Tag Archives: Rockextractor

April 2018 meeting

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The RRS held its monthly meeting on April 13, 2018 at the Ken Nakaoka Community Center in Gardena. We had a full agenda with the most important item being the 75th anniversary RRS symposium that is coming in only 8 days. We had a prompt start at 7:30pm with Osvaldo calling the meeting to order and giving the reading of the treasury report. We had a full attendance including our new RRS members, Jack, Dylan, Connor, Cooper and Byron from the former Chaminade High School rocketry club. They have been very busy with their solid rocket project. We didn’t have time to add their progress to our agenda, but we hope they’ll give an update at the May meeting.

Bill Janczewski and Chris Lujan just before the April 2018 meeting

The first agenda item discussed the work done by the Aerospace Corporation of El Segundo, California, on March 26th and 27th at the RRS MTA site. RRS member and Aerospace Corporation employee, Drew Cortopassi gave an excellent summary of the work. Aerospace Corporation’s experimental work was a success and we hope that Aerospace may return to use our site to advance their designs. Aerospace Corporation is one of our exhibitors and presenters at the meeting. A fuller discussion of their rocket testing at the RRS MTA will be given at the RRS’s 75th anniversary symposium, next Saturday, April 21st.

Aerospace Corporation tests an experimental solid motor design at the RRS MTA, 3/26/2018.

The next agenda topic was discussing the results from the launch event held last weekend with Florence Joyner Elementary School with the LAPD CSP program. Frank gave an excellent summary and Osvaldo discussed a theory explaining the odd bending of each alpha rocket found at the event. Most alpha rockets come down nearly vertically and burying themselves straight into the hard dry lake bed. At the launch event of April 7th, nearly all of the rocket propellant tubes were bent. Typically, this only happens if the rocket strikes a rock beneath the surface, but it is quite uncommon. Osvaldo’s invention of the Rockextractor proved to be a swift tool for reclaiming found alpha rockets.

Osvaldo’s newest invention, the Rockextractor

As a side note, Frank had mentioned that the USC short film “Rockets in the Projects” covering the November launch event with Grape Street Elementary class and the LAPD CSP program will be screened with other short films at Annenberg Hall on the campus of USC on Wednesday, April 18th. Seating is very limited so those interested in seeing the film should act quickly.

The third agenda topic was about the RRS expanding its roster of licensed pyrotechnic operators (pyro-op’s). We have great support from our current pyro-op’s but the society would benefit from having more. The RRS will be building a training manual that includes the materials mandated by the California Fire Marshal’s office to attain a license in rocketry. This tool will be an effective study tool for members looking to become licensed pyro-ops. At the very least, the training helps spread safe practices in the society. Given the limited time we had at this month’s meeting, we agreed to discuss this topic further at the next month’s meeting in May.

RRS pyro-op manual and training guide

The fourth agenda topic was something that Larry Hoffing discovered. The 2-bit Circus Foundation is a non-profit educational organization dedicated to the next generation of inventors to advance environmental stewardship and spur community engagement. The 2-bit circus has a futuristic arcade in downtown Los Angeles and has reached out to the RRS to be an exhibitor at their next event in Hawthorne, California. The RRS was supportive of this idea and once more details become available we will find a few members to attend the exhibition to help us reach more people at this event for STEAM (Science, Technology, Engineering, Art and Mathematics) education which our shared passion.

Two Bit Circus Foundation – STEAM education

The fifth agenda topic briefly discussed an idea that I have developed a second-stage design that fits with the RRS standard alpha payload tube. With a short segment of 1-1/4″ PVC tubing turned down to fit inside the 1.75″ OD payload tube and machined PVC end cap, a second stage motor with a graphite nozzle can be fired atop of the micrograin booster. A short length of Type-1 PVC round stock was donated to the RRS by Industrial Plastic Supply Inc. of Anaheim, California. There are many plastic suppliers, but not many that offer such a range of plastics in small quantities better suited for experimenters and hobbyists with modest personal budgets. I happily recommend them to all.

Industrial Plastic Supply Inc. – Anaheim, California

An interstage piece is necessary to trigger the second stage after a set time delay. I have designed an umbilical connector piece that uses a 3.5mm audio plug and panel-mount jack as a switch.

