HD Explorer

The HD Explorer is a new rocket design originally intended to be a camera carrier.  It was started when the Bandit HD needed serious repairs, and no other rocket was available to lift the camera. It is being cobbled together mostly from parts of both the Estes Magician and the Cosmic Explorer.  It shall be a D or E powered rocket, standing just over 30" tall with the camera and altimeter payload section included.

Since I have started construction, I have changed my strategy to only use this as a back-up camera carrier for two reasons.  First, The DEFCON 1 and the C-Thru (also under construction) are also designated as camera carriers, so this need is not critical.  Second, computer simulations show that the combined length of this rocket and the heavy weight on the nose will make this rocket over-stable with its large fins, so it is more likely to turn into the wind and fly sideways, making the camera's aim worse.  Without the payload weight though it appears that it will fly well.  Since the other rocket, the C-Thru is much shorter and has smaller fin area, I expect this to fly better. Additionally the C-Thru has a square payload section, making it much easier to insert an optically clear flat glass.

Still, I want to proceed with the construction of the HD Explorer because I plan on giving it a cool paint scheme (originally intended to make it more visible if it was lost with the camera).

The plan is for a Yellow nose cone, Orange payload, and a Red upper body tube with the lower part white.  The fins will have a base of white also, but will have the yellow, orange and red vertical stripes on the tips of three fins.  The red portion of the body will continue down on 1/4 of the tube and meet with a single red fin out of the four. This fin will also have yellow and orange stripes on the fin tip.  No decals are yet decided except for the number 30 (series number) and perhaps the name "HD Explorer".

The D and E-sized motor mount was constructed first.

The motor mount is shown next to the BT-55 body tube where it will be inserted.  The tube has slots for thru-the-wall fins, which provide additional strength to both the fins and the motor mount. I intend to extend the motor tube about 3/8" from the rear.

A close view of the forward centering ring and thrust block where the motor presses against during liftoff. The hole allows the ejection charge to pass through.  I will not attempt to make a baffle for this, as in the past it proved to be trouble for these higher power motors. I'm glad I learned this before starting construction.

The balsa fins were cut out, shaped and then laminated with a heavy cardboard stock on both sides using photo mount adhesive. This will make the surface smooth and easy to paint and will add strength to the fins.  I will never make fins the "old" way again with multiple coats of balsa fillercoat.

The cardboard is removed from the root edges by sanding so the Titebond III glue has a lot of wood surface to bond to.

Now I prepare the shock cord mount. Since this rocket has a long body tube joined by a coupler, I will use this instead of the motor mount for the shock cord mount.  The Kevlar thread is run through a small hole in the coupler, knotted, and the ends are frayed into individual fibers so there will be a lot of gluing surfaces.

The frayed Kevlar is glued flat against the coupler, and a small indent is made on the coupler before inserting into the upper body tube. This is to make sure that the Kevlar doesn't produce a bulge in the outer body tube.

The launch lugs are attached.  I like to use two lugs spaced far apart. This allows for a better alignment on the launch rod during liftoff than a single short lug.  I also like to space them a bit away from the body tube to reduce the sliding along the body tube and the marks and friction it causes.

After the fins are glued into the body tube slots, I apply a glue fillet along the edges to strengthen the joint. When that is dry, I add a fillet with a lightweight filler to smooth the joint out between the fins and body tube.  It not only looks nicer, but it reduces the parasidic drag from right angled surfaces.

Now the lower assembly of the rocket has been primed and is ready for final sanding.  The first layer of primer was gray, and this second layer is white which may allow the final paint color to be a bit brighter.  I used a contrasting color on the first primer coat so that it could act as a visual indicator that I have sanded down to the lower layer of primer.

When the primer is sanded, the first coat of white paint can be applied.  Although I used the same brand of primer and paint, the crazing on the finish shows a lack of compatability. The primer may not have been completely cured, or the first white coat was a little thick.  When this rocket was painted however, I painted two different rockets at the same time, with the same primer and the same paint. The other rocket came out beautiful though, I don't know why this happened here.  Either way, this requires sanding off all the cracks and making another attempt.

It's as strange and predictable as Google's blog editing screen. Sometimes it works, other times you can't add text NEXT to the pictures. Very frustrating!

I don't know why, but this time the coat of white paint has worked well. Here I am satisfied with the fillets on the fins (it's the first time I have used filler for the fillets, and it looks much better than the irregular glue fillets I generally leave visible).  This body will still need masking and spray painting with yellow, orange and red on the fins.

The other sections of the rocket have been primed and sanded, but still need final paint. Since I left each section seperate, I don't have to mask to apply the right colors. From the top, the nose cone will be yellow, the payload section orange, and below that the upper portion of the body tube will be painted red.

I am trying a new method to secure the altimeter in the payload section.  Instead of plastic foam padding, I am making a lightweight wood structure to hold securely both this and a video camera.  I hope that this will be both lighter and stronger.

I had an option when I was designing this model to add a small forward fin set to compensate for the over-stable condition. It has been optomized for the heavier weight of an F engine, but will make the model less stable with even an E or D motor.  These fins will compensate for the extra weight in the payload bay, but it should also fly well without the additional noseweight.

The large fin area in the back of the rocket produces too much of a restoring force which turns the rocket towards the apparent wind, so these small fins ahead of the center of gravity will do the opposite, and nullify some of the restoring force generated by the large rear fins.  I hope to make two identical payload sections, so I can fly this model both ways and see if this theory actually works in the real world.  I will be able to compare the performance of this rocket both with and without the forward fins.  These fins were placed far below the camera's aperture and tapered away to prevent them from being in the picture frame. If I could have moved them further up and away from the center of gravity, they could have been smaller and would have generated less aerodynamic drag.

These forward fins were cut, laminated, and attached to the payload section in the same way as the main fins. So now all the pieces of this rocket are ready for finishing.

Here is a picture of the nose cone (yellow) and the payload section (orange) sitting on top of the HD Explorer. This section has been primed and I started painting it, but stopped when I found the color (flourescent orange) was not to my liking, so I will finish it with a 'normal' orange paint.

As of this day, Nov 21, 2012, this is as far as I got.  The weather turned cold outside and it is not a good idea to do spray painting in the cold air.  I will need to wait for a warmer day to finish this rocket.

Spring, 2013:  I get the chance to spray paint more. Most of the rocket painting is going well, but when I attempt to add some detail to the fins, the orange paint (Rustoleum: same brand as the primer, and the white base coat) is giving me crazing trouble again.  I wish I didn't buy so much of that paint! Here is the result of painting a vertical orange stripe over the white basecoat. Apparently, I need to let the paint cure for days...weeks even, before another coat can be added.  At this rate, the rocket will be finished in November!

As usual, I sanded down the orange scum and tried again with better results.  I am starting to get excited about the project, as it is mostly complete and beginning to look pretty sharp.

