A New Toy For The Shop

A package from Amazon arrived at my doorstep today containing my latest shop tool - an airbrush:

With the Artemis plastic conversion project getting nearer to the painting stage, this should be perfect for rendering the complicated surface patterns on the SLS core.

The best part of having the airbrush is that I can use the non-stinky acrylics to my heart's content - indoors!

Gone will be the days of having paint-ready models sitting around in the shop waiting for a warm, windless day to take them outside for spraying. Sometimes the wait can last for weeks on end.

No more bugs landing in the fresh paint,  either!

Let the fun begin....

A Mystery Solved

 Back in 2021, I posted a report here on the blog for a launch outing on May 13th.

One of my models launched was the maiden flight of an Estes Super Shot.

After I pulled a still frame from the flight video of the liftoff, I made note of a mysterious object appearing in the sky just to the left of the smoke plume.

At the time I shrugged it off as an anomaly in the digitally produced image and didn't bother to investigate further.

Last night, I revisited the flight video, focusing on the liftoff portion starting at the moment of ignition.

What I found was not an image glitch, a UFO, or anything else,  but the motor igniter plug striking the launcher and bouncing into the air.

The reason it looked so large and prominent is that it bounced in my direction while staying in the series of video frames.

Here are more pics from the video sequence:

Cheers!

Artemis I, Part 9 - "A Trick of the Tail"

 That's the title my all time favorite Genesis album from 1976.

It also applies here with the Artemis build as I embark on the model's tail piece, which might be a bit tricky to engineer into position.

The piece is designed to be glued onto the rear of the main core rocket tube (where else, eh?). It also bears a lot if the small detail at the aft end of the rocket.

Since my core BT-50 motor tube protrudes a bit further than the end of this piece when installed, I will have to cut the bulkhead to fit.

A drill and Dremel tool does a fine job with that:

Here is the finished tail section dry-fitted in place...

I have decided that the four scale RS-25D engine nozzles will be retained on this model, but in order to do that, they must be cut back on the inner surfaces to clear the working BT-50 tube and protruding motor. Here are the four nozzles fitted in their locations. I've applied small guide marks with a Sharpie marker to show where the parts must be cut back:

The nozzles will attach to the tail base plate via two locator pins apiece.  Each nozzle is finger-held while being carefully trimmed back with the Dremel.  Delicate work, folks.

Here is the first finished nozzle after cleaning the edges up with needle files:

Now to make theee more just like it.

The nozzles won't be glued on until after all the parts are painted separately.

Moving on...

Meanwhile, Back At The Other End Of the Workbench...

 In between work on the various sections of the Artemis build, I have a few other small projects in progress at the far end of the workbench.

First, I managed to cut and seam-fill a section of BT-55 body tube to replace the damaged one on the Estes Solo model that lawn-darted on its last flight. The tube also got fitted with a set of launch lugs.

Yesterday, I took advantage of some very nice weather outdoors, so the tube received a coat of primer.

While I was at it, I shot some primer on the two open-gap booster stages I had finished assembling last fall.

Over the next couple of days, these items will get sanded, painted, and made entirely flight ready.

Cheers!

Artemis I, Part 8 - The 'Topper'

 Initial assembly of the of the nose portion of the model is quite straightforward - two molded halves to cement together topped with a very tiny nose cone to complete the escape system.

I did find that, after the cement dried, the escape motor section appeared a bit crooked. Time to break out the 'thermal assembly modification apparatus' (Mrs. BlastFromThePast's hair drier) to attempt to warm the plastic part up enough to straighten it out.

The next process in the assembly is to build a shoulder for the nose section that will fit inside the core section's BT-55 parachute compartment.

A quick check of my parts stash revealed that I had no spare 55-sized stage coupler, so this was going to require an improvised approach.

Normally, a short piece of BT-55 slit lengthwise and cut down to fit inside a 55 tube can be used as a makeshift coupler.

But, I happened upon an different solution...

As a consummate scrounger, I always hang on to any cardboard core tubes from gift wrap rolls and food service products.

To my surprise, one of the tubes in my stash just happened to fit nicely inside a BT-55!

Out came the tube cutting rig again...

The fit inside the 55 was a tad bit loose, so a strip of printer paper was glued around the coupler, giving it enough diameter to fit snugly.

Next, a bulkhead was cut from a sheet of 1/6" basswood and epoxied in place.

To center the coupler in the plastic nose assembly, eight 1/16" basswood spacers were glued around the perimeter.

For the parachute/shock cord attachment point, I'm going with a section cut from a large paper clip.  Two small holes get drilled into the basswood bulkhead to accommodate the wire.

Since this part will be taking a lot of recovery deployment stresses, I deemed it a good idea to reinforce the bulkhead. For this I went with a metal washer epoxied to the inside of the coupler. This will also serve to add a bit of nose weight that I know will be needed down the road.

The paper clip wires were then inserted and bent over atop the washer. As an extra precaution, I flowed some solder into the joints to keep them attached.

Looks ugly, but it should hold...

This project has definitely morphed into a true scratch-builder's dream (or nightmare, depending on one's perspective) !

The coupler will not be glued into the plastic nose section at this time to allow the later insertion of whatever additional nose weight will be required when the model is fully assembled.

Cheers!

Artemis I, Part 7 - Constructing The SRBs

 With the core rocket assembled, it's time to turn my attention to the model's two SRBs.

These will be powered by A10 plugged motors, so the mounts will be fairly straight forward, and modification of the kit plastic parts will be relatively simple.

The first order of business is to fire up the Dremel and remove the plastic alignment pins and sockets at the aft ends of the SRB halves.

Building the motor mounts

Here I will be using the two-inch sections of BT-5 that were cut to length earlier. These each get a motor block glued in, spaced so that the motor casings will be flush with the SRB nozzle details. I am foregoing use of the music wire retainers, as the plugged motors won't have much of a kick-back. They may however, get friction taped in to prevent the casings from ejecting as the core motor continues thrusting.

I found that I was out of stock on manufactured BT-5 sized motor blocks, so a couple of spent casings, a razor saw, and a bench hook remedied that problem.. 

Why I save cereal boxes...

They come in handy for making some scratch-built rocket parts.

In this case, pieces cut from a box panel are the perfect thickness for fashioning the required centering rings.

Glue-up time...

As with the core rocket assembly, I am using 30-minute epoxy to install the motor mounts.

Then working quickly with more epoxy and the required amounts of plastic cement, the SRB halves are pressed together and secured with rubber bands.

Oh, and must not forget the tiny SRB nose cones...

More to come!

Artemis I, Part 6 - gluing up the SLS Core Rocket

This is a short post. 

Using 30 minute epoxy, the motor tube and parachute compartment were glued into position. 

Liquid plastic cement was applied to the model's alignment pins and external seams. The assembly was secured with rubber bands to keep everything tight while all the adhesives dried and cured.

Tomorrow, a little extra plastic cement will be carefully brushed into the seams to flow into any remaining gaps. The seams will then get a light finish sanding to remove any irregularities that might remain. 

I don't anticipate much work in this area, as the seams will be mostly hidden when the SRB units are attached.

Moving on...