--- /dev/null
+[[!tag tags/debian]]
+[[!tag tags/misc]]
+[[!tag tags/photography]]
+I learned something new yesterday, that probably shouldn't have shocked me
+as much as it did. For legacy reasons, the "creation time" in the
+[Exif](https://en.wikipedia.org/wiki/Exif) metadata attached to digital
+camera pictures is not expressed in absolute time, but rather in some
+arbitrary expression of "local" time! This caused me to spend a long evening
+learning how to twiddle Exif data, and then how to convince
+[Piwigo](https://piwigo.org/) to use the updated metadata. In case I or
+someone else need to do this in the future, it seems worth taking the time
+to document what I learned and what I did to "make things right".
+
+The reason photo creation time matters to me is that my wife Karen and I are
+currently in the midst of creating a "best of" subset of photos taken on our
+recently concluded family expedition to Antarctica and Argentina. Karen
+loves taking (sometimes
+[award-winning](https://arvadapress.com/stories/right-time-right-place-twice,78126?))
+nature photos, and during this trip she took thousands of photos using her
+relatively new
+[Nikon COOLPIX P900](https://www.nikonusa.com/en/nikon-products/product/compact-digital-cameras/coolpix-p900.html)
+camera. At the same time, both of us and our kids also took many photos
+using the cameras built into our respective Android phones. To build our
+"best of" list, we
+wanted to be able to pick and choose from the complete set of photos taken,
+so I started by uploading all of them to the [Piwigo](https://piwigo.org/)
+instance I host on a virtual machine on behalf of the family, where we
+assigned a new tag for the subset and started to pick photos to include.
+
+Unfortunately, to our dismay, we noted that all the photos taken on the P900
+weren't aligning correctly in the time-line. This was completely unexpected,
+since one of the features of the P900 is that it includes a GPS chip and adds
+geo-tags to every photo taken, including a GPS time stamp.
+
+# Background
+
+We've grown accustomed to the idea that our phones always know the correct
+time due to their behavior on the mobile networks around the world. And for
+most of us, the camera in our phone is probably the best camera we own.
+Naively, my wife and I assumed the GPS time stamps on the photos taken by
+the P900 would allow it to behave similarly and all our photos would just
+automatically align in time... but that's not how it worked out!
+
+The GPS time stamp implemented by Nikon is included as an Exif
+extension separate from the "creation time", which is expressed in the
+local time known by the camera. While my tiny little mind revolts at this
+and thinks all digital photos should just have a GPS-derived UTC creation
+time whenever possible... after thinking about it for a while, I think I
+understand how we got here.
+
+In the early days of Exif, most photos were
+taken using chemical processes and any associated metadata was created and
+added manually after the photo existed. That's probably why there are
+separate tags for creation time and digitization time, for example. As
+cameras went digital and got clocks, it became common to expect the
+photographer to set the date and time in their camera, and of course most
+people would choose the local time since that's what they knew.
+
+With the advent of GPS chips in cameras, the hardware now has access to an
+outstanding source of "absolute time". But the Nikon guys aren't actually
+using that directly to set image creation time. Instead, they still assume
+the photographer is going to manually set the local time, but added a
+function buried in one of the setup menus to allow a one-time set of the
+camera's clock from GPS satellite data.
+
+So, what my wife needs to do in the future is remember at the start of any
+photo shooting period where time sync of her photos with those of others is
+important, she needs to make sure her camera's time is correctly set, taking
+advantage of the function that allows here to set the local time from the
+GPS time. But of course, that only helps future photos...
+
+# How I fixed the problem
+
+So the problem in front of me was several thousand images taken with the
+camera's clock "off" by 15 hours and 5 minutes. We figured that out by a
+combinaton of noting the amount the camera's clock skewed by when we used
+the GPS function to set the clock, then noticing that we still had to account
+for the time zone to make everything line up right. As far as I can tell, 12
+hours of that was due to AM vs PM confusion when my wife originally set
+the time by hand, less 1 hour of daylight savings time not accounted for,
+plus 4 time zones from home to where the photos were taken. And the remaining
+5 minutes probably amount to some combination of imprecision when the clock
+was originally set by hand, and drift of the camera's clock in the many
+months since then.
+
+I thought briefly about hacking Piwigo to use the GPS time stamps, but quickly
+realized that wouldn't actually solve the problem, since they're in UTC and
+the pictures from our phone cameras were all using local time. There's
+probably a solution lurking there somewhere, but just fixing up the times in
+the photo files that were wrong seemed like an easier path forward.
+
+A Google search or two later, and I found
+[jhead](https://www.sentex.ca/~mwandel/jhead/),
+which fortunately was already packaged for Debian. It makes changing Exif
+timestamps of an on-disk Jpeg image file really easy. Highly recommended!
+
+Compounding my problem was that my wife had already spent many hours tagging
+her photos in the Piwigo web GUI, so it really seemed necessary to fix the
+images "in place" on the Piwigo server. The first problem with that is that
+as you upload photos to the server, they are assigned unique filenames on
+disk based on the upload date and time plus a random hash, and the original
+filename becomes just an element of metadata in the Piwigo database. Piwigo
+scans the Exif data at image import time and stuffs the database with a
+number of useful values from there, including the image creation time that is
+fundamental to aligning images taken by different cameras on a timeline.
+
+I could find no Piwigo interface to easily extract the on-disk filenames for
+a given set of photos, so I ended up playing with the underlying database
+directly. The Piwigo source tree contains a file piwigo_structure-mysql.sql
+used in the installation process to set up the database tables that served as
+a handy reference for figuring out the database schema. Looking at the
+piwigo_categories table, I learned that the "folder" I had uploaded all of
+the raw photos from my wife's camera to was category 109. After a couple
+hours of re-learning mysql/mariadb query semantics and just trying things
+against the database, this is the command that gave me the list of all the
+files I wanted:
+
+<pre>
+select piwigo_images.path into outfile '/tmp/imagefiles' from piwigo_image_category, piwigo_images where piwigo_image_category.category_id=109 and piwigo_images.date_creation >= '2019-12-14' and piwigo_image_category.image_id=piwigo_images.id;
+</pre>
+
+That gave me a list of the on-disk file paths (relative to the Piwigo
+installation root) of images uploaded from my wife's camera since the start
+of this trip in a file. A trivial shell script loop using that list of
+paths quickly followed:
+
+<pre>
+ cd /var/www/html/piwigo
+ for i in `cat /tmp/imagefiles`
+ do
+ echo $i
+ sudo -u www-data jhead -ta+15:05 $i
+ done
+</pre>
+
+At this point, all the files on disk were updated, as a little quick checking
+with exif and exiv2 at the command line confirmed. But my second problem
+was figuring out how to get Piwigo to notice and incorporate the changes. That
+turned out to be easier than I thought! Using the admin interface to go into
+the photos batch manager, I was able to select all the photos in the folder
+we upload raw pictures from Karen's camera to that were taken in the relevant
+date range (which I expressed as taken:2019-12-14..2021), then selected all
+photos in the resulting set, and performed action "synchronize metadata". All
+the selected image files were rescanned, the database got updated...
+
+Voila! Happy wife!
+
--- /dev/null
+[[!tag tags/debian]]
+I joined the
+[Debian](https://debian.org) project in late 1994, well before the first
+stable release was issued, and have been involved in various ways continuously
+ever since. Over the years, I adopted a number of packages that are, or at
+least were at one time, fundamental to the distribution.
+
+But, not surprisingly, my interests have shifted over time. In the more than
+quarter century I've contributed to Debian, I've adopted existing packages
+that needed attention, packaged new software I wanted to use that wasn't yet
+in Debian, offered packages up for others to adopt, and even sometimes
+requested the removal of packages that became obsolete or replaced by
+something better. That all felt completely healthy.
+
+But over the last couple weeks, I realized I'm still "responsible" for some
+packages I'd had for a very long time, that generally work well but over time
+have accumulated bugs in functionality I just don't use, and frankly haven't
+been able to find the motivation to chase down. As one example, I just
+noticed that I first uploaded the gzip package 25 years ago today, on
+2 December 1995. And while the package works fine for me and most other
+folks, there are 30 outstanding bugs and 3 forwarded bugs that I just can't
+muster up any energy to address.
+
+So, I just added gzip to a short list of packages I've offered up for
+adoption recently. I'm pleased that tar already has a new maintainer, and
+hope that both sudo and gzip will get more attention soon.
+
+It's not that I'm less interested in Debian. I've just been busy recently
+packaging up more software I use or want to use in designing high
+power model
+rockets and the solid propellant motors I fly in them, and would rather spend
+the time I have available for Debian maintaining those packages and all their
+various build dependencies than continuing to be responsible for core
+packages in the distribution that "work fine for me" but could use attention.
