Rare Bear profile-2
MORGAN RC
A division of www.morganmill.com
Made in the USA
Jpower/Sky Angel
RareBear
Engine Cowl
$6.95
What more can be said - those of you who have flown it know...
This Gal is Red Hot - Other Gals ain't Doodly Squat...
Combo #1
1 Cowl and a pair of Servo Rod covers
$12.95
RareBear
Control Rod Covers
$6.95
RareBear
Winglets
$6.95
Combo #2
1 Cowl
1 pair of Servo Rod covers
1 pair of Winglets
$19.95
RareBear/Skyangel
Warbird
Motor Mount
$6.95
RareBear
Rev.1 Canopy
$5.95
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.
Wingtip Vortices:

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.
http://en.wikipedia.org/wiki/Wingtip_device
http://www.aviationpartners.com/hawker.html
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.
Links:
Motor Mounts
SkyAngel RareBear Parts
IMG_7718e IMG_7123
IMG_7103 IMG_7123 S5003250e
IMG_7718e IMG_7103
motor mount parts-2 S5000004e S5000008e
IMG_7123 2011-05-24_13-49-43_523
S5003249e S5003237e S5003255e
IMG_7617 IMG_7615 IMG_7616
2011-05-24_13-40-51_336 2011-05-24_13-41-42_256 2011-05-24_13-43-14_985 2011-05-24_13-43-24_166 2011-05-24_13-44-09_736 2011-05-24_13-44-29_439 2011-05-24_13-44-59_848 2011-05-24_13-45-13_774
2011-05-24_13-48-45_876 2011-05-24_13-49-04_531 2011-05-24_13-49-25_111 2011-05-24_13-49-43_523 2011-05-24_13-51-16_971 2011-05-24_13-51-32_695 IMG_7100 IMG_7101
IMG_7103 IMG_7104 IMG_7105 IMG_7106 IMG_7107 IMG_7108 IMG_7109 IMG_7110
IMG_7111 IMG_7112 IMG_7113 IMG_7114 IMG_7115 IMG_7116 IMG_7117 IMG_7119
IMG_7120 IMG_7122 IMG_7123 IMG_7124 IMG_7608e IMG_7609e IMG_7610e IMG_7611e
IMG_7612e IMG_7613e IMG_7615 IMG_7616 IMG_7617 IMG_7655 IMG_7655e IMG_7657
IMG_7657e IMG_7658 IMG_7658e IMG_7659 IMG_7659e IMG_7660 IMG_7660e IMG_7661
IMG_7661e IMG_7662 IMG_7663 IMG_7663e IMG_7664 IMG_7664e IMG_7665 IMG_7665e
IMG_7666 IMG_7666e IMG_7667 IMG_7667e IMG_7668 IMG_7668e IMG_7669 IMG_7669e
IMG_7671e IMG_7672e IMG_7673e IMG_7675e IMG_7677e IMG_7678e IMG_7679e IMG_7681e
IMG_7682e IMG_7683e IMG_7684e IMG_7685e IMG_7686e IMG_7713 IMG_7713e IMG_7714
IMG_7714e IMG_7715e IMG_7716e IMG_7717e IMG_7718e motor mount parts-2 RAREBEAR COWLSe S5000004e
S5000008e S5003237e S5003238e S5003239e S5003241e S5003242e S5003243e S5003249e
S5003250e S5003251e S5003253e S5003254e S5003255e S5003257e
Figure 3-4 Wingtip vortices before and after winglets
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