Wednesday, July 19, 2017

MPC Lunar Patrol, Part 7 - A Minor Setback

It has been quite some time since I have had a chance to resume work on the Lunar Patrol.  Lot of life stuff happening since the beginning of the year.
So, last night I grabbed the booster rocket off the bench and headed for the 'BlastFromThePast Vehicle Finishing Facility'  (a large cardboard box in the corner of the back yard), to apply the first coat of primer.
When I tried to insert the engine casing on the end of the painting wand into the main tube, I found it to be exceedingly difficult.
Here's why:

In this photo, it can readily be seen that the main tube is a distinct oval shape, and one of the fin units is somewhat warped.
How did this happen?
Here's the answer:
After assembling the three tubes, I had applied a very liberal set of fillets using Elmer's white glue to hide the big gaps and bubbles that invariably plague parallel-glued tubing.


This attempt to make things pretty led directly to the dreaded 'Elmer's Effect' - severe glue shrinkage that warped the body tubes completely out of round.  Things are so bad that one of the gliders will no longer fit between the fin projections.  To make it fit in the present condition would require inner surface of the fins to be sanded down to 1/32" thickness.
No good.
I have a couple of options here.  The first is to use the 'Forced Air Thermal Alignment Apparatus'   (my wife's hair drier). 
The idea is to insert engine casings into all three tubes for support, then heat up the joints with the hair drier to soften the glue and allow re-alignment.  It is hoped that, when things cool down, the components will retain the proper position.
If this doesn't work, I am afraid the only other course is to scrap this booster, buy another BT-20 tube, and start it all over.
Sigh.
Live and learn.
In the meantime, the filling and sanding of all those balsa glider parts is still progressing.




Wednesday, July 12, 2017

Back In The Day, Part 6 - "When I Grow Up, I Want To Be...A STARLORD !!"

This was never a childhood dream of mine,  but that very thing happened in 1976 when I was contacted by a Mr. Dennis Bishop to join the Starlords International Association of Rocketry.
Mr. Bishop ran this club out of Hawaii, and, at its height, it boasted many members across the U.S. and all over the world.  The group operated under their own sporting code - the 'Gold Book', independent of that used by the NAR.
After joining, I happened to mention to Mr. Bishop that I had mechanical drafting experience.  I was readily appointed as the 'plans editor' for the Starlords new letter, The Stellar Winds.  I soon received from Mr. Bishop a large envelope full of rocket plans submitted by various Starlords members for publication.  It was my job to make pretty drawings of them to send back and be printed in the news letter.
Perhaps the best part of being a Starlord was in the opportunity to correspond with model rocketeers from around the globe.  One of the best acquaintances I made through the group was with Mr. Herb Desind - 'Mr. Cineroc' himself! The ensuing friendship will be the subject of a future blog post.
This is a 'fuzzy' picture of my old Estes Spaceman model rocket, painted in the likeness of the Starlord mascot.  The inscription around the model's base reads 'Starlords International Association of Rocketry'.




















And a real, honest-to-goodness Starlords membership ID card!














Fun times!

Wednesday, July 5, 2017

Launch Date: 4 July, 2017


A few weeks ago, I made a happy discovery in the town of Castle Rock, Colorado, where I live:  There is a moderate sized grassy field about half mile from my home which is perfectly suitable for LPR flying up to B engine range.  This area is the football practice field adjacent to Douglas County High School.  I walked it and found it to be roughly 700’ by 1000’ total.  The area includes a soccer field and baseball field on the east end.  The school buildings occupy the west end, and residential areas border the north and south sides.   Another nice feature is in the form of a couple sets of bleachers located atop a grassy slope about mid-field.  These are each on a cement pad, so it is a perfect place to set up and launch. The bleachers make for a handy ‘prep’ bench, and there is plenty of room on the cement pad for launchers.   A couple of small trees are close by to provide shade on a hot day.  I hadn’t discovered this location until recently because it is not easily visible from any adjacent streets.
Having had some free time on Independence Day morning, I took advantage of the prevailing calm weather conditions to go out and give this field a try.  My wife and I arrived around 8:30 a.m.  This was the first rocket launch to which she has accompanied me in my BAR activities.  I believe the last time she watched me launch rockets was back in August, 1983 at the HOTROC-4 Regional contest in Colorado Springs!
Anyway, I quickly got things set up at what I will now call DCHS Proving Ground.  The first bird off the pad was the Estes Mini-Brute Hornet on an A3-4T engine.

 
 
Perfect straight up boost, chute deployment, and recovery!  The model drifted down and landed within forty feet of the launch pad.  The flight was a perfect christening of the new launch field.
Mrs. BlastFromThePast was duly impressed, as well!
 
Next up was the Mini Maggot 3 boost/glider, which had turned in a less-than-perfect maiden flight about a month ago.
This time I used a 1/2A3-2T engine, hoping for better results.


A strange thing happened at the launch of this bird.  With my finger hovering over the controller button, I was fumbling with my cel phone to get my usual launch video started.  I began the countdown, and just as I said “5….” My finger twitched and the model launched!  I missed seeing the boost!  Luckily my wife was there and tracked the flight to apogee.
“I don’t see it!” I exclaimed.  She pointed me in the right direction, and there it was…the Mini Maggot glider wheeling gracefully in a somewhat tight right-hand circle.  It had worked!  Perfect pod separation.  No Red Baron!  “WooHooo!!!"
I followed the glider during its descent.  By the time of this launch, the wind had picked up to around 5 mph in the direction of the short side of the field.  The glider was heading dangerously close to the residential area to the south.  I saw it touch down just this side of the fence. 
I didn’t time this flight, but I estimated the duration to have been well over a minute.  Luckily there was no thermal activity to speak of or I would have been kissing this one goodbye.
It still took about a 10 minute search before I found the glider in some tall grass just outside the park perimeter.  Both it and the pop-pod were recovered with no damage whatsoever.  I was elated at my first successful boost/glider launch in the new BAR era.
The only negative aspect of the flight was the discovery that the engine casing had ejected from the pod.  Had this been a competition flight, it would have been a DQ.  But since this was a sport flight:  Meh!
I had intended to fly the Delta-II as well, but since the wind was starting to become increasingly present, I opted out and packed up the gear, satisfied with two excellent flight missions.
My wife and I headed home to enjoy the remainder of the Independence Day festivities…..