Old MRN Idea Box, June 1964

Mojo1986 (Joe) was selling some old Estes Model Rocket News issues on Ebay.
Here's an "Idea Box" post from the June 1964 issue.

Old MRN Idea Box, Feb. 1965

Mojo1986 (Joe) is sellng some old Estes Model Rocket News issues on Ebay.
Here's an "Idea Box" post from the Feb. 1965 issue.

I have pretty good luck cutting body tubes, I usually won't end up with the "rough cut" shown on the left.
Using a coupler to stiffen up the end is a good idea, especially when cutting the thin wall BT-5, 20 and 50 tubes.

Old MRN Idea Box, June 1963

Mojo1986 (Joe) is sellng some old Estes Model Rocket News issues on Ebay.
Here's an "Idea Box" post from the June 1963 issue.

I recently used this launch lug wrap piece after realizing I forgot to glue on a launch lug on the AVI Nike Tomahawk. Here they use a wrap of stiff paper. I used a split body tube segment.

TIP - Night Launch Lights?

These LED "Finger Lights" are sold through the Publix supermarket during the Halloween season. Kids wear them for safety after dark and as part of their Halloween costume.

I actually bought these with the idea I could use these on stage.
Imagine a dark stage, a fast banjo roll and colored lights. (Yeah, I know, stupid idea. I'm always looking for the next big thing.)

It didn't occur to me to use these for a night launch!
It's pretty obvious, the lights have an elastic band to go over the fingers.
The elastic could be slipped right over a body tube. A little tape for insurance and you have a cheap light for night launches.

Cheap?

Four lights for $2.00!

This is the back of the package with the catalog number and other information.

I did a quick search and they are available through many online vendors!
Search under LED Finger Lights.

I tried the elastic around everything from a BT-20 to the BT-60 on my Red Max.
The fit is pretty tight around the BT-60 size. Be careful the back side of the plastic light casing doesn't scratch the finish or decals. Two layers of electrical tape on the back of the housing could help prevent scratches.

On a BT-20 you'll have to add some tape over the elastic band or it might slide down the body tube during a quick boost.

These little LEDs are bright!

Engine Hook Idea from Greg Poehlein

Recently a member of the OldRockets@yahoogroups.com was asking about an engine hook that seemed too short for a newer Estes E engine.
Greg Poehlein responded back with a great new idea of putting a reverse bend in the top of an engine hook.

Thu, October 20, 2011 1:15:23 AM[OldRockets] Re: Estes Engine Hook
From: Greg Poehlein
To: OldRockets@yahoogroups.com
--------------------------------------------------------------------------------
If you are planning to use it in a rocket with a body tube of BT-55 or larger, you can still use these hooks. My suggestion is to put a motor block in the tube at the depth you want for an overhang. Then, bend the top end of the motor hook AWAY from the motor tube at a 90 degree angle. Glue the centering ring just behind the hook, so at ejection, the ejection charge will be pulling the motor hook against the centering ring between the motor tube and the body tube. For that matter, you could do the same thing with a standard (2.75") length motor hook as well. Good luck with the build.

Here's what one of these hooks could look like if used on a standard 18mm engine mount tube.
While Greg mentioned using this hook in a BT-55 or larger, the hook as shown (with a shorter top bend) could fit into a BT-50 sized tube.

The bend on the right side goes under the nozzle end of the engine. The upper (shorter) bend faces away from the mount and and would sit over the top of the upper centering ring.

The engine hook from the side. Notice how the upper bend of the hook faces out and goes over the top of the upper centering ring.

With a "shotgun" ejection charge any movement of the hook is against the top centering ring, not pulling down inside a thin walled BT-20 engine mount tube.

In this example, the upper outward bend of the hook is shorter so it won't overhang the centering ring diameter.

Viewed from the top, you can see the engine block (or thrust ring) in place.
The thrust ring keeps the engine in place during the boost stage.
The lower and upper reverse bend in the engine hook keep the engine in place at ejection.

A simple, brilliant idea. Thanks Greg!
Check out Greg's Project Paper on TRF HERE

More Shock Cord Ideas Part 3

Continuing on with Jason's shock cord design, Here's what it looks made with 24 lb. paper.

The shock cord was laced through the three holes.
The lower half was folded over and glued over the shock cord.

I like this design because it is thinner than the Estes Tri-Fold design. The shock cord is not folded over itself two or three times.

Even from the back you can see how the cord lays beside itself. I did thread the cord under the top weave.
The low side of the mount (facing up) is less of a obstruction and more of a "ramp" before the low side of the shock cord.
The parachute would pass by this style of mount easier at ejection.

Jason uses the "Double Glue" method to attach the mount in the body tube. Use a rounded dowel to press the mount into place.

After the glued mount is dry, Jason recommends a coat of glue over the top of the mount - Good advice.

More Shock Cord Mount Ideas Part 2

While Jason Wentworth (Blackshire) used standard copy paper, I wanted to try some Tyvek.
This is used in strong envelopes, you can't tear through it every easily.
THE TYVEK DID NOT WORK!

I had an extra Express Mail envelope I never used. The entire big envelope is made of Tyvek.
It does say on the envelope: "This packaging is the property of the U.S. Postal Service and is provided solely for use in sending Express Mail. Misuse may be a violation of federal law."
I wouldn't call it misuse, but instead - research!

When cut into a shock cord mount, it reminds me a little of the old Centuri self adhesive mounts. Sure, this is white, the Centuri mounts were a flame resistant silver. But it has reinforcement fibers running throughout the paper.

The Tyvek feels a little slippery, it'll be interesting to run a few tests to see it it can be glued in securely.
Elastic shock cord was woven through the holes.
The side without the holes got a coating of glue and was folded over onto the corded side. After drying, I glued the finished Tyvek mount into some scrap BT-50 and let it dry overnight.

In the morning I pulled on the shock cord. It pulled out of the Tyvek!
The Tyvek was too slippery and probably resisted being permiated by the white glue. Without much trouble, the entire mount was pulled out with tweezers.

Lesson learned:
DON'T USE TYVEK FOR A SHOCK CORD MOUNT!
This style mount will work fine using paper or cardstock.

More Shock Cord Mount Ideas Part 1

In a recent YORF post, James Jason Wentworth (Blackshire) came up with a great variation of the G. Harry Stine "Shock Lock" shock cord mount.

Anytime there is a post by Jason, I always read it thoroughly. In the past he has come up with great innovations such as a new style 13mm to 18mm engine mount adapter and a removeable shock cord mount that allows you to replace the burned through Kevlar.

In Jason's newest mount idea, he starts with a longer piece of paper or light card stock. Jason says he has had good results just using standard 20 lb. copy paper. You can see how the holes are punched on one side. The mount is folded in the middle.

One advantage to this type mount is after the shock cord is threaded through the holes, you fold over and glue the side without the holes over the threaded shock cord. This smooths out the entire surface leaving much less of an obstruction for the parachute or streamer. It is also more flat towards the lower, parachute side of the mount.

The shock cord isn't folded over itself twice making a thick mount. Instead, when laced through properly, this finished mount is smooth and quite flat.

The second layer of (folded and glued down paper) paper also make the mount much stronger.

The length to width ratio is 5 to 1. For a smaller tube, I made mine 3/4" wide by 3 3/4' long.