3.5 mm audio jack, panel mount

To internally mount the switch at a shallow angle for easy extraction of the plug as the alpha rocket lifts away from the launch rack required a unique plastic piece that Richard Garcia was able to 3D print for me in plastic. The fit check was a success so now I have to get the connector wired and mounted.

two of the umbilical jack mounts, plastic nozzle puck in the foreground

The solid motor grain itself was thought to be simple rocket candy, but other solid propellant types could be tried. Chris Lujan offered to pour a second stage grain for my design. Richard Garcia also offered to make his next motor grain to fit in this standard payload tube size. I have designed most pieces, but some aspects of this design need more work and testing. The RRS would like to encourage our members and our partner organizations to design and fly payloads with our standard alpha rockets which are easy to produce. Time was short so this topic was also tabled for the next month’s meeting as this work evolves.

RRS standard alpha, second stage assembly (work in progress)

The sixth agenda topic similarly had no real time to get into the details. The quarterly progress report of the SuperDosa project had only the RRS ballistic evaluation motor (BEM) to discuss. This workhorse tool will help the RRS accurately determine burn rate with variable nozzle puck sizes. Richard Garcia did turn out a basic set of graphite puck nozzles for the BEM.

RRS BEM graphite nozzle pucks, courtesy of Richard Garcia

The cylinder piece is with Osvaldo once he can find time to machine the bore and pressure ports. The top and bottom plates will be made soon by CNC Specialty Machining of Huntington Beach. This is the same machine shop that did a quality job with milling the S-type load cell adapter blocks for the RRS horizontal thrust stand. Thanks to Matt Moffitt of CNC Specialty Machining which is soon to relocate their business in Huntington Beach next month.

RRS ballistic evaluation motor design concept

The last agenda topic was the last preparations necessary for the RRS symposium coming next Saturday, April 21st. This event will easily be larger than last year’s event with over 400 Eventbrite reservations made just before the meeting. We have a longer list of speakers including new participants such as NASA Goddard Spaceflight Center’s (GSFC) Wallops Island Flight Facility (WFF) in Virginia. We will need all of our members to help us support this event. Please spread the word!

There will be a lot of work in setting up the night before. Members are encouraged to come help set things up at 7PM on the Friday night beforehand, April 20th. Contact Frank Miuccio who is our symposium coordinator if you would like to help.

vicepresident@rrs.org

The RRS meeting went out to the exhibition hall of the Ken Nakaoka Community Center in Gardena. The RRS will have the whole center for our public event and we hope everyone can come. Frank will send me the final agenda with the speaker list and the presentation times. This is an all-day event, but consult the RRS.ORG website for updated information. I plan to make a posting for the RRS symposium soon.

The meeting adjourned as the Ken Nakaoka Community Center closed. Osvaldo did some work for our new members with a clamping assembly to hold their rocket casing in their own horizontal thrust stand to test their full-sized boosted dart motor. Although independently conceived, this work nicely fits with the SuperDosa project and the RRS is glad to have another project to help advance the work of the society and our members.

RRS members stand outside of the Ken Nakaoka Community Center after the meeting with the horizontal thrust stand

If there is anything I have missed or misstated, please email me:
secretary@rrs.org

Our next meeting will be Friday, May 11, 2018. Please come as we will have much to discuss after the symposium and plenty to do in this summer of our 75th anniversary as a society.

MTA launch event, 2018-04-07

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The RRS held a launch event with the students of Florence Joyner Elementary School at the MTA on April 7th, 2018. This event was the final step in the five-week RRS program that started in February thanks to the support of the Los Angeles Police Department’s (LAPD) Community Safety Partnership (CSP). The students got a tour of the RRS Mojave Test Area where both amateurs and professionals can test rockets in the open space of the Mojave Desert.

Students from Flo Jo Elementary at the RRS MTA

As always, we gave a safety briefing to the students to the hazards of the desert and our testing site. Dave Crisalli was our pyro-op for the event and gave an excellent background of the exciting work we do at the RRS.

Dave Crisalli addresses the students and officers as Frank Miuccio looks on

Safety briefing inside of the George Dosa building at the RRS MTA

The tour also included a live demonstration of burning the micrograin zinc/sulfur powders in the open air. The bright yellowish flame is a vivid demonstration of the combustion process.

Live demonstration of micrograin propellant at the MTA

We also demonstrated the burning of a more common solid propellant, an ammonium perchlorate, HTPB and aluminum powder composite grain. The same constituents used in the Space Shuttle’s solid rocket boosters (SRB’s). Thanks to Larry Hoffing for making the sample grain for the test.

Sample of a composite solid propellant grain just before the demonstration.

The Flo Jo elementary class built 10 RRS standard alphas for the event. Each painted uniquely by each of the teams.

Standard alpha rockets from Flo Jo Elementary

Once everyone had the safety briefing and completed the tour, we proceed to send everyone to our safety bunker as Dave Crisalli and I loaded each rocket into our rail launcher.

