shooting fixture

[willie]

Here is a couple of pics of a fixture I am building for some Bodnik Mohawk Hybrid takedown limbs. It still needs an arrow rest, a way to draw the mechanical release back and to be mounted to a stand at the range.
The purpose of placing the limbs in a fixture is so that different arrow designs can be shot with some degree of repeatability. Limb spacing and angle of deflex is adjustable for further evaluation of any particular arrow.
About 60 pounds of mostly inch and an eighth plywood.  hope this pic is better.

[Danzn Bar]

Wow Willie .....your really spending a lot of time designing and building some mighty fine fixtures.......But I would love to see more bows that you build.   Do you make selfbows?
DBar

[Badger]

   That is cool Willie!

[BowEd]

Yea DBar.....I sent him 2 very nice staves.1 osage and 1 hickory.Figured I'd see a bow built on here from that.Looks like a good set up though.Took some well thought out planning.

[Del the cat]

Great set up.
Handy for plotting the FD curves with the various configurations to
Not so useful for wooden limbs tho' 
Del

[avcase]

I think that’s will work for a consistent arrow launch platform. Do you plan to use a small winch to draw the bow?  Do you want the thing to fire automatically at a pre-determined draw length, or will you fire it manually? What is your plan for the arrow rest?

You might consider adding an extension out the front to mount a chronograph too.

Alan

[Jan de Bogenman]

I hope there will be lots of snow and time to work...great setup! Maybe a high speed camera?
Is it to compare speed of different arrow designs only? Or also arrow flight and take off, than maybe a mechanism to simulate finger release?

Jan

[willie]

Not so useful for wooden limbs tho' 

Perhaps not, Del. It is primarily for experimenting with different arrows, but I did have a plan brewing about putting some shorter billets together into a sort of three piece all wood semi-takedown.

Alan, a chrono and some sort of steady draw + auto-trip release is definitely in the making. Haven't given the rest too much thought yet, but the space between the limbs is wide open to possibilities. I suppose that adjusting the height or centershot can be used to fine tune the arrow spine needed.

Is it to compare speed of different arrow designs only? Or also arrow flight and take off, than maybe a mechanism to simulate finger release?

Yes, not only to compare initial speed of different arrow designs, but hopefully a way to evaluate cast and stabilization with arrows of identical weight, but different fletchings, FOC and spines, etc. I am sure the hard part for me as a archer will be seeing just what the difference is between the machine and my fingers once I put the limbs back on the factory riser.

[DC]

Willie, I'm curious why you made it to just hold the limbs rather than the whole bow. Were you planning on experimenting with deflex angles?

[willie]

Don,
not only the deflex angles, but I can move the limbs closer together or further apart by sliding the aluminum mounts in the unistrut. this will hopefully allow adjustment in the poundage, string tension at brace, and draw length, so that I can quantify how a specific arrow responds.

The pics below show the factory bow profiles. The mfg makes some surprising claims and warranties about the limb construction and durability with light arrows.  I probably have written too much about them on account of their forbidden f-word construction. This project is really about wood arrows.

[Selfbowman]

Willie is that for flight shooting ? I have a three piece I would maybe like to shoot at the flight shoot but don't know if there is a class for the three piece Longbows? Nice set up by the way. Arvin

[avcase]

Willie is that for flight shooting ? I have a three piece I would maybe like to shoot at the flight shoot but don't know if there is a class for the three piece Longbows? Nice set up by the way. Arvin

I had built a takedown bow a number of years ago that met the rules for primitive flight. It is really challenging however because metal fasteners are not allowed.  On my primitive takedown, I bound the limbs to a wood handle using numerous wraps of flax twine, but it was only good for a few shots before the limbs would start shaking free of the binding.

Takedown limbs for the modern Longbows were disallowed retroactively after my oldest daughter showed up with one and exceeded the standing record by a large margin. It took her 11 years to finally repeat that distance with a single piece bow. Under the present rules, 3-piece bows with bolt down limbs are shot with the Modern Field recurves.

Alan

[joachimM]

I had built a takedown bow a number of years ago that met the rules for primitive flight. It is really challenging however because metal fasteners are not allowed.  On my primitive takedown, I bound the limbs to a wood handle using numerous wraps of flax twine, but it was only good for a few shots before the limbs would start shaking free of the binding.

Takedown limbs for the modern Longbows were disallowed retroactively after my oldest daughter showed up with one and exceeded the standing record by a large margin. It took her 11 years to finally repeat that distance with a single piece bow. Under the present rules, 3-piece bows with bolt down limbs are shot with the Modern Field recurves.

Alan

What a pity! so bows like this one aren't even considered primitive? http://www.primitivearcher.com/smf/index.php?topic=38514.0

[avcase]

What a pity! so bows like this one aren't even considered primitive? http://www.primitivearcher.com/smf/index.php?topic=38514.0

Yes, this bow seems to meet the US Primitive Flight rules for a complex composite. It uses wood dowels and looks like natural material binding for the takedown feature. It does not meet the Modern American Longbow rules however.

Alan

[willie]

Willie is that for flight shooting ?

yes, I hope to be able to shoot at full range, and maybe also come up with some kind of backstop/target that can gently stop a fragile flight arrow at 75 yards or so.

maybe a mechanism to simulate finger release?

Jan, the more I think about your suggestion, the more useful something like that seems. Did you build a release to do that on your machine? I would be interested in how it works.