The red paint is next. I intended to use the red paint not only as another color accent, but I will make a roll pattern (an identifying mark used to see and analyze the rolling motion of the rocket upon liftoff). One single fin and 1/4 of the body will be painted red, so I had to mask off all of the other fins and the orange & yellow stripes of the fourth fin to be painted red.  Fortunately this went well. I had similar good results with my other rocket the C-Thru which was painted white then red.

Here is the end result of the one red fin. Seperately, I will mask and paint a red stripe on the other three fins.  I will then go back and touch-up the orange then the yellow edges of the paint.

Of course I did have an "issue" with the red coat as shown just above/left. As I always heard, colors come out brighter when applied to a white base. I didn't think of that when I painted the upper section of the booster solid red. So when I connect the two pieces, instead of looking like an exact match, there is a noticeable color difference.  Both shades of the red color is fine for me, but not at the same time.  The only solution is to repaint the upper section white and then red again.  I haven't decided if it is worth the time and weight penalty yet.

So here is the assembled rocket so far. Yes, it does look almost a bit too colorful and kind of like a kid's toy, but that is actually the original intent: To make sure it is visible in the air or the ground as it will contain several hundred dollars of electronics.  It will look better when I get some decals on it.

This may be a little late in comming but I have produced a digital rendering of what the HD Explorer should look like.  The blue dot shows the aproximate center of gravity, the red dot shows the aproximate center of pressure.

 A year and a half later, I finally completed this rocket. I glued together the lower body tubes, completed touch-up painting and added all the decals.  I attached a Nomex parachute protector and a 5-foot long Kevlar shock cord, having learned the hard way numerous times that elastic springs back and damages the rocket. Although I did create a light wood structure in the payload section to hold the Altimeter 2 and a video camera, I didn't follow through installing a lens opening and the small glass window.  I can always add that later if I need to use this as a camera carrier, if she proves to fly well.  I present to you the finished HD Explorer.

 OK, this is a weird optical illusion:

Look at the Estes logo above, it is reasonably well placed,

don't you agree?

So now look at the bottom picture.

Same logo (there is only one on the rocket).

Does it still look striaght to you?

 

I love this view of the 24mm motor opening, looks powerful.

Truthfully, I like the effort and the design seems nice enough. It indeed does meet the original requirement of being very visible, but I think it came out a little funny, perhaps a bit too cluttered looking, maybe the orange payload should have been red, yellow or white.

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SPECIFICATIONS

Stages: 1

Overall Length: 30.6"

Main Body Tube Length: 18"

Nosecone Length: 5.05"

Payload Internal Length: 4.5"

Payload Internal Diameter: 1.28"

Payload Volume: 5.79 cubic inches

Diameter: 1.325" (BT-55)

Flying weight with altimeter: 141.7 grams

Motor Diameter: 24mm

Motor Mount: Spring clip

Typical Parachute: 20" dia. returns at 8 mph

Recovery Protection: Nomex cloth 6"x6"

Shock Cord Mount: Kevlar

Payload: Space for mini video camera

Altimeter Capable: Yes

Fin Material: Cardboard Laminated Balsa

Unique Features: 4 fins span 4.375", 4 forward fins span .875"

Launch Lug size: 1/8"

Glue: Titebond III

Paint: Rustoleum PT2X

Motors Used: C11-3, D12-5, E9-6, E12-6, E15-7W, E30-7, F32-6

Designer: Me, Rich DeAngelis

Started: August 2012

Completion: Oct 22, 2013

2019, May 25: Indiantown Gap, PA, 5-10 mph wind, 70deg.F

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As we look at the next 4 photos in this series, we can see that this may be a good camera carrier rocket because it did not rotate on liftoff.  There is one red-painted fin which can't be seen from the camera's angle at launch.  In the next three photos on the liftoff, that single red fin never becomes visible - it hasn't rotated even 90 degrees.

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D12-5: The first ever flight of my new rocket was to happen today.  Yes, it was

later in the day and the wind picked up a bit, but since I purposely considered

winds when making this design, I thought I’d test it with a trial-by-fire.  The

forward fins should keep it from being over-stable, and not turn too much into

the wind.

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Upon ignition, it accelerated well with a 10.3G boost, as expected of a D12

motor.  The burn was 1.8 seconds as also expected, giving the rocket an average

acceleration of 3.2 Gs.  This flew up without turning too much.  It reached a top

speed of 123 mph.

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The delay was longer than most at 5.8 seconds.  It only coasted for 4.8 seconds

to an apogee of 595 feet, while the last second of delay it dropped 21 feet where

the ejection fired.  At 574 feet I got a good parachute, allowing the rocket to

return at 10 mph.  It landed about 300 feet to the east, not downwind to the

north as expected.  This was a 44.8 second flight, and all 44 seconds of the

flight was a success.

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This design was now shown to be at least workable.
My rough prediction was 750 feet, so for an untested design that wasn’t terribly

far off.  Since this model can take an E or even an F composite, 595 feet is the

low end of its performance range.  It has at least verified that it should fly

well enough with a C11 motor.

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D12-5: I sent the HD Explorer up again with the same motor, which could prove or

dis-prove the validity of the previous readings.

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On this second flight, the red fin is visible on the right side.  Note that this fin remains visible in the next three photos, indicating that the rocket has not rolled on liftoff.  That's why one fin is often painted a different color, for camera analysis of the flight.  It's not for artistic purposes - or at least that wasn't where the idea came from.

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This second ever flight took off with a similar 9.9 Gs and burned for 1.8 seconds

also.  The average acceleration was identical at 3.2 Gs. Remarkably, it also

reached a top speed of exactly 123 mph.

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This motor had less of a delay, only 4.6 seconds long.  As a result, it ejected

at 597 feet.  It apparently wasn’t travelling to fast upwards at that point,

because in the next 8/10 second it only gained another 8 feet to reach an apogee

of 605 feet.

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With a good parachute (home-made by the way), it may have caught some thermal

lift, because the average descent was only 6 mph, and it drifted far down wind

into the next field.  It barely missed a wide row of trees and a swampy area, as

it landed only 10 or 15 feet from the tree line in the adjacent dry, flat, and

short cut field.  This flight lasted for 69.4 seconds. Over a minute!  Nice.
The wind, the launch location decided by the club, and the choice of high power

nearly combined to produce a disaster flight, having my first original design to

hang in a high tree that may not have ever been seen, or a wet landing in the

swampy, watery area nearby.

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I speak with authority on the difficulty of the swampy area.  As I was walking

thru to search the other side of the tree line, I stepped in progressively more

muddy soil and grasses, only to find myself in the next step sinking deep enough

to pour mud and water into my boots.  I began to worry about snakes and other

biting critters, then refocused on my search.

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A nice pair of Land's End hiking boots with cakes of mud on the inside.

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A pair of socks that used to be white, but may never again be called white.

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I think I got lucky with these two flights, unlike the previously destroyed X-Ray

flight.  I was also lucky that I had another pair of waterproof shoes in the car.

