Shawnusa

My Feedback: (3)

Hi,

I'm just about done building my F-5 and need some ideas or possibly plans for building a lanch rail system. Also, any recommendations on what I need for lauch band?

Thanks,

Shawn

Shawnusa

My Feedback: (3)

Gee,

I did not realize that the bungee lauch rails and such was a undesired topic. Any one ..... Any one..... Looking for help in building a lauching rail setup and need ideas, and how to size a bungee line. Any one..... Any one.....

Shawn

woodduck-RCU

Check out yourzagi.com they have plans for a low cost bungee launcher.

CTulanko

Shawn,

I had one heck of a time trying to squeeze info out of people when first wanting to build a launcher and sympathize with you! For this reason, I have a couple places to compliment the build that is shown at the “zagi” site. I use a modified version of the Bungee Launcher found at www.yourzagi.com/launcher and I would recommend this one as it is cheap and easy to build.

I built my launcher a bit different. Mine was shortened to 48” long and works just fine with the jets I launch, which means it can handle just about anything. It also makes it easier to transport in a car if needed. I also made three types of launch platforms, a Padded Rail, a Launch Ramp and a Low Friction Rail. The Ramp is a piece of 1x12x48” white shelving board I got from Lowes or Home Depot and it works great. The Padded Rail uses the stiff insulation; don’t use the soft rubber type insulation as the wings/fins tend to dig into it. The Low Friction Rail was made from 1” PVC bored to accept the ¾” PVC short tube and coupler. I glued a short piece of ¾” PVC to a coupler, then inserted and glued it into the hole I bored in the 1” Rail…that way there is no interference as the width of the coupler doesn’t exceed the width of the 1” PVC. You can drill a small hole into the ¾ PVC from inside the 1” and use a screw so it definitely won’t come apart when dismantling.

Here are some pics and tips:

My first launcher, a wood one from old plans-
http://www.rocketryforum.com/ctulank...=bungee%2Fwood

My PVC Bungee Parts and some assembly-
http://www.rocketryforum.com/ctulank...r=bungee%2Fpvc

The Bungee Assembled showing different setups and how it hooks up-
http://www.rocketryforum.com/ctulank...%2F&startpic=0

The Bungee in use showing new Low Friction Rail(see pics at end)-
http://www.rocketryforum.com/ctulank...f4dfirstlaunch

Here are some tips:

I used Surgical Tubing for my Bungee cord rather than Bungee

Use the ½” Surgical Tubing, ¼” diameter center with 1/8” walls

You can also use the 7/16” bungee sold by www.hobby-lobby.com

Length of the Bungee was 30-33 feet.

Use at least 12” long steel nails to secure your launcher

Get a fish scale at the store

Set tension using the fish scale to 5 times your aircrafts weight. My FA-18 weighed in at 43 oz and the bungee was stretched and tension was set to 19 lbs. My friend had a digital scale and it showed up 15 lbs, so the digital ones do make a difference.

Use Quick Links to hook up your system…it makes assembly and takedown easy

I lengthened my legs by 5 ½” all the way around on my bungee to get it up off the ground a bit.

Do not exceed a 10 degree angle

Make sure your launch rails/ramp are in a straight line with the bungee cord


I hope this helps and gets you started on your way to launching. I use mine a ton and keep in the the car at all times these days. Let us know what you come up with and how it worked out.

Cya,

Carl

Shawnusa

My Feedback: (3)

Thanks fellas,

appricate the links and I now can visualize the needed setup. Also appricate the info on the bungee setup. Now I have a secondary project for the weekend. Hope to fly my F-5 soon! Will share what I do when complete.

Has anyine built a cool looking lauch system that resembles a UAV CO2/compress air lauch system? Just curious as it would cost more than it's worth.

Thanks,

Shawn

andrewjet

My Feedback: (16)

shawn that's a nice launch system. I've been using it for almost a year with no miss-haps. It works great you just need to get a hi-lift kit with it and some spikes and your'e set! I would recommend you treat it with caution because it's made of light aluminum. Also, add lock-tite to screws because after hundreds of launches they will work themselves loose (theres only two screws on the rails)! Also remember that this launch systems is designed for approx. up to 2.5 to 3lbs planes at max. Just remember that It's important to get the hook placement correct or you find yourself picking up carnage instead of a plane. If you take your time and check everything, it should be OK. Also, if the hooks to far forward the plane will pull down, !QUOT!right after it leaves the ramp!QUOT! and you'll have to fly it up or if it's to far back it might pull it up to disaster. But not to be too alarmed should workout OK when you get it placed correct. Like i said earlier i've never had a mishap and i have hundreds of launches off this bungee. Good luck!!!