Dave Crisalli and Dave Nordling load an alpha into the launching rack

Each of the rockets flew straight and fast from the rails and did not disappoint the class seeing their hard work fly off the rails in a huge yellow cloud.

wide-angle still shot from Osvaldo’s high-speed camera, 2018-04-07

An RRS alpha rocket takes off, view from the bunker

After the clean launch of all of the rockets, the kids and the LAPD ventured out to the desert to try to find each of their rockets. Flag poles were made for the occasion to mark the locations so that they could be extracted later by shovel. 7 out of 10 rockets were found and two older rockets from previous events were also found and marked. It is tough to find each rocket in the desert scrub, but with the hard work of the students it’s good to recover at least some of the parts as they can be reused with some work.

After launch, the students and their mentors march to the desert to search for their rockets

The kids were very organized and had a great time. After taking a group photo at the gate, they returned to the city. The RRS was glad to host them and hope they can come back soon. Also, thanks to the LAPD CSP program for being supporters of this project to give this experience to the hard-working students of Watts.

Flo Jo Elementary and LAPD CSP pose before the RRS MTA sign

The RRS membership stayed behind to try a few experiments. The first test was trying to finish the foot plate welds on the horizontal thrust stand I have made for static testing alpha rockets motors of similar size with S-type load cell donated to the RRS by Interface Force Inc.

Interface Inc. – Precision Load Cells

The construction of the horizontal thrust stand is nearly complete, but unfortunately the desert winds made welding of the plates impossible. This steel frame will firmly hold alpha-sized rockets for static fire testing when bolted down to concrete slab in front of the old blockhouse. As a historical note, it was a young Dave Crisalli that helped pour this slab in the late 1960’s.

Osvaldo prepares to weld the foot plates of the horizontal thrust frame at the MTA

Scribe marks were made on the plates and the assembly was taken back to the city to be completed later. Many thanks to Jim Shirley of Shirley Design and Custom Fabrication in Huntington Beach for finishing the structural welds. The integration of the load cell and final mounting to the concrete slab will take place at the next launch event where the RRS hopes to measure the thrust and impulse bit of our standard alpha rockets.

The RRS horizontal thrust stand frame is complete and ready for mounting at the MTA

Richard Garcia built his own vertical test frame to support a small steel engine case he made for a rocket-candy grain.

Richard mounts his frame to the MTA structure for his experiment.

Rocket-candy is a simple mixture of potassium nitrate and sugar. Under moderate heat, the sugar caramelizes to form a viscous but firm mixture that suspends the oxidizer and can be packed in to the paper tube cases.

Richard “cooks” the sugar and potassium nitrate under low heat of the electric hot plate.

Richard’s work was documented by RRS member, Alastair Martin, who is working on a larger documentary of the RRS classes and our members’ experimental work at the society.

Alastair Martin films the tools and process of Richard Garcia’s rocket candy production

Once the motor grains had set, they were test fired to verify the quality of the mixture. The second motor grain was loaded in the steel rocket tube mounted to the vertical stand. Results were not spectacular as the end-burner grain design didn’t create much pressure. More testing will be done to improve performance, but the steel case and nozzle were undamaged.

Richard Garcia’s steel motor case and nozzle, just before loading the motor grain

Richard’s sugar rocket motor fires securely from the vertical mounted stand

One of the newest tools invented by our president, Osvaldo Tarditti, is a new ratcheting tool that pulls the rocket straight from the ground by a simple portable frame that can be angled to get the rocket to come out straight. The tool must be operated by two people to pull the rocket body straight from the ground. The tool was successfully demonstrated and nine rockets were pulled from the ground without any of the back-breaking work of shoveling. This is an excellent advancement for the society and will be very handy in the future.

Osvaldo’s newest invention, the Rockextractor

As this is the first launch event of this 75th anniversary year of the society those of us that were at the MTA at the end of the day took a group photo by the old I-beam which has been a part of the RRS since our earliest days of rocket testing. You can see the I-beam by itself in many of the old society photos. At the new MTA site, it is an integral part of our larger test structure that has seen hundreds of uses and still going strong.

Frank Miuccio, Alastair Martin, Dave Nordling, Richard Garcia and Osvaldo Tarditti pose by the iconic RRS I-beam

The RRS will be having their next monthly meeting on Friday, April 13th. The RRS 75th anniversary symposium is also happening on Saturday, April 21st. Please come out as it will be a great occasion with speakers and exhibitors from industry, universities and other amateur rocketry groups.