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2019, Sept 21: Halifax PA, 5 mph wind, 75deg.F

C11-3:  This promised to be a fine day for launching.  Light winds, good temperatures, clear sky, large field, dry earth and low cut grass all combined to make this an ideal field. Even with the predicted light winds, I needed a low flight to boost my confidence, so I chose to do the low-power test for the newly minted HD Explorer.

Having never flow with a C11 motor, and in fact no model of this exact type has flown with a C11, I could only predict 275 feet apogee for this flight.

The small-ish motor lit on que, and pushed the rocket off the pad with a high 13.4 Gs, more than the D12s.  The average acceleration was also higher than a D12, at 5.6Gs, expected because of the lighter propellant load and the short burn time of 0.6 seconds.  This was enough impulse though to get the HD up to 78 mph.

This was followed by a 2.1 second delay, and upon reaching an altitude of 219 feet, the ejection charge fired early, slowing the rocket for the next 1.2 seconds.  With a total coast to apogee time of 3.3 seconds and another 33 feet gained, it peaked at 252 feet above ground.

By that time the 21” parachute was opened, and the rocket began a descent at a leisurely 7 mph.  After a 22 second flight it touched down in the grass safe and sound.  The low altitude combined with the light winds and large field allowed me to use a big parachute.  Even then, it landed only about 100 feet away.

Being the lowest power flight, of course the altitude, speed, coasting time, and flight duration were the lowest.  Compared with the recovery efforts of previous flights though, this may have been the best.

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D12-7:  Having flown twice with a D12-5, I knew what to expect.  The 5 second delay was shown to be good enough, but since I only had a 7, I had no choice.  As it happened I had nothing to worry about.

The flight began with a strong launch creating 11.5 Gs.  The burn of 1.8 seconds of power produced 3 Gs of acceleration on average, which was the lowest of all the HD flights.

After reaching a top speed of 118 mph, it coasted for a full 5 seconds, made apogee at 592 feet, then fell 30 feet before ejection at 562 feet above the earth.  The speed and apogee were just slightly below the previous D12 flights, while the average acceleration was lowest.

The ejection of this D12-7 was close at 6.2 seconds of delay.  Everything was nominal.  I got a good parachute which let this rocket return at 9mph, and it landed safely about 250 feet downwind.

I know this rocket is good with C and D power, now I only need to see it with E power, and maybe someday try to fly it as initially intended – with a camera.
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Bandit II, Bandit HD, Bandit III

This is NOT the modern Estes Bandit.  (I hate when Estes re-uses model names!!!) This is a beautiful favorite, classic kit from the '70s. This model had built-in ejection gas baffles that require no wadding (in theory).  The model also included a reasonably large payload section of 4-1/2 cubic inches.  The Bandit has a long and storied history as I describe below. This does not include its use as a data transmitting rocket from back in the late '70's.  The Bandit comes stock with a payload section already. As usual, I recently added vent holes for a barometric altimeter.

Here is a picture of the original Bandit kit.

My kit was originally built with a wire down the main tube to be used as a transmitter antenna (but not used anymore, it was for a high-school science project - won 2nd place!). With that experiment I used an alternate, longer payload tube and nosecone with features just for the transmitter.

Usually I fly it with a little 'safety' wadding, when I didn't, the 12" chute seriously stuck together but not totally melted, probably because of its age(?).  For its weight, it should have a 15-inch parachute anyway. It has been refitted with a more reliable nylon parachute.

After some motor mount damage on its last flight due to a faulty parachute deployment, this model has been re-built with a better, smaller ejection baffle and a bigger 95mm long motor mount that can handle 24mm wide C, D and E motors, and using an adaptor, the standard 18mm B, C and (composite) D motors. I called this variant of the Bandit the Bandit II.


It now flies very well and quite high with the new motor options! Before it was limited to 400+ feet on a C6 motor; flying higher than the Saturn V Apollo spacecraft, and the Spire of Dublin.  With the new mount and a D12 motor, this rocket can fly higher than the Eiffel Tower, the Two Prudential Plaza in Chicago, the Chrysler Building in NY, and the JP Morgan Chase Tower in Houston. If the fins don't shear off, could it even break 2K with a strong E-motor?  Here is a picture of the rebuilt Bandit HD.

Most recently, this model was selected to be the booster for my HD video camera payload, so the Bandit II took on the variant name Bandit HD. The HD variant will need to lift about 2 or 3 ounces of payload.  It does away with the shock cord, and instead uses a 12-inch parachute for the booster, and three 9-inch parachutes for the payload. The three parachutes are there for redundancy so the video camera and altimeter are less likely to fall at high speed and get lost or damaged.

The camera in the HD faces sideways, looking at the horizon on liftoff and also while hanging upside-down when descending. This payload is a bit longer than stock, at 7.4 inches. The HD missions were succesfully completed four times, before the new motor mount became too damaged for continued use (I believe because the ejection baffle was too good at holding in the ejection pressures, after a similar problem occurred with a different D-powered rocket (DEFCON 1) with the same baffle design.)

I am now building a custom rocket specifically for future HD missions, so the Bandit HD will no longer exist. When repaired, the new-new Bandit will be designated the Bandit III, and hopefully I will never need to change the name again (due to major rebuilds).

When I get this model repaired again, I will install another 24mm mount, but only 70mm long for D-motors, since I can easily get over 1000 feet on the D's, I no longer desire to use the E-motors for this rocket. (Never had the chance to use the E on this rocket.) I have since fallen out of favor of ejection baffles, and instead will use a Nomex cloth for both this and other rockets.



Out of three different models I have flown with the C11-5 motor, this particular model holds both the altitude and speed records, reaching an apogee of 458 feet, and a speed of 109 mph.

Out of five different models I have flown using the D12-5 motor, this model reached the highest altitude: 1005 feet.

SPECIFICATIONS

Series Number: 11
Number of Stages: 1
Stock Length: 25.062" (was 25.75" before repair)
Stock Payload Length: 4"
HD Payload Length: 7.4"
Diameter: 1.325"
Fin Width: 2.6"
Fin Circular Span: 7"
Stock Empty Weight: 100.8 grams
Additional Noseweight Needed for D engines: 11.1 grams
Additional Noseweight Needed for E engines: 23.1 grams
HD Payload Weight: 83.3 grams
HD Quad Parachutes and Rigging Weight: 12.4 grams
Normal, Single 15" Parachtue Weight: 9.6 grams
Liftoff Weight Range: 136.4 - 189 grams
Motor Diameter: 24 mm (18 with adaptor)
Motor Length: 95 mm (70 with adaptor)
Motor Retention Method: Clip
Payload Interior Length: 2.5"
Payload Interior Diameter: 1.28"
Standard Payload Volume: 3.22 cubic inches
HD Payload Volume: 7.59 cubic inches
Altimeter Capable: Yes
Recovery Method: Standard15" Nylon Parachute (1x12" and 3x9" for HD payload)
Typical Descent Speed: 11 mph
Recovery Protection Method: Ejection Baffle
Shock Cord Mount: Kevlar
Nosecone Material: Balsa Wood
Number of Fins: 3
Fin Material: Balsa Wood
Launch Lug Size: 1/8"
Kit Brand: Estes
Completion: about 1977

FLIGHT LOGS

(Estimated about 5 flights on this rocket back in the 1970's)

2010, November 13: Tanguy Soccer Field, Light wind

C6-3: Great flight & recovery. Never touched the ground! Altitude was an estimated 420 feet, there was no altimeter onboard.

