Throw Line Launchers


Climbing Up
Dec 28, 2005
Boston, MA
Here's a site that details making a low-cost tennis ball launcher for stringing antennas for ham radio.

These things shoot a tennis ball with line attached 150 to 200 feet and look like they would be great for throw lines. They are made from PVC and one guy uses as little 12V portable air pump to recharge his in less that 1 minute.

Looks like it might be the ticket for an arborist with a little mechanical skills.


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I saw a video of one of those in development on AS about a year ago... I don't feel getting on there and looking for it though... I can't even remember my password.

It was very effective... and he was actually launching throwline like zing-it rather than fishing line. The biggest problem at that point was the pipe. If you over pressurized it would shatter explosively. They have a note about it on the site. I might have to try building one sometime... like a mini pumpkin cannon.

This one looks almost the same except it's more compact and launches fishing line. You have to have compressed air or a pump to charge it.

I have a friend who's working on one made from a paintball grenade launcher...

It will launch a modified throwbag about 100' with no line attached. It still needs work though and he's one these guys who has dozens of projects going at once and hasn't messed with it in a while. The launcher itself costs about $350.

Anybody ever made tennisball cannons using old style beer cans with Calcium carbide/H2O for propellent?

I still throw by hand until I get pissed and then pull out the big shot.
I want the .22 cal line gun in your Fundamentals book, Jerry.
I can just imagine that tennis ball bouncing every which way as it hits branches...
Years ago the navy had a 45:70 line thrower.

Now that tennis ball launcher is something I had cogitatated about a little bit.I've often wondered about a spud gun to throw a line .

To fling a line by hand you are darned lucky to sling one 40 feet with any accuracy.
The thing about a tennis ball is... will it come down through a twiggy oak or a big pine?
Al, the navy's 45-70 gun is still in production. It can launch the line 850ish feet, used for getting lines between ships from what I hear.

Funny you mentioned it, earlier this week I saw one for sale for $850ish, normally goes for $1300.
Anybody ever made tennisball cannons using old style beer cans with Calcium carbide/H2O for propellent?

About 35 years ago (young and crazy) we made one out of Coke cans (maybe beer cans) taped together, I think...I do know that we used white gas for the propellent...had a "touch hole" at the rear where we held a lighter to it. We were bored out of our mind on a summer rainy day when we were supposed to be rock climbing...too much lightning to go up on the cliffs. We were in a quonset hut, got creative and took it outside to try it. Jon held it on the other side of a tree and I touched off the gas. The tennis ball hit the ground about 50 feet away and bounced another 50 feet and hit a guy in the chest as he walked out of the hut...knocked him and his beer on his butt. :lol:
That how we got started, but we used naptha at first, pretty cool but then... we learned about calcium carbide, fuel for old mining headlamps. You add a little water and it gives off acetylene.

Same basic design except for an extra chamber to catch the calcium carbide rocks. Two or three rocks, a squirt of H2O, pack a ball in, give it a minute, angle it at 45 degrees and fire the touch hole. You never see the tennis ball again, easily 500' high and no telling how far. The upper barrel section had to be rebuilt every 10 shots or so... that's with the older tin cans.