Sled Kite Out Of Control
We have been having great fun with your kites in my class. However, our sled kites are giving us difficulty. They launch well, but then quickly veer to one side or the other in a loop, often hitting the ground.
I have played with tail length and point of attachment of the string to the bridle. Minute adjustments in this regard seem to have dramatic effects - a small shift can change a left looping kite to a right looping one. Any thoughts or suggestions would be appreciated.
Since you haven't mentioned which design you are using, I will start by recommending the Simple Sled kite. If you stick strictly to the dimensions of both dowel and sail, you can't really go wrong with this one! It does not require any tail at all, so that eliminates one variable.
I suspect that if you use dowels that are too thick and heavy, any Sled design will become less stable. Try making another kite, or re-sparring an existing sail with lighter spars.
Another design which has proven itself to many visitors to this site is the 1-Skewer Sled. (See the video at the bottom of the page, in which you can see how I have made one tail longer than the other to help it fly even better) Although tiny, if made according to the instructions with 300mm x 3mm bamboo skewers, it is very reliable with light long twin tails. It will happily fly on 50 meters (160 feet) of 20 pound flying line. Or even lighter line - you could even try polyester sewing thread with this kite.
You are doing the right thing by making tiny adjustments to the bridles! With practice you will get quicker at finding the perfect position for the knot. Varying tail length on one side is useful for more minor adjustments, as you saw with the 1-Skewer Sled in the video.
Hope this helps...