Tuesday, January 24, 2017

Estes Galactic Taxi #1914 Build Part 6, Forming Cardstock

To pre-emboss the folds in card stock I use the back side of a single edge razor blade. The rolled over metal is tight and rounded.

Tape over the blade side with a few wraps of masking tape.
TIP: Set the back embossing side of the blade down on the dotted line first. Then slide the ruler up to the blade. This will compensate for the thickness of the embossing tool.

The backside of a Sharpie pen was used to make a sharp fold over the already embossed lines.

The fairing support pieces are scored first.
Start the fold over the side of your straightedge (upper right).
Finish and sharpen the fold with the Sharpie barrel.

The canopy looks pretty strange before scoring and folding to shape.
While the glue dries, the tabs are held down with long tweezers.
You need very little glue on card stock shrouds or canopy tabs.

Monday, January 23, 2017

Estes Galactic Taxi #1914 Build Part 5, Engine Mount Fitting

Both ends of the main tube got a wipe of medium CA glue.

After it dried the hardened ends got a light sanding with 400 grit.

The kit instructions have you glue in the mount so both tubes are even. On a 20/50 mount this doesn't allow enough space for engine hook movement without pressing against the outside tube. (On left)

I decided to let the mount tube extend 1/4" beyond the end of the main tube for more hook flexibility. (see inset picture)

Magazine Article Submission

I just submitted a new short article to Sport Rocketry Magazine.
If accepted (and looking at the submission deadlines) it might end up in the May/June issue.

Why not post it here or submit to the Apogee Newsletter?
Apogee was concerned it could hurt sales of a certain product.
I would reach a larger audience in the NAR Sport Rocketry magazine.
This simple technique could make for faster, more reliable LPR ignitions.

Why am I being vague about the submission?
It's a magazine article and the content is first reserved for the customer.
If the article isn't accepted and published it'll be posted here.

Sunday, January 22, 2017

Estes Galactic Taxi #1914 Build Part 4, Engine Mount

Anytime you get the black Letramax centering rings be sure to wipe down the laser burnt sides. Otherwise the black ash will get on everything it touches.

Two 20/50 rings were laminated together to form a single thicker ring.

Slide the rings down the engine mount tube for perfect alignment while they dry. Be sure they aren't glued to the tube - yet.

The rings were slotted for an easier fit over the engine hook.

The Kevlar got a small loop knot and was slipped under the upper bend of the engine hook before the upper ring was glued in place.
This is the way many Semroc kit engine mounts are assembled.

The top end of the mount also got an engine block.
Here's the finished mount.

Saturday, January 21, 2017

Estes Galactic Taxi #1914 Build Part 3, Fins

I didn't have any 3/32" balsa so I glued up some scraps to make a full sheet.
Two of these pieces were leftover sides from some Estes kit laser cut fin sheets.

After the glue dried the new flat sheet was sanded flat with a block.

The low "Ventral" fin grain surprised me. That extension on the lower left looked too easy to break off. I cut a separate piece with the grain going in a better direction.

Here's all the fins cut out.
Some strange shapes here.

The instruction drawings of the fins aren't accurately drawn.
Pay very close attention to the leading edges, they are the only edges that are rounded.
The fins are confusing to glue on correctly. It helps that some leading edges are rounded for forward positioning reference.

Friday, January 20, 2017

Estes Galactic Taxi #1914 Build Part 2, Parts

All the parts were assembled from my spare parts stash. I didn't buy anything new.
The only new parts will be the printed card stock and decal sheets.

Above you can see the new drawn fin pattern, shroud and canopy printed on 110 lb. card stock.
The balsa fin stock should be 3/32" thick. The sheet I found turned out to be 1/8" thick. Presently I don't have any 3/32" balsa. More on that later.

The kit used the 1/4" thick green 20/50 centering rings. I couldn't find those but had plenty of the BMS Letramax rings. These will be laminated to make two complete rings.
The red 12" chute was one of the transition parachutes Estes included in kits while the print ink problem was worked out.

The body tube I used is BT-50H or heavy walled BT-50 tubing. I hate regular thickness BT-50 tubing, it's just too weak and prone to crimping.
While the kit used a plastic blow molded nose cone I substituted a balsa Alpha style nose cone. The lip was wide enough to evenly cover the outside diameter of the thicker BT-50H tube.

Here's a test fit of the original online fin fairing around the BT-50H tube. This is not my redrawn pieces.
Before forming the fold line was scored. It's difficult to fold a sharp tip like this. It's a little easier creasing it over a straightedge.

With the rear former glued in place the fairing sits neatly around the BT-50H tube.

Bill Cook's Engine Test Stand

Bill Cooke built his own engine test stand.
Check out the great article on his blog - Rocketeer's Corner,

He got some pretty interesting results on his first tests using A8-3 engines.