I needed something to help me draw and sight fish's powerful Hunter Bands. My existing Y-fork could handle the forces, but wasn't ideal ergonomically, so together with my daughter, I designed a new slingshot as a gunsmith would design a target shooter's stock. I worked out the position my hand needed to be in to handle the stresses and then filled in what was needed to fill out the gaps.
As you can see, there's just the right amount of wood to cover the frame and no more.
It is held in a Hunter-style grip with the forefinger wrapped around. The effective fork height is a little under an inch. This helps reduce wrist strain when using heavy bands and this helps improve accuracy. Under tension, the metal frame is about vertical. A strong platform for the lower three fingers is also needed to maintain a proper grip. I have to stretch just a little bit and this unconsciously makes my fingers grip.
The fork tips were turned backwards for longevity and attached as fish recommends. I used a contrasting tie colour to aid sighting.
The frame is 3/16" mild steel plate which was sandblasted and phosphated coated in 2400 series ceramic Gun Kote in flat black to a thickness of .00045". This finish gives superior wear and corrosion resistance.
The grip has a rhomboid cross section. It doesn't look like it should shoot straight, but it does. It's just the way the hand is shaped.
The I used 8mm (5/16") carbon tubes for the pins. The bottom one goes all the way through. The top one stops a little below the surface at the front.
The design looks bulky and heavy, but Sheoak is light despite being a hardwood. In addition, I have heavily skeletonised the hidden parts of the frame. Below is what the frame looked like before final assembly. The total weight is about 6.5oz; 7oz including the bands and pouch.
You can see that I provided for a lanyard strap at the bottom to go round my wrist. In the end, I found it unnecessary.