Printing an Ogive Nosecone for Model Rockets

BT-50 Nose cone assembled

I took my own advice and bought the Flashforge Creator X 3D printer. It has two MK8 print heads, for printing two colors, and an aluminum plate. So far I like it. I’m using ABS plastic and so far have had no jams. I’ve replaces the Kapton(tm) build plate covering once so far. I beat it up after seven or eight builds. The initial instructions suggest a plate temperature of 90C. I’ve had better luck with parts sticking to the build plate at 110C.


My initial interest in 3D printing is to make model rocket nose cones with a capability of carrying small payloads. Getting a 3-D printer has given me a opportunity to develop some ideas. I’d like to have a nosecone that can carry small circuit board payload. The version described here does not have that capability, but it is a step toward that goal. It includes a shell of a nosecone. I’ve included some internal bulkheads, though I’m not sure they are needed. The nosecone needs to survive the launch pressures. The bulkheads will need to be reduced, but could be thickened, to carry a payload.

Printing a nose cone

Printing a nose cone

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The Global War on Christians by John L. Allen, Jr.

The Global War on Christians: Dispatches from the front lines of Anti-Christian Persecution
John L. Allen, Jr

Book Cover: Global War on Christians
Rating: 5/5
Publication Date: 2013.
Crown Publishing Group (Random House), New York,

Format: Epub version, 278 pages.
eISBN: 978-0-7704-3736-7





It appears that our nation is beginning a period of religious persecution, as our government begins taking on itself to direct what the Church can and cannot do, and some groups blame Christians for all our social problems. It becomes important to understand that persecution occurs throughout the world and often in extreme forms.

Allen reports some of the statistics of the present persecutions. However, these seem to very by orders of magnitude. The numbers of those persecuted are understandably not readily reported by local sources. He uses a poor/broad definition of “Christian” (not that I have a better one) using those who are self-identified as Christians. You may question whether, on a per capita basis, Jews, or some loosely Christian sects, suffer more persecution, but the numbers involved make Christians the most persecuted.

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Retirement Income from a 401K Account – Part 1

I recently retired, so deciding what my income is, deciding how quickly to drain my retirement account, has gained a new urgency. Unless the goal is to live off Medicaid, or its expected that the government will put us down once we reach our life expectancy, its important to have a plan. And since the future is even harder to predict than the past, its a plan that must be flexible, and can adjust with the economy. Its important to remember that accommodations made early in retirement will be smaller than the forced reductions made later.

I’m hoping to do this in three parts. First, look at some trial & error estimates based on subtracting annual amounts. Second, look at mortality tables and life expectancy. And third, try to come up with some algebraic expressions, or simple formulas to make periodic reassessment easier. Yes, this has been done by more knowledgeable people than me, but for my sanity, I want to know what goes into these estimates and understand why I should make sacrifices now.

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Prayer Request for South Sudan

I’ve been reading John Allen’s “The Global War on Christians”.  So this prayer request from a group I support is hitting home.  Please include the Christians in South Sudan in your prayers.

from: info (at)
Subject: Prayer Request for South Sudan

Your prayers are requested…You may have seen in the news that there is a great deal of civil unrest and fighting in South Sudan, where the Evangelical Lutheran Church in Sudan/South Sudan is based. While the town of Yambio (where ELCS/SS headquarters and the CLIHM seminary are located) has not suffered attacks, ELCS/SS pastors and their parishioners have not been so fortunate.The fighting seems to be primarily between the Nuer and Dinka tribes. It’s estimated that 1,000 people have been killed and some 200,000 displaced by the fighting that began on Dec. 15. Even in the “safe” areas, fuel, food and other necessary supplies are running low.

Today, the LHF office has received this email from Rev. Edward Nzeme, general secretary of the ELCS/SS:


Greetings from Yambio.The situation in our country South Sudan is not stable. Our church has been badly affected by the events in the country. Continue reading

Happy New Year 2014

I like to say I’m optimistic for the next year, but I’m not. “Hope for the best, expect the worst.”

For whatever it is worth, here are some predictions:

  1. There will be wars. Marauding warlords will continue to pillage civilians in the Middle east and Africa. Civil war may come to South America as Venezuela continues to collapse.
  2. Climate will continue to change. Ice will melt and water will freeze.
  3. Lawyers, Judges and Government will not save us. Those in charge will continue to pervert justice.
  4. Social conservatives will continue to be ignored. Babies will be continued to be born without fathers.
  5. Cleveland Brown will fail to sign a front line. Quarterbacks beware!
  6. Economic growth will be slow at best. The economy received a huge stimulus in 2013 as stocks rose 30%. It remains to be seen whether this creates stending, profits and earning. Against this upward force is implementation of the Obamacare mandates on employers, sapping hiring and earning. Also artificially low interest rates will continue discourage investments.
  7. The Church will survive.

I expect that, whether we deserve it or not, we will muddle through.

And the President said, “It’s Really Good!”

Uhl Pottery Company 1 gallon crock


I first saw this story many years ago, but recent events made me look for it.  It apparently dates back to the early 60’s.  But as a wise man once said, “There is nothing new under the sun.”  It could as well apply to the tower of Babel.


from  SNAFU Principle


In the beginning was the plan,
and then the specification;
And the plan was without form,
and the specification was void.


And darkness was on the faces of the implementors thereof;
And they spake unto their leader, saying:
“It is a crock of shit,
and smells as of a sewer.” Continue reading