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REV 2.4 - Sun Dec 26 17:46:42 2010

Sunward Aero
Rocket Glider
9 Rooksgrove Place
Toronto, ON, Canada, M6M 2W3
 
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SPECS: 14" x " - 2.0 oz
ROCKSIM FILE: MISSING - please submit here
SpaceCAD FILE: MISSING - please submit here
REC'D MOTORS: A2-2(first flight), A8-3, B4-2, B6-2

Rating
(Contributed - by Chan Stevens [Who's Who Page] - 07/21/06) Sunward Aersopace Rocket Glider

Brief:
Slightly misnamed, this is a boost glider, not strictly a rocket glider. It's a standard boost pod configuration made from laser-cut parts with an easy to build design.

Construction:
Parts were all good quality and the laser-cut work was very good with clean cuts and only small areas needed to be finished off to free the parts. In the surprisingly large bag I found:

  • BT-56 (8") body tube
  • Plastic nose cone with canopy
  • BT-20 motor tube
  • 20/56 centering rings
  • Metal motor clip
  • Balsa wing halves
  • Balsa stabilizer halves
  • Balsa rudder
  • Balsa boom
  • Streamer/rubber shock cord
  • Peel n stick trim decals

Construction is fairly easy on this although is a bit time consuming. It is rated a skill level 4 kit, however, I think that could be overstating the complexity a bit. I wouldn't necessarily recommend this as a first glider, but if you have any previous boost glider experience under your belt you'll find this fairly easy.

Sunward's instructions are clearly written and include decent illustrations, and if you're so inclined are written in both English and French. Not knowing French, I find the duplication distracting and would rather see them go the route that most instruction manuals take these days--written start to finish in one language (English), followed by start to finish in a second language.

The pod assembly is quick and easy work: slot the BT-20 motor tube, slip on the motor hook, glue on a couple of centering rings, then glue the assembly inside the larger pod tube. You'll finish it up by gluing on the launch lug and a retainer assembly where the glider hook slips in during boost. I can understand the efficiency of using Sunward's stock BT-56 tubing and nose cone, but for this glider design, the larger/bulky pod tube is a bit of a weakness. Most other boost gliders use minimum diameter tube in their pod design.

The glider construction is where the real work takes place. While there are a few low-effort designs out there (any Edmonds kit, Quest QEZ glider, etc.), most gliders involve a lot of sanding and hand work to properly airfoil the flying surfaces. I spent a good hour progressing from 120 grit down to 400 grit, working the airfoil into my wings and stabilizer. For this design, only the top surfaces are airfoiled.

The wing halves are designed to be mounted at an 18 degree dihedral. This is a pretty detailed measure, and I think most builders would benefit by having the math done for them by calling out the target height of the wing tip from a flat surface instead of a dihedral angle.

After sanding, you can bond the wing halves, stabilizer halves, and rudder to the boom. The instructions were not that clear, but if you pay careful attention to the drawings, you'll see that the stabilizer is to be mounted flat on top of the boom. I deviated a bit from the plan, and in order to build a slight incidence into this (generating more lift), mounted them to the side of the boom at a slight cant.

Construction wraps up with attaching the rubber shock cord via paper tri-fold mount to the BT-56. (I'm not big fan of paper tri-fold, but noticed this pattern appeared a little too small for the width of the supplied rubber.)

Finishing:
Gliders in general should not be painted. The header card for this one shows an unfinished bird, trimmed with a couple red checkerboard pattern decals. That's the scheme I went with, but you could also consider using a light thinned dope on this or Japanese Tissue or even colored magic markers. If your glider goes very high or far, coloring can aid quite a bit in tracking and recovery.

Construction Rating: 4 out of 5

Flight and Recovery:
The recommended motors for this are A2-2 (good luck finding those in the US), B4-2, and B6-3 (or in the US, probably have to go with a -2).

Prior to flight, I spent an evening hand tossing and trimming the glider for flight. After following the instructions for glider construction (with noted slight deviation for stabilizer), I found my CG well aft of the wing aft edge. As a general rule of thumb, the CG of a glider should be right at the CP, which tends to be where the wing's airfoil is (roughly a third of the way back from the front edge). I needed to add 5 BBs for nose weight before I could get the glider to fly through a stall.

