NASA Lunar Collector

Last crawled date: 1 year, 10 months ago

NASA Lunar Sampling System

Prerequisites:
• The collector is mounted on lander or rover handling arm. The interface is adapted to the arm (here as a flange)
• A parallel arm system should be inserted so that the collector can keep contact to the surface. For weight reasons, this is not included in the weight indication
• The collector may be mounted on a vertical axis swing arm so that it can be driven around and thereby cover a circular area
• To minimize the weight, switch between the different containers (here 5) and the chute location, the handling arm is used to push the container row and chute (see below). However, it would be quite easy to add motors or actuators to handle these movements.
• An operator is monitoring the flow by camera and is operating the arm/collector remotely

Comment added 30/9-2018:
3D-printed the hole assembly in half scale 28/9 to test the function, see note below.
- added a STL-file of a stronger screw-helix (Screw -helix thick.STL) 30/9, as the down scaled model was to weak.
Video link added 2/10-2018

Contents:
• A slanted Screw/helical (20 degree) with progressive pitch and conical end. The outer edges of the screw are fitted with a soft edge made of Teflon, to achieve a certain scraper effect.
• A Screw Pipe Housing designed so open that it is possible to follow the movements of the rocks through the screw. The inlet will restrict how big the rocks can be. The front opening will allow 20x20mm and the back opening will allow 10mm high rocks, so depending of which direction, the sampler is moved over the surface, two different restriction are active. Bigger rocks are guided away from the opening holes.
• A Sorting Grate located at the end of the screw tube as part of this. The longitudinal ribs of the grate have a growing distance, so that small stones will fall through the grate in its narrow end, while larger stones will be led further up before they fall through the grate. Very small rocks and sand is collected by pushing the chute towards the inlet.
• An open Chute-tube that can be moved in the longitudinal direction of the grate so that the chute opening can be placed under the desired grate opening, and so that stone sizes up to the grate size can pass into the container.
• A Container Magazine, where a number of containers (here 5 pcs.) can be placed in. The magazine is placed underneath the chute's opening and can be slided so that each container can be placed underneath the chute.
• 5 Containers with a stop edge at the top, mounted in the magazine.
• A motor / drive system for rotating the screw fastened to the end of the screw housing. If possible blockage or need for emptying the screw, this can be rotated backwards. Possibly it can be driven
intermittent to avoid blocking.
• A parallel arm system could be mounted between the handling arm and the collector, which ensures that the collector inlet always has contact with the ground in the right orientation. In this way, the operator can concentrate on bringing the collector's inlet across the terrain to hunt stones .
Description:
• The collector is clamped / clicked on the rover or landers handling arm.
• The collector has been made as open as possible so that the entire process can be monitored from the camera.
• The operator guides the arm / Collector opening over the surface where rock is to be collected.
• The Screw rotates and pulls the stones and ralts that have been able to pass through the restrictive opening in the inlet opening.
• When the rocks approach the upper end of the Screw Housing, they pass over a Sorting Grate.
• Depending on where the Chute is located under the Grate, the stones of the correct size will fall into the Container. The Chute is moved according to the wanted size of the rocks, which can be observed through the camera.
• If large items are desired, the Chute is slided away from the inlet and if small rocks are desired, the Chute is pushed against the inlet.
• The setting of the Chute and Container takes place with the lander's arm as the opening in the he end of the Magazine plate is maneuvered over a fixed anchor pole. When moving the arm, the fixed Magazine will be moved relative to the Chute and the relative to the Screw Housing. Once the desired setting is reached, the entire Collector is released from the anchor and thereby ready to continue the stone collection with the new settings.

Options / capabilities:
• Can work on fairly uneven surfaces, as the inlet opening has a rather small touch point. Works best on flat or wavy surfaces.
• Growing cross section -> Less chance of clamping
• Easy to remove the filled container magazine
• Only very little power consumption (only one motor)
• Simple construction -> less problems (KIS)

Data:
• Most of the construction is made of aluminum
• Total weight (excluding motor): less than 1000 grams
• The Collector is printed 3D (in Nylon Onyx, scale 1:2, 0.125mm layer), on a Markforged X7 (results show in the pictures) and therefore the walls are made thicker than necessary than if it was made of aluminum. It seems to function ok, but the print was just finished this afternoon, so I have not testet it yet.
• The uploaded STL-files are 1:1

I have also added a few pictures of my first attempt, which was very compact and light (less than 500 grams :-) I suppose that it will function quite well also.