Delta Dart and other Beginners

From: <parkreation_at_msn.com>
Date: 25 Mar 2016 07:45:36 -0700

I have never been a big fan of the Delta Dart, but....

Having once worked at Midwest Products, one of my tasks was to improve the Delta Dart problem that they were having. The easiest change was to move away from the expensive and heavy 6" diameter black prop to the North Pacific style prop (actually copied from NP not SIG) and move the wing back slightly towards the tail. BTW, three separate companies were tasked by the AMA to produce Delta Darts, Midwest, SIG, and one other in New York(?). All the companies used their own prop assemblies causing unique challenges.

I found that reducing the the tail feathers by at least 20% and reducing the wing dihedral by 20% really improved performance and reduced the need for nose ballast. I made a set of thin ply outlines to re-line the tail assemblies to allow the plane to be constructed as instructed.

Note that the classic way to set the dihedral was to place the plane upside down using the prop tip and fin tip as the measuring device to set the dihedral. Midwest used a larger diam black prop at first and in doing so really caused a severe dihedral. Great for gale force winds outdoors but arrow-like in a gym.

Reducing the fin height and the prop diameter was a vast improvement for indoor flight. The other trick was to re-pitch the prop on-site using a line on the floor. An old Gary Underwood trick. If the prop is re-pitched, 3/32 rubber (12" loop) was used and a proper motor hook was added... minute flights were easy. If the airplane was covered grocery bag plastic or Jap Tissue, over a minute is commonplace.

Walt Van Gorder made a classy Delta Dart kit with red tissue covering for years. His version was a stellar performer as DD's go.

On my wish list is an updated Sleek Streak without the wheels. It actually had a lighter wing loading than most stock Darts and lent itself to many modifications ala' Bill Winter. A new version would not have that cambered airfoil (an expensive process) but a quick round with a foam emery board and that toy would fly quite well.

Tom

     
 

Received on Fri Mar 25 2016 - 07:45:36 CET