+
+I'm writing about this partly to mark the passing of more than a quarter
+century as a package maintainer for Debian, partly to encourage other Debian
+package maintainers with the right skills and motivation to consider adopting
+some of the packages I'm giving up, and finally to encourage other long-time
+participants in Debian to spend a little time evaluating their own package
+lists in a similar way.
+
Bdale Garbee, KB0G
==================
-Welcome to my "new" personal home page.
-
After retiring at the end of August, 2012, from my long-held position as
[HP](http://hp.com) Open Source & Linux Chief Technologist... I worked
part-time for [Samsung](http://samsung.com) as Senior Adviser to the Open
Source Group that is part of Samsung Research America. In September of 2014,
I was recruited back to HPE and served for 25 months as an
-[HPE Fellow](http://h20195.www2.hp.com/v2/GetDocument.aspx?docname=c04839247)
+[HPE Fellow](http://www.hp.com/united-states/Bdale-Garbee-External-Bio-V2.pdf)
in Martin Fink's Office of the CTO at what became
[Hewlett Packard Enterprise](http://hpe.com), driving open source
strategy and advocacy for the company. At the end of September 2016, I
returned to early retirement... and am now enjoying "Retirement v2.0".
-I serve on the boards of [Aleph Objects](http://alephobjects.com).
-the [FreedomBox Foundation](http://freedomboxfoundation.org), and the
-[Linux Professional Institute](http://lpi.org). I'm also a member of the
-[Evaluation Committee](https://sfconservancy.org/about/eval-committee/)
-for the [Software Freedom Conservancy](https://sfconservancy.org).
+I currently serve on the boards of
+the [Software Freedom Conservancy](https://sfconservancy.org),
+[Tripoli Colorado](http://tripolicolorado.org),
+and [Amateur Radio Digital Communications](http://ampr.org), where I am
+also President.
+
+I served for a while on the board of the
+[Freedombox Foundation](http://freedomboxfoundation.org)
+and made significant technical contributions early in the project history.
+
+I served for a while on the board of the
+[Linux Professional Institute](http://lpi.org) helping it recover from
+some organizational trauma and transform to a membership-based entity.
I served for a decade as President of
[Software in the Public Interest](http://spi-inc.org), and as a member of
the board of directors for some time before that.
I also served for several years on the board of the
-[Linux Foundation](http://linuxfoundation.org).
+[Linux Foundation](http://linuxfoundation.org)
+representing the interests of developers and individuals.
I remain actively involved in the [Debian](http://debian.org) project,
where I served for a year as the elected Debian Project Leader, and for nearly
My "spare nanoseconds" are mostly consumed playing with
[rockets](http://gag.com/rockets), which includes managing
[Altus Metrum, LLC](http://altusmetrum.org) with business partner
-[Keith Packard](http://keithp.org).
+[Keith Packard](http://keithp.org). I hold a "Level 3 certification" and am
+a member of both the [National Association of Rocketry](http://nar.org)
+and the [Tripoli Rocketry Association](http://tripoli.org). My personal
+confirmed flight altitude record is 36,555 feet above ground, my highest
+recorded acceleration is 86 g, the heaviest project I ever built weighed 168
+pounds on the launch rail, and I've flown a rocket I designed and built
+that reached Mach 3.21. I served on the committee that defined the
+[Tripoli Mentoring Program](http://www.tripoli.org/TMP), and am
+immensely proud that my son aced the test to become one of the earliest TMP
+participants.
I miss the early days of the web, when it was mostly informative text...
but if you're really curious, there are some pictures of me on my
in high-end computer equipment. There are only a few carbohydrates I've met in
my life that I didn't like, I have very eclectic tastes in music, enjoy old
movies, and I have this "German metal habit"... Porsche flavored. My
-current such toy is a 1984 Porsche 928S Euro, moss green metallic
-with beige interior and a dog-leg 5-speed.
+current such toys include a 1984 Porsche 928S Euro, moss green metallic
+with beige interior, a dog-leg 5-speed, and a fairly loud custom exhaust
+system based on [Magnaflow](https://www.magnaflow.com) components. I also
+have a base-model 1987 Porsche 944 with the hard-to find "sunroof delete"
+option like the 928. And my current track-day car is a bit of a mongrel...
+it started life as a 1987 Porsche 944 Turbo, but now has a Chevy LS V8
+engine, a Ford Hydroboost brake system, a transaxle from a 1989 944 Turbo S,
+and many suspension upgrades. Looks like a Porsche, sounds like something
+completely different, and is a hoot on track wearing Hoosier R7 tires!
Over the years, I've spent a lot of my "spare time" on various facets of
[Amateur Radio](rf/). KB0G is my current callsign, previously I was N3EUA
and before that I was KA3ORU. I'm a life member of
-[AMSAT](http://amsat.org/),
+[AMSAT](http://amsat.org/) and of the [ARRL](http://www.arrl.org),
President of [CODE](http://gag.com/code/),
a former Vice-President of [TAPR](http://tapr.org/),
a past Chairman and member of the Technical Committee of
the
[Pikes Peak FM Association](http://www.ppfma.org), past board member
of the [Pikes Peak Radio Amateur Association](http://ppraa.org),
-and a member of the
-[ARRL](http://www.arrl.org).
+and a member of the [QCWA](https://qcwa.org).
Perhaps my best-known early contribution to the hobby was the silly little
mail program I wrote for KA9Q's NOS networking software, called
[BM](ftp://ftp.ucsd.edu/hamradio/packet/tcpip/mailers),
communication with the other experiment modules that RUDAK talks to over the
CAN bus... SCOPE, MONITOR, CEDEX, and the thermistor SmartNode boards. More
recently, I led the design and delivery of the IHU design for the AMSAT-NA
-[Fox](http://ww2.amsat.org/?page_id=1113) cubesat program.
+[Fox](http://ww2.amsat.org/?page_id=1113) cubesat program, and one of my
+boards has been "in the stack" on every recent AMSAT-NA satellite.
If you want to find me "on the air" for a QSO, about the only chance
right now is to catch us
Not sure how to pronounce "Linux"? Why not let Linus himself
[tell you](ftp://ftp.kernel.org/pub/linux/kernel/SillySounds/english.au)...
-In recent years, my son and I have become very active building and flying
-small and large model [rockets](http://gag.com/rockets). I hold a
-"Level 3 certification", and am a federally-licensed user of
-low explosives, which means I'm authorized to buy, store, and fly the largest
-motors currently available in the rocket hobby. My personal confirmed
-flight altitude record is 21,654 feet above ground, my highest recorded
-acceleration is 86 g, and I've flown a rocket to beyond Mach 2.2. I served
-on the committee that defined the [Tripoli Mentoring Program](http://www.tripoli.org/Certifications/TripoliMentoringProgram/tabid/322/Default.aspx), and am
-proud that my son aced the test to become one of the earliest TMP
-participants. My current focus combines rocketry with my electronics
-background and strong interest in radio, see the
-[Altus Metrum](http://altusmetrum.org)
-community web site for more details...
-
* [Bdale's blog](blog)
* [Bdale's biographical information](bio)
* [Garbee Gallery](http://gallery.gag.com)
* [Cabell Garbee](http://www.garbee.net/~cabell), Bdale's brother, restores
neat old vehicles as a hobby.
-* [Allen B. Loyd](href="http://sites.google.com/site/allenloyd/Home),
- one of Bdale's first cousins, has a site documenting his theatrical set
- designs, paintings, and other fun stuff.
-* [Space Machine & Engineering Corp](http://space-machine.com),
- operated by another of Bdale's first cousins. It's kind of cool
- having a waveguide company in the family!
* [Graves Mountain Lodge](http://www.gravesmountain.com),
owned and operated by "my extended family" in Virginia. We used to
visit often... and still get back once in a while!
[Wikipedia page](http://en.wikipedia.org/wiki/Alfred_D._Barksdale)!
* A [photo](http://digitalcollections.vmi.edu/cdm/singleitem/collection/p15821coll7/id/2862/rec/1) of him
from 1919, in uniform.
-* He was a [Judge of the United States Court](http://air.fjc.gov/servlet/uGetInfo?jid=97)
* Many of his papers were gifted to the
[University of Virginia Library](http://ead.lib.virginia.edu/vivaead/published/uva-sc/vivadoc.pl?file=viu00129.xml)
* There are scholarships in his name at
- [VMI](http://www.vmi.edu/media/content-assets/documents/human-resources/Faculty-Handbook.pdf) and
+ [VMI](http://www.vmi.edu) and
[Hollins](http://www.hollins.edu).
