Wednesday, July 23, 2014

ASP Corporal Build, Part 5, Tunnel Shaping

The tunnel pieces are cut to size.
The 3/16" square pieces are cut to 8 1/4" long. The two 1/8" square sticks are cut to 4 1/2" long.

The tops are rounded off.
Initial shaping as done with 220 grit on a block. The block helps keep the shape consistent.

The ends get an egg or elliptical shape.
Mark a center line with pencil and sand the ends round centering  towards the pencil line.
The end tops are sanded to a half round with the block.
Knock off any squared edges hand sanding with 400 grit.

The inset picture shows the two tunnels back to back (root edge to root edge). This is an easy way to check the consistency of the end shaping.
After you check both sides, flip the top tunnel over and check it again against the lower tunnel.

The BIG Fix, FlisKits MMX Crayon, Part 2

The replacement lug was cut from the back end of a ball point pen ink tube. The walls of the ink tube are thicker than a MMX lug but slide easily over a Micro launch rod.

The paint had torn off around the old lug glue area.
This was touched up with a black Sharpie.

The lug was roughed up with sandpaper for a better bond.
The lug was glued on using medium CA. (I know, the glue joint will get brittle over time. I'll just keep an eye on it.)

The new wrapped rear ring was a little high and the fit too tight.
Before sanding down, it got a coat of CA applied with a Q-tip.

The CA hardens the ring and prevents it from unrolling when sanding to size.
A four-sided fingernail file and 400 grit brought it down to the right diameter.
The hardened CA polishes well and made a very smooth surface.

Fixed and ready for flight!

Tuesday, July 22, 2014

Moon Landing Anniversary Launch, Schoolyard, July 20, 2014

It seemed appropriate to launch a Saturn V this morning.
The Dr. Zooch SATURN V flew with a Estes B6-4.

I was hoping for a good launch and recovery, this ninth flight wasn't the best. It left the rod and turned 45 degrees to the Southeast. Altitude was only 125 feet.
It was nose down and 50 feet above the ground when the parachute ejected. It landed in the middle of the two-lane perimeter street. I ran to get it before a car could run over it.
The fin broke free at the fairing root. Wes (Dr. Zooch) told me the fins were designed to do that on a hard landing. An easy fix.

An old standby, the Quest (Cobalt) ORANGE was launched with an A6-4 engine to 275 feet.
I'll pack the shock cord in the nose cone with the parachute on top of it. The shock cord usually pulls out the parachute. The parachute stayed in the nose cone.
With just nose-blow recovery, the Orange fell gently enough.

My Estes GYROC clone launched with an A8-3 to 250 feet.
The engine ejected with a loud pop and the rocket helicoptered in.
When it was picked up one of the small fins had pulled loose.
More repairs!

This was a test of the second Odd'l Rockets prototype,
the LITTLE GREEN MAN. It's naked, not enough time to paint it.
(It doesn't look like much without the eyes and mouth.)
With the upturned feet set closer to vertical it did seem to get better altitude with an Estes B6-4. I would estimate the peak of flight at 325'. Very stable!

The new 12" Odd'l parachute opened and brought it back close. I caught it before it touched down. This was my best flight of the day.

Normally a MicroMaxx could be my first of the day, but this morning the Saturn V was launched first.

I had just repaired the FlisKit CRAYON two days ago.
Today there were no problems getting the small engine to ignite. The Crayon is fast off the launcher. Altitude was an estimated 100 feet.
The body sections did separate but the streamer stayed in the upper half. No damage when it was picked up.
Five up, five down and two broken fins.

ASP Corporal Build, Part 4, Engine Mount and Fins

The instructions say the Kevlar should be 11 3/4" from the top of the engine mount to the tied loop. This would put the upper loop end right over the top of the body tube.
I made the Kevlar line shorter so there would be no chance of a zipper.
The engine mount is glued in the rear of the tube, both tube ends are even.

The fins are cut from 1/16" thick basswood.
Be sure to check the grain direction. These fins look like they should go the other way.

The leading and trailing edges are rounded.
Again, check the grain direction before rounding the edges. They are easy to get mixed up.

Monday, July 21, 2014

Elmer's Glue - Uh-Oh!

This was talked about on the forums two years ago.
Elmer's had thinned out their glue and is now calling it a "NEW STRONGER FORMULA".

Many builders had problems using it, especially on couplers and engine mounts. The thinner glue quickly saturates the Kraft tubes and couplers. Engine mounts and couplers were freezing up and locking before they could be slid into the desired position.

Two years ago I bought six bottles of the old formula Elmer's Glue All.
My old bottle of the original "Bonds Strong" formula on the left.
On the right is one of the six bottles I bought two years ago.

The glue in the bottle on the right is thinner.
I had suspected it then, it seems Elmer's filled the old bottle with the new thinner formula!

I didn't use the new bottle until this morning on an engine mount/centering ring fillet.
The new formula is VERY thin and easily runs.
The thinner glue could shrink up body tubes at internal glue fillets - the "Coke Bottle effect".

I read somewhere the G. Harry Stine preferred Aleene's original Tacky Glue.
It's thicker than the older Elmer's glue. It does dry clear.
We'll see if it allows couplers and engine mounts to slide without locking up.

Last November I did a test of all threes glues: CLICK HERE
It was a little more interesting than watching paint dry.
The final results are worth the test.

I took the nozzle off the thin bottle of Elmer's and put it on the Aleene's.
Most all the nozzles are interchangeable.
I like the smaller hole on the Elmer's nozzle tip.

Before I put it on the Aleene's bottle I ran it under some water to clear out the new formula Elmer's glue. The thinner Elmer's easily washed out of the nozzle.
I mean - easily washed out. No picking or scrubbing.
The running water was all it took to clear the glue.

ASP Corporal Build, Part 3, Engine Mount

The engine mount now includes an engine hook. An instruction addendum is included, the picture is at the right.
The instructions are a little vague saying the centering rings are glued between 1/4" and 1/2" from the ends of the red engine mount tube.
This type of mount doesn't require a wrap of tape over the middle of the hook.
Top left: The upper ring was glued on just below the top bend of the engine hook.
Top middle: The rear ring was glued 7/8" from the rear of the tube. This allows movement of the engine hook. If the lower ring were glued any farther down the tube the hook would be hard to lift.

The inset picture shows the finished mount.
The Kevlar was tied around the tube and pressed into the centering ring fillet.

Sunday, July 20, 2014

ASP Corporal Build, Part 2, New Kevlar Knot

First up you are instructed to tie a loop knot in the upper end of the Kevlar. This loop will tie to the elastic shock cord.
Usually I tie an overhand knot to make an attachment loop.
This might be my new upper attachment knot.

The instructions say to tie an overhand knot 6" or 7" from the end. I thought this was a bit long so I tied the overhand knot at 4" from the end.

The end is brought back through the loop in the knot and the knot tightened.
Then a half hitch is tied and pulled tight against the overhand knot.

The instructions state the loop can end up between 1" and 2".
I went for a 1" loop. A 2" loop seemed too long.