For the first flight, I opted for a B4-2. I got a very good boost, looping a little during coast phase. At apogee, I got a clean transition and the glider spun around into a decent glide for around 60-90 seconds although it still showed a bit of a porpoise stall. I added a little clay and flew it a second time, after switching to a B6-2. The B6 turned out to be too much thrust and I lost one wing half during boost. The wings mounted at a dihedral angle are very precariously bonded to my boom.

Having had to reattach the wing, I'll now be looking at more trimming/adjusting, although based on the first flight, I would rate this a pretty good glider.

Flight Rating: 4 out of 5

Summary:
I would rate this a 4 as a good boost glider although it's not exactly high performance. It's heavy duty enough to handle winds of 6-8mph, so you don't have to wait for one of those perfect weather days to fly.

Its main PROs are solid/stable design and it is fairly easy to build. It's main CON would be the short, fat pod. I'd also consider changing to a pair of tip dihedrals rather than a single wing center dihedral.

Overall Rating: 4 out of 5

[Submit your Opinion]

GUEST's OPINION:
05/07 - "This was a good review. I had good luck, or should I say better luck with my glider after spending some time sanding the wing. I used a flat sanding stick with fine sandpaper glued to it. The wing was sanded for a better airfoil by thinning and tapering the trailing edge of the wing. Then the wing tips were sanded to a thinner section. Finally the edges of the horizontal stabilizer and vertical fin were sanded round. The glider seemed to tighten up in a turn during test glides so extra orange paint was sprayed onto one wing tip to help pull it out of the turn. The next flight was fantastic with a long smooth 1 minute plus glide" (H.W.H.)

[Enter Rocket Specific Tip]

SPECIFIC ROCKET TIP:
"" (x.x.)

[Enter Flight Log]
Date Name Motor Ejection/
Altitude
Wind Notes
05-28-2005 Donald Besaw Est SU A8-3 Just Past (1-2sec) 5-10 mph winds - Nice first flight, glider failed to seperate from booster but detached on impact. Tough kit, no damage sustained.
05-28-2005 Donald Besaw Est SU A8-3 Just Past (1-2sec) 5-10 mph winds - Made a second attempt, great flight. Glider seperated from booster and glided in nicely, noticed quite a bit of stalling though. No damage.
06-16-2005 Donald Besaw Est SU A8-3 Just Past (1-2sec) 0-5 mph winds - Excellent flight, arrow straight boost and perfect release. Glider descended in a hovering mode, practically zero airspeed for a bit and then entered gliding phase. Long walk for recovery. No damage.
07-26-2005 Donald Besaw Est SU A8-3 Just Past (1-2sec) Calm - Nice launch but the glider performance was a bit strange, I counted 7 stalls during descent. I somehow need to find a way to add more nose weight. Very nice otherwise. No damage.
04-22-2007 Hank Helmen Est SU B4-2 Apogee - Perfect
(127 ft)
0-5 mph winds Event: Field Day 07
Boomerang - First flight for this rocket glider. Glider flew down in tight circles for 21 seconds. Booster recovery nominal. No damage. Some very slight rocket motor exhaust discoloration on top of right wing of glider.
05-08-2007 Hank Helmen Est SU B4-2 Apogee - NC Down
(100 ft)
Calm Event: Evening Launch
Boomerang - flt aftr tweakd glider by sanding wing, Booster & glider rotated slowly straight up. Glider hung on couple sec. after ejection & streamer deployed, broke free better(awsome)glide. 1 min.+ after seperation! Fun!
07-08-2006 Chan Stevens Est SU B4-2 Just Before 0-5 mph winds - Decent glide, but a bit of a stall
07-08-2006 Chan Stevens Est SU B6-2 None - Unknown 0-5 mph winds - Added a bit of nose weight, wing shredded off during thrust. Boom cracked when it flopped down on road.
05-20-2007 Chan Stevens Est SU B4-2 None - CATO 5-10 mph winds - Clips snagged and broke tail off
   

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