[Eugene Hoy Barksdale](http://www.barksdale.af.mil/library/factsheets/factsheet.asp?id=4409)
was my third cousin twice removed. I had the chance to visit the base museum
in the fall of 2016, and I must say I'm proud of his accomplishments!
-<
+
Encrypting email is good. My currently preferred public key is
<pre>
-pub 4096R/C095D941 2009-07-26
- Key fingerprint = 8470 F20B 0625 9218 7CBA 7BB3 3A93 6196 C095 D941
-uid Bdale Garbee <bdale@gag.com>
-uid Bdale Garbee <bdale@hp.com>
-uid Bdale Garbee <bdale@debian.org>
-sub 4096R/166755FB 2009-07-26
+pub rsa4096 2019-10-21 [SC]
+ 1E0B AAD8 5C22 32A1 B3CE 92EB B704 7105 830B 9FA1
+uid [ unknown] Bdale Garbee <bdale@debian.org>
+uid [ unknown] Bdale Garbee <bdale@gag.com>
+sub rsa4096 2019-10-21 [E]
</pre>
You should be able to fetch that key from any of the major keyservers.
On Life
-------
+<p>
+"The American story is, really, just enough of us did just enough of the
+right thing at the right moment to push us forward."
+<br> -- Jon Meacham</p>
+
+<p>
+"In a very real sense, we are all aliens on a strange planet. We
+spend most of our lives reaching out and trying to communicate. If
+during our whole lifetime, we could reach out and really communicate
+with just two people, we are indeed very fortunate."
+<br> -- Gene Roddenberry</p>
+
+<p>
+"Bob Dylan is Bob Dylan not because he hits all the right notes...
+ but because he hits all the right emotions."
+<br>-- Will I Am</p>
+
<p>
"Taste your words before you spit them out."
<br>-- Andy Card</p>
sitting in a lecture, or even by simply doing problems that are assigned."
<br>-- Richard Feynman, in his preface to the printed Lectures on Physics
+<p>
+"If every trace of any single religion were wiped out and nothing were passed
+on, it would never be created exactly that way again. There might be some
+other nonsense in its place, but not that exact nonsense. If all of science
+were wiped out, it would still be true and someone would find a way to figure
+it all out again."
+<br>-- Penn Jillette
+
<p>
"For every vision, there is an equal and opposite revision."
<br>-- "Thal's Law", which I first heard quoted by Lyle Johnson
"Fools live to regret their words, wise men to regret their silence."
<br>-- Will Henry
+<p>
+"Have more than you show, speak less than you know."
+<br>-- William Shakespeare
+
<p>
"Kids are more nimble than wise..."
<br>-- Nancy Gibbs, in a Time opinion piece
is traded for a worthy price."
<br>-- Orson Scott Card, a realization by an older Columbus in Pastwatch</p>
+<p>
+"Enduring pain to do something good for someone you care about, isn't that
+what life is?"
+<br>-- Dr Eric Foreman, a character on the TV series House
+
<p>
"Some films are slices of life, mine are slices of cake."
<br>-- Alfred Hitchcock</p>
sacred and virtue safe."
<br>-- John Walter Wayland</p>
+<p>
+"A lady is never unintentionally rude."
+<br>-- Mrs Walter Russell Winfree
+
<p>
"If ever a World Government should come into existence, it had better be a
government designed to be run by crooks rather than a government designed to
--- /dev/null
+[[!map pages="bdale/talks/2020/* and ! bdale/talks/2020/*/*"]]
* [FreeCAD](http://www.freecadweb.org/) design file for
[guitar body](guitarbody.fcstd)
-* [STL output](guitarbody.stl) from FreeCAD for guitar body
More to come!
--- /dev/null
+[[!map pages="pcb/* and ! pcb/*/*"]]
--- /dev/null
+[[!map pages="pcb/csm84/* and ! pcb/csm84/*/*"]]
--- /dev/null
+# Surface Mount Robot
+
+For a long time, we've hand-loaded prototypes and then sent production board
+runs out to one of several 3rd-party surface mount assembly shops. We've
+tired of dealing with these assemblers, however, would like more control
+over the process, and are intrigued by the [OpenPnP](https://openpnp.org)
+project.
+
+After playing around for a while with building a machine from scratch, Bdale
+was offered a surplus Philips (Yamaha) CSM84 pick and place robot. This is
+a massive thing to make room for in a home shop, but as designed it's meant
+to be able to hold 84 reel feeders with 8mm width reels, has a conveyer belt
+for loading and unloading assembly panels, 3 placement heads, and very good
+fundamental mechanical accuracy and repeatability. Unfortunately, the machine
+controller is 1980's era technology, and the machine isn't really capable of
+handling 0402 parts as-is. The goal, therefore, is to convert the machine
+over to using a modern control and vision system running OpenPnP, capable of
+loading [Altus Metrum](https://altusmetrum.org) and other products that make
+heavy use of 0402 passive components, and fine-pitch integrated circuits.
+
+## Challenges
+
+* The existing control computer will be replaced with a PC-compatible system
+ running [Debian GNU/Linux](https://debian.org) and
+ [OpenPnP](https://openpnp.org).
+
+* It appears that the stock board for doing things like sensing axis limits,
+ operating pneumatic actuators, etc, is actually attached to the control
+ computer using SCSI-1, and is based on an Intel 8031 with external EPROM.
+ Bdale hopes to reverse-engineer the protocol in use over this bus and use
+ a simple SCSI-1 interface on the control computer to interface with this
+ working board, so that it doesn't need to be replaced. This would also
+ allow us to leave almost all of the system wiring harness, all of which
+ is working, in place.
+
+* The existing analog servo amplifiers are fairly tightly coupled to the
+ control computer's electronics. Since the CSM84 came with some DC servo
+ control modules that take step and direction inputs and thus look can make
+ the axis servos look like stepper motors to the rest of the system, we're
+ going to try using a Smoothieboard and these modules to run the axis servos
+ using the existing power supplies.
+
+* The axis limit sensors currently feed into the main system I/O board, but
+ we'd like the Smoothieboard to be able to read them. This may require a
+ custom interface to extract those signals and feed them to the Smoothieboard
+ at appropriate interface voltages.
+
+* The existing vision system will be completely replaced by USB camera modules
+ attached to the new control computer.
+
+* The head-mounted vacuum sensor board will be replaced with something better
+ suited to OpenPnP's needs.
+
+* The reel feeders provided with the machine advance 8mm tapes by 4mm per
+ step, which is correct for parts that are of 0603 geometry and larger.
+ To feed 0402 parts, we either need to modify these feeders for a 2mm
+ advance, replace them with feeders that do 2mm advance per step, or just
+ throw away every other part on our 0402 reels.
+
+## Sub-Projects
+
+* The stock machine has a nozzle vacuum sensing board that uses an analog
+ amplifier and comparators to output 3 states per nozzle as a 2-bit digital
+ signal. OpenPnP would rather have simple analog vacuum sensors on each
+ nozzle, readable by one of the system's control interfaces, then implement
+ the thresholds in software. That that end, Bdale designed a [replacement
+ vacuum board](https://git.gag.com/?p=hw/csm84vacuum;a=summary) that uses
+ 3 NXP 4115 series analog output vacuum sensors, intended to be attached to
+ three of the "thermistor" inputs on the Smoothieboard that also provides
+ axis servo control.
+
--- /dev/null
+# PCB Assembly Line
+
+In support of [Altus Metrum](https://altusmetrum.org), Garbee and Garbee runs
+an in-house printed circuit board surface-mount assembly line.
+
+## Machines
+
+* [laser engraver](laser/)
+* [paste station](paste/)
+* [CSM84](csm84/)
+* [reflow oven](oven/)
+
--- /dev/null
+[[!map pages="pcb/laser/* and ! pcb/laser/*/*"]]
--- /dev/null
+# Laser Engraver
+
+Most of the printed circuit boards we load need to have a serial number
+associated with them. After trying stickers, and spending years using a
+fine-tip Sharpie pen to write on a silk screen rectangle, we've decided to
+try a laser engraver instead.
+
+Digging around on the web, we found an article on
+[laser marking circuit boards](https://jtechphotonics.com/?p=1164)
+that made it clear this was something we should be able to do with a 1W
+laser module. Since Bdale had a spare [Lulzbot](http://lulzbot.com) TAZ 5
+printer sitting around unused, and the J Tech folks had a pointer to a 3d
+printable mounting bracket that can replace a TAZ head, we decided to give
+one of their [1W 405nm](https://jtechphotonics.com/?product=900mw-405nm-laser-and-2-5amp-safety-compliant-driver-kit)
+ packages a try. A big motivator for going with this
+laser module instead of one of the higher power units (which might have had
+other uses) was that this module can focus down to 0.003 inch spot size!
