Ceramic Blast Deflector History

An interesting Blast! Deflector back story from YORF:

The MPC starter kit pictured earlier featured a unique parabolic blast deflector.  The design made its first appearance as an R&D entry at NARAM 11 submitted by Sven Englund of New Canaan, CT.  

This was the very same Sven Englund who was the winner of the Estes "Launch Pad Sweepstakes" which had a trip to see the Apollo 11 launch with Vern Estes as its grand prize.  Methinks that ol' Sven might have been the object of envy by a few thousand rocketeers over that win!

Only a few months later the April 7, 1970 issue of Model Rocketry magazine would report that MPC had purchased the rights to his deflector design from Sven for the princely sum of $75 dollars.  Here's the story from Ninfinger.org:  Model Rocketry Magazine April, 1970 (http://www.ninfinger.org/rockets/ModelRocketry/Model_Rocketry_v02n07_04-70.pdf) 

The design is still available today from various model rocketry dealers. (an Odd'l Rockets product!)

***************

New Break-Away Kit!

Check out the Blog Topper picture!

The NEW BREAK-AWAY kit is now available from JonRocket, Apogee and Sirius Rocketry.

New design features include:  
The main body tube is now a heavy walled BT-50, even stronger than the original ST-10 tubing.
The segment ties have been improved, now stronger and more secure.
The couplers are longer for more stable joints.

Some of the new batch of kits have already sold out - be patient, more are on the way!

New, Wider BLAST! Deflector Coverage

Under a BT-60 based model - 

Here's the flame "hit" on the side of the new, wider Blast! Ceramic Deflector.
This new design better protects wider diameter models against flame flashback which could damage the underside of a model.
To the lower right of the black soot you can see where the flame ended up - some flame was redirected to the flat metal deflector.

BT-5 to BT-70 models - Covered!
BT-80 rockets? Maybe not!

New FLARE Model Shroud Lug Slot

This is a condensed version of two posts from the Model Rocket Building Blog.
It will be part of a new model in the Combo Kit offered by Odd'l Rockets.

A launch lug has to pass through the shroud at the base of the model. The picture on the right shows a fit of the shroud around a 1/8"  diameter launch lug. The sides of the lug slot are straight.
The top edges don't wrap around the top end of the lug. There are gaps.

Here's the new shape of the launch lug cut.

The teardrop shape ends up hugging the sides of the lug better.
The top corners end up wrapping underneath the lug.
A better fit, less to fill and more aerodynamic!
Well, about as aerodynamic as you can get with a high drag tail shroud!

Bagged Sub-Assemblies

I learned a lot from building Semroc kits.
One thing I found were bagged sub assemblies. The engine mount and recovery system parts were in separate small bags.
The picture shows the engine mount bag from a typical Odd'l Rockets kit.
As a teen I remember tearing open an Estes or Centuri kit bag. Loose parts would fly! A launch lug or engine hook could roll under the table and be lost.

Why don't the big producers do this? It costs an extra three cents per kit for two extra ziplock bags.

Extra Centering Ring Punches

Where possible, I try to incorporate a few extra features on the Odd'l Rockets kits to make them stronger and easier to assemble.

Here's some centering rings from the Pigasus and Little Green Man kits.
On the left is the lower engine mount centering ring. The ring is punched for movement of the engine hook - pretty standard.

On the right is the upper ring.
On the bottom is a second smaller "relief" for the upper end of the engine hook. This allows an easier fit over the engine hook and the engine tube won't be compressed inward.
Right above that is a small hole for the Kevlar to pass through. Again, no extra pressure on the engine mount tube.

What's In The Box?

In the box is a well padded old MPC Ceramic Blast Deflector.
The guy who makes the Odd'l Rockets Blast Deflectors will be making a new mold from the original MPC Deflector.

The new deflectors will be larger with a 3 1/8" wide base diameter. The larger deflector will be more effective with larger diameter models.
The new deflectors are improved with a (flat) rolled lip under the bottom. This makes the deflector stronger than the old MPC ceramic domes and less likely to break.
My supplier is busy! The new BLAST! deflectors "should be available" after the first of the year.