Last edited: Furst (08/26/20)

Instructor:

Date:

• This training provides an introduction to using and operating the Sherline CNC glass drill including:
  • Safety
  • Applications
  • Software
    • File types
    • Flashcut
  • Sample prep
  • Drilling
  • Printer Maintenance
    • Changing Print Heads
    • Changing Fulfillment Type
    • Cleaning
• Remember to enter job information into the 3D print job log!

Eye injuries can result from flying chips or broken bits. Cuts can occur from contacting sharp tools or broken glass. Burns can result from hot cutting tools or parts. Serious injury can result from pinching or entanglement in moving parts. Poor housekeeping creates tripping and cutting hazards for other users. Do not leave machine running unattended. Eye protection, closed toe shoes, long pants, and protective clothing must be worn when using this machine to prevent injury. Long hair must be tied back and jewelry must be removed before operating this machine to prevent entanglement.

The Sherline CNC is used exclusively for for drilling holes in glass, ceramic, silicon, or other brittle materials. Milling of brittle materials is not supported. The Sherline uses a high speed spindle in combination with abrasive diamond drill bits to slowly abrade the material away.

Typical applications include adding macro to micro interface connecters to Microfluidics chips.

The Sherline CNC uses a retrofitted Sherline mini mill in combination with the FlashCut CNC software. This SOP does not cover dxf2fgc conversion code.

FlashCut CNC offers a user interface for positioning, zeroing, and running the G-code, however it has no CAM capabilities. This means that G-code must be hand written based on the location of holes.

A backing plate is required for drilling, and should be bonded to the substrate to be drilled to improve backside cut quality. If bonding is not permitted, slowing down cut speed may result in less blowout on the backside of the hole.

1. set CrystalBond hotplate to 121 degrees C
2. place a sheet of tinfoil or wax paper over hotplate to avoid spilling of crystal bond
3. place sample and backing plate on covered hot plate and allow them to reach equilibrium
4. using the CrystleBond stick and a pair of tweezers to hold the sample in place, gently paint on a thin layer of Crystal Bond to both the substrate and backing plate
5. using tweezers, flip the substrate over and place CrystalBond sides together, wiggle side to side to minimize air bubbles.
6. place the hot bonded slides on the teflon fixture and align the substrate and backing plate. Remove from heat.
7. After sample has cooled, use a razor blade to remove any CrystalBond on the edges of the sample. This will insure that edge finding finds the edge of the sample, rather than the edge of the crystlebond.
8. After drilling is done, place back on hotplate to separate backing plate from sample before placing sample in acetone to remove any remaining CrystalBond.

1. At the Computer::
   1. Load your STL file into the print software on the computer adjacent to the printer (Cura for Ultimaker, GrabCad Print for F270).
   2. Set Print Parameters:
      1. Position the part on the build tray in a way that is conducive to 3D printing (flat side down)
      2. Select appropriate layer or slice height (the more slices the higher the print resolution but the longer it takes to print)
   3. For Ultimaker:
      1. Select “generate support” if necessary
      2. Check appropriate filament and bed temperatures (should be set if using standard filament load out)
      3. Send job to Ultimaker using USB drive
   4. For F270:
      1. The F270 the printer will print a raft before printing the model. Make sure first layer is set to support material or removal will be incredibly difficult.
      2. Send job to F270 over Ethernet
   5. Record the material used and print time in the online log along with the other job information requested. The print log should be on the desktop or https://docs.google.com/forms/d/e/1FAIpQLScS3URUxoHOR62PdQeeSTAYg_suV061UsoFafrgoN0qn6DWYg/viewform.
2. At the printer:
   1. Ultimaker:
      1. Make sure print bed is clean
   2. F270:
      1. Make sure that there is enough room on an CLEAN build tray for your part, and that the build tray is secured in the printer with the locking arm horizontal. Build trays may be used until the entire build area has been printed on, but printed areas should ideally not be reused.
   3. Start the job at the printer

Ultimaker

• Remove part from print bed using a spatula or razor being careful not to cut yourself or scratch the build plate. Make sure no body part is in line with the tool should it slip or the part break free unexpectedly.
• If support was used, submerge print in warm water for several hours to dissolve PVA filament. (prints can warp if submerged in water for over 24 hours)
  

F270

• Remove the build tray and flex it to break the bond between the material and the tray.
• Separate your part from the build tray with a spatula and scrape off any debris so they tray can be reused.
• Put on the appropriate PPE: don gloves, a face shield, and a lab coat.
• Carefully, slowly, and without splashing cleaning solution, open the support removal tank lid and remove and open the tank.
• Place large parts directly in the tank, small parts may be put in the SS box and placed into the main basket.
• Carefully, slowly, and without splashing lower the basket back into the tank and close the lid.
• Set timer for 8 hours using the “set” button.
• Select the temperature to be 70 degrees C and push the power button to warm the tank.
• After cleaning time has elapsed, follow the instructions above for opening and removing parts.
• Rinse part in warm water.

F270:

F270 hourly charge: $1/hr to pay for head replacement

Ultimaker: ABS: .12/gram

Tool Lead: Andrew Furst
Contact: Andrewfurst@ucsb.edu

• Both print heads and bed are heated during operation. Do not attempt to clean, remove, or adjust without allowing for adequate cool down time.
• Keep hands clear of printer during operation. Pause print before clearing or adjusting part.

1. On the F270 printers computer, launch GrabCad Print
2. Select File → New Project → Add Models → Import desired models
3. Move models around on virtual build tray so that models on a used build tray do not overlap any previously printed spots
4. the purge block and printed model should be placed close together to minimize print time
5. Select “Print Settings” from the menu on the right hand side
6. From menu, select desired slice height, and verify that the first layer material is set to support.
7. Open and place build tray into F270, making sure that the tray is locked in place by pulling up on the front locking arm until arm is PARALLEL to build tray.
8. Select print, and send the job to the F270 3D printer
9. on the F270 touch screen, select your job, and then select print.

• If support was constructed from dissoluble filament clean using the F270 Support Removal Apparatus which is filled with heated caustic chemicals. GLOVES, LAB COAT, AND FACE SHIELD MUST BE WORN
• Build tray should be scraped clean and free of any support or build material then placed in the USED F270 tray drawer if printable space is left. Any material protruding from the build tray will damage print heads during the next print.

• Clean oven chamber weekly
• Clean platen weekly
• Inspect, wipe, and clean tip wipe assemblies monthly
• Clean exterior of printer as needed
• Clean touchscreen as needed