2011, May 29: Indiantown Gap, Light wind

C6-5: I launched this on my first launch day as a new member of my rocket club.  All my other flights went well, but this had a wadded parachute. So embarrassing! Not packed very well - but at least it wasn't burned!  Seem to have a lot of trouble with this old 1975-era parachute; it's going to be replaced.  Onboard altimeter recorded the apogee altitude of 434 feet.

2011, June 12: Penn Manor, Light wind

B6-4: The altimeter onboard for this flight measured 162 feet.  Smallest practical motor was used for this heavy bird (although in the 70's, Estes also recommended an A8-3 for this, or was that the Nike?).  I never made the time to change the parachute from the last flight. As usual, the parachute wadded/tangled again, not melted, just appears to be too old.  Needs 18" ‘chute.

2011, July 2: Indiantown Gap, Light wind

C6-3: The altimeter recorded an apogee of 420 feet. I tested new parachute and a reduced delay on the ejection. Came down fast and hit hard, body tube first. Saw chute lying on ground perfectly folded but not tangled at all...why didn't it deploy? Further inspection showed a slight kink in the head of the body tube - repairable, and the motor mount pushed up into the body about two inches, the rear cardboard centering ring failed, as well as any internal glue also, but it is a 34 year old rocket. That too is repairable but very difficult. For now, it's going to be just a decoration model.


In the repair shop, the old Bandit was repaired by replacing the standard 18x70 mm motor mount with a 24x95 mm mount, and the integrated ejection baffle was replaced with a seperate baffle. The kink in the body tube was straightened and hardened with CA glue, but did not require replacing. The cause of all this trouble: the parachute was again replaced at that time with a stronger, sewn Nylon parachute. With its upgraded motor mount, this rocket was now designated the Bandit II.

2011, November 6: Penn Manor, Breezy wind

C6-3: After a stay in the repair shop, I was going to test a new motor mount. I upgraded it to accommodate 24mm motors, but this first test flight used an 18-24mm adaptor. It flew well and didn't get bothered by the winds. Ejection was close to apogee and was followed by a nice, slow descent under a full canopy. Attained at least a few hundred feet - perhaps 300 (but it should have gone beyond 400 feet), and recovered well, but the Altimeter data was totally wrong. It said only 5 feet and the peak G-force was LOWER than the average! That's the second of 4 altimeter errors this day. I suspect it was falsely triggered by winds on the launch pad.

D12-5: I was getting a thrill out of the other's higher-powered flights today, so I sent this old rocket up for
the first time using its newly installed 24mm mount. The D engine got this girl up in a hurry and kept it going, probably to 1000 feet or abouts. (I'll be conservative and document 900.) It took a while to come back to earth, but it was very satisfying. I watched this flight from a far distance with binoculars and saw it very well.

It landed about as far as I was standing, but unfortunately in a different direction! I don't recall removing the engine casing but I couldn't find it afterwards. Did it eject in flight? Either way, the altimeter errored again - twice for this model and 4 times today! Wind gusts on the pad? I dunno.

The Altimeter recorded 6 feet and 51 mph - NO WAY! A D12 burns for 1.65 seconds but the Altimeter 2 said 0.8, it also said it ejected 1/2 second too early but I saw it with my own two eyes through quality binoculars, so I know it was a well-timed ejection. It also said the flight was over in 11 seconds but I stood there for quite a while watching it float down. Apparently the Altimeter 2 sucks for wind-gust immunity while it's in standby. $70 dollars for nuthin'. At least the Bandit flew well today!

UPDATE: After corresponding with Jolly Logic (maker of Altimeter 2), it turns out that the model '2 is not triggered by pressure like the '1 is. It senses acceleration - and I'm sure I knocked the rocket around some and triggered it before launch - that explains the bad data I've been getting. Stay tuned for some valid data on upcoming flights!

2011, December 4: Penn Manor, Steady 10 mph wind

C6-5: Like the Nike-X before this, I wanted to see how the Bandit performs with a C6-5. Dumb decision given the winds aloft, but I got lucky this time. The 2 second burn only accelerated this model at 1.7 Gs, peaking at 5.7 Gs. It reached a speed of 74 mph and then coasted for 2.4 seconds to an apogee of only 232 feet as it turned straight into the wind.

It then continued for another 2.7 seconds progressing downwards to an altitude of only 136 feet before deployment way, way upwind. Fortunately the heavy and rugged nylon chute held up and brought this model back at 11 mph. Flight time was only 15.3 seconds. It could have gone twice as high if not for the strong winds one hundred feet up. Still, it was a successful flight and recovery.

2012, March 18: Penn Manor, Light wind

D12-5: I sent the Bandit II up again on a D12-5 since last time I falsely triggered the altimeter. I was sure it could pass 1000 feet with the new 24mm mount. The D12 burned for 1.9 seconds and the rocket peaked at 14.1Gs. Average Gs was 4.2. It reached a top speed of 170 mph and the ejection charge was a bit late at 5.4 seconds, but not late enough as it turned out. The empty casing was ejected, apparently pushing the steel clip out of the way. Fortunately the D-E spacer/converter was not lost.

The ejection was at 977 feet, stopping the rocket 1.1 seconds later and 28 feet higher at 1005 feet. It could have done better with a D12-7, but hey, that's what this test flight was for, right? It descended at 15 mph, a bit fast because the shroud lines were twisted pretty good, it appears the swivel clip didn't do its job. It landed about 2-300 feet from the launch pad after a total flight time of 51.3 seconds.  Good enough - this rocket will be used to boost my $150 HD video camera this summer, so a few more test flights will be performed.

2012, May 26: Indiantown Gap, 5 mph wind

C11-5: Although it seemed calm at the surface, all of my previous flights into the 1000 foot range were drifting pretty far, so for this flight I aborted plans to launch a D12-7 and use a C.  I wanted to see how much better the Bandit II performed with a C11 motor than a C6 anyway, so this flight was a go. This was to be this rocket’s 5th flight with the new motor mount/baffle. This was also expected to be the last flight of the day because the club’s launch officers declared “last-call” because a thunderstorm was spotted on radar and was fast approaching.

