Tag Archives: CNC Specialty Machining

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.

March 2018 meeting

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The RRS held its monthly meeting on Friday, March 9, 2018 at our usual location at the Ken Nakaoka Community Center. We got a timely start at 7:31pm. After the reading of the treasury report, we proceeded to discuss the agenda items.

The first item is the release of the Astrojet newsletter. We’ve sold the first twenty copies already. Copies are $10 each and proceeds go to benefit society activities in this 75th anniversary year. The RRS’s newsletter hasn’t been in print for nearly 20 years. The RRS is very proud to offer a tangible token for the public’s reading pleasure. The RRS is grateful to member Bill Janczewski for making a very professional looking newsletter to commemorate this milestone year for our society.

75th anniversary issue of the Astro-Jet is now on sale for $10/copy.

The second item on the agenda was to get an update on the on-going RRS educational event with the students at Florence Joyner Elementary supported by the growing and successful LAPD CSP program. The program that started in February is going well and the students were able to visit the California Science Center as part of the five session program. The rocket build was completed today and the painting will commence on Saturday. Frank had the students make the paper tube rockets for use with the air launcher. The launch event at the MTA was rescheduled to April 7th. The forum has also been updated with this change.

Flo Jo Elementary students visit the California Science Center with the RRS

Frank has compiled a lot of educational materials from the many Powerpoint presentations over the last few classes, but the amount of material is getting pretty large. Some work should be done to pare down the content to have a greater impact to our younger audience. Also, Frank has bound the information in a booklet which might make for a fine publication as we refine our content with the great questions we get from the students.

For the third agenda topic, we discussed the progress on the RRS symposium. All is going very well and our speaker list is nearly fully confirmed. We held our first teleconference and will hold the next one on Tuesday, March 13th to continue the many planning activities left. 116 free tickets on Eventbrite have been sold already. Frank has been putting out flyers to local high schools such as Redondo Beach, Torrance, and Gardena. We ask all members to download the flyer and spread the word to colleagues, friends and other fans of rocketry both past and present.

The RRS 75th anniversary symposium will be Saturday, April 21st, 2018 and will have speakers and exhibitors from academia, industry and government agencies on topics related to professional and amateur rocketry. If there are any questions, please contact Frank Miuccio our society vice president and symposium coordinator.

vicepresident@rrs.org

At the symposium, the RRS would like to show photos of people and projects throughout our long history. We have received a lot of great items from members past and present and we encourage everyone to contribute whatever they can to the on-going RRS history project. In particular, photos, articles or stories from the 1970’s and 1980’s are of particular interest to us as we have little from this time period.

I am happy to lead this project and hope to give a nice montage to display before all of our symposium attendees and also invite people to write articles describing their experiences and past projects with the RRS. It is through storytelling that the RRS history is kept for future generations to learn and appreciate those that have come before us. Please email the RRS secretary if you have anything to share for the RRS history project.
secretary@rrs.org

On the next agenda topic, we discussed the possibility of moving the meeting start time to 7:00PM. The purpose was to try to have more time to discuss the growing activities at the RRS. The RRS is growing and the meeting time is important. After some discussion, it was decided to keep the meeting time at 7:30PM. The meetings will start on time and discussions will have to stay on the topics of the agenda. Many people come from great distances, but if other topics want to be discussed they can be done before the meeting starts.

For the next topic, a lot of progress was made on the horizontal thrust stand that will be used at the MTA on the small concrete slab just in front of the old blockhouse at the MTA. I had the load cell adapter pieces made and they fit quite well. Many thanks to Matt Moffitt of CNC Specialty Machining in Huntington Beach.

adapter blocks made for the S-type load cell

The horizontal thrust stand will go out to the MTA on the April 7th launch event, but this will be only for final fit checks. Osvaldo is also helping with getting the last mating hardware pieces to complete the set.

load cell adapter matching a standard alpha payload tube

The main frame pieces were welded, but we will not be able to use the thrust stand at the next launch event until the foot plates are aligned and welded. Many thanks to Jim Shirley of Shirley Design and Custom Fabrication in Huntington Beach for his welding skills. I hope to complete the thrust stand and have it ready to static fire alpha rockets at the next launch event after April 7th.

main structure of the horizontal thrust stand to be used for alphas at the RRS MTA

Richard spoke briefly about the progress he’s made to date on his liquid rocket vehicle build. The RRS standard liquid rocket will be the result of a few builds and a lot of testing to arrive at what will be a practical and effective standard design. Richard has built his thrust chamber with a G10 fiberglass internal liner insert and a graphite nozzle. Richard found a good supplier of fiberglass tubes and pipes that are sold in convenient 5-foot lengths.

