Anyone who has ever installed a wire antenna in a tree knows the frustration: throwing weights, sinkers, or tennis balls tied to a string that often get tangled in branches. After the last windstorm, KE2GYH decided to create something more elegant instead of improvising.
The result is 'The Free Shot' - an affordable, 3D printed antenna launcher that you can make at home for a few euros.
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Why was The Free Shot created?
The project author originally used the classic method, but after the antenna fell during a storm, he decided to spend a few hours designing in a CAD program. The goal was to create a device that is compact, has an integrated coil, and costs a fraction of the price of commercial solutions. Although the author considered selling the files through Patreon, he ultimately decided for the community and published the files for free (Open Source).
Key Features and Tricks
Integrated Coil: The line unwinds directly from the body of the device, minimizing the risk of tangling.
Storage Space in the Handle: The grip contains a compartment for spare weights, so you always have them on hand.
Utilizing the Power of Latex: The device uses the principle of a pocket slingshot. Just attach the latex pouch and fire.
Low Cost: The total material cost (excluding 3D printing) is in the range of 10 - 15 USD.
What will you need (BOM)?
To assemble, you will need approximately 230 g of filament (about €3) and several commonly available components:
1. Latex pouch for slingshot: (approx. €2 - 4). The author recommends a shorter version (11 cm).
2. M6 screw and nut: For the drill adapter (used for quick winding of the cord).
3. Weights: Ideally 1 oz (about 28 g) with a diameter of up to 21 mm (to fit into the handle). Important: Smooth weights with a hole in the center are recommended, not those with loops that could tear the latex.
4. Cord: The author used an 80 lb braided cord with high visibility but recommends a slightly thicker cord for better unwinding.
Practical tips from testing
When building and using, pay attention to these details:
Post-processing: A notch in the spool may require fine trimming with a craft knife after printing to allow the cord to pass smoothly.
Length of the pouch: If you use a longer 16 cm pouch, when fully stretched it may pass in front of the spool and the cord may get caught on it. If you have a long pouch, do not stretch it to the maximum (you will still reach a height of over 15 meters).
Procedure for throwing
1. Find a suitable tree.
2. Attach the weight to the cord.
3. Shoot over the branch and let the weight drop to the ground.
4. Tip: Instead of directly pulling the antenna with a thin cord, the author recommends first threading a sturdier paracord through the tree. The thin cord will not get damaged and the weight will not get stuck in the branches while winding.
Where to download the models?
You can find the 3D printing files at https://makerworld.com/en/models/2549978-the-free-shot-antenna-line-launcher
If you like the project and want to support the author in further development (for example, in preparing an improved cord guide), you can do so on his Patreon .