Saturday, March 16, 2024

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!