Richard’s liquid rocket thrust chamber with fiberglass interior wall liner

Richard’s design also includes a pintle-type of injector which is in the works. We hope to see more details when he finishes this piece in the coming month or so.

The last agenda topic was about that fact that we are flying a lot of alphas, but few of them have payloads besides the smoke grenade which works well to help spotting them in flight at apogee. I have looked into making flight speed sensor and my parachute system. I am hoping this will be a semi-regular topic in future meetings.

A future topic for next month’s meeting will be to discuss the pyrotechnic operator’s exam. Licensing is done by the California Fire Marshall’s office and it is an important qualification to have. The RRS is working to get more members trained to help us expand our rocketry activities at the MTA and help us expand knowledge about safety in our hobby.

The meeting adjourned at 9:03pm. The next RRS meeting on April 13th will likely be spent working on the final details of the RRS symposium which will take place 8 days later at the same Ken Nakaoka Community Center in Gardena, Saturday, April 21, 2018.

If there is anything from the meeting that I missed or misstated, please let me know. I am also trying to keep the email list updated. Please let me know if anyone isn’t getting the meeting notices.

secretary@rrs.org

MTA launch event, 2017-11-18

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The RRS held a launch event with the Imperial Courts class on November 18, 2017 at our private Mojave Test Area (MTA). This launch event was the latest in a series of events we’ve had through the support of the LAPD CSP program. The event had 13 alpha rockets including 3 of these having smoke tracers in the payload section and the last one with a pair of keychain cameras on the tail. The USC Impact News crew was also in attendance to document this last event in the series with the Imperial Courts class.

Dave Crisalli was our pyro-op for this event. I was glad to assist on the loading and launching operations.

smoke tracer lead wires sticking out from the payload tube

One of the keychain cameras was only a dummy to balance the rocket. The actual camera was first thought to have been destroyed on launch only to be found a few inches into the soil when the rocket was recovered by shovel. We hope to show the footage if the data on the chip was also intact.

last alpha with the two cameras on the fins, one dummy, one actual

smashed keychain camera with XD memory chip still in place

Osvaldo tried a new method of loading of the micrograin propellant in preparing the alphas for this event. His method involved weighing out the whole propellant load and pouring it all at once in a large funnel being careful not to trap air pockets. Knocking on the side of the metal tubes with a wooden hammer is done to encourage settling then slowly lowering a heavy machined aluminum piston on a string down into the tube to gently but firmly tamp the propellant down and get a better and more consistent packing density in the tubes.

big funnel with aluminum piston on a string; new alpha loading method

The weight of the loaded alphas at the MTA before launch did show a small improvement by being slightly heavier from more propellant packed in the same tubes. The main advantage was the loading procedure was less messy than the prior method of incrementally loading the powder propellant then bouncing the bottom of the tube on a wood block. Despite the best efforts with this approach, small air pockets in the packed powder “grain” often results with packets of micrograin burping back up the tube getting on the propellant loader.

Osvaldo gives instructions on the weighing of the alphas before flight

The alphas from Imperial Courts had bright color schemes from each of the individual teams. Having each of the rockets labelled with the paper tags was very helpful in keeping track. We should continue this practice for future events.

alphas from the Imperial Courts class

I have been slowly working on a small horizontal thrust stand to incorporate the load cell transmitter donated to the RRS by Interface Inc.
Interface Inc. – Precision Load Cells

An existing concrete pad with a three anchor-bolt pattern will be used and I have the first piece which is a steel footing plate to mate up with the hole pattern. Many thanks to Matt Moffitt of CNC Specialty Machining of Huntington Beach, CA, for his craftsmanship.

anchor plate for an RRS horizontal thrust stand

The students of Chaminade High School in Chatsworth also hot-fired their 4-inch solid rocket motors of their own making. After resolving some problems with the casing, the results of the firing were good.

4-inch solid motors from Chaminade High School

We also hosted UCLA as they hot-fired their liquid rocket. They attached their propellant tanks to one of our thrust frames for a full system demonstration.

UCLA NO2 and kerosene liquid rocket being mounted for firing

UCLA makes final preparations for firing

After a lot of preparations and waiting until after sunset, UCLA’s hot-fire did not disappoint those of us who stayed into the cool hours of dusk. Their nitrous-oxide and kerosene liquid rocket fired for full duration and to what looked like great results.

UCLA fires for full duration.

RRS director of research, Richard Garcia, with his brick as a camera tripod

We thank all of the parents and the LAPD officers who made the event a success. Also, many thanks to Dave Crisalli and the RRS membership who helped with the hundreds of things that needed to be done. We look forward to the next launch event at the MTA early next year.