The C11 motor flew well, accelerating this rocket at a peak of 13.2 Gs. It burned for 0.8 seconds while averaging 6.3 Gs – enough to keep this model from turning into the wind and about 50% more than the D12 motor was able to do on a previous flight. Also, this was significantly more than the C6 was able to accomplish.  This acceleration got the Bandit II to a max speed of 103 mph, compared to only 76 mph when I used a C6 motor.

After thrust burn-out there was a (too short) 4.5 second delay, catching the model still ascending though just barely at 395 feet. During the next 1/10ths of a second it only made another foot in altitude, reaching 396 feet.

The flight time was 17.1 seconds, rather short because the model descended at about 22 mph. The parachute was stuck in the body tube, so it came down like a lawn-dart with the nose cone and altimeter bay dangling along side. I had hoped the tall grass would have softened the blow on landing, but it was not enough.

With the parachute still in the body tube, it struck the ground and crumpled the body tube into a serious buckle about an inch down from the end.  Another one bites the dust. In this single month of flying I now have three rockets – all classics from the ‘70s – back in the repair shop with serious damage.

In retrospect I don’t particularly recall prepping the parachute so I can assume I did not pay close enough attention to the process. A contributing factor was the distraction of the approaching storm and the announcement that the launch activities would be closed shortly.

The Bandit II was again repaired. This time I had to remove about 1/2-inch from the top of the body tube, making this rocket a bit shorter than the stock Bandit.  The old "Experimental" decal now just reads "mental".

While in the shop, although not part of the repair, this rocket was outfitted with the special HD payload I have been working on for several months now. This new, longer payload section is shown in the picture below. The payload section houses an altimeter/accelerometer and above that a tiny HD video camera which looks out a silvered window on the side.

Also as part of the re-fitting of this rocket, the recovery system's old 15" parachute was replaced with a single 12-inch parachute for the booster, and three 9-inch parachutes attached to the payload section. With no connecting shock cord, there are two discrete parts to recover after the flight.

The old Bandit II designation has been changed to the Bandit HD.

2012, June 30: Indiantown Gap, Erratic winds

Bandit HD, D12-5: This was a special flight: the newly re-built Bandit HD was carrying a special payload, a miniature $150 HD video camera as well as a $70 Altimeter 2.  The new payload featured three parachutes for redundancy, and no shock cord to snap the rocket back to the payload (the booster had its own parachute). The winds were growing lighter, and with the extra weight on the D12 motor I only expected about half of the typical 1000 foot altitude, so I thought it was safe to fly. As it happened it went much further than I expected!

The payload closeup shows the tinted window for the camera. Below that sits the Altimeter 2. It's static vent holes are just below the red marks, and allows air pressure to reach the altimeter's sensor.

Note: If you want to see the results of these aerial photography missions, please find my blog page on Aerial Photography.  However, here are a few examples from the next four flights:

Flight 1 shows us State Memorial Lake in Fort Indiantown Gap, PA:

Flight 2 shows the booster descending under parachute over Halifax, PA. The Sesquahanna River is in the background:

Flight 3 shows us another view of the Sesquahanna River looking upstream to the North:

Flight 4 shows us the town of Halifax lying aside the Sesquahanna River:

Here, the first flight of the Bandit HD lifts off!

The D12 burned for 1.8 seconds and accelerated the heavy rocket at 11.6 Gs – wow! Average acceleration was 3.6 Gs. It reached a top speed of 142 mph and then coasted for 5.4 seconds. At 787 feet the ejection fired, and 3/10 second later it stopped its upward climb at 797 feet – much higher than expected.

I thought I’d get some nice pictures at that altitude, but worried I’d never get to see them. I lost sight of the rocket, and only after a while spotted the tiny orange parachutes of the payload. I couldn’t see the booster but I wasn’t quite so worried about that.

From 800 feet up (that’s fair – the rocket started 3 feet off the ground you know) the rocket’s payload descended agonizingly slow at only 7 mph with all three ‘chutes fully opened.  It seemed to hang in the air forever. It also drifted a good bit and across the road to the next field over 500 feet away.  It came very close to landing on the road, and even closer to a tree which I’m sure would snag at least one of its three ‘chutes.  Flight time for the payload was 81.4 seconds (my longest duration flight ever!).

As for the booster, someone from the club said they saw it land “over there”.  I went “over there” about 400 feet in the opposite direction (upwind) to find it in the grass without a parachute.  Apparently it became stuck in the tube and did not deploy.  The already shortened body tube was crushed again, this time a good two inches or so.  Also, as happened before, the D12 casing ejected itself instead of ejecting the fourth parachute. Also again, fortunately the D-E engine adaptor was not lost.

I now think I understand why the parachute did not deploy. With a normal configuration, the nose cone or bulkhead is popped out into the airstream and pulls the parachute out with it. This parachute arrangement did not have a means of pulling the parachute out, and with no wadding, nothing caused it to be pushed out either. The high pressure gasses just went around the small, packed 12” parachute, leaving it behind. Next time I’ll need to pack the three payload parachutes in first, with the booster parachute on top. When the three lower chutes are pulled out, they will take the booster chute out with them. Hopefully they will not tangle.

As for the pictures, they came out well enough.  The boost was rapid and mostly blurry, the audio was great though. During the coast I could hear a distinct, slowing whistle like a bomb dropping. A bit of the parachute was photographed by the side-facing camera, which was designed to then descend upside-down for more horizon pictures.  These came out better but the rocking under the three chutes blurred many of them, and there were too many sky pictures for my taste.

I learned that my next design will use a much longer tether to the chutes to slow down the rocking motion, and by tethering all three chutes to different points on the bulkhead I believe I can get the rotation to stop.  Also, I will not use swivel clips for this attachment. Currently, each of the three ‘chutes has a swivel, and the bulkhead has one too. I believe the swivels do not rotate because there is too much friction in them for the amount of weight they carry. I decided a long rubber cord which can twist slowly will act as a better swivel point as it slowly winds and/or unwinds. This can do double-duty as a long tether. Perhaps backed-up with a small piece of string in the event that the rubber fails.

Just after deployment, the camera caught three frames of the booster falling in the air, but oddly it appeared white, even though the booster is painted blue and black!  Did I instead capture a picture of a UFO? To look at it, you would never identify it as the booster, so by definition it DID capture a UFO up there at 800 feet!  (add weird Theremin sounds here.)  Granted, it may have just been the exposure of a line of glare that made the image appear as a white rectangle, with the actual blue/black body blurred out.

I have to dub this flight a success, because its mission was to get aerial photographs and test out this first version of the camera rocket. Too bad the booster was damaged again.

The Bandit HD was repaired by cutting away the collapsed part of the tube and gluing in a new and longer section of tube. This has the added benefit of giving this rocket more room for the four parachutes. This rocket is now longer than stock, with both the main tube longer and the payload tube longer. She is ready to fly again and take some hopefully awesome aerial photographs with the improved, longer parachute tether. I also bent the motor clip in hopes that it would not let another D-casing escape.

