- 1 Securing the Workpiece
- 2 Orienting the Workpiece
- 3 Ensuring workpiece is plumb
- 4 Two-sided Cutting
- 5 Drilling Holes
- 6 Clamp Designs
- 7 Usage
- 8 Commercial Accessories and Products
- 9 Table designs
- 10 Fixture designs
- 11 Machining stock square
- 12 References
Securing the Workpiece
You'll need some sort of option to hold the workpiece, from the basic double-sided tape (this is described in the makercam.com tutorial) to clamps along the edge of the piece to more sophisticated work-holding methods such as V- and T-slot beds w/ custom clamps or a vacuum table (Forum discussion).
A comment on spacing --- some sort of ratio (phi?) is likely more useful than even spacing.
- adapted for M5 inserts: https://www.shapeoko.com/forum/viewtopic.php?f=30&t=8938&p=67605#p67605
- Wasteboard workholding w/ HDPE Wasteboard, T-nuts and hardware workholding boot-strapped on the SO3: http://www.shapeoko.com/forum/viewtopic.php?f=35&t=6045
- Easy Hold Down Table, Re: My Machine --- using T-nuts for hold-downs
- Workholding with Threaded Inserts --- easier to install if one doesn't have access to the bottom of the wasteboard (e.g., if one has built a torsion box)
- or just use M5 nuts
- http://community.carbide3d.com/t/success-in-drilling-holes-for-threaded-inserts/1388 --- drilling an already mounted wasteboard
Note that with a two part wasteboard and supporting structure as on an XXL, one can decouple a half, machine it, and then switch as shown in: http://community.carbide3d.com/t/2-inch-grid-my-first-project-xxl3/4826/9
- https://shop.carbide3d.com/collections/tools/products/shapeoko-threaded-table --- see below for details, including PDF drawing
- http://community.carbide3d.com/t/washboard-plans/3965/10 --- design in Autodesk Fusion 360 for Shapeoko 3 waste board with holes for M6 threading, 10mm thick with over 300 thread holes. http://community.carbide3d.com/t/threaded-table-files/3534/12
https://www.reddit.com/r/shapeoko/comments/5wseg5/custom_workholding/ --- elegant aluminum clamp to use with threaded table
http://community.carbide3d.com/t/wasteboard-plans-with-threads/3544/19 --- includes Carbide Create files: S3 BED LEVEL.c2d, S3 GRID 1 inch.c2d, 4 Clamps.c2d
- wagon vice - low profile workholding --- aluminum table modified so as to have an integrated vise.
- Using drill press side clamp is shown in Ran the Circle Diamond Square test
- Hold Down Design
- MDF spacer, T-track, PVC spoilboard: http://www.shapeoko.com/forum/viewtopic.php?f=37&t=8332&p=65068#p65068
- My Machine, Adjustable Hold Down Bed --- T-slot
- Just Enlarged my Shapeoko with some UpGrades --- T-track in an MDF spoilboard
- Shapeoko #0735, mods evolution... (at least my version) ;-) --- aluminum extrusion
- Cheap t-slot wasteboard idea --- making a T-slot bed of three layers of lumber.
- T-Track hold down for my Shapeoko
- Just finished my new base --- Shapeoko 3, plywood base with Shop Fox T-track.
- Rockler 17-Piece Universal T-Track Kit
- Reddit: Finished new wasteboard with rails for clamping!
- My T-slot System (SO3) --- using http://www.mcmaster.com/#1850A14
- MDF spoilboard w/ cut-in T-slots: http://community.carbide3d.com/t/success-in-drilling-holes-for-threaded-inserts/1388/8
- http://www.grizzly.com/products/24-Aluminum-T-Slot-Track/D2724 
- Fastenal: 10 Profile 1 Slot 1"W x 1/2"H x 145"L Grooved Extruded T-Slotted Bar 
- Simple & cheap clamping of workpieces --- ingenious use of plastic screw anchors in drilled holes allowing the re-use of screw holes and accurate placement of screws for workholding.
- Nio's V slot bed
- CNC Machine Horizontal Work Piece Clamping --- shelf pins in a gridded hole array with wedges
- Thingiverse: Shapeoko 2 Modular Table Vice 1"
- Shapeoko 3 Joinery Vice for cutting joints into the ends of vertically oriented boards.
