Since my last update, I've done the "tip-to-tip" fiberglass on one set of the fins. This should provide an unnecessary level of strength to the fin joints for high performance flights or hard landings.
I'm using 6 oz./ sq. yrd. fiberglass cloth, and I am doing two layers. The first layer is a bit smaller, and the second layer covers the entire fin and airframe tube surfaces.
I used the tape to mark where the smaller, inner piece of fiberglass goes.
The inner pieces cut out from the template that I made from paper.
I used some epoxy with tiny pieces of fiberglass mixed in to first fill the fin/airframe
tube joints. Then I added the small piece of fiberglass and wetted it out with West Systems epoxy. Once the smaller piece was wetted out, I removed the tape and laid the second, larger piece of fiberglass on top. That was wetted out, and I improvised a way to keep the fiberglass down in the joint of the fins and airframe tube. I used the brass rods on top of the peel-ply with some rubber bands, then
applied some weights to the whole setup for curing.
Showing the rubber band pulling the brass tube into the fillet area.
The weights piled onto the brass rods to keep the joints tight while the epoxy cured.
Fiberglass trimmed around the fins, and the weights removed.
The brass rod and weights technique seemed to work quite well,
with only two small spots that look like air got into the joint.
I attended the June sport launch in Geneseo. It was a much calmer launch than NSL two weeks ago, with only a couple dozen flights in the time we were there. The weather was nearly perfect, with light and variable winds. Overall, it was a fun and relaxing day for rocketry.
I did two flights and put together videos with ground views from my phone, pad videos from my GoPro, and onboard video from my Mobius:
First, I launched my X-Calibur on a CTI H87 Imax. It reached 1748 feet and had a perfect recovery. It landed only about 200 feet away.
Then I launched the Eclipse on an Aerotech I327 Dark Matter. It reached 2042 feet and landed about 400 feet away. It showed its characteristic wiggle on the way up, which is visible in the ground videos.
I've gotten a good amount of work done on the Tomach since the previous posts.
The First Time Fitting Everything Together!
Electronics Bay:
Updates since the last time:
Electronics sled is finalized (assembled and layout complete)
The bulkhead plates have been JB Welded together
I have also installed the "switch band" (the small piece of body tube that attaches to the electronics bay
I have installed the forward tube retention hardware
Work needed to complete electronics bay: Install wire for the e-match attachment points into the bulkheads. Drill the two air sampling holes/altimeter arming holes.
Electronics Bay: JB Welding the Switch Band
Switch Band Taped in Place while JB Weld Cures
Hex Nuts JB Welded in Place for Forward Tube Retention
Nose Cone:
The little bit of work that was needed for the nose cone is complete.
The bulkhead is assembled with an eye bolt and epoxied into the nose cone coupler
The nose cone coupler has hex nuts JB Welded in place, in the same manner as the electronics bay. This will allow for secure nose cone retention as well as simple access inside the nose cone if needed.
Hex Nuts JB Welded in Place
Looking Inside the Coupler to the Bulkhead
Completed Nose Cone
(Note the black screw that is visible.
There are two that hold the nose cone to the coupler.)
Motor Mount and Drogue Recovery Harness
A decent amount of work was done here as well since the previous update.
I built up a third "centering ring" with masking tape that aligns with the forward end of the fin tabs. This is to prevent the future internal fillets from leaking all over inside the motor mount.
I placed heat shrink tubing in place on the Kevlar recovery harness at the end of the motor mount tube. This will prevent fraying over time during descent when there is tension and vibration on the harness.
I also applied a combination of electrical tape and heat shrink tubing on the Kevlar recovery harness at the exit of the body tube, for the same reasons as above.
The motor mount has been JB Welded in place in the main body tube.
Work needed to complete the motor mount: Fin installation and internal/external fillets.
The Masking Tape "Centering Ring"
Showing the Alignment with the Fin Tabs
Motor Tube: Recovery Harness Protected by Electrical Tape and Heat Shrink Tubing
Aft Airframe Tube: Recovery Harness Protected by Electrical Tape and Heat Shrink Tubing
I attended NSL 2018 over Memorial Day weekend. NSL is the National Association of Rocketry's (NAR) largest launch. This year it was hosted locally by the MARS club in Geneseo.
I did several flights with my rockets. All were successful and it was a great time. As usual, thanks to everyone that came out to help and watch!
Weather ranged from overcast to mostly clear skies with winds light to about 7 mph from the South, varying a bit from WSW on Saturday to SSE on Sunday.
In the order of the launches:
1) 5/26/18: Eclipse on an Aerotech J340 Metalstorm to 2358 feet.
2) 5/26/18: X-Calibur on an Aerotech H148 Redline to 2484 feet.
3) 5/27/18: Competitor on a CTI J355 Red Lightning to 3046.5 feet.
4) 5/27/18: X-Calibur on a CTI G68 White to 852 feet.
I did more editing work than I ever have for the videos, particularly the Eclipse and Competitor 4 flights. I used Windows Movie Maker to compile photos, ground videos (from my phone), pad cam videos (from my GoPro Hero5 Session), and onboard videos (from my Mobius Actioncam HD).