Experimenting with the parachute rigging, it turns out that a rubber strip is not very flexible in twist at all. Instead I used a 3 to 4 foot long Kevlar string, and a ball-bearing swivel I found. The hope is that the rotational inertia of the camera will cause it to stop spinning much, and the back-and-forth twisting of the parachutes will not greatly affect the camera through the low friction ball-bearing swivel joint. I abandoned the plan to use three tether points, thinking that may actually increase the random motion of the payload.

2012, August 11: Halifax, 6-10mph winds, some gusting

Bandit HD, D12-5: This was the first flight of the day. Before the wind picked up even more and the summer sky gets hazy, I wanted to get the camera up there. It was a good flight.  Unfortunately I spent too much time fussing with the camera and the altimeter went into battery saving mode, so it was off for the flight and I have no data. I can assume the altitude was similar to the second and third flights later that day, reaching about 715 feet.

The boost was pretty straight even with the winds, and I was rewarded with four good parachutes.  This time I packed the booster parachute last, above the three payload chutes.  The force of the three payload chutes pushed out the booster chute and all was well for recovery.  However, the motor casing breeched the motor clip and was ejected again. The booster and payload landed pretty close to each other this time, less than about 50 feet apart, with both about 300 feet from the launch area. No damage to either part.

The video pictures came out well enough, but with the extra-long tether and ball bearing swivel, I expected a much smoother video.  I guess I’ll have to go much more hi-tech to solve the erratic motion problem.  This flight was also a drag race with another rocket using a B6 motor which left the pad first, but I saw no signs of the other rocket in the aerial video.  I did get some nice close pictures of the booster with its parachute high above the ground!

Bandit HD, D12-5: I sent the HD up again for a backup flight in case I didn’t get good pictures from the first flight somehow.  The second flight of the day went better for collecting flight data.  The D12 motor did not light right away, although there was continuity, the clips had to be cleaned for the second attempt.

The D12 lit the second time, burned for 1.9 seconds and accelerated quickly with a peak of 12 Gs. Average acceleration for the boost was 3.1 Gs, enough to fight the winds and get the rocket to 128 mph. It then coasted for 4.6 seconds to an altitude of 650 feet, ejecting the parachute a bit early and the payload reached an apogee of exactly 700 feet. This D motor had a short delay of only 4.5 seconds.

All four parachutes opened well, but the booster and the payload chute rigging tangled together and did not separate.  Everything came down together on 3-1/2 good parachutes at a safe descent rate of 10 mph. The total flight time was 49 seconds. The video motion was worse because it was tossed by the motion of the four parachutes and the rocket booster.  Here we see the two parachute systems tangled, and the whole thing is descending well on 3-1/2 parachutes.

I had bent the motor clip to be much tighter before today’s flying, since on most of my other D12 flights with this rocket the motor ejected past the clip.  This motor also ejected, but it ripped the motor clip out of the rocket with it and both the casing and the clip was lost, as well as a fair amount of damage to the Bandit HD’s new motor mount. Seems this rocket just doesn’t like D motor casings.

Bandit HD, D12-5: After launching two other flights on this day, the sky was clearing and turning into a picture-perfect day with blue skies and puffy clouds, so I sent the Bandit HD up again for a third flight, just to make sure I got some good still photos.  Even though the motor mount was damaged, it was well enough without the clip to friction-fit another motor into it.

On this flight the motor burn was exactly like the last flight, burning for 1.9 seconds with a peak acceleration of 12 Gs and an average acceleration of 3.1 Gs. This time it reached 129 mph and an apogee of 730 feet, coasting a little longer – 5.1 seconds. The delay was better but still just a tad short at 4.8 seconds.  This time the rocket continued upwards for another 3/10 seconds to apogee.

At the time of parachute ejection, the three small payload chutes got stuck in the rocket tube and never deployed.  Fortunately they moved up enough to push out the booster’s main chute which deployed cleanly, and with that same luck the jammed chutes kept the expensive payload connected to the booster for a safe recovery at a slightly faster descent rate of 12 mph.  Total flight time for this flight was 43 seconds.

The video pictures from this flight were also a bit erratic with the compromised recovery system.  Also the friction-fit motor casing ejected again, damaging the motor mount a little bit more.  This rocket seriously does not like empty D12 casings!  It could be that there is too much resistance in the baffle.

Here we see the motor mount that keeps spitting out D12-5's. The motor tube is completely disintegrated up there, and will no longer hold ejection pressure. Funny though that the ejection baffle looks fine and is clear.

Needing further repair, the Bandit HD was back in the shop for a quick turn-around.  The next launch is in two weeks. I took a quick look at the damaged motor mount. Without a motor clip, if I can friction-fit a motor in it and it holds the ejection pressure, it can be used again. That means the centering rings are not torn and will not allow air pressure out. Otherwise it will need a complete rebuild of the motor mount, and the next video flight will have to be scrubbed, as I don’t have any other completed D-powered booster with a BT-55 top.

Concerning the 2/3 chance of parachute tangle, I will revert to the original scheme of loading the booster chute on the bottom to come out last. A long tether will be attached to the payload, so when it is sufficiently far away, it will pull the booster chute out from a slip-cover.  There is a slight chance the slip-cover will flap and interfere with the picture though, but if light enough, it will flap above the three parachutes.

After all that thinking, I decided instead to retire the Bandit HD, rebuild the Bandit II as the Bandit III, and build a different rocket customized specifically for the HD camera. The new camera-carrying rocket will be called the HD Explorer. There are two other (new) rockets that may also be used for photography, the DEFCON 1 and the C-Thru.  Meanwhile, the Bandit III will have a motor mount for the C11 and D12 engine size only, and will again use a single parachute with a shock cord. It will be used for sport flying only.  Long live the Bandit III !

Here is another view inside the Bandit, after the remains of the damaged motor tube was removed. You can still see the forward centering ring and the thrust ring. The Kevlar shock cord is still attached to this point.  Beyond that is the ejection baffle, partially drilled out.












I finally got around to the business of repairing this rocket. After removing the old motor mount, I had to drill out the old baffle, since I believe this was the cause of all the trouble. Using a large drill bit mounted on a long extension, I had to make the cuts blind as I couldn't see what I was drilling deep inside the body tube.  Fortunately I didn't cut through the body tube which would have essentially destroyed the entire rocket.

Here is a picture of the baffle from the motor point-of-view, where I enlarged the small 1/8" holes in the plywood to about 3/8" each.  Closer to the camera you can see the old forward thrust ring, centering ring and kevlar mount. Since this was an 'E' sized mount, this part is further forward than the new motor mount will be, and I decided to leave it in thinking that cutting it out could likely damage the body tube.

I did the same thing to the front baffle as seen from the parachute's side. I drilled two holes, and because of the grain direction of the wood, the center peice split and fell out, so I thought good enough. You can see some daylight clear through the tube now, and there should be very little resistance from the ejection charge.

