1 / 13

Agenda

Agenda.

oni
Télécharger la présentation

Agenda

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 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)

  2. Traditional Sectioning Methods • Jim, talk about slicing with Skok • Drawback 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

  3. Diamond Wire Tech A summary of what we have learned from our visit. Special thanks to Cynthia Christianson for all the help and expertise.

  4. 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

  5. Tangential Cutting • Reduced cut time • Must determine if cut time reduction is worth the energy requirement • Allows for a higher quality cut (less drift) • Patented by DWT

  6. Process Quality http://www.diamondwiretech.com/process/process.html

  7. 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 reel • Reverses cutting direction every 5 sec • Fairly simple to rethread wire in case of a break

  8. Reel to Reel Wire Management • Holds long wire lengths (2 km) that runs between two reels • Wire wears faster because it lays over itself • More compact package overall • Cutting direction reverses less often (~30 sec – 90 sec?) • Slightly more complicated to re-thread wire in case of a break

  9. 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

  10. 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.

  11. Preliminary Concepts • Insert various solidworks sketches

  12. 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?

  13. System Requirements • Minimal consumables (epoxy, wire, guides, etc.) • Low Power Usage per function (quantify?) • Least Mass Possible to do the job • Fewer moving parts means fewer broken pieces • Robust enough to last for X-months or X-many sections? • No fluids, all electromechanical • Must be able to function at ~40 Kelvin? Would we be able to simulate anything near that?

More Related