For the bungee I used the large colored rubber bands from the office supply store, doubled, for about 15 to 20 feet of elastic with 8 feet of nylon cord and a steel ring on the airplane end. Works great and probably could use a shorter rubber span.

I just recently built one of these. My only regret is I did not do it sooner. This makes launching the pusher planes soooo easy! The launches are consistent and smooth.

well its all done and tested,it worked fine but i need to mod the pin release as the ring does not slide off it smoothly.
the only other thing i did was put a steel pole in the front leg as when the bungee cord was stretched and attached to the pin the pipe bowed some.now its solid.
so now i can fly my pushers safely on my own and keep my fingers lol.
thanks for all the input on this build.

my home made bungee ramp launcher, (0 min 31 sec)

THANK YOU! THANK YOU! THANK YOU!
THANK YOU! THANK YOU! THANK YOU!

In case you can't tell, I can't thank you enough for this thread, the comments from those that have built the Pedal Launcher, and all that have contributed to this effort! For a long time I have had an incredibly hard time solo launching a series of Alfa A-4 Skyhawks due to the fact that the only place to grab the fuselage is well aft of the CG, requiring timing on the swing, release, and power application, all of which I've had very spotty success. With the Pedal Launcher I get a perfect launch every time, allowing me to truly enjoy how well my little Skyhawk flies!

Here's a couple of pics of my latest version, inspired by others who have painted it in the camouflage markings of the Israeli Air Force. This is my first attempt at free-hand air brushing. Powered by a Dick's Wicked 4800KV motor driving the Alfa 5-blade fan, this little jet is FAST!

Thanks again!

Marsh

I'm wondering if pedals and rails are even necessary. See these pictures I found of a guy launching a sizable propane-powered commercial UAV by himself. It looks to me as though with a 1-5lb plane you could do this with just one hand.

I like the idea of mounting the far end of the bungee on the top of a pole, maybe 4' off the ground.

Anyone have any experience with this approach? My electric glider is 3-axis stabilized, which may make this approach more reliable than it would otherwise be.

From those photos it looks like the man launching the plane is doing so for someone else who has the radio and is controlling the plane. If you have two people that system would work. It would be far more difficult if you had the radio in your hand and were trying to launch the plane as well.

I think it would depend on the model. The general consensus is the bungee load needs to be about 4X the model weight, so if you are going to hand hold it the model needs to be strong enough that you don't crush it. My A-7 weighs 4lbs. so at 16 lbs. of tension it would be very hard to hold on to!
Bill

I've used 3/4" OD sugical tubing for my launcher. Purhased a 10' piece from www.4fishin.com and cut it into 4 pieces 2.5' long. Each piece stretched around 3.5' gives 25lbs of tension. So I use 2 pieces attached to a pvc dolly which slides up the rails of my pvc launcher and it's plenty of force to launch my 7lb 1oz X8 with ease. My launcher looks pretty much BStaley's except it has a dolly made of a bigger diameter pipe to slide over the rails. Two aluminum brackets from the dolly push against the trailing edge of the wing to move the plane and eliminates the need for tow hook on the fuselage. Also, the bungee is attached between the dolly and the front of the launcher so nothing is stretched across the ground. I might post pictures of it if anyone wants to see it.

please post thye pics.
david

Hey this is the thread i've been looking for! Thank for the build list,since its winter it is a perfect time to build one. I am not familiar with the pico jet but it looks very similar to my radjet so this should work perfectly! If you have not flown a radjet btw they are awesome.....and cheap

Yes please post those pics...i like this dolly idea!

I tried the wood step method to release but saw a very early bungee build that used a long PVC pipe to raise a U bolt of a screw up front. Looks clunky but works great! Also like that there is nothing dangling. The tow hook is the end of the line. Here's a video from last year showing a launch and a bit of the release mechanism..

bungee (0 min 29 sec)

Newcomer & jfrederick,

I spent today shoveling out from the snow storm and will post pictures tomorrow.

This is my very simple self contained launcher. Most of it is 3/4" pvc with the exception of the bottom long rail being 1" because it needed more strength for the surgical tubing tension. The long rails are 6' and when disassembled are only 3'. The 3/4" OD surgical tubing is cut into 2.5' sections with each one providing over 25 lbs of tension when stretched. Two pieces are enough to launch my 7 lbs 1 oz X8 so i haven't used the other 2 pieces. The dolly is 1" pvc sliding over the 3/4" pvc top rails. The aluminum is bent to slip over the back of the wings. Last night, I extended the aluminum to be able to power the motor while it's being catapulted but it accelerates fine without any throttle to be honest. The actual pedal release is a metal rod extending up from the wooden pedal, through another 2x4 and into to bottom on the pvc dolly. Step on the pedal and the rod slips out of the bottom and off it goes. The next one will be all 1" pvc, some sort of rollers on the dolly to eliminate all of the friction and angle iron replacing the 2x4. This one seems to work fine but I just want an excuse to build a better version. I can take more pictures if anyone needs specifics.

Questions:
Someone asked me how I joined the upper pieces of 3/4" pvc? I took a short piece of 1/2" pvc, ground it down, and slid it into the center as a joiner. And it can be seen that the larger 1" pieces are joined at the T-joint. If you have a heavy plane, it's probably a good idea to make both the upper and lower sections from 1" diameter pvc. Also, the pedal (long 2x4) has the pin hinged with a small screw going through the middle of 1 end. That allows the pin to pivot since the angle of the pin to the pedal will change as the pin moves down. I'll post some more close ups later on tonight.

Originally Posted by chillybee

This is my very simple self contained launcher...

That looks fantastic, any chance you have a little video showing how it works?

I am building a 110" wing, so I'm debating what would be the best launcher for a wing that size.