EASEL

Last crawled date: 1 year, 12 months ago

Individual Entry for: NASA Experiment Attachment System (EAS) Challenge

A higher intelligence (whether from NASA or not, I can’t tell) is summoning the Earth community to solve a 3D puzzle. I was inspired. Down the line, I figured it out, though the journey seems all uphill. Touchdown! The last piece has landed! I guess…

This is EASEL, which “stands” for Experiment-Attachment Stackable and Engineered Lego-set. (Forgive me of the word play, but this “easel” is not for a lunar portrait masterpiece but portrays as the masterpiece itself.)

The kit basically consists of two stack shapes, a zigzag main frame and a triangular brace, and components for attachment pins. Furthermore, it has multiple framing configurations: It may consist of at least three pieces of only the zigzag frames—enough for diminutive experiments—and can be stabilized further by a maximum of six zigzag frames plus two triangular braces, for a total of eight rigid links for the most stable configuration primed for serious conditions.

Some pins and studs can be screwed and attached already to the frames before launch or can all be screwed and snapped-on onboard ISS. Yet, to obtain the most compact stacked package, only the outer framein a given stack has pins and studs already attached.

Aside from being stackable, one great advantage of its modularity is that it can be assembled with a variety of material configuration, as exemplified later. Yet, in this way, the astronaut will only grab either of the two basic components with less interpolation and can figure out a given attachment system.

The pin assemblies are of stainless steel (SS). The zigzag frames are of SS, aluminum (Al) and ABS. The triangular braces and studs are of SS and Al. For the most rigid framing configuration, an all-steel EAS assembly is needed. On-ground aquatic framing experiments can be performed before launch to choose the best material configuration for a given ISS experiment that uses the attachment, whether an all-steel configuration is necessary or a mixture of ABS and Al frames will suffice. A practical configuration could probably be of two ABS zigzag frames an inch below the attachment plate, four Al zigzag frames attached to the rails, and two Al triangular braces.

One added bonus is that the frames, especially those lying parallel to the attachment plate, can also function as wiring harness, as bracket for the harness or cable ties, and as cable organizer—whether in attached or in detached configuration.

In case of accidental bending of the attached EAS, the bent frame will just be straightened out and reinforced by cut-out frames, cable tied in perfect tandem/sandwich configuration—another advantage of its stacking attribute.

Also, in case when a particular EAS framing configuration is already established, the cut-out feature can accommodate plastic cable ties or similar straps and articulating detachable clips for permanent and reinforced connection.

The intricate part features are taking advantage of the ability of the latest CNC machines and CADCAM interfaces to machine out almost any features in hyper fast and efficient way on a wide variety of materials and cutting conditions. The raised and recessed mating-surfaces features will be of close tolerance just to lock the assembly in place with a snap-fit.

THE MOUNTING PLATE

A CNC milling machine will cut holes and grooves on the bottom surface of the mounting plate for effective anchoring of rotary latches of the captive pin assembly. There is no need for any other features and the surface stays flat in accordance to the specifications.

A finger access to the compact rotary latches for locking and unlocking are cut out from four latching places. Just simply position the rotary latches according to the embossed mark on the mounting plate.

THE ROTARY LATCH ASSEMBLY

The captive pins consist of two assembly configurations. One is of split-type rotary latches with a rigid base plate that can be pushed-fit to a dovetail groove on the zigzag frame. The other is of screwed-type rotary latches that are screwed independently to the zigzag frame. The rotary latch can be as few and simple as one per assembly or four at most. The screwed-type assembly is preferably screwed already on earth but can still be dismantled onboard ISS as spare components. An Allen wrench is all that is needed to firmly screw down the components.

If there is no need of a much tighter launch envelope, the pins and studs can already be attached to the frames before launch as there is ample envelope requirement in this challenge. Then all the astronaut will do is to sort out which of the assembled components will be properly positioned and to assemble the EASEL by hand with no need of tools.