- Thingiverse: Horizontal Work-Holding Clamps for Shapeoko 2
- http://blog.heliumware.com/category/projects/low-profile-vise-for-mill/ --- easy to fabricate design
- Simple custom wasteboard and vice in one --- uses angular wedges
- CNC Pressure Foot™ Clamping Attachment Build Your Own Mounting Bracket 
- L-shaped bracket for use w/ cam clamps: http://community.carbide3d.com/t/tips-for-using-cam-clamps/2632/2
- http://www.thingiverse.com/thing:1245968 --- ingenious technique of cutting slots in the wasteboard, allowing the use of bolts and washers and wingnuts for workholding
- Carbide 3D
- Prototype Carbide 3D clamping system
- Nomad: http://community.carbide3d.com/t/bamboo-work-clamps-made-with-carbide-create/2177/17
- Shapeoko: http://carbide3d.com/docs/tutorials/shapeoko-clamps/
- https://www.shapeoko.com/wiki/index.php/File:HoldDown_clamp.svg --- Cut them in mirrored pairs, pocket the inset half the diameter of a #10-24 or M5 bolt and assemble w/ #8-32 or M3 hardware. Cut a 3/4" dowel to length and drill a hole in it for the selected hardware.
- wooden cam clamps: http://www.woodworkstuff.net/HoweClamp.html
- wooden eccentric clamps: http://community.carbide3d.com/t/clamping-idea-anyone-tried-this/2821/9
- https://www.youmagine.com/designs/low-profile-step-block-clamps-for-cnc 
- http://www.hightechsystemsllc.com/pt_NomadPlateWithCams.html 
- wedge clamps.zip 
- http://www.grizzly.com/products/Hold-Down-Clamp-for-T-Slot-Track/D2726 
- Peachtree https://www.ptreeusa.com/shop_hold_down.htm
- PVC tipped
Suggestions for when using adhesives:
- mill a pocket or recess to hold the piece laterally
- tape down all edges w/ waterproof tape if using coolant
- Fixturing wax
- https://shop.carbide3d.com/collections/tools/products/machinable-fixturing-wax --- available in strong (blue) or water-soluble (white)
- Double-sided tape --- most frequent suggestion for 1/16" aluminum in this thread: http://www.reddit.com/r/CNC/comments/2w8td4/workholding_116_aluminum_piece/ https://www.reddit.com/r/CNC/comments/46lhmm/double_sided_tape_recomendations/
- Ace hardware, light duty plastic carpet tape, 36mm wide, 12.8m long --- included w/ the Nomad 883
- Duck Brand 240200 Double-Sided Duct Tape, 1.4-Inch by 12-Yards, Single Roll
- Scotch® Double Sided Tape 665, 1 Inch x 1296 Inches, Boxed
- Best Deal Depot Double Sided Foam Tape Adhesive
- Nitto (Permacel) P-02 Double Coated Kraft Paper Tape: 1 in. x 36 yds. (White)
- Spray adhesive --- e.g., 3M Super 77
- Rubber Cement
- CA glue
- for aluminum CNCZone: Thin metal work holding. Super glue to the rescue...
- http://community.carbide3d.com/t/masking-tape-ca-glue-to-hold-the-workpiece/1671 c.f., http://community.carbide3d.com/t/tacky-spray-for-holding-parts/2062/4
- Use with blue painter's tape: http://community.carbide3d.com/t/how-to-hold-small-cut-out-parts/3632/11
- hot glue gun
- Polymer nails for CNC workholding --- if you have access to a compressor and a nail gun, polymer nails afford a quick, easy option which is easily removed.
- http://raptornails.com/product-applications/cnc-woodwork.php 
- Simple CNC Clamp Workholding System --- Innovative system using a pair of inexpensive clamps to create a sliding side-clamping system.
- SO3: Vacuum Table!
- Vacuum Table for Shapeoko 2
- Large Format Fabric Cutter
- Drawer Pulls (vacuum table used to cut) --- Google picture link
- https://grabcad.com/library/mini-vacuum-cnc-table-1 --- photos ~100x130mm using vacuum cleaner for PCBs.
- Vacuum table
- Gast vacuum pump
- CNC Cookbook on vacuum tables
- Axiom Precision Vacuum Hold-Down Kit (5 Pods) (Amazon)
- vacuum pods
Discussion of making one's own: http://community.carbide3d.com/t/rockler-vacuum-pods/5798/5
Orienting the Workpiece
Considerations when placing the workpiece on the machine:
- Which side should be up / down?
- If you're milling blind rabbets for a box-bottom, then the nice side should be on the top
- Where should one reference the machine origin?
- If you're milling rabbets, then the reference should be to the work surface where the nice side is
- If you're willing a piece which has countersinks for mounting hardware, then the reference should be the top of the workpiece
Once it is placed, the Zero position will need to be set. It may be necessary to do this sequentially, one axis at a time, possibly even using relative offsets from the desired origin.
Location of a small piece relative to larger stock: http://community.carbide3d.com/t/printing-small-object-on-large-stock/1831
Ensuring workpiece is plumb
There are several options for this:
- Tram the wasteboard
- Probe the workpiece/surface
- Mill a holding pocket in a suitable material
- Shim the workpiece
https://shop.carbide3d.com/products/nomad-flip-jig?variant=5742272707 --- holds material up to 1.25" thick, 2.9" x 4.9"
- http://m.youtube.com/watch?v=BLD4dFoXC7o or http://vod.com.ng/en/video/BLD4dFoXC7o/Platform-CNC-Milling-a-Two-Sided-Soap-Dish
- http://community.carbide3d.com/t/can-i-use-nomad-to-cut-dowel-holes-in-spoil-board/379/8 --- includes discussion of flipping material and hand-coded G-code for alignment holes.
