Thursday, March 23, 2017

Estes Nike Smoke #7247 Build, Part 7, 24mm Engine Mount

I'm making two Nike Smoke kits, one with the standard 18mm engine mount, the other with a 24mm mount with the Enerjet smoking nose cone.
First up is the 24mm engine mount.

I used the kits 18mm centering rings to make 24mm rings.
A D engine casing was set in the center and traced with a sharp pencil. The new larger centers were carefully cut out.






220 grit sandpaper was wrapped around the expended 24 mm casing and light sanding brought it to the correct fit around a BT-50H engine tube.





The tubes were punched for an engine hook relief (at the bottom)
The upper smaller holes are for a cotton swab plastic tube. The mount will have a replaceable Kevlar line feature. The small tube will guide the Kevlar through from the bottom centering ring tie.

Wednesday, March 22, 2017

California Trip Extended?

I'll be here in California through next Monday, maybe longer.
Without going into much detail - My Mother is having heart issues.
Depending on how she does I may extend my stay until we can work out
her care.
Until then I'll be doing one post a day. I still have some posts in draft form
but in time those could all be used.
So bear with me while I do my internet at McDonalds.

Estes Nike Smoke #7247 Build, Part 6, New, Harder Fins

I've described how to shape this style fin in the past on the blog:
http://modelrocketbuilding.blogspot.com/2016/06/shaping-estes-nike-smoke-fins-part-1.html
http://modelrocketbuilding.blogspot.com/2016/06/shaping-estes-nike-smoke-fins-part-2.html
http://modelrocketbuilding.blogspot.com/2016/06/shaping-estes-nike-smoke-fins-part-3.html
http://modelrocketbuilding.blogspot.com/2016/06/shaping-estes-nike-smoke-fins-part-4.html

And in the Apogee Peak of Flight newsletter:
https://www.apogeerockets.com/education/downloads/Newsletter357.pdf

Just what you wanted - HOMEWORK!
I won't be going into detail on how to shape the fins here on the blog. Use the addresses above to see one way to do it.

I'm building two Nike Smoke kits at the same time. While one kit had dense hard balsa, the other kit balsa was too soft. Press a fingernail in a border area to see if your balsa is soft. If it gives too easily to pressure you might want to buy some stiffer wood and cut out your own fins.
Shaping Nike style diamond tapered fin requires harder wood. The final fin shape will be thin.

There is so much extra wood on some laser cut sheets I cut more fins from what was left from the harder kit sheet.

With the edges glued back to back I had enough area in the center to cut four more fins.









Sand the edges flat and glue them back to back. The pencil tracing shows how the new fins were drawn.

Tuesday, March 21, 2017

Estes Nike Smoke #7247 Build, Part 5, Fin Observations



Look at the low end of the fin and you can see the lighter wood tip.
Some kit wood is pieced together from smaller strips. The problem is the differences in the different wood densities. It becomes a concern when you are shaping the fins.



The fins are set over the full size instruction sheet drawing and the bevel lines are drawn in pencil with a straightedge.








You'll never get a sharp diamond fin profile by using little squares of sandpaper shown here in the instructions.



I've used the Great Planes sanding block many times before on the blog. The block is perfectly flat and the sandpaper is self adhesive. If you don't have one yet - trust me and buy one!

Monday, March 20, 2017

Job Opportunity At Centuri? 1979

While I'm in California taking care of family business, I looked through some of my old files and found this. I had thought it was lost . . .
It's dated September, 1979, from Grant Boyd.

Chris,
I need to talk with you about an opening here at Centuri. If I have not made phone contact with you by the time you read this, please call me collect.
Grant

I had my first real contact with Centuri when I won a design contest in 1972. I got to know some employees (among those Bob Del Principe) at the 1975, 76 and 77 NARAMs.
I was lucky to have a strong graphics art background, could design rockets and build clean models. I was considered for a position at Centuri the first time around in 1975 when I was 19 years old. That job went to Jeff Flygare. Jeff had a good background in photography and knew the NAR people better than me.
I was disappointed to say the least. I left rocketry to pursue a musical career.

When I got this letter in 1979 I had just finished a Summer run at Knott's Berry Farm and did a Gong Show appearance. I was playing out again in the Monterey Bay area and probably returning to Great America for the following Summer. Still disgruntled by that first opportunity lost from Centuri I respectfully turned it down.

In the early 1980s, NARAM returned to Central Florida near Kissimmee, just South of Orlando. I was entertaining at a Sea World venue and in walks Bob Del Principe from Centuri. We talked about the current state of Centuri, things were moving to Penrose then. He told me I probably made the right decision by choosing to play the banjo for a living! The rocketry business as we knew it from 1969 had changed.

Estes Nike Smoke #7247 Build, Part 4, The Enerjet Smoking Nose Cone

Two holes are drilled into the nose cone base for a shock cord loop tie.

Start the hole by spinning the tip of a #11 blade in the plastic. Use an older blade, this really dulls a new one.
The hole is widened by spinning a small diamond file in the holes.
One of the raised plates is cut for a smoke release hole.

Trace around the raised plate with a pencil so you can better see it.
This plastic is harder and a bit more brittle than the old blow molded nose cones. It takes quite a few passes with the knife to cut through it. Leave the top 1/3 of the hatch still attached to make a "hinge".

The port is bent open and upwards making a pressure "hinge" in the plastic. Be careful, this plastic is not as flexible as what Centuri used on their Nike nose cones. It can crack at the hinge.
It has to be opened wide enough to allow the talcum powder to easily blow out.

Sunday, March 19, 2017

Estes Nike Smoke #7247 Build, Part 3, The Enerjet Smoking Nose Cone


I used my aluminum angle to get side slot sides straight.

The short end cuts were made by punching the tops and bottoms with a sharp blade tip. Punch the top corner with the sharp side down. Turn over the blade and punch cut the bottom with the sharp side up.
The shock cord attachment lug will be in the way of the internal BT-5 tube.
A hobby saw cut it close to the surface. The remaining nubs were sanded off. A small sliver was opened up after sanding smooth.

The hole was continually widened until I could get a dowel in. 220 grit was wrapped around the dowel and the hole widened.
Sand a little and check the tube fit.



The tube was slid in from the bottom and can be seen inside the cone end.

Shave off little by little until the tube slides through.






Here's the BT-5 fit at the bottom and top.

On the left I've pencil marked two holes that will be drilled out for the shock cord tie.