Flight Details:
Flight #1) Eclipse on an Aerotech J340 Metalstorm: This flew on a motor I bought and built something like 7 years ago. I was slightly concerned about motor failure due to the o-rings taking a set, but it burned perfectly. The flight was straight up and had a slight, lazy corkscrew. It tail slid at apogee, rather than arcing over. It landed about 1000 feet away. After recovering the rocket, I realized that the tracker was gone. I had only used masking tape to hold it on to the main recovery harness, which tore during the main ejection at 500 feet. Fortunately, the tracker survived the fall, and it was easily recovered close to where the rocket had landed.
Flight #2) X-Calibur on an Aerotech H148 Redline: This was a nice flight to just within the limits of visibility in the sky conditions at the time. It was the first flight using the electronic deployment that I set up last year for this rocket. The parachute didn't fully open because the parachute protector slid up the parachute shroud lines. It landed hard but there was no damage.
Flight #3) Competitor on a CTI J355 Red Lightning: This was a perfect and graceful launch. It reached 3028 feet according to the PerfectFlite HiAlt 45K altimeter, and 3065 feet according to the PerfectFlite SL100 altimeter. The SL100 also reported a top speed of 292 mph. The performance of this flight was incredibly close to what Rocksim had predicted, which was 2967 feet and 294 mph. 1.25 grams of black powder in the drogue and 3 grams for the main was perfect.
After the adventurous recovery of the K600 flight last year, I tried the TAC-1 60" main parachute instead of the 72" Top Flite one that I had been using. Originally, I elected not to use the TAC-1 because the rocket came out heavier than expected. However, the 72" Top Flite one is a bit too big, causing it to lazily float down and drift unnecessarily far. For this flight, I also lowered the main deployment altitude from 700 feet to 500 feet. The TAC-1 opened quickly and nicely, and recovered the Competitor without damage. However, the descent was a bit too fast for comfort, confirming that my previous decision not to use it was the right one. The descent rate was about 30 feet per second.
Flight #4) X-Calibur on a CTI G68 White: This was a quick and low flight to only 852 feet. The altimeter ejection worked perfectly again with about 0.8 grams of black powder. The X-Calibur showed a little bit of a wiggle right at motor burnout. In the past, I've noticed a wiggle quite a few times with this rocket, so it doesn't surprise me anymore when it does it. I think this is due to the asymmetric 6 fin configuration.
One more note: I bought motors for more flying this year! I bought a motor for the Competitor, a motor for the Eclipse, and two motors for the X-Calibur.
In addition to the motor mount work I did today, I also started laying out the electronics bay. This is particularly challenging because there just isn't much room to fit the equipment inside.
Bulkheads, Bulkplates, Plywood Electronics Sled that Came with the Kit
Bulkplate. These came pre-drilled incorrectly.
This picture shows my marks for drilling it correctly.
Dry Fitting the Components
Threaded Rods for the Electronics Sled
After realizing I never would have been able to fit two altimeters
and two 9 Volt batteries (for deployment redundancy) on the included electronics sled, I decided to make my own wood plates, while still using the included threaded rod guide.
Custom Cut 1/8" Plywood for Electronics Sled
One of the pieces has been marked for notching.
The notches are used to assemble with the laser cut
threaded rod guides that were included.
Test Fitting the Electronics Sled.
I had to notch one end to clear
the hardware from the 1/4" eye-bolt.
Altimeter Mounting Hardware Installed
Electronics Sled
Bulkplate Assembly (2 Plates) being JB Welded
Using Weights to Press the JB Weld
into the Fiberglass Bulkplate Assembly
I spent most of the day working on the Tomach today. I started by wiping everything with alcohol to remove mold release and other residue from the fiberglass. Then I started sanding pieces to break sharp edges, and to make sure everything fits together properly, and to rough up where bonds will be made. These pictures show the progress on the motor mount. I also worked on the electronics bay.
Sanding the Glue Areas of the Fins
54mm Motor Mount with CTI 54mm 3 Grain Case
Aeropack Motor Retainer Fit Check
Inserting a Motor
Fully Seated Motor
Aeropack Motor Retainer Threaded Into Place
Widening the Fin Slots with a Needle File
Showing the Internal Alignment of the Fin Slot,
Aft Centering Ring, and Aeropack Motor Retainer
Forward Centering Ring with Notches Filed for Recovery Harnessing Clearance
Forward Centering Ring In place with Kevlar Recovery Harness
I have gotten excited about rocketry again this year. I decided to get a new kit to build and fly. I wanted something less expensive than the Competitor 4 but still capable of great performance. After a few days of research I bought a Madcow Rocketry 2.6" Tomach Dual Deploy.
This is an all fiberglass kit that is 2.6" in diameter and 63" in length. In other words, it is small, but not so small that it won't be fun to fly. What's great is that with average building techniques, the fiberglass construction and 54mm motor mount mean that it is capable of extreme performance. Mach 1+ and altitudes of 17,000 feet should be achievable.
Here are some pictures of the rocket kit and some of the gear I bought to go with it:
Tomach 2.6" Kit
Paper Insert
Parts
Recovery Gear from Top Flight Recovery
54-38mm Adapter, 54-29mm Adapter, Aeropack Motor Retainer
