|
|
5 Guests On
|
|
|
|
|
|
|  |
REV 2.4 - Wed Oct 20 00:03:09 2010
|
|
| SpaceCAD FILE: | MISSING - please submit here |
| REC'D MOTORS: | 1/2A6-2, A8-3, B4-4, B4-6, B6-4, B8-5, C6-5
|

(Contributed - by Tom Eldredge) Brief:
A rocket. My wife's favorite, because the prep time after a
recovery is about 2 minutes -- put the engine, igniter, and igniter plug in,
and the rocket is ready for another go!
Components:
- Body tube: BT-20D (7")
- Nose cone: BNC-20B (balsa) (any blunt one will do)
- Fins: 2 large, 2 hinged, 4 rudders
- No motor mount, just an engine block
- No shock cord, parachute, or streamer
- Short length of elastic string
- Short length (2") of hardwood (popsicle stick works well)
- Launch lug 1"
- Hinge material (unscented bounce sheets work well)
- Other materials you will need (as usual): pencil or pen, hobby knife to cut
the fins, a sewing needle, and some white glue (no plastic parts).
Construction:
Construction PRO's: This rocket is pretty simple to build. There are relatively
few steps, due to the simple design. Typical Estes picture-heavy instructions
make everything go together well. Most of the "gotcha's" were spelled
out in the instructions (gluing the fins together where the hinge goes). The
only hard part of this whole "kit" is getting the elastic into the
fins without destroying them. A sewing needle is almost too big, but the
elastic is too thick for most everything else.
Another PRO is the sturdiness. You would think that the rocket repeatedly
landing on the nose would dent it, or rip the fins off. However, while it looks
like it is screaming down, it is really floating -- an optical illusion because
it is spinning, I guess. Finally, there are only two fins to glue onto the body
tube, so it is much easier to align than 3 or 4. You could probably use a ruler
or other straight-edge to help also, if needed. Gluing the rudders is pretty
easy, they need to be opposite of each other, which you can tell by sighting
down the fin.
Construction CON's: Nothing really. A very simple rocket to build.
Finishing:
As this is a JimZ plans, there are not any decals supplied. So, you are free to
make up your own scheme. I painted it in a spiral by painting the undercoat
white, then masking off with a length of 3/4" tape. I also painted the
fins and rudders alternating colors, so it really blurs when it comes down.
This makes the finishing much harder than it has to be. Not too many nooks and
crannies, so is easy to spray paint.
Construction Rating:
5
out of 5
Flight:
Flights are great. Put an A engine in (a B engine is almost too much, a C is
out of sight for a LONG time), add an igniter and its plug, and you are good to
go. The engine holds the fins straight until it ejects, which lets the elastic
pull the bottom part of the fins into the helicopter configuration. No wadding
to forget. No parachute to fold or get tangled. No shock cord to burn through,
or cause a zipper. Man, what a waste! How are you supposed to CATO this? ;-)
Mine flies pretty straight, but has a spin to it while boosting. I can't tell
if I didn't position the hardwood against the engine right, or got the fins
cocked while gluing them on, or the wind pushes it. However, it just adds to
the "helicopter" feel!
Recovery:
The only CON here is that the elastic and hinge material wear out after a
while. Mine has had about ten flights, and one fin only pulls a little.
However, it doesn't seem to affect the spin much. I'll bet I have to replace
both elastic strings, and maybe the hinge material too. I don't know what you
could do to make it better, though! Ten flights and still going strong, better
than most of my rockets ... but that's another story.
Flight Rating:
4
½ out of 5
Summary:
Simple to build, very simple to prep, very little to go wrong on this baby. A
great rocket. An added bonus: All the old-timers get a real kick out of seeing
this one, too.
Overall Rating:
5
out of 5
|
|
|
![[Submit your Opinion]](../../images/enter_your_opinion.gif)
GUEST's OPINION:
"" (x.x.)
|
|
|
![[Enter Rocket Specific Tip]](../../images/enter_a_rocket_tip.gif)
SPECIFIC ROCKET TIP:
06/07 -
"I would recommend resisting the urge to use CA on the knots, at least the thin stuff. When I tried it the CA wicked up the entire length of the elastic, making it very stiff. I did the other side with plain old white glue, and it works great. Patience Grasshopper." (S.T.
)
SPECIFIC ROCKET TIP:
07/06 -
"Use a smaller, less destructive sewing needle by threading the eye of the needle with a loop of thread, pass the elastic thread through the loop, then pull the loop of thread back out of the needle's eye drawing the elastic thread through as well. The smaller needle reduces the size of the hole in the balsa parts reducing the chance of damaging the parts." (D.L.S.M.
)
SPECIFIC ROCKET TIP:
10/05 -
"Another great alternative hinge material is Tyvek paper cut from Tyvek shipping envelopes. The stuff is cheap, glues down like paper with white or yellow glue, and tear resistant. I've been using Tyvek as elevon hinges for my boost gliders with very good results." (D.L.S.M.
