Wednesday, August 24, 2016

Apogee Peak Of Flight Article - TIPS

Tim at Apogee asked me to come up with two articles for the Peak Of Flight e-newsletter based on TIPS from this blog. To see the first article: CLICK HERE

If you've been following the blog you've probably already seen some of these ideas. There are always new blog readers and an item in the two articles might give you something new to think about.
The second TIPS article will be published in two weeks.

Centuri Moonraker #KB-11 Build, Part 3, Fin Prep and Gluing

The outside fin edges got a smoothed bead of white glue.
After that dried it was rounded and smoothed with 400 grit. Another bead of glue and smooth sanding followed.

The glue bead seals the exposed edges and prevents delamination. It also gives a slight rounded edge to the fin.

The fins were sprayed with primer/filler and sanded smooth.

The root edge was sanded down to get a better glue bond. The fillet area was also sanded down.

A vertical alignment guide is printed on the instructions sheet.
These work well and insure the fin spacing is correct.

With the fins glued on the sections were slid over an engine casing. An empty casing is needed to hold the halves together when displayed.

Tuesday, August 23, 2016

Body Tubes!

Just received a BIG order of body tubes from BMS for Odd'l kits.
It doesn't look like much until you look in from the side and that's a small portion of all the tubes. These are all 34" long - there are tubes in tubes!

Centuri Moonraker #KB-11 Build, Part 2, Fin Prep

I'll be spending some time on the fibre fins. Most builders would simply punch them out and immediately glue them to the body.
Die cut fibre (mat board) fins require some edge prep to get smooth.

The hold down tabs were larger than normal. Don't punch these fins out! You would end up with more to clean up later.

The fins were removed using an X-Acto knife.

After removing the fins you can see the corner hold down ticks.
These will be cut back and the edges sanded.

The sides of the fins were lightly sanded with 400 grit on a block.
The picture shows the darker sanded edges where the raised sides were taken down a bit. These edges are rougher now and will need to be smoothed out.

Model Rocket News Idea Box - Piston Ejection

From the Estes Model Rocket News, Vol.3, #1, February/March, 1963

Here's an early piston ejection drawing making wadding or parachute protectors unnecessary.
A solid nose block is slid down and rests against the engine block. The nose block is attached to a shock cord and to the nose cone.
Note the engine block recessed down from the top of the body tube. it is glued in place and stops the travel of the piston. That upper engine block could block passage of the parachute.
The instructions say to securely friction fit the engine so it doesn't eject. Where is the ejection charge supposed to go or vent?
It's still a great idea and used in some MPR kits.

Monday, August 22, 2016

Centuri Moonraker #KB-11 Build, Part 1, Parts

At $.85 how could you go wrong? This was one of those models you'd throw to get your order total high enough for free shipping. I would think the price of the packaging was more expensive than the actual parts in the kit. For such a little rocket there are some few, interesting parts.

Taped to the instruction sheet is the engine retaining wire. This isn't an engine hook but is meant to flex out of the way at ejection.
At ejection the engine does eject and the two body section separate. the upper section has one fin and nose cone. The lower section has two fins.

This wire goes around the top longer fin, down both sections and bends under the engine casing. It helps hold the rocket together.

Here's the fibre fins.
The top side (where the die-cut blades strike first) has rounded edges.
The back side edges are squared off. Look at the tip of the longer fin and you can see where the die-cutting has slightly pressed out and creased the leading edge.

Below that is a black dot. I don't know what caused it. It doesn't go into the fin area. A black dot of oil or ink would be hard to cover up with spray paint.

The Centuri plastic nose cones were of great quality, injection molded with no seams.

Below the body tube is a small depression. I'll flip over the tube and glue a fin over it.

The launch lug "luglets" are short, only 1/4" long.
They were set over a Q-tip so I wouldn't lose them.

Hobby Lobby Resets

Hobby Lobby is resetting the rocket shelves with some new Estes products.
Many of last years kits were on clearance at 40% off.

It looks like they are keeping some standard fare next year, including the Mercury Redstone.
The Quinstar is there along with the new Expedition and BT-60 based Nike Smoke.
Others include: Super Neon, Goblin, Super Nova, Comanche 3, PSII Star Orbiter, Sequoia and Puma.

About the only thing I've ever searched on my smart phone is the Hobby Lobby 40% off coupon when I buy engines.