Unfortunately, while drilling the front baffle out, the drill bit grabbed the Kevlar shock cord mount and cut it, so I had to mount a new one. For this, I frayed the end of a short piece of Kevlar to greatly increase the gluing surfaces, and glued it into the tube about 2 inches down where the thicker tube coupler is located.






The new 24mm x 70mm motor mount was constructed and is now installed in the body tube.  The end of the motor mount protrudes about 1/2" to ease insertion and removal of the motor.  I painted this part gray.  Finally, I attached the new 30" shock cord, a 15" parachute and the upper section.  This rocket is now ready for flight again.  I still have the option of using the non-stock payload tube with a window to carry the HD camera and altimeter, but for now I will just make a few sport and test flights with C11 and D12 motors.  Just waiting for the weather to warm up a bit!

Since I have completed construction of a new camera booster, the Bandit II is now configured as a sport payload rocket only.  She performed her mission well at great personal risk, and is now retired from photography duties. I flew a few new test missions to see how she performs, and the answer is very well!

2013, August 10: Downingtown MS, 4 mph winds, 80 degrees

C6-5:  One day shy of a year and the Bandit II finally has the chance to fly again. This re-test flight will use a lower power 18mm motor and an 18-24mm adaptor, later to be compared with the C11 motor. Also, I was breaking in a new launch field.

The motor lit right up, and the rocket launched with 6.8 Gs of acceleration. The motor burned for 2.1 seconds and averaged 1.7 Gs acceleration. Upon burnout, the Bandit was travelling at 76 mph and still traveling straight up. It then coasted for 3.6 seconds to an apogee of 379 feet.

The ejection charge fired 1.2 seconds early, but that was just about perfect, as the rocket only fell 3 feet before the Nylon parachute met the air. The chute opened fully, and the rocket descended at 6 mph to a soft grass landing, about 70 feet downwind. Flight time was 42.8 seconds. Perfect success!






C11-5: This next flight will compare the higher impulse C11 to the C6 from the previous flight. The Bandit in this configuration is 5.5 grams lighter without the 18-24mm motor adaptor.

The Bandit lit without delay, and took off straight and fast.  It peaked at 16.2 Gs acceleration – the record highest on this model.  The C11 burned for 7/10 seconds and averaged 6.7Gs – also a record high.  This pushed the rocket to 107 mph at burnout.  It then coasted for 4.6 seconds to an apogee of 435 feet – the highest yet for a C11, and higher than any C6 motor.

1/10 second later, after falling only 2 feet, the Nylon parachute ejected and filled with air. The rocket then came back at 8 mph to a soft, grass landing about 100 feet away. Flight time was 39.8 seconds. This was a perfect flight.


C11-5: This was a second test flight with the C11 motor.  This particular C11 burned a bit slower and gave a better performance.

The C11 belched flame, and the rocket shot off straight up with slightly less acceleration of 14.7 Gs. It burned 1/10 second longer, with an average of 6.4 Gs.  This allowed the rocket to reach 109 mph and then it coasted for 4.8 seconds to an altitude of 449 feet where the ejection fired too early (4.2 second delay).  This slowed the rocket in the next 6/10 seconds while it gained another 9 feet to an apogee of 458 feet, still the highest ever from a C11 motor.

With a good Nylon parachute, it came back at 9 mph to a soft grass landing about 250 feet away. Flight time was 38.2 seconds, the third perfect flight of the Bandit II today!



2013, August 31: Fort Indiantown Gap, 6 mph winds, 86 degrees


C6-5: This is a second test flight of the newly configured Bandit II using the C6 motor with an 18-24mm adaptor. The previous flight was in calm winds, but this flight was a bit windy, perhaps 6 mph.

The igniter caught the black powder and the rocket took off with 6.7 Gs, averaging 1.7 Gs for the 2.1 second burn time while turning into the winds. Bandit reached a top speed of 78 mph. The turn continued as the rocket coasted for 4 seconds when the ejection fired a full second early while at 250 feet.

The rocket continued upwind and slightly up another 28 feet in 4/10 seconds while the parachute deployed. It reached an apogee of 278 feet before returning to the earth at a speed of 8 mph, landing softly in the grass. It was a good 300 foot walk though. Flight time was 25.6 seconds.

Good flight, no damage, but the significant wind-cocking was concerning. Compared to another C6 flight in calm winds, this C6 flight was 100 feet lower even though the rocket reached the same top speed and acceleration. In the future I should only use C11s when the wind speed is up. It will gain me another 50 feet or so and 20 or 30 mph in speed.

B6-2: This is the first low-power test of the Bandit II. I made sure to pack the parachute well, since there would be little time for it to deploy before hitting the dirt.

The black powder fired up from the intense heat of the igniter, and the rocket left the rod with 8 Gs of acceleration. The motor burned for 9/10 seconds while averaging 2.5 Gs, giving the rocket a top speed of 47 mph.

The delay was only 1/10 second late, and at 121 feet the parachute opened up while essentially horizontal, gaining only 2 feet in the 4/10 seconds to full deployment at 123 feet above ground.  Under a good parachute, the rocket descended at 6 mph for a soft grass landing. While returning, the shock cord was somehow wrapped around the screw eye of the bulkhead, holding the payload and rocket body close together, but it did not affect the descent. Flight time was 16.1 seconds. This flight landed only about 50' from the launch rod.

A good flight, perhaps a 4-second delay could have been used, but I did not consider that safe because of how the previous flight weather-cocked a lot, and another two seconds of delay at only 100 feet could have been enough time for the rocket to become a lawn dart.

2014, June 15: Penn Manor, 5 mph winds, 75 degrees

B6-4: It was a bit windy and I wanted to send the bandit up with a B6-2 but I didn’t have any.  I took the chance with the B6-4 instead, hoping that the longer delay would not lead to a destroyed rocket. This was to be the final test of the Bandit with a low-power motor.

All systems well, she took off without a hitch. The thrust burn was 9/10 seconds, with a peak acceleration of 6.2 Gs.  Average acceleration was 2.3 Gs. Both were some of the lowest numbers for the Bandit. 

At burnout it was moving up at 45 mph, the slowest ever, and coasted to a stop in 2.2 seconds at 113 feet altitude. 2/10 second later as it turned over and dropped only 3 feet, the ejection fired and pushed out the parachute that was safely inside a Nomex blanket.

 

 Here we see we have a good ejection with all recovery components well separated.

 Unfortunately, the rocket body rebounded up through the shock cord, causing it to wrap around the body tube. Shock cord on one side, parachute shrouds on the other.

 

 The parachute now partially open, pulled itself up through the loop of the shock cord as the body tube moved the shock cord out of the way.

The parachute is now fully inflated and creates a knot that is stopped by the Nomex blanket. This is a perfect example of Murphy's Law.

As the rocket fell through the parachute and shock cord, the Nomex caught the shroud lines of the parachute and tangled, letting the rocket return at a rapid 15 mph.  It landed in the soft grass after a flight duration of only 8.1 seconds – the quickest of any flight of the Bandit.

