Effortlessly Send Antenna Wires Skywards With A Spud Gun

The heroes of action films always make it look so easy. Need to climb a tall building? Simply fire a grapnel hook from a handy harpoon gun, it’ll always land exactly where you want it and gain a perfect purchase so you can shin up the rope and arrive at the top barely having raised a sweat. If Hackaday ran Q Branch, we can tell you, we’d make ’em work a bit harder. If only because nobody likes a smartass.

If you’ve ever had to get a real line over something tall, you’ll know it’s a lot more difficult than that. You can only make it work with the lightest of lines that you can then use to pull up something more substantial, and you would be amazed how poor a thrower you are when you’re trying to throw upwards. Try attaching fishing line to a weight, try a bow and arrow, and nine times out of ten you won’t make it. There’s a serious amount of skill and luck involved in this line-throwing game.

[WB5CXC] has an interesting solution to this problem, at least as far as the application of throwing antenna wires over tall obstacles. He’s made a spud gun from PVC pipe, powered by compressed air. It takes the form of a U-shaped tube with one side of the U being a pressure vessel separated from the other by a ball valve.. Place a close-fitting puck with your wire attached in the open side with the valve closed, pump the pressure vessel full of air with a bicycle pump, and open the valve to send both puck and wire skywards. He says it will clear 100′ trees, counselsĀ the user not to go higher than 100psi, and warns that the speeding puck can be dangerous. We like it already.

We’ve covered many spud guns here at Hackaday in the past, but it seems this is the first wire launching one. We’ve had a steam one for example, or this bolt-action spud gun, but pride of place has to go to the spud gun to end all spud guns.

Via DXZone.

29 thoughts on “Effortlessly Send Antenna Wires Skywards With A Spud Gun

  1. If it uses fuel, it could be classified as a firearm, which would be illegal to use in cities.
    Ain’t America great?

    If you don’t care, get a can cannon.

    1. But it uses compressed air, so all you have to worry about is lugging around your air compressor and something to power it. And the possibility of a trip to the hospital if the PVC fails.

      There’s nothing like overcomplicating things when a slingshot or bow and arrow will do a better job more simply and more cheaply.

      1. You wouldn’t really require an air compressor and accompanying power source, a manual bike tire pump (those long ones with the T-handle) would just as well maybe even more suitable for the job.

          1. I’ve seen some awesome builds using a bow and a fishing reel. I completely agree unless one needs ridiculous distance.

            There is an amazing video from Nat. Geo., but I can’t seem to find it. They were shooting things into trees so they could rig up a pulley system for the crew and cameras. Really good documentary if anyone remembers it. I think they had several versions of modified bows and air launchers.

          2. I recently used a professionally-manufactured t-shirt launcher (like the spud gun pictured here, without the shatter-prone PVC) to fire a tennis ball over a 100 foot tall tree in my front yard. The shot itself was at a 45 degree angle, so about 141 feet. The ball pulled 7-pound-test fishing line, and I pulled a heavier string and then 440 lb cord in place of this.

            There is just no way I would have been able to do this with a slingshot or arrow. 100 feet is not an unusual height for a redwood tree that might be on someone’s property where I live.

    2. Even if it used propane I dont think it would be classified as a firearm federally.
      We can buy fireworks and model cannons. I’m not sure exactly when one becomes classified as a ‘destructive device’. I don’t feel like linking a PDF right now but will look at it later. I could be wrong.

    3. The BATFE has ruled on them & have determined intent rules the day.
      Novelty/entertainment is ok but if you destroy property you’re in trouble.

      Also of note, Line throwing devices are specifically exempt.

    4. Here it is a gun regardless. It uses a “propellant” (compressed air) to launch a projectile. I.E. In this town it is technically illegal to fire a Nerf gun. But this is California. Champion of everything overly broad and selectively enforced.

  2. Nope, not the first. It’s a good idea, but not a new one. These have been around for years. Several of the guys in my ham radio club have them and lend them out to other hams as needed.
    Google “antenna launcher plans” if you want to see other iterations of the same idea.

    All that being said, I do appreciate Hackaday showing this, because I’m sure there are people who haven’t seen these before.

    Now let the “don’t use PVC as a pressure vessel” wars begin!

    1. 20 years ago there was a guy in the village where I grew up who would use a potato gun to set up antenna wires over trees. The heaving line was attached to an empty soup can placed over the muzzle.

      Warning: They’re lots of fun. Once he did some repair work on the boat I worked on….afterward him and one of the owners stayed up late at the dock launching potatoes out into the inlet. We were under way the next day when I went to cook breakfast and found there were no potatoes left on board!

  3. LSD ( labor saving devices), made it big with their first product. A Zebco fishing reel attached to a Whamo Wrist Rocket slingshot. Especially used for above suspended ceilings where there is no throw room or space for Errol Flynn.

  4. We used to use a wrist rocket with a sinker and fishing line to run network cables through drop ceilings. You can shoot a sinker sideways within a 3 foot vertical area almost 75 feet on a flat shot – which is usually across a good sized office. Tie of the network cable with a small funnel that has a notch cut in it to encompass the front of the cable so it doesn’t get caught on the cross ribs, and you are in business. I’m betting you could use this to shoot a sinker a couple hundred feet high with fishing line – maybe get some line that is 25-35lb test for heavier cables and use a heavier sinker.

  5. These have been around a while. There were a couple at our ham radio Field Day this last weekend. One guy even had a very nice one he bought on-line as a kit.
    The pressure needed for these is not all that high. 40 psi will sent my line up at least 70′. I build a folded one very similar to the one in this article a couple of years ago. I use a bicycle pump with a gauge. Much better than a fueled device which is going to be hard to control the exact altitude you hit.

  6. Yeah… when I read “…it seems this is the first wire launching one,” I knew that someone didn’t perform a simple Google search. The Joplin Amateur Radio Club has been selling antenna launchers as kits for YEARS, and there are many others out there. The guy even says in the linked article that his launcher was a re-design of one that he already had that he built from plans in a magazine… so… anyway… all that said: I have one of the JARC launchers, and they are FUN.

  7. I built the WB5CXC launcher almost exactly as shown, I could not find the 1 1/4 to 1″ reducers so used a 1 1/4 valve, and could not find street ells, so used regular 90 deg with a bit of pipe between. My Lowes did not have one bit of 1 1/4 PVC fittings except for under sink work, and also had no 1 1/4 pipe, even a place for it. Home Depot had it all, except as noted for the street ell and reducers. I put my bike pump on it and gave it 10 pumps, put one of the bullets with no string in the tube, aimed it skyward and fired away. I thought I would have to call NASA telling them I just launched space junk. I put ten more pumps in it, and this time read the pressure and it was 20 pounds. 15 pumps gave me 30 and 20 gave me 40. I used builders twine, the kind used for batter boards when laying out a foundation, this particular string was pink, put in 30 lbs of air and fired away. It easily pulled the line to 80 feet straight up Tried an aimed shot at 20 pumps, 40 pounds, and it put the string over the branch I picked out and through the tree clear to the other side. I did flake the lines before the shot, it did not come off a reel or bobbin.You are told if your bullet end caps have a ridge, to smooth it off. My did have a ridge, but fit the tube with no issues so left them, think they contribute to overall tube/bullet sealing. All new stuff, including the eye hooks was less than 25 bucks and saved at least 25 bucks worth of cussing and loss weights using my slingshot.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.