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» Medieval wooden crossbows in Ireland
by Juniper Thu Feb 19, 2026 8:05 am
» Shooting lockbows with low string friction
by hullutiedemies Sat Jan 17, 2026 11:19 am
» 910 feet per second
by hullutiedemies Sat Jan 17, 2026 10:59 am
» [solved]Skane/Lillohus crossbow thread
by stuckinthemud1 Wed Oct 08, 2025 3:58 pm
» Making bolts
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» double axle trigger
by kenh Sat Aug 09, 2025 6:49 am
» Two simple crossbows and bolts, image heavy
by stuckinthemud1 Thu Jun 26, 2025 11:18 am
» Finally found proof of sinewed crossbows
by Juniper Sat Jun 21, 2025 1:41 am
» Other forums like this one?
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» jens sensfelder
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» Jens Sensfelder
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by stuckinthemud1 Fri Aug 02, 2024 7:13 am
» What you building?
by hullutiedemies Tue Jul 09, 2024 12:39 am
» 12th Century Chinese Crossbow Chronographed
by stuckinthemud1 Fri Nov 24, 2023 3:50 pm
» Crossbow Stock
by kenh Tue Oct 31, 2023 6:19 am
» Cocking - how
by stuckinthemud1 Thu Aug 03, 2023 4:24 am
» Questions around heavy crossbow lath buildin
by stuckinthemud1 Wed Apr 26, 2023 1:10 am
» Arab Crossbow
by stuckinthemud1 Tue Apr 25, 2023 7:57 am
» prod angle, and lever trigger for sale anyone?
by stuckinthemud1 Mon Mar 20, 2023 5:54 am
» flexible string
by jasper1978 Mon Mar 20, 2023 1:25 am
» 400lb Windlass crossbow bolts weight and accuracy shooting high.
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» Codex Löffelholz crossbow
by stuckinthemud1 Tue Jan 24, 2023 4:14 pm
» Digitar prodsc
by stuckinthemud1 Sun Jan 15, 2023 2:42 pm
» Troubleshooting
by Andy. Fri Jan 06, 2023 12:29 pm
» Wood Prods
by stuckinthemud1 Fri Dec 30, 2022 12:47 pm
by Juniper Thu Feb 19, 2026 8:05 am
» Shooting lockbows with low string friction
by hullutiedemies Sat Jan 17, 2026 11:19 am
» 910 feet per second
by hullutiedemies Sat Jan 17, 2026 10:59 am
» [solved]Skane/Lillohus crossbow thread
by stuckinthemud1 Wed Oct 08, 2025 3:58 pm
» Making bolts
by stuckinthemud1 Sat Aug 30, 2025 2:28 pm
» double axle trigger
by kenh Sat Aug 09, 2025 6:49 am
» Two simple crossbows and bolts, image heavy
by stuckinthemud1 Thu Jun 26, 2025 11:18 am
» Finally found proof of sinewed crossbows
by Juniper Sat Jun 21, 2025 1:41 am
» Other forums like this one?
by kenh Sun Jun 08, 2025 7:54 am
» jens sensfelder
by Zardoz Wed Jan 15, 2025 5:58 pm
» Jens Sensfelder
by Zardoz Tue Jan 14, 2025 8:04 pm
» Colletiere a Charavines continuing experiment
by stuckinthemud1 Fri Aug 02, 2024 7:13 am
» What you building?
by hullutiedemies Tue Jul 09, 2024 12:39 am
» 12th Century Chinese Crossbow Chronographed
by stuckinthemud1 Fri Nov 24, 2023 3:50 pm
» Crossbow Stock
by kenh Tue Oct 31, 2023 6:19 am
» Cocking - how
by stuckinthemud1 Thu Aug 03, 2023 4:24 am
» Questions around heavy crossbow lath buildin
by stuckinthemud1 Wed Apr 26, 2023 1:10 am
» Arab Crossbow
by stuckinthemud1 Tue Apr 25, 2023 7:57 am
» prod angle, and lever trigger for sale anyone?
by stuckinthemud1 Mon Mar 20, 2023 5:54 am
» flexible string
by jasper1978 Mon Mar 20, 2023 1:25 am
» 400lb Windlass crossbow bolts weight and accuracy shooting high.
by stuckinthemud1 Sun Mar 05, 2023 2:53 pm
» Codex Löffelholz crossbow
by stuckinthemud1 Tue Jan 24, 2023 4:14 pm
» Digitar prodsc
by stuckinthemud1 Sun Jan 15, 2023 2:42 pm
» Troubleshooting
by Andy. Fri Jan 06, 2023 12:29 pm
» Wood Prods
by stuckinthemud1 Fri Dec 30, 2022 12:47 pm
5 posters
910 feet per second
hullutiedemies- Workshop Savvy
Did you see my tool collection?
- Posts : 214
Join date : 2012-07-03
Location : Fennoscandia
zky105 likes this post
hullutiedemies- Workshop Savvy
Did you see my tool collection?
- Posts : 214
Join date : 2012-07-03
Location : Fennoscandia
This is the simple and obvious trick I mentioned several years ago.