+Since some of our circuit boards are quite small and we're way up in the
+4 digits now, being able to engrave thin lines seemed like a good plan.
+
+More details to come...
--- /dev/null
+[[!map pages="pcb/oven/* and ! pcb/oven/*/*"]]
--- /dev/null
+# Reflow Oven
+
+After placing surface-mount parts on boards either by hand or using the
+[CSM84](../csm84/), the next step is to melt all the solder paste in a
+reflow oven causing all the joints to be soldered simultaneously.
+
+Our current oven is a T-962A IR oven modified with open source firmware
+and a number of hardware upgrades. While it's been fine so far, on the
+advice of friends with more experience doing this, we're currently gathering
+the parts to build a better reflow oven, and will document it here as we
+proceed.
--- /dev/null
+[[!map pages="pcb/paste/* and ! pcb/paste/*/*"]]
--- /dev/null
+# Paste Station
+
+After [laser engraving](../laser/) serial numbers on each board image in an
+assembly panel, the next step in our process is to apply solder paste to all
+of the pads on each board that we intend to populate with surface mount
+components.
+
+Initially, this was done "by hand" using a frameless stencil on a desktop
+with bits of scrap PCB to form a frame and bits of masking tape to hold
+things in place. However, we've got a clever idea about how to do this
+better without investing in an expensive solder-paste stenciling machine.
+
+More details to come...
--- /dev/null
+[[!map pages="rockets/airframes/AltusARCAS/* and ! rockets/airframes/AltusARCAS/*/*"]]
--- /dev/null
+# Altus ARCAS
+
+## Motivation
+
+This airframe started as an on-sale 4.5" HV ARCAS kit with 98mm motor mount
+from [Composite Warehouse](https://compositewarehouse.com/).
+
+## Design Details
+
+As the prototype ARCAS included a boat tail but the kit did not, I decided
+to modify the kit. I added a a fabricated-in-place epoxy tailcone about 3
+inches long, which shifted the fins aft by that amount. This in effect gave
+me another 3" of length to play with in the fin can part of the airframe, which
+meant a CTI Pro98 6xl case would fit very nicely.
+
+I also did a thing I'm growing to like where the "electronics bay" is just a
+stepped bulkhead with stuff hanging behind it, which also serves as the forward
+end of motor retention using all-thread into the forward closure and a lifting
+eye ahead of the electronics. This allows for hard attachment of the forward
+airframe tube in flight, with dual deploy from a single airframe break at the
+back of the nose cone
+
+The plan was to complete the project in time to fly at Airfest 2022 when my
+son would be in attendance. A CTI N3301 White motor which was in stock at
+Chris' Rocket Supplies was purchased for the flight, and a high altitude
+flight request was filed with and approved by the Kloudbusters. The motor
+was delivered to us on the flight line during setup on Thursday evening in
+the Rocket Pasture (to avoid hazmat shipping charges).
+
+Sadly, a glue-bonding disaster occurred that night in our hotel room, as the
+Gorilla Glue recommended for use in glue-bonding the grains in the liner
+"kicked off" before we could get the last grain in the liner, leaving us with
+an utterly un-flyable mess!
+
+To avoid just tossing the motor, my big plan then became to use my huge 1930's
+era metal lathe to cut the liner off the grains, cleaning them up to be glued
+in to a replacement liner. Thanks to help from Chris, we managed to procure
+an exact replacement liner assembly from CTI.
+
+I hoped to get the motor rebuilt in time to fly on the Argonia Cup weekend in
+2023, and the Kloudbusters re-approved my high altitude flight
+request. Unfortunately, my father passed away in March before the motor work
+could be done, throwing that plan out the window.
+
+Fortunately, I was able to make time to extract the grains from the original
+liner over the summer of 2023. The only problem is that at one point, the
+cutting tool on the lathe got loose in the holder and jambed into the end
+of one grain, forcing me to trim that grain to get a non-damaged end. I lost
+about 303 grams of propellant in the processing, leaving 98.1% of the original
+propellant mass. With a third high-altitude flight approval in hand from the
+Kloudbusters, my business partner Keith and I managed to get the grains
+bonded in to the replacement liner before leaving for Airfest 2023, and the
+rest of the motor assembly went smoothly.
+
+The recovery system plan was a 2' Giant Leap TAC drogue to be released at
+apogee by blowing the nose with 2 2-56 nylon shear pins off using 2.5g primary
+and 3.0g backup 4F BP charges in CPVC charge cannons, then releasing the main
+in a deployment bag witn a Tender Descender slightly modified to fit two of
+the Chinese e-matches I prefer so both flight computers on board could have
+a chance of getting the laundry out.
+
+The OpenRocket design file is
+[ARCAS_ala_Bdale.ork](/rockets/airframes/AltusARCAS/ARCAS_ala_Bdale.ork),
+and that design file plus all content on this page are released under the
+[Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/legalcode) license.
+
+### Electronics ###
+
+One each TeleMega v3.0 (primary) and TeleMetrum v2.0 (backup).
+
+## Build
+
+## Photos
+
+## Result and Lessons Learned
+
+The airframe was 49 lb 13 oz on the rail, and flew on Saturday of Airfest
+weekend, reaching Mach 2.2+ on the way to 36555 feet above ground! This was
+a new personal best for Bdale.
+
+Recovery went well, except that the main parachute was clearly under-sized.
+The ground hit appears to have been at about 47.5 ft/sec. One fin popped
+loose as a result of the hard hit on landing, and later inspection revealed
+that the fin can airframe tube "banana'd"! There is a clearly pronounced
+bend in the tube starting a bit aft of the front of the motor case. Since
+the motor mount is fairly short and it's a 98mm case inside a 4.5" inside
+diameter tube, it sure looks like the tube really was bent on landing. It
+could not have bent during ascent, and the hard hit plus long moment arm
+plus very high temperatures on the day and from Mach 2+ flight must have
+contributed to soften the tube enough to let it bend!?! None of us have
+ever seen anything quite like it!
+
+I'm still satisfied in considering the first flight of the airframe a success
+since my mission objectives of a new personal best altitude and proper
+operation of the recovery deployment were achieved. However, the fact that I
+clearly will need to rebuild/replace the fin can before I can fly again (on
+a larger main parachute next time!) is annoying.
+
only considered safe to launch from Terry Lee's launch trailer with 20 feet
of very stiff 1515 rail.
+### Revisions for Version 2 ###
+
+Because the main airframe zippered somewhat on the first flight, and the
+ARRD released at apogee, rather than just repairing the existing airframe
+tube, I designed and built a complete replacement.
+
+To increase stability, the main airframe tube length was extended from
+the original 4.5 feet to approximately 6 feet. This increased stability
+allowing a reduction in nose weight, increasing safety. It means the
+length is more than a strict scaling of the Lil Nuke, but is less than
+the Nuke Pro Maxx.
+
+For main deployment, the ARRD was replaced with a
+[Tender Descender L3](https://tinderrocketry.com/l13-tender-descender-tether),
+which has the advantage that the release mechanism is orthogonal to the
+axis of flight. That seems important when the airframe is this heavy and
+apogee occurs at a non-nominal velocity, as in the first flight.
+
+The original build had internal 1x2 ribs and a baffle yielding a "D" shaped
+main bay with the apogee charge gasses going up the channel without pushing
+on the main deployment bag. For this rebuild, 3 ribs were run the airframe
+length between the 12" airframe and a concentric full-length 8" deployment
+bay, with centering rings on each end. One sector of the rings was
+vented to allow apogee ejection gasses to flow from the charge cups on the
+leading edge of the fin can to the nose, bypassing the main chute bay.
+
## Design / Simulation File
-[mehganuke.ork](/rockets/airframes/MehGaNuke/mehganuke.ork)
+ * Original [mehganuke.ork](/rockets/airframes/MehGaNuke/mehganuke.ork)
+ * Revised [mehganuke-v2.ork](/rockets/airframes/MehGaNuke/mehganuke-v2.ork)
## Construction Log
## Flight Log
+### First Flight
+
The first flight of this airframe was at the
[Kloudbusters](http://kloudbusters.org/)
[Airfest 24](http://kloudbusters.org/airfest/) in Argonia, Kansas, USA,
All in all, this first flight was an outstanding group effort, a lovely
flight, and a huge crowd-pleaser!
