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.

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!

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.

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.

Estes Nike Smoke #7247 Build, Part 2, The Enerjet Smoking Nose Cone

The original Enerjet Nike Smoke had a smoking nose cone. To see how it was done - CLICK HERE

The tip of the nose cone was cut off and a BT-5 was slipped in acting as a ram-jet. During boost, the forced air pushed talcum powder out of a vent at the base of the nose cone.

At this point I don't know if a B6 or C6 engine would get the model to the velocity speed needed to make the nose cone work properly.
I'm building two rockets, one will be a normal 18mm model, the other will be for 24mm engines with the ramjet nose cone.



All that is needed to make a smoking nose cone is the hollow blow molded nose cone, a length of BT-5 and a 5 sized plastic nose cone.

The tip of the nose cone is cut off.
Slide the BT-5 over the tip and mark around the tube base with a pencil.

The BT-5 on the right inset picture shows more tube than needed. I cut it larger than probably needed and will cut it to size after sizing.

Near the base of the inside tube are two slots, 1/8" wide by 1" long. The slots are marked and cut 1" up from the bottom of the tube.

NOTE: The new Estes Nike Smoke nose cone has a longer shoulder than the old Centuri nose cone. I wanted the rectangular vents directly opposite the open hatch on the nose cone. I had to re-cut a new tube with the slot bottom 1 7/8" up from the bottom of the BT-5 tube.

The picture shows the slots (at the earlier 1" mark) on the BT-5 ready for cutting. Draw the slots 1 7/8" up from the bottom of the tube edge.