Recently I have found a new niche in making catapult and sling bows. I harvested some nice forks from my permission the other day and recently made one into a simple au natural catapult.
I harvested this fork on Sunday, stripped the bark and rough carved it. It has been drying in my conservatory since. As is typical with tree forks it has split a little as I didn't seal the ends. I have now fitted it with yellow tubes and also fitted a screw in hook that doubles as a site/arrow rest should I choose to fire arrows. I also wrapped the lower handle in some standard silver duct tape to help with the grip.
I shoot this OTT held at a 45 degree angle in the hand. My ammo of choice is 3/8 or M10 hex nuts that hit with a thud.
Shown here on the left and another project on the right.
Shown here fitted with the yellow bands and with duct tape on handle.
Here is a video of it shooting:
[video=youtube_share;nOtHRNcumbk]http://youtu.be/nOtHRNcumbk[/video]
I also decided today to test how fast it was shooting. As I don't have a chronograph machine I found rave reviews about an app that has been designed for smart phones. After seeing a tutorial on the slingshotforum about Chrono Connect I decided to download and use it to test this out.
After setting it up and inputting my data I shot 4 shots over it before my ammo catch box and back plate gave out to the strain.
It was shooting consistently at 290 feet per second with a 10 gram, M10 hex nut. For you air rifle shooters that equates to 28ft/lbs of energy, consistently which is FAC territory for an air rifle! In order to double check the math I reverse engineered it with an online ft/lb calculator and it gave me the same figures so I know it is right. Here is a screen shot from the app showing the string with no deviation.
After shooting this string I decided that some playful target practice should ensue. This was all well and good until I missed my ammo catch box and back plate hitting my shed. The hex nut went straight through the siding and ricocheted off a bike in the shed up towards the roof where it stopped. Suffice to say SWMBO wasn;t very happy and that was the end to tonight's fun. My shed now has a plaster of duct tape over the remaining hole after I tried to piece it back together.
A lesson to be learnt that these things are serious tools that are more powerful than standard issue air rifles and are in S1 license territory for comparison!
I will be making another one soon with the other fork and trying to tune that into a faster hunting weapon. I aim to break 300 FPS with the same hex nuts and this will be more than adequate for hunting small game.
Dan
I harvested this fork on Sunday, stripped the bark and rough carved it. It has been drying in my conservatory since. As is typical with tree forks it has split a little as I didn't seal the ends. I have now fitted it with yellow tubes and also fitted a screw in hook that doubles as a site/arrow rest should I choose to fire arrows. I also wrapped the lower handle in some standard silver duct tape to help with the grip.
I shoot this OTT held at a 45 degree angle in the hand. My ammo of choice is 3/8 or M10 hex nuts that hit with a thud.
Shown here on the left and another project on the right.
Shown here fitted with the yellow bands and with duct tape on handle.
Here is a video of it shooting:
[video=youtube_share;nOtHRNcumbk]http://youtu.be/nOtHRNcumbk[/video]
I also decided today to test how fast it was shooting. As I don't have a chronograph machine I found rave reviews about an app that has been designed for smart phones. After seeing a tutorial on the slingshotforum about Chrono Connect I decided to download and use it to test this out.
After setting it up and inputting my data I shot 4 shots over it before my ammo catch box and back plate gave out to the strain.
It was shooting consistently at 290 feet per second with a 10 gram, M10 hex nut. For you air rifle shooters that equates to 28ft/lbs of energy, consistently which is FAC territory for an air rifle! In order to double check the math I reverse engineered it with an online ft/lb calculator and it gave me the same figures so I know it is right. Here is a screen shot from the app showing the string with no deviation.
After shooting this string I decided that some playful target practice should ensue. This was all well and good until I missed my ammo catch box and back plate hitting my shed. The hex nut went straight through the siding and ricocheted off a bike in the shed up towards the roof where it stopped. Suffice to say SWMBO wasn;t very happy and that was the end to tonight's fun. My shed now has a plaster of duct tape over the remaining hole after I tried to piece it back together.
A lesson to be learnt that these things are serious tools that are more powerful than standard issue air rifles and are in S1 license territory for comparison!
I will be making another one soon with the other fork and trying to tune that into a faster hunting weapon. I aim to break 300 FPS with the same hex nuts and this will be more than adequate for hunting small game.
Dan
