New to us anyway. We tried using 2 sticks in an "X" configuration toward the end of the line to raise the pulling point. you lean it a little toward the end stake and it falls away. Worked great on our edf 's to get them up a little higher. I'll try to get a vid, but here is a pic.

Interesting idea..if it works why not!

Chris Golds and his flying buddies were launching 1/2A ducted fans 20+ yrs ago using this method. They used an A-frame. A lot of their methods were in Quiet Flyer, years ago.

Hello St. Martin...


...1/2a...?

Hi Larry, yeah..you remember those screaming, smelly little things, we used to turn props with?

Originally Posted by rekit500

New to us anyway. We tried using 2 sticks in an "X" configuration toward the end of the line to raise the pulling point. you lean it a little toward the end stake and it falls away. Worked great on our edf 's to get them up a little higher. I'll try to get a vid, but here is a pic.

Pointless exercise, great way to hit the "target", just move your release point (hook) on the model further back and you rotate in no time.
I used to launch lot of my early EDF jets in the old 'nicad' days with the model holding up high at shoulder level with the bungee pulling it down, and it still worked well.
These days I use lot easier system, just pull&let go, DIY! (pics)

On some planes, you can't always put the hook where you would like to.

Wow it took a whole day for Jo to tell you your doing it wrong..He is slacking

giggle

It isn't easy to come up with something new
https://www.youtube.com/results?sear...ngee+launcher+

Take a look through may be something is relevant for You too.

Thanks. Yes, I copied the PVC ones and it works well. Just noticed some of the planes came close to skimming the ground as did my Stinger on first launch so we tried raising the pull point and it helped. I see some trying to get around 15 degree angle as the plane hangs from a string but I have even more angle because I put the hook further back. Still don't get a high AOA. I had to go to full rate on elev also.

Different designs need varied hook locations and pull ratio. 15deg is a good srting point. But, one only has to look at the forward hook location on an RBC design, to throw a wrench into the thoughts. Too far back, and you can get the dreaded bungee death roll. Using the tube and cotter pin method vs a hook, allows varied locations of attachments. Not easy to move a hook. I have jets that are fine with 3# pull per # of frame. Others needed up to 6#, to avoid striking the ground. Also, nose heavy will make it sag more.

"tube and cotter pin method vs a hook,"
Sounds good. Details?

Just a brass tube mounted in the fuselage. The cotter pin to the bungee chord lead. Cotter pin inserts in the tube. Positive release. Another plus, no ugly hook to be seen. https://www.rcgroups.com/forums/show...t-Wings-Hunter

i like it, if it works then sweet. id thought about this before, but have just figured il make a jetapault if i need it.
i like the ingenuity

ahhh yes, jofro chiming in with his infinite wisdom as always.