Agenda

Preliminary Agenda:

1. Overview - schedule and plan (chris)2. Tradiational thin section preparation (skok and jim)3. Epoxy, self-supported thinsection, and support concepts (cbd)4. Sectioning stage with diamond wire (steele)5. Profilometer results (chris)6. Thin section grinder (kris zacny)7. Requirements discussion (chris and all)

Traditional Sectioning Methods

Jim, talk about slicing with SkokDrawback being it takes a lot of power,

large amount of dust generated, and it would take a 12” diameter blade to cut a 5” rock

…. Which leads us to diamond wire

Diamond Wire Tech

A summary of what we have learned from our visit.

Special thanks to Cynthia Christianson for all the help and expertise.

Wire characteristics

Small size (.006”-.012” diameter)

Expect low energy requirements

Little material loss (kerf = wire diameter + .001”)

Small amount of debris generated from cut

Excellent flatness capabilities

A Microphotograph of Diamond Wire

Cross-Section of Diamond Wire

http://www.diamondwiretech.com/diamond_wire/diamond_wire.html

Tangential Cutting

Reduced cut timeMust determine if cut

time reduction is worth the energy requirement

Allows for a higher quality cut (less drift)

Patented by DWT

Process Quality

http://www.diamondwiretech.com/process/process.html

Capstan Wire Guide

Capstan holds short wire lengths (100’ held on ~3” OD x 5” length shown above

Maintains wire integrity better than reel to reel system

Larger package than reel to reelReverses cutting direction every 5 secFairly simple to rethread wire in case of a

break

Reel to Reel Wire Management

Holds long wire lengths (2 km) that runs between two reels

Wire wears faster because it lays over itselfMore compact package overallCutting direction reverses less often

(~30 sec – 90 sec?)Slightly more complicated to re-thread

wire in case of a break

DWT Cutting Control

Wire tension is maintained with air pressure (set to ~15 psi)

The wire is programmed to cut at a set rate OR at a set rate with bow no greater than θ˚ (Typically 3˚)

Downward cutting force is less than 1 lb which allows us to use a light holding force on the rock

Low cutting forces cause rock to resemble ground rock face finishes

Wear Items

Pulleys will need to be replaced after ~250 hours of use (AL hub stays, neoprene V guide slides over hub)

Wire tends to break from bending stresses, not wear of diamond.

Preliminary Concepts

Insert various solidworks sketches

Questions

Do you have a preferred delivery method for receiving the cubic? In a container, a “vise” on a stage, with robotic manipulator?

How do you plan to hold this for grinding? Are there temporary epoxies, tapes that could be used or

reused? I believe C Dreyer mentioned something about this.

If we are to do this without a slide, doesn’t that limit you to boring into our cubic to create the thin section?

What materials are you looking at to do the grinding? If we wanted to collect dust from cutting to analyze there

would be very little from the diamond wire. Would we be able to rely on the rover to pull a dust sample from the ground?

System Requirements

Minimal consumables (epoxy, wire, guides, etc.)Low Power Usage per function (quantify?)Least Mass Possible to do the jobFewer moving parts means fewer broken piecesRobust enough to last for X-months or X-many

sections?No fluids, all electromechanicalMust be able to function at ~40 Kelvin? Would

we be able to simulate anything near that?