+### Second Flight
+
+In 2021, the NAR National Sport Launch was held near Alamosa, CO. Doug
+Gerrard planned to be there with his camera-laden launch pad so there was
+the possibility of a highly-documented launch. Since I
+really wanted to fly this project in Colorado and that was a national-scale
+event, plans were made. As a NAR sanctioned event, the motor needed to be
+commercial and not research. Simulations led to the choice of a CTI N3301
+White Thunder which would fit case hardware already on hand. This would
+require fabricating an adapter from the 6" motor mount to the 98mm
+motor, but that seemed easy enough. My thanks to the good folks at
+[Moto-Joe Rocketry](http://moto-joe.com/) for helping me obtain the reload.
+
+Unfortunately, logistics issues prevented flying at the NSL. The second
+flight ended up happening on Sunday, 19 September 2021, at the
+[Tripoli Colorado](https://www.tripolicolorado.org/) Fall Frenzy launch.
+
+In addition to the rebuilt main airframe section and motor adapter, a
+TeleGPS was added to the nose bay. Then, at the last minute, Meh-ga Nuke
+was equipped with two keychain cameras mounted looking up and down.
+
+The rocket was about 145 pounds on the rail of Terry Lee's launch trailer,
+and was flowing with 2 e-matches and a pinch of Pyrodex P in the Tender
+Descender, and apogee charges of 6g primary and "fill the cup"
+secondary. The rocket departed the rail with about 5.5g max acceleration
+on the way to Mach 0.7 and an apogee altitude of 9183 feet. The dual
+deployment process worked as designed, but unfortunately the shround on
+the main tangled, probably due to a hasty repacking of the deployment bag
+during assembly on the rail. Wind pushed the airframe ENE out of the
+optimal landing area and into a "field of rocks", where the higher than
+expected landing velocity of the main airframe and fin can assembly and
+wind drag resulted in cosmetic damage to the fin can and more significant
+damage to the main airframe tube. The nose cone also suffered damage as
+a result of the wind causing the chutes to pull it across rocks.
+
+Both TeleMega boards returned good data logs. The TeleGPS in the nose
+cone wasn't heard during launch and flight (it turns out the unsupported
+antenna wire broke off sometime before landing, perhaps even before
+launch?), but the data recovered from the board shows a clean trace of
+the nose cone's path during flight. Good thing we didn't need the
+GPS to locate and recover the nose cone!
+
+The video from the up-looking camera worked great through apogee, but
+unfortunately the video froze before the main deployed so only audio was
+recorded for the rest of the flight. The down-looking camera video came
+out very well, though! It shows only a couple rotations of the airframe
+during ascent with some great view of the flight line, etc. It also
+captured the nose cone and two 5 foot surplus military parachutes deployed
+at apogee travelling past the main airframe rapidly at apogee. The
+shadow of the nose cone and associated chutes descending independently can
+be seen in the video before landing... and the very violent landing of
+the fin can and main airframe can be clearly seen.
+
+All in all, this second flight was another huge crowd-pleaser and very
+satisfying overall. Particular thanks to Terry Lee for his help
+rebuilding the main airframe and the use of his launch trailer, George
+Barnes IV for his outstanding photos on launch day, and my wife Karen who
+attended the launch with great enthusiasm despite being only a few weeks
+into the recovery from major surgery.
+
+I think the primary lesson learned from this flight is that the design
+of the airframe pretty much guarantees the main airframe tube is going
+to be damaged in each flight. The video proof of what we already
+understood intellectually about the dramatic reversal of direction the
+airframe
+undergoes at apogee when the nose comes off and the drogue chutes deploy
+alone is enough to rip the leading edge of the airframe apart back to the
+first centering ring below the nose shoulder. So, even without landing
+in rocks and being dragged due to high winds by the main chute, we
+probably just need to acknowledge the main airframe is in some ways a
+"single use" design.
+
--- /dev/null
+[[!map pages="rockets/airframes/V2-8/* and ! rockets/airframes/V2-8/*/*"]]
--- /dev/null
+# 8" V-2
+
+## Motivation
+
+The [V-2](https://en.wikipedia.org/wiki/V-2_rocket) has a significant place
+in the history of rockets, and Bdale always thought it would be cool to build
+and fly a model of one. After learning how to make APCP research motors and
+experimenting with a variant of Everclear (which has visible flame
+characteristics reminiscent of the LOX and ethanol fuel used in the original
+V-2) the idea became even more appealing.
+
+And then, [Composite Warehouse](http://compositewarehouse.com/) put their
+[8 inch V-2 kit](https://www.compositewarehouse.com/index.php?route=product/product&path=18_70&product_id=158)
+on sale during their Black Friday sale in 2020... and it was just impossible
+to resist buying one!
+
+## Design Details
+
+This 8-inch diameter kit is all filament-wound fiberglass, with an
+aluminum-tipped nose cone and 98mm motor mount. A short coupler section is
+provided to attach the pre-slotted tail transition section to the main
+airframe tube, and a longer coupler section is provided to double as the
+nose cone attachment and electronics bay. Beautiful, thick, stepped glass
+bulk plates with central 1/4-inch holes were included to enclose this bay.
+
+When the kit finally arrived in mid February 2021, the parts all seemed to be
+of outstanding quality, and the coupler sections in particular showed up in
+thick-wall glass that seems really robust. An hour or so of fun involving
+a bathtub, a couple shop towels, warm water, and dish soap cleaned everything
+up and eliminated the residual fiberglass dust on all the parts in the kit.
+
+Further examination showed that there was one minor problem. The aft
+centering ring's inside diameter was fine, but the outside diameter was
+smaller than the opening at the aft end of the fin section. It wasn't a
+grossly un-usable part, and the gap could have been addressed by using some
+small balsa shims to center the ring in the opening and sufficient epoxy with
+fiber filler to close the gap. But, since a CNC router was available, the
+decision to fabricate a custom replacement aft ring with precisely positioned
+mounting holes for an
+[Aeropack 98mm retainer](https://aeropack.net/motorretainers.asp)
+was easy to make. The ring was cut from 1/2-inch birch plywood, stepped with
+about a 1/8" lip to the outside diameter of the glass, and 12 holes the
+correct size to directly tap for a #8 screw thread. The point of the lip
+was to make assembly easy. With the machined lip, the ring could be epoxied
+in place by itself but still assuring axial alignment. The part was designed
+in [FreeCAD](https://www.freecadweb.org/) and cut on Bdale's
+[Probotix](https://www.probotix.com/) Comet CNC router.
+
+I originally anticipated this would be another "dual deploy from one
+airframe break" design, which to be honest I've had mixed results using. But
+once I saw how the longer coupler in the kit was intended to be assembled, I
+changed my mind. The kit came with a switch band for the coupler that is
+meant to be both ebay and nose coupler, and when I realized there's enough
+volume inside the nose cone to hold my choice of "laundry", a "traditional"
+dual deploy setup with two pyro initiated separation events became plan A.
+
+The airframe geometry should easily support a 4-grain 98mm motor, which can
+be a "full M", so this should be a fun airframe to make research motors for!
+
+## Design / Simulation File
+
+## Construction Log
+
+2020.11.22
+Kit ordered during Black Friday kit-buying spree.
+
+2021.02.17
+Kit arrived! Fun in the tub cleaning up all the kit parts. Dry fit various
+bits to get a feel for how it should all go together. Discovered aft
+centering ring OD too small, reported to kit seller not asking them to take
+any action since I want to make a custom replacement anyway.
+
+2021.02.19
+Built up an [OpenRocket](http://openrocket.info/) model of the airframe,
+except that using the latest released version, 15.03, it's not possible to
+model the fins correctly. The fundamental issue is that this version of
+OpenRocket doesn't support fins on transition sections. Several work-arounds
+were explored, but the net effect is that Bdale needs to package a fresher
+version of OpenRocket for [Debian](https://debian.org) despite the lack of
+a new upstream release, since it appears this deficiency got addressed sometime
+since the 15.03 release.
+
+2021.02.21
+Designed and machined replacement aft ring, located the unused 98mm Aeropack
+retainer already on hand.
+
+2021.02.23
+Installed aft ring with 5-minute epoxy.
+
+## Photos
+
+## Flight Log
+
### Others
+* [Altus ARCAS](./AltusARCAS)
+ 4.5" ARCAS with 98mm motor mount
+
+* [V2-8](./V2-8)
+ 8-inch V-2
+
* [Meh-ga Nuke](./MehGaNuke)
12-inch diameter up-scale of the [LOC Lil Nuke](https://locprecision.com/product/lil-nuke/)
Building and launching model rockets is one of our favorite hobby activities
right now. While everyone in the family gets into the act in one way or
-another, Bdale
-and Robert are the most serious and so most Garbee rocket projects end up
-being father and son affairs...
+another, Bdale and Robert are the most serious and so most Garbee rocket
+projects ended up being father and son affairs before Robert went off to
+college.