The flight was ugly but successful.  I was pleased that this B6-4 had only a 2.4 second delay, which helped keep the rocket from plummeting faster before ejection.

Another inglorious recovery.


2015, July 5: Cross Keys Field NJ, 5 mph winds, 88 degrees F, 50% RH

C11-5: This was my first time out after a long dry spell.  I was excited, yet
apprehensive.  Not sure I remembered all the little details for a successful flight.  But
like a fellow club member said, “It’s like riding a bike.”, and I suppose it was.
The long dry spell was mostly due to a lot of bad weather with the launch club launches,
but even if the weather was good, the dry spell in my wallet probably would have
convinced me not to fly.  Sure, the rockets were cheap enough to fly, but the club
launches are at least an hour drive, some of them two hours, so at least three or four
gallons of gas and wear-and-tear on my car made me shy away from the fun.

The launch site was a new site for me, and my first day with a new club after a “test”
launch last summer.  The field was ample but not well groomed, areas of heavy brush and
just a dirt trail that made me thankful for my 4-wheels of drive.

The day turned out to be very sunny, quite hot at about 88 degrees, but the humidity was
only about 50%, so not oppressive, but the strong July sun took its toll after a long
day.

It seemed a bit breezy, so I sent the Bandit up for a re-test flight with the C11 motor.
An earlier C11 flight had a poor ‘chute deploy, it was stuck in the tube and came down
hard at 17mph and damaged the tube.  I fixed it and flew it as a camera carrier for a
while before reverting to the current “sport” configuration.

I started prepping the rocket with a new Nylon parachute, newly sewn by me, but I
selected a Nylon material that was a bit too thick, and I couldn’t fit it in the BT-55
tube with the Nomex around it, so after three attempts, I swapped it out for a thinner,
lighter plastic ‘chute.

The C11 lit up and the Bandit blew off the pad with a highest recorded peak acceleration
of 16.3 Gs. The burn was 7/10 second and during that time it averaged 6.7Gs.  That got
the Bandit moving at a decent speed of 107mph, followed by a 4.8 second coast to an
altitude of 433 feet.  There the ejection charge fired and the rocket continued for
another 3/10 seconds to an apogee of 441 feet.  That was only six feet higher than my
prediction of 435 feet!

This time I had a good 17” chute deploy, and the rocket drifted back at 7mph to a soft
landing about 125 feet downwind. Flight time was 46.5 seconds.  The minimal drift gave me
a bit of confidence that the winds were plenty light enough for this large field.

D12-7: With that confidence of my first flight in a year, I chose to do a test flight
with a mighty D12 motor this time.  The test was to see if indeed the 7 second delay was
better for this model (though I knew it needed more than the usual 5 second delay).
For this flight, I chose a smaller 12” parachute because I predicted an apogee of 1005
feet, and the winds were not very light.

She fired up and jumped off the pad with an peak acceleration of 12.7 Gs, and averaged
4.5 Gs for the 1.8 second burn.  This pushed the Bandit to a top speed of 179 mph, better
than any D12 flight to date.

After a slightly short delay time of 5.8 seconds (seems they never are as long as
spec’d!), the Bandit was at 1020 feet, setting an all-time altitude record for this
model. She wasn’t done yet. After the ejection pushed the chute out, in that last 3/10
second, she climbed another 8 feet to a final apogee of 1028 feet, 23 feet higher than my
prediction.  With the sun and haze I couldn’t see it at all up there.

The smaller 12” chute brought her back to earth at a somewhat faster 11 mph, landing in
the grass about 160 feet upwind.  Judging from this and other rocket flights, it appeared
the various layers of winds were at very different directions, so like other flights it
returned drifting this way and that way, with a happy result of almost every flight on
this day landing fairly close to the launch pad.  Total flight time was one minute and
6.9 seconds.  If you disregard some of the Bandit’s camera flights with a 12” and three
9” chutes, this was the longest duration recorded for this rocket.  That made two good
flights for the day with the Bandit, so why not go for a third?



D12-7: Flight three for the day saw the Bandit loaded with a D12-7 again.  By this time I
was fairly confident that it wouldn’t drift too far, and – spoiler alert – it didn’t. 
Again I chose to stick with the home-brew, 12” plastic parachute.

This D12 motor fired up and showed how hot she was.  It recorded the highest ever peak
acceleration at 17.3 Gs.  The burn measured 1/10 seconds less than the earlier flight,
and less than any D12 motor I’ve used on this rocket.  The average acceleration during
this burn was 4.9Gs, also higher than any D12, and has been bested only with C11 motors
in the Bandit. Like I said, hot!

Hot enough that the recorded top speed of 182 was also a record for any motor in this
rocket, and beat the previous flight by 3 mph. One might think that all this “hot” lead
to the altitude record, but as is common in rocketry, the fastest speeds always brings
with it the highest drag, and so this did not set any altitude records.

It had a short but still very good delay burn of 6.5 seconds, which was enough this time
to get the Bandit over the top of 981 feet.  Another 4/10 seconds saw the Bandit only
drop 3 feet, and at 978 feet the 12” parachute came to life.  Again this brought the
rocket home at 12 mph.  Half way back I re-acquired it visually, and watched it fall
maybe 30 yards or so in front of me.  Total flight time was 1 minute and 2.6 seconds.

While she landed in plain sight, just a mere 100 feet from the launch pad, she seemed to
cuddle up under a few soybean plants and I had to spend the next half hour searching and
cursing.  The tiny lime-green parachute didn’t help with visibility either.  Oh well, at
least she was found without damage, making for the 3rd successful flight of the day, and
enough work for the Bandit today.


2018, Nov 4: Penn Manor Field, 7 mph winds, 57 degrees F


B6-2: I wanted to send up the Bandit II for a third test flight in it’s latest configuration with a B6 motor. The last B6 flight had a bad tangle with the shock cord, Nomex, and parachute.

Upon ignition, the Bandit II burst forth with 7.4 Gs of acceleration, typical, but burned for 1.1 seconds – a real slow burn for a B6.  That gave it a low average acceleration of 1.8 Gs, and had it moving at 43 mph at burnout. Not a lot of force for this motor.



This Bandit is still flying after more than 40 years.

It coasted up for 2.6 seconds and turned some into the wind, and after 1.7 seconds of delay the parachute ejection popped at 113 feet up. It climbed for an additional 9/10 seconds to reach an apogee 5 feet higher at 118 feet.

The parachute is about to be pulled out of the red Nomex blanket. This is before the shock cord rubber has stretched out.

A nice 15” chute opened, and the rocket returned at 8 mph. It landed downwind about 100 feet safe and sound for an 11.8 second flight.
Other than the long burn time and slow speed (a record slow), most of the other numbers were typical for these B6 flights. It was just a lazy motor, with the fastest delay I’ve seen on this rocket.

   

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