)
SPECIFIC ROCKET TIP:
10/03 -
"For better hinges, use thin flex hinges sold for small RC aircraft. They last longer and will take more abuse. Use 1/16th inch sewing elastic for the elevons. You can use an awl to make your hole (carefully), then burn the end of the elastic and crimp it so that it does not fray when it's placed through the holes. thread through rudders first, then elevons. This will make tying easier. Put a dop of CA at each hole after tying." (J.R.
)
|
|
| Date |
Name |
Motor |
Ejection/ Altitude |
Wind |
Notes |
| 05-15-2010 |
Bernard Cawley |
Est SU A8-3 |
Apogee - Perfect |
0-5 mph winds |
Event: Missile Mayhem 2010 - Spiral up (as usual). Good deploy. Practically landed on my canopy (on edge of road). Minor dent in NC. |
| 09-18-2010 |
Bernard Cawley |
Est SU B6-4 |
Didn't See |
0-5 mph winds |
Event: Rolling Thunder 15 - Squirrelly boost (one flap doesn't seat quite right anymore). Good on-field recovery typical of a Gyroc. |
| 01-20-2001 |
Tom Eldredge |
Est SU A8-3 |
Apogee - NC Up |
0-5 mph winds |
- Great flight, as usual. Fell mostly straight down, even in wind gusts. |
| 11-12-2005 |
Matt Gillard |
Est SU A8-3 |
None - CATO |
10+ mph winds |
pt1 - Incorrectly balanced, wildly unstable flight, hit ground and then ejected motor - fins deployed nicely! no damage, need to add nose mass. |
| 11-19-2005 |
Matt Gillard |
Est SU A8-3 |
Apogee - NC Up |
Calm |
pt1 - altered nose mass, straight lift with spiral during coast phase, clean separation, fast spin and a slow decent. perfect -will upscale this plan to a 24mm motor. |
| 11-22-2005 |
Matt Gillard |
Est SU B6-4 |
Apogee - Perfect |
Calm |
pt1 - straight up with large rotation at top, good spin on the way down, 11 seconds in total |
| 11-24-2005 |
Matt Gillard |
Est SU B6-4 |
Just Past (1-2sec) |
5-10 mph winds |
- spiralled up badly, not a high altitude flight, clean ejection, came down really fast. |
| 12-08-2005 |
Matt Gillard |
Est SU B6-4 |
Apogee - Perfect |
Calm |
pt1 - nice staight lift, core ejected at apogee, fast spin, landed near pad |
| 12-08-2005 |
Matt Gillard |
Est SU C6-5 |
Didn't See |
Calm |
pt1 - wild spiral up, did not deploy fins, came down hard and fast - no damage |
| 04-14-2006 |
Matt Gillard |
Est SU A8-3 |
Very Late |
5-10 mph winds |
pt1 - squirreled up, ejectionabout 50 foot from ground, spun in hard - no damage. |
| 09-16-2007 |
Bob Harrington |
Est SU A8-3 |
None - Tumble |
0-5 mph winds |
Event: CMASS section launch - Went higher than expected. Nice slow helicopter recovery. |
| 06-09-2007 |
Geoffrey Kerbel |
Est SU A8-3 |
Apogee - NC Down |
Calm |
Event: Club launch at local park - Nice straight up and down flight. This thing is a great small park flier! |
| 07-21-2007 |
Geoffrey Kerbel |
Est SU A8-3 |
Just Past (1-2sec) |
10+ mph winds |
Event: School opening launch - Major wind blowing and it still flew good! Very squirrly on the way up and still drifted quite a bit downwind even with max rod angle. Just stayed in school yard. |
| 07-21-2007 |
Geoffrey Kerbel |
Est SU B6-4 |
Just Past (1-2sec) |
10+ mph winds |
Event: School opening launch - Same flight as last but higher and more twists and turns on the way up. Actually came down a little closer to the pad than the last flight. Good flight! |
| 07-22-2006 |
Dwayne Surdu-Miller |
Est SU A8-3 |
Didn't See |
5-10 mph winds |
Event: SAROS 22-Jul-06 - High straight boost, but squiggled a bit near the end of coast phase. Helicoptered with a very rapid spin rate, moderate decent. Landed softly on nose, didn't even mar the paint. Great flight! |
| 07-22-2006 |
Dwayne Surdu-Miller |
Est SU A8-3 |
Didn't See |
5-10 mph winds |
Event: SAROS 22-Jul-06 - High straight boost, but squiggled a bit near the end of coast phase. Helicoptered with a very rapid spin rate, moderate decent. Landed softly on nose, didn't even mar the paint. Great flight! |
| 06-15-2008 |
Dwayne Surdu-Miller |
Est SU A8-3 |
Apogee - Perfect |
0-5 mph winds |
- Slowly spinning boost and coast, straight up. Spinning helicopter descent. |
| 03-23-2003 |
T Yaeger |
Qst SU A6-4 |
Apogee - NC Down |
0-5 mph winds |
- Corkscrew up and hellicopter down. Not as pretty as straight up but not bad. |
|
|
|
|
|
|
|
|
|
|
|