A division of www.morganmill.com
Made in the USA
What more can be said - those of you who have flown it know...
This Gal is Red Hot - Other Gals ain't Doodly Squat...
1 Cowl and a pair of Servo Rod covers
Control Rod Covers
1 pair of Servo Rod covers
1 pair of Winglets
Scroll for more pictures, research links and text for RareBear Parts.
All parts will arrive rough cut and made from White .040 High Impact Polystyrene. Ready for your paint and finishing. Canopy will be clear.
The action of the airfoil that gives an airplane lift also causes induced drag. It was determined that when a wing is flown at a positive angle of attack, a pressure differential exists between the upper and lower surfaces of the wing-that is, the pressure above the wing is less than atmospheric pressure and the pressure below the wing is equal to or greater than atmospheric pressure. Since air always moves from high pressure toward low pressure, and the path of least resistance is toward the airplane’s wingtips, there is a spanwise movement of air from the bottom of the wing outward from the fuselage around the wingtips. This flow of air results in “spillage” over the wingtips, thereby setting up a whirlpool of air called a “vortex.” [Figure 3-4] At the same time, the air on the upper surface of the wing has a tendency to flow in toward the fuselage and off the trailing edge. This air current forms a similar vortex at the inboard portion of the trailing edge of the wing, but because the fuselage limits the inward flow, the vortex is insignificant. Consequently, the deviation in flow direction is greatest at the wingtips where the unrestricted lateral flow is the strongest. As the air curls upward around the wingtip, it combines with the wing’s downwash to form a fast spinning trailing vortex. These vortices increase drag because of energy spent in producing the turbulence. It can be seen, then, that whenever the wing is producing lift, induced drag occurs, and wingtip vortices are created.
Just as lift increases with an increase in angle of attack, induced drag also increases. This occurs because as the angle of attack is increased, there is a greater pressure difference between the top and bottom of the wing, and a greater lateral flow of air; consequently, this causes more violent vortices to be set up, resulting in more turbulence and more induced drag.
If you google “wingtip vortices” and click images - there are lots of cool pictures.
The original motor mount for our RareBear and all the Skyangel Warbirds is a thing of beauty for its simplicity - except for its attachment shortcomings. I found hot glue has held mine in for a stock or minor upgrade in power. I’ve always felt it was hanging on by a thread. The future holds something a whole lot less tame. At the speeds we are starting to shoot for I thought we might need an upgrade in the way the mount attaches to the aircraft. So I machined a new mount which can be used a couple of different ways.
The first is an addition to the existing mount - it adds embedded tabs that give it substantially more purchase in the foam. It’s placed right behind the mount utilizing the existing down and right stock incidence - leaving the stock mount in place. A small bit of foam removal will be necessary for installation. (.100” or 2.5mm). (Original motor mount with stiffener) Longer screws of the correct size will be included in the kit. The bolt pattern by the way is a fairly standard 16mm x 19mm center to center bolt circle. This first option is for enhancement of the existing mount and higher thrust levels.
The second is for a complete replacement of a broken mount if you installed the stiffener prior to a crash. If so you will have the correct right and down incidence for the mount without too much hassle.The stiffener has a couple of notches to accept the side rails - they need to be glued to the stiffener and fit in the existing indentations in the foam if possible. They add more strength and attachment to the foam. Some cutting and fitting will be necessary for the rails - Not sure this is needed - option is there.The spacer takes the place of the missing motor mount and puts the stock setup in the correct position - it through bolts to the stiffener that is glued into the foam. The spacer can also be used to adjust the position of the motor if you have a different setup.
The best way would be to install the stiffener before a crash or a motor ejection due to mount failure.
The kit will include Stiffener, Spacer, Rails and Screws.
SkyAngel RareBear Parts