[Bdale](http://www.gag.com/~bdale) is
[NAR](http://nar.org/) Sr member 87103 and
[Tripoli](http://tripoli.org/) member 12201, and holds a level 3
high power certification. Robert is [NAR](http://nar.org/) Sr member
87104 and [Tripoli](http://tripoli.org/) member 14036, and also holds a
-level 3 high power certification. Robdert was one of the first kids to
+level 3 high power certification. Robert was one of the first kids to
pass the [Tripoli Mentoring Program](http://www.tripoli.org/TMP)
exam, and flew a lot of high power including a fair number of research
motors in mentored projects before turning 18...
We have family memberships in (and regularly enjoy flying our
models with!) local clubs
[Tripoli Colorado](http://www.tripolicolorado.org/),
-[SCORE](http://scronline.net),
-and
+[SCORE](http://scronline.net) (which is now dual-homed and also
+known as Tripoli Southern Colorado!), and
[NCR](http://ncrocketry.org).
We have also flown with
[Metra](http://metrarocketclub.org/),
[NRVR](http://nrvr.org/),
[NZRA](http://www.nzrocketry.org.nz/),
+[Oregon Rocketry](http://oregonrocketry.com),
and
[QRS](https://qldrocketry.com/).
## Electronics ##
-Lots of people make electronics for use in hobby rockets. This is a brief
-list of only the things we've actually used ourselves.
-
-First off, Bdale and friends develop fully open hardware and software
-designs for rocketry avionics, under the name
-[Altus Metrum](http://altusmetrum.org).
-
-We also fly commercial altimeters in some projects. The cheapest off the
-shelf altimeter we've used and often recommend to beginners is the
-[Missile Works](http://www.missileworks.com/) RRC2-mini. At about $80, it
-gets the job done for simple barometric control of dual deployment. Note
-that while early versions had a firmware bug that we believe is at least
-partially responsible for Bdale's loss of his first L3 project, recent
-versions seem fine. For another $20, the
-[PerfectFlite](http://www.perfectflite.com/)
-[miniAlt/WD](http://www.perfectflite.com/catalog/MAWD.html)
-adds the ability to records the barometric flight altitude profile. Both
-of Bdale's L3 certs flew with one each of these two commercial altimeters,
-and we often use the MAWD as a backup for our
-[TeleMetrum](http://altusmetrum.org/TeleMetrum) units during test flights.
-
-The [BeeLine TX](http://www.bigredbee.com/BeeLine.htm) boards from Big Red
-Bee are radio tracking transmitters that just work. They require an
-[amateur radio](http://www.altusmetrum.org/Radio) license, but we think
-anyone flying big rockets can and should get one of those anyway!
+Bdale and friends develop fully open hardware and software designs for
+rocketry avionics, under the name [Altus Metrum](http://altusmetrum.org).
## Books ##
--- /dev/null
+# Test 2019-3 #
+
+Re-starting the process of characterizing "Everclear" now that we have a new
+1600psi pressure sensor on the test stand.
+
+This was a 2-grain 54mm Everclear motor using a #24 nozzle. Ignition was
+with one of Terry's igniters, on Saturday at the Tripoli Colorado Spring
+Fling event near Hartsel.
+
+The grains used were from the 21 May 2019 batch:
+
+* 21 May grain 4
+* 21 May grain 12
+
+Small profile o-rings were used between grains, leaving the grains still
+slightly "loose" in the case. The buna-n o-rings on the nozzle and forward
+closure were lightly greased, and the liner exterior was heavily greased.
+
+## Results ##
+
+Test stand data in 2019-05-25-serial-3634-flight-0029.eeprom.
--- /dev/null
+# Test 2019-4 #
+
+This was a 3-grain 54mm Everclear motor using a #24 nozzle. Ignition was
+with one of Terry's igniters, on Saturday at the Tripoli Colorado Spring
+Fling event near Hartsel.
+
+The grains used were from the 21 May 2019 batch:
+
+* 21 May grain 5
+* 21 May grain 14
+* 21 May grain 7
+
+Small profile o-rings were used between grains, leaving the grains still
+slightly "loose" in the case. The buna-n o-rings on the nozzle and forward
+closure were lightly greased, and the liner exterior was heavily greased.
+
+## Results ##
+
+Test stand data in 2019-05-25-serial-3634-flight-0030-4.eeprom.
+
+There was a fairly significant liner burn-through in the middle of the first
+grain near the nozzle, burned-looking area was dime-sized, with maybe 1/4"
+"hole" in the middle. Some extra ash on case there, but no obvious signs of
+weakening of the case. Not sure what that was caused by?
--- /dev/null
+# Test 2019-5 #
+
+This was my second flight with "Everclear".
+
+5 grain 54mm Everclear motor with #36 nozzle, using one 45-cal pyrodex
+pellet on an e-match for ignition. Flown at Tripolo Colorado Spring Fling
+2019 on Sunday morning.
+
+The grains used were from the 21 May 2019 batch:
+
+* 21 May grain 6
+* 21 May grain 3
+* 21 May grain 16
+* 21 May grain 8
+* 21 May grain 2
+
+Used abou 16.75" of ARR liner. Small profile o-rings were used between grains,
+leaving the grains still slightly "loose" in the case. The buna-n o-rings on
+the nozzle and forward closure were lightly greased, and the liner exterior
+was heavily greased.
+
+## Results ##
+
+PFND.
+
+Tiny bit of liner burn-through at the junction between grains 6 and 3 (one
+grain forward of the nozzle). The buna-n o-rings were pretty cooked on the
+nozzle end, but no evidence of blow-by.
+
+Forgot to get pre-flight masses. The post-flight mass of the airframe and
+motor was 4140g. That's complete except for maybe 3-5g in the ejection
+charges, and of course the propellant consumed.
+
+Flight data in 2019-05-26-serial-1257-flight-0018.eeprom shows 9170 ft GPS
+apogee.
--- /dev/null
+# Test 2019-6 #
+
+This was a 4-grain 54mm Everclear motor using a #32 nozzle. Ignition was
+with one 45-cal pyrodex pellet on an e-match, on Sunday at the Tripoli
+Colorado Spring Fling event near Hartsel.
+
+The grains used were from the 21 May 2019 batch:
+
+* 21 May grain 1
+* 21 May grain 5
+* 21 May grain 11
+* 21 May grain 10
+
+Small profile o-rings were used between grains, leaving the grains still
+slightly "loose" in the case. The buna-n o-rings on the nozzle and forward
+closure were lightly greased, and the liner exterior was heavily greased.
+
+## Results ##
+
+Test stand data in 2019-05-26-serial-3634-flight-0030-5.eeprom.
+
+About a 2.5 second burn. Sadly, we only got pressure and not load cell data,
+so no real characterization.
+
+No liner burn-through, no discernable throat erosion, nozzle end o-rings
+were fairly cooked but no evidence of blow-by.
--- /dev/null
+# Test 2019-7 #
+
+This was a 11-grain 54mm KNSB motor using a #? nozzle. Ignition was
+with one 45-cal pyrodex pellet on an e-match, on Friday at NCR North
+on Mile High Mayhem weekend.
+
+The grains used were from the ? batches:
+
+
+Small profile o-rings were used between grains, leaving the grains still
+slightly "loose" in the case. The buna-n o-rings on the nozzle and forward
+closure were lightly greased, and the liner exterior was heavily greased.
+
+## Results ##
+
+CATO.
# Batch 2019.01.07 #
-4 Terry-length Everyclear grains for 54mm cases, with 0.625 inch cores,
+4 Terry-length Everclear grains for 54mm cases, with 0.625 inch cores,
cast as two 6-inch-long double grains with 0.5" delrin coring rods, then
cut, cored, and trimmed as necessary.
--- /dev/null
+# Batch 2019.05.21 #
+
+A total of 16 Terry-length Everclear grains for 54mm cases, with 0.625 inch
+cores, cast as 2 batches of 4 6-inch-long double grains with 0.5" delrin
+coring rods, then cut, cored, and trimmed. Grains 1..8 cast by Bdale, grains
+9..16 cast by Jamie and Luke with Terry observing.
+
+The 54mm casting tube I'm using weighs 1.84g per inch.
+
+Third time mixing APCP propellant. Bdale again used the 4.5qt mixer, Jamie
+and Luke used Terry's mixer, all hand packed with no vacuum processing. Same
+formula as previously, but with quantities doubled.
+
+Most materials measured with Bdale's new 600g by 0.01g scale, R45 measured
+straight into mixing bowls using Terry's larger scale that goes by 1g.
+
+These grains were cast on 2019-05-21.
+
+## Results ##
+
+The batch size was pretty good, there was a bit of excess propellant in each
+batch so we can make density and burn rate measurements after cure. The excess
+weighed in at g after cure.