Take any flat top crosbow,
mount a second thin rail on top of it,
loop a light well waxed fishing line around the top rail and under the string - tie it somwhere behiund the lock,
cock ther bow,
pull the line back and clip it down with projectile ( 150 mg hook of insulated wire was used here)
The projectile wil launch twice the speed of the main string
The bow used here is 100#/9" double compound with ~25 J potential energy ( inswingers stack F/D-curve )
Take any flat top crosbow,
mount a second thin rail on top of it,
loop a light well waxed fishing line around the top rail and under the string - tie it somwhere behiund the lock,
cock ther bow,
pull the line back and clip it down with projectile ( 150 mg hook of insulated wire was used here)
The projectile wil launch twice the speed of the main string
The bow used here is 100#/9" double compound with ~25 J potential energy ( inswingers stack F/D-curve )
stuckinthemud1- Crossbow Junkie
I live here!
- Posts : 557
Join date : 2014-02-05
Age : 58
Location : south wales valleys
Well, I like it. Any chance of a photo showing the whole thing?
hullutiedemies- Workshop Savvy
Did you see my tool collection?
- Posts : 214
Join date : 2012-07-03
Location : Fennoscandia
I have not yet figured out a practical way to post photos since I lost my website couple years ago, the reason to go through the trouble of making a video.
But the video above should have everything relevant,
since this is just test rig put together from available left over pieces ( like a left-over crossbow
).
I need to build a better one from scatch . There are several ways to make it more efficient.
But the video above should have everything relevant,
since this is just test rig put together from available left over pieces ( like a left-over crossbow
).I need to build a better one from scatch . There are several ways to make it more efficient.
stuckinthemud1- Crossbow Junkie
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- Posts : 557
Join date : 2014-02-05
Age : 58
Location : south wales valleys
So, it works like when the Chinese paired bows on the same stock? Really impressive speed, any idea what the draw weights are?
zky105- Fresh Blood
Doesn't mean
I'm new to crossbows
- Posts : 2
Join date : 2017-12-24
Location : china guangxi
This is the development I’ve been waiting for over the past few years. It effectively bridges—and in some aspects even exceeds—the transitional performance gap between traditional crossbows and spring-powered airguns. For decades, most commercial compound crossbows have focused almost exclusively on maximizing draw weight and peak energy, relying on high-cost carbon-fiber bolts, increasingly complex cam systems, heavier overall mass, and firearm-styled ‘tactical’ aesthetics. None of these trends address practical efficiency or functional utility as directly as this design does. Excellent work — I’m looking forward to seeing your next project.
hullutiedemies- Workshop Savvy
Did you see my tool collection?
- Posts : 214
Join date : 2012-07-03
Location : Fennoscandia
stuckinthemud1 wrote:So, it works like when the Chinese paired bows on the same stock?
Hetre is one of my earlierst postings to this forum almost 14 years ago:
https://thearbalistguild.forumotion.com/t689-paleo-legal-compound
The one seen on the video above is just a twice abandoned old project that had suitable size and shape for this test.
stuckinthemud1 wrote:any idea what the draw weights are?
The specs are in the OP
hullutiedemies- Workshop Savvy
Did you see my tool collection?
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Join date : 2012-07-03
Location : Fennoscandia
zky105 wrote:This is the development I’ve been waiting for over the past few years.
Kind of funny that nobody has ever done this before. Because this principle is the same as with those linear coil-spring or vacuum-pump dart launchers that used to be popular here a few years ago. Just replacing a slow linear spring with a fast bow. It does not even have to be a compound, I've gotten close to 200 m/s with a simple wooden stick bow.
And those secondary strings can be connected into series, the first loop accelerating a second will make a sonic crack even from a small 50#/4" toy pistol. - I have not had time to test this with projectile yet. It can be done , but that will require a double length bolt rail and coming up with some way to conveniently cock the main crossbow while avoiding to accidentially bend the thin long rail that will be sticking out from the back.
kenh- Crossbow Junkie
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Location : Living Aboard a Sailboat in Fort Myers, FL
I remember this PaleoCompound from IIRC Paleoplanet years ago... have some of those photos in my files but never got around to making one. Might just have to give one a try using some thick bamboo slats I've got laying around just now!
Anatine Duo- Tinkerer
If there is a will, there is a way.
- Posts : 66
Join date : 2013-10-07
Location : Muskoka, Canada
Sick!!!
kenh- Crossbow Junkie
I live here!
- Posts : 899
Join date : 2012-08-03
Age : 77
Location : Living Aboard a Sailboat in Fort Myers, FL
But very effective, and inexpensive to build!
hullutiedemies- Workshop Savvy
Did you see my tool collection?
- Posts : 214
Join date : 2012-07-03
Location : Fennoscandia
Tightening the cables increased the draw weight to 110#, and fastest speed so far is 327 m/s (~1100fps) .
And my chronograph appears to be showing speeds up to 7% too slow, so it may be bit faster than that.
- Calibration was done by mounting the chrony vertical and dropping things through it. ( the rest is high school physics ). Microphone tests done at 22m range have also repeatedly indicated speeds bit faster than my chronograph.
The energy efficiency is in 25-30% ballpark for the faster speed record shots. This is bit low but acceptable. And there is room for improvement as the test rig is far from optimized.
The next challenge is to develop a better projectile. Those ultralight wire hooks have such poor aerodynamics that the practical maximum range is only about 5 paces.
And my chronograph appears to be showing speeds up to 7% too slow, so it may be bit faster than that.
- Calibration was done by mounting the chrony vertical and dropping things through it. ( the rest is high school physics ). Microphone tests done at 22m range have also repeatedly indicated speeds bit faster than my chronograph.
The energy efficiency is in 25-30% ballpark for the faster speed record shots. This is bit low but acceptable. And there is room for improvement as the test rig is far from optimized.
The next challenge is to develop a better projectile. Those ultralight wire hooks have such poor aerodynamics that the practical maximum range is only about 5 paces.
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