- http://community.carbide3d.com/t/registration-pins-solution/3843 --- use of threaded rods as registration pins in sea of holes bed
Using the center of the stock will double any errors, instead opposite corners are suggested: http://community.carbide3d.com/t/flipping-job-strategy/3719/5
- http://www.winstonmoy.com/2016/03/simple-workholding-clamps/ --- SVG files
- Mill Clamps
- Colorful Clamp Set
- Simple clamps may be fashioned from mending brackets, different lengths of bolts, nuts, and washers
- Thingiverse: CNC Table Clamps
- HoldDown_clamp_MM.dxf --- jzhvymetal's clamp CAD Forum discussion in Re: Easy Hold Down Table
- Table clamps adapted from Thingiverse for cutting in plywood by Tom Smith
- Re: Hold Downs and Sacrificial Board. --- .dxf files for board and hold downs
- Thingiverse: Mini vice
- Thingiverse: Woodwork Clamp (Cramp) --- 3D printed design using 12mm threaded rod
- Carbide 3D flip jig
- Carbide3D: vise jaws for repeat work --- ingenious design which allows clamping parts into a vise while allowing machining on all sides of the stock.
- Thingiverse: Sacrificial vise covers for Carbide3d Nomad Vise
- My cheap clamping solution to hold any piece (MDF + 4 screws)
- Shapeoko 3 Joinery Vice
- Lumberjocks: CNC cut cherry hold downs and knobs.
- Woodsmithtips: Shop-Made Hold-Down
- Simple custom wasteboard and vice in one --- simple wasteboard w/ pocket shaped to allow wedges to clamp rectangular stock.
- https://engineering.purdue.edu/MECL/OLDMECL/pshop/projects/clamp/clampmain.htm 
One option is to mill a rabbet along the bottom edge of a piece and clamp into that: https://www.facebook.com/groups/232744457133521/permalink/259281501146483
Use a bar across large flat stock: https://www.reddit.com/r/CNC/comments/5cvnck/best_way_to_hold_material_on_cnc_bed/d9zq4oa/
Commercial Accessories and Products
- Shapeoko Threaded Table sp3001.pdf --- seems to not have holes suitable for direct use on the XL or XXL. Manufactured of 6061-T6 aluminum, 1/2" thick, anodized black, +/-0.003" in flatness. Note that it has fewer mounting holes than the MDF.
- Nomad Threaded Table --- unofficial redrawing at: http://community.carbide3d.com/t/nomad-883-threaded-table-and-clamps/4691
- silk-screened Waste Board with Threaded Inserts
- Clamp Set
- Rock River Tools CNC Router Vise --- 10 X 14 Vise. A Vectric VCarve file to face the base of the vice is available.
- http://www.stickvise.com --- a low profile PCB vise.
- https://www.amazon.com/Proxxon-24260-Precision-Machine-Vise/dp/B000S8HPLG 
- Rigidax Tooling & Fixturing Wax --- discussion of using it: http://www.shapeoko.com/forum/viewtopic.php?f=7&t=5870&p=46230
- Re: Workholding with Threaded Inserts --- interesting re-purposing of a wood thread box and thread cutting tap to make hold downs.
- Surface Toggle Clamp --- includes link to parts files (on Dropbox) and pdf diagram
- T Wrench for 1/4"-20 Inserts
- http://www.hightechsystemsllc.com/pt_work_holding_system.html 
- Taig accessories including a low profile milling vise: http://www.leevalley.com/US/wood/page.aspx?p=50249&cat=1,330,50260
- http://www.harborfreight.com/58-piece-combination-step-block-and-clamp-set-3-8-eighth-inch-16-nc-studs-1-2-half-inch-clamps-5952.html --- Aluminum Hold Downs
- http://littlemachineshop.com/products/product_view.php?ProductID=2718 --- noted as compatible w/ both #8-32 and M6 threaded holes (as used on most aluminum replacement beds).
- http://tradetools.co.nz/products/7000200 
- http://vacuumtables.co.uk/product/cast-aluminium-t-slot-plate-low-profile-6040/ 
- machinist’s parallels --- http://community.carbide3d.com/t/facing-a-brass-cube/1670/4
- Grizzly low-profile cam clamps
- http://www.incra.com/jig_fixture-build-it_system-clamp.html 
- http://www.harborfreight.com/42-piece-machinist-clamping-kit-90752.html 
- https://lwmcnc.com/cnc-accessories/ 
Carbide 3D wasteboard thicknesses
- original SO3 two-part MDF wasteboard ~12.7mm
- SO3 alu. threaded table ~13mm
- XL MDF wasteboard ~19