BTW the bolt has just 2 flights fixed at a slight angle to help it spin.
Del

Cool, I think Im gonna have to try this sometime.

Offline bubby

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Re: Del's Primitive Crossbow
« Reply #10 on: October 30, 2011, 04:21:33 am »
that'a sweet cross bow del, did you wrap the rawhide with cord to get the corregated look, Bub
failure is an option, everyone fails, it's how you handle it that matters.
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Offline TBod

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Re: Del's Primitive Crossbow
« Reply #11 on: October 30, 2011, 06:01:50 am »
Very nice!

Any shooting video? I'd like to see how you hold it.


Offline Del the cat

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Re: Del's Primitive Crossbow
« Reply #12 on: October 30, 2011, 06:05:56 am »
that'a sweet cross bow del, did you wrap the rawhide with cord to get the corregated look, Bub
Yup, spot on, that's exactly what I did.
Del
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Offline Del the cat

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Re: Del's Primitive Crossbow
« Reply #13 on: October 30, 2011, 06:11:27 am »
Very nice!

Any shooting video? I'd like to see how you hold it.
None yet, but I hold it like a modern rifle, the butt droops down about half an inch and has a bit of a cast off to the right so with my cheek on the butt my eye is right in line with the bolt.
It's a bit of a mix of styles really, it doesn't look that primitive and there's a hint of the Gothic in that bolt clip. Early crossbows had a dead straight norrow stock, but would imagine it wouldn't take longe before some guy made his a bit more comfortable to shoot. The long straight stocks are a pig to shoot as it's not comfortable however you hold 'em.
The bigger one on my website is a bit of a cheek rattler, there's a vid of that one on my website and it shoots pretty similar to this one.
Del
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Offline TBod

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Re: Del's Primitive Crossbow
« Reply #14 on: October 30, 2011, 02:50:23 pm »
Yes I saw that video "game over" :)

Must be difficult to hold a straight stock crossbow against you shoulder. Is it not sufficient to rest it against your cheek. (maybe grow a beard or something if it hurts to much)