Re: Bungee launch for electric models
Posted: Fri Dec 04, 2009 1:31 pm
Lawrie, thanks for the reply.
I tried a few things and found roughly what you said. The tow position is extreme forward and leads to very little climb but that's ok. Getting the towhook to release is harder than it looks, and a very smooth hook that easily detaches is safer than the alternative, i.e plane suddenly pulled backwards by the nose!
I have about 30' of rubber and 20' of line, with a few washers tied to the line just aft of the towhook to encourage disengagement when it goes slack. This is sufficient to pull up the 3 lb plane to speed and about 5' off the ground. However, due to balance and trim problems (and an elevator the size of a trim tab), it subsequently crashed. So for this model, now that I fixed the wing, it will only fly off snow from now on. Waiting for Coote's to freeze.
At least the bungee concept worked.
I tried a few things and found roughly what you said. The tow position is extreme forward and leads to very little climb but that's ok. Getting the towhook to release is harder than it looks, and a very smooth hook that easily detaches is safer than the alternative, i.e plane suddenly pulled backwards by the nose!
I have about 30' of rubber and 20' of line, with a few washers tied to the line just aft of the towhook to encourage disengagement when it goes slack. This is sufficient to pull up the 3 lb plane to speed and about 5' off the ground. However, due to balance and trim problems (and an elevator the size of a trim tab), it subsequently crashed. So for this model, now that I fixed the wing, it will only fly off snow from now on. Waiting for Coote's to freeze.
At least the bungee concept worked.