+
+Grains were cut, core drilled to 0.625", and sanded more or less ala Terry's
+process. In the data below, lengths are a bit approximate due to imperfectly
+squared ends, gross masses are precise using my new 600g by 0.01g scale!
+
+* Grain 1, 3.015" long, 163.98g gross, g casting tube, g net
+* Grain 2, 3.005" long, 161.27g gross, g casting tube, g net
+* Grain 3, 3.020" long, 163.80g gross, g casting tube, g net
+* Grain 4, 3.045" long, 164.84g gross, g casting tube, g net
+* Grain 5, 3.058" long, 166.03g gross, g casting tube, g net
+* Grain 6, 3.010" long, 164.85g gross, g casting tube, g net
+* Grain 7, 3.040" long, 164.70g gross, g casting tube, g net
+* Grain 8, 3.010" long, 162.85g gross, g casting tube, g net
+
+* Grain 9, 3.011" long, 164.15g gross, g casting tube, g net
+* Grain 10, 3.008" long, 164.44g gross, g casting tube, g net
+* Grain 11, 3.020" long, 165.51g gross, g casting tube, g net
+* Grain 12, 3.015" long, 164.38g gross, g casting tube, g net
+* Grain 13, 3.030" long, 166.97g gross, g casting tube, g net
+* Grain 14, 3.012" long, 162.41g gross, g casting tube, g net
+* Grain 15, 2.963" long, 160.36g gross, g casting tube, g net
+* Grain 16, 2.957" long, 158.61g gross, g casting tube, g net
+
+The mass per unit length was within ?g/inch.
+
--- /dev/null
+# Batch 2019.06.21 #
+
+A total of 12 3" KNSB grains for 54mm cases. These were cast in two batches
+that each consisted of a two 9" casting tubes, one each with 0.5 inch steel
+and 0.625 inch Delrin cores. One batch was pure KNSB, the other was my usual
+mixture with RIO and Polystep-B1 surfactant. Simple pour, insert coring rod,
+top off grain. No vacuum processing or vibration.
+
+The 54mm casting tube I'm using weighs 1.9g per inch.
+
+The purpose of casting these grains is to do test stand burns of identical
+motors in each of the two propellant variants, so I can tell how much the
+RIO is affecting ignitability and burn rate.
+
+These grains were cast on 2019-06-21.
+
+## Results ##
+
+Batch with RIO:
+
+* Grain 1, " long, 0.5" core, g gross, g casting tube, g net
+* Grain 2, " long, 0.5" core, g gross, g casting tube, g net
+* Grain 3, " long, 0.5" core, g gross, g casting tube, g net
+
+* Grain 4, " long, 0.625" core, g gross, g casting tube, g net
+* Grain 5, " long, 0.625" core, g gross, g casting tube, g net
+* Grain 6, " long, 0.625" core, g gross, g casting tube, g net
+
+Batch without RIO:
+
+* Grain 7, " long, 0.5" core, g gross, g casting tube, g net
+* Grain 8, " long, 0.5" core, g gross, g casting tube, g net
+* Grain 9, " long, 0.5" core, g gross, g casting tube, g net
+
+* Grain 10, " long, 0.625" core, g gross, g casting tube, g net
+* Grain 11, " long, 0.625" core, g gross, g casting tube, g net
+* Grain 12, " long, 0.625" core, g gross, g casting tube, g net
+
+The mass per unit length was within ?g/inch.
+
--- /dev/null
+# Batch 2019.11.23 #
+
+A solid slug of KNSB propellant cast in PML 75mm coupler tube, intended to be
+cut into 1" long grains to be used in James' ballistic test motor. For
+6 grains, thinking about saw kerfs and shrinkage, we'll try casting about a 7"
+length. That calculates to about 1321g.
+
+After trying with and without RIO last year, then losing the notes on which
+tests were which, I'm kind of starting over. For prior with-RIO motors, I
+used 1% RIO and about 1.5 drops per 100g of Polystep-B1 surfactant. At this
+motor size, I don't think the surfactant is useful, but I do think some RIO
+helped with igniteability. So this time, let's try running with less RIO
+and no surfactant. Like 0.25% RIO.
+
+Formula for a batch size of 1325g:
+
+* KNO3, 859.10g
+* Sorbitol, 462.59g
+* red iron oxide, 3.31g
+
+This formula is completely fluid with 225F indicated on the Presto Multicooker.
+
+## Results ##
+
+These grains were cast on 23 November 2019, in the wee hours.
+
+The actual measures of the batch (using shipping scale for primary ingredients
+and my 0.01g resolution scale for the RIO) were:
+
+* KNO3, 860g
+* Sorbitol, 462g
+* red iron oxide, 3.4g
+
--- /dev/null
+# Test 2020-1 #
+
+8 grain 75mm sorbitol motor with pyrodex pellet ignition in 4-inch Wildman
+re-rebuilt airframe flown on 7 September 2020 at Airfest in Argonia, KS.
+
+48" purple "Woody" case, Loki #58 (long) nozzle with 2 o-rings, customized
+forward bulkhead with 1600psi pressure sensor and EasyMotor prototype.
+
+The original model using Kuker's Motorsim said this should be a 43% M-2690
+with a slightly progressive burn about 2.5 seconds long, using 5355g of
+propellant or 73% volume loading, and a max pressure of 825 psi.
+
+After casting and weighing the grains, we ended up with a net propellant
+mass of 4924g. The grains seemed to have fairly uniform density.
+
+## Results ##
+
+Motor cato'd just off the rail on pad 61. Airframe and electronics a
+total loss.
+
--- /dev/null
+# Test 2020-2 #
+
+4 grain 54mm Everclear motor with pyrodex pellet ignition in 3-inch test
+mule flown on 10 October 2020 at October Fun Fly in Argonia, KS.
+
+Used 4-grain 54mm Brazell case, #32 (0.5" throat) Loki-style nozzle, forward
+closure had pressure sensor and EasyMotor protototype mounted. Three grains
+with 0.5" cores (I think!), nozzle end grain bored out to 0.75" core.
+
+Burnsim called this a 21% K-788, with about 1.97 sec burn time, and max
+pressure on a somewhat progressive burn of 923.6 psi.
+
+## Results ##
+
+Perfect flight, no damage. However, due to firmware issues, the EasyMotor
+failed to launch detect and so we got no motor data recorded on this flight.
--- /dev/null
+# Test 2020-3 #
+
+4 grain 54mm Purple Pig motor with Aerotech igniter in 3-inch test
+mule flown on 11 October 2020 at October Fun Fly in Argonia, KS.
+
+Used 4-grain 54mm Kosdon case, Loki-style nozzle with about an 0.390" throat,
+forward closure had pressure sensor and EasyMotor protototype mounted.
+Four grains with 0.625" cores.
+
+Burnsim called this a 72% J-493, with about 2.23 sec burn time, and max
+pressure on a relatively flat burn of 752.8 psi.
+
+## Results ##
+
+Perfect flight, no damage. However, due to firmware issues, the EasyMotor
+captured acceleration data but no pressure data.
--- /dev/null
+# Test 2020-4 #
+
+3 grain 54mm Purple Pig motor with a Terry Lee dipped igniter in 3-inch test
+mule flown on 17 October 2020 at the first-ever Tripoli Southern Colorado
+launch at Hudson Ranch. In fact, this was the first-ever research flight
+flown at this location!
+
+Used 3-grain 54mm Kosdon case, Loki-style nozzle with an 0.390" throat,
+forward closure had a 1600psi pressure sensor and EasyMotor protototype
+mounted with an A23 alkaline battery, and shooter wire as a "twist and tape"
+power switch.
+
+The motor used three loose grains with 0.625" cores, thin o-rings as spacers,
+and a greased phenolic liner.
+
+[Burnsim](2020-test-4-burnsim.pdf) called this a 31% J-355, 838 Ns with
+about 2.36 sec burn time, and max pressure on a relatively flat burn of
+559.3s psi.
+
+## Results ##
+
+Perfect flight, no damage, easy recovery.
+
+This was the first flight during which we successfully captured in-flight
+chamber pressure data with an EasyMotor prototype board. A quick look at
+the data shows about 540 psi maximum, which is pretty close to the Burnsim
+prediction! Some software work remains to convert the data capture into
+actual motor performance data. The EasyMotor data is logged in file
+2020-10-17-serial-7085-flight-0007.eeprom
+
+The airframe's launch mass was about 4420 grams. The TeleMega on board
+reported 9.54 G max and 6.29 G average acceleration to a max speed of
+Mach 0.5 and a GPS apogee of 4669 feet. The TeleMega data is logged in file
+2020-10-17-serial-6667-flight-0003.eeprom
+
--- /dev/null
+# Batch 2020.08.31 #
+
+8 grains of 75mm KNSB, intended to be a reload for my long purple case.
+with Loki-style #58 nozzle. Grain length 5.125" with 0.125" spacing per
+grain planned using o-rings. Delrin coring rods of 0.75" diameter since
+that's what I have bases and caps for, then bored out to 0.875" final ID
+before assembly.
+
+Kuker's Motorsim says this should be a 43% M-2690 with a slightly progressive
+burn about 2.5 seconds long, using 5355g of propellant or 73% volume loading,
+and a max pressure of 825 psi.
+
+Since this is too much propellant to handle in one batch, we'll plan to use
+two 2700g batches, the formula for each of which is:
+
+* 65% KNO3, 1755g
+* 35% Sorbitol, 945g
+* 1% red iron oxide, 27g, added after melt
+* 41 drops Polystep-B1, added before pour using eye dropper
+
+This formula is completely fluid with 225F indicated on the Presto Multicooker,
+but viscosity is noticeabley lower making for easier pouring at 250-275F.
+
+These grains were cast on 2020.08.31.
+
+## Results ##
+
+The 5.125" grains were poured to a 119mm fill line, and then an 0.75" Delrin
+coring rod was twisted down into the goo puncturing foil over the coring rod
+hole at the grain base. About 18 hours later, the grains were "topped off"
+and smoothed level to compensate for shrinkage. The coring rods were pulled
+about 48 hours after casting, and each grain was observed to have some bubbling
+around the base of the coring rod, presumed to be due to air below the foil on
+the casting base pushing up as the rod went down. We should arrange for
+explicit venting of that in the future. The top faces of the grains were knife
+scraped smooth, the cores were bored out to 0.875", and the bottom of each grain
+was chamfered around the core to eliminate the bubbly bits. Thus, the grain
+masses were highly likely to be less than anticipated.
+
+* Grain 1, 630g gross, 16.21g casting tube, 613.79g net
+* Grain 2, 634g gross, 16.20g casting tube, 617.80g net
+* Grain 3, 640g gross, 16.14g casting tube, 623.86g net
+* Grain 4, 632g gross, 16.17g casting tube, 615.83g net
+* Grain 5, 626g gross, 16.34g casting tube, 609.66g net
+* Grain 6, 628g gross, 16.11g casting tube, 611.89g net
+* Grain 7, 628g gross, 16.17g casting tube, 611.83g net
+* Grain 8, 636g gross, 16.28g casting tube, 619.72g net
+
+Average casting tube weight 16.2g. Measured total propellant mass of 4924g,
+or about 616g per grain, which is 92% of what Kuker's simulator projected.
+
+Borrowed Terry's Loke #58 nozzle, which is a few thousandths over-sized.
+
+The as-built motor is projected to be a 30% M-2300 or so.
--- /dev/null
+# Batch 2021.11.12 #
+
+5 grains of 75mm KNER, intended to be a reload for a Loki 76/6000 case.
+with Loki-style #36 short nozzle. Grains to be cast 5.25" long using Delrin
+coring rods of 0.75" diameter. Liner calculates to be 28 inches long. Will
+"glue" grains in liner using clear silicone and o-ring spacers.
+
+Nakka's SRM spreadsheet suggests this could be an 84% L968, with 3473g
+of propellant, a 4.88 second burn time, and max pressure of 655psi.
+
+Will mix a 3500g batch, the formula for which is:
+
+* 65% KNO3, 2275g
+* 35% Erythritol, 1225g
+
+I started by setting the multi-cooker to 300F indicated for this batch, but
+had to turn that up to 350F to get the entire batch melted, or the heating
+element would keep turning off. It still took a very long time to all melt.
+Once it did, I dialed back to 300F indicated. It's true that the ambient
+temperature was lower in the shop than on other days I've cast sugar.
+
+The 5.25" grains were poured to a 122mm fill line, and then an 0.75" Delrin
+coring rod was twisted down into the goo puncturing foil over the coring rod
+hole at the grain base. A casting cap was then placed over the top to hold
+the coring rod centered and protect the grain during cooling.
+
+The first four grains poured easily. There was enough propellant sticking
+high on the sides of the pot that I couldn't figure out how to break loose,
+though, that I paused and added 3 old 38mm KNER grains to the pot and waited
+for them to melt and get mixed in before casting the last grain. The last
+grain was also problematic in that the casting cap didn't want to go down
+over the casting tube, perhaps due to a bit of KNER splash already hardening
+on the outside of the tube?
+
+I noted that there were lots of small bubbles visible on the surface
+of the melt, all of which were popping easily at the time of the pour. I did
+the usual thing of twisting the coring rod as it went in and saw bubbles
+come to the grain surface, then tapped each grain on the table top after the
+cap was on to hopefully further settle the propellant. It's hard to imagine
+vacuuming KNER helping this, as the KN wants to settle to the bottom of the
+pot, requiring re-stirring to homogonize the mixture before pouring... which
+necessarily lets more air back in?
+
+## Results ##
+
+The grains came out very poorly, with lots of cracks and voids. My guess is
+that since the shop was colder than normal, and I could see massive amounts
+of propellant solidifying on the sides of the multi-cooker, that rapid and/or
+differential cooling as the propellant was being poured into cold casting
+tubes and cold Delrin coring rods were inserted was the root cause.
+
+The only credible choice is to set them aside to be re-melted in a future
+batch.
* [Richard Nakka's Site](http://www.nakka-rocketry.net/)
* [Scott Jolley's Site](http://ajolleyplace.com/scott.html)
-* [Scott Fintel's Site](http://www.thefintels.com/aer/rocketindex.htm) - defunct?
+* [Scott Fintel's Site via Wayback Machine](https://web.archive.org/web/20160727001518/http://www.thefintels.com:80/aer/rocketindex.htm)
* [James Yawn's Site](http://jamesyawn.net/index.htm)
+* [Loki Research Tech Info Page](https://lokiresearch.com/page/Tech_Info)
## Activity Log ##
+### 2021 ###
+
+* [2021 batch 01](2021.11.12.html) - 12 November 2021 - 5 75mm KNER grains
+
+### 2020 ###
+
+* [2020 batch 01](2020.08.31.html) - 31 August 2020 - 8 75mm KNSB grains
+* [2020 test 01](2020-test-1.html) - 7 September 2020 - 8-grain 75mm KNSB at Airfest
+* [2020 test 02](2020-test-2.html) - 10 October 2020 - 4-grain 54mm Everclear at Kloudbuster October Fun Fly
+* [2020 test 03](2020-test-3.html) - 11 October 2020 - 4-grain 54mm Purple Pig at Kloudbuster October Fun Fly
+* [2020 test 04](2020-test-4.html) - 17 October 2020 - 3-grain 54mm Purple Pig at Tripoli Southern Colorado's first-ever launch!
+
### 2019 ###
-* [2019 batch 01](2019.01.07.html) - 7 January 2018 - 4 54mm Everclear APCP grains
-* [2019 batch 02](2019.01.08.html) - 8 January 2018 - 4 54mm Everclear APCP grains
-* [2019 test 01](2019-test-1.html) - 28 April 2018 - 2-grain 54mm Everclear on test stand
+* [2019 batch 01](2019.01.07.html) - 7 January 2019 - 4 54mm Everclear APCP grains
+* [2019 batch 02](2019.01.08.html) - 8 January 2019 - 4 54mm Everclear APCP grains
+* [2019 test 01](2019-test-1.html) - 28 April 2019 - 2-grain 54mm Everclear on test stand
+* [2019 test 02](2019-test-2.html) - 4 May 2019 - first flight using Everclear
+* [2019 batch 03](2019.05.21.html) - 21 May 2019 - 16 54mm Everclear APCP grains
+* [2019 test 03](2019-test-3.html) - 25 May 2019 - 2-grain 54mm Everclear on test stand
+* [2019 test 04](2019-test-4.html) - 25 May 2019 - 3-grain 54mm Everclear on test stand
+* [2019 test 05](2019-test-5.html) - 26 May 2019 - second flight using Everclear
+* [2019 test 06](2019-test-6.html) - 26 May 2019 - 4-grain 54mm Everclear on test stand
+* [2019 test 07](2019-test-7.html) - ? - 11-grain 54mm KNSB CATO at NCR North
+* [2019 batch 04](2019.06.21.html) - 21 June 2019 - 12 54mm KNSB grains, half with RIO
### 2018 ###
--- /dev/null
+[[!meta title="pages tagged tags/photography"]]
+
+[[!inline pages="tagged(tags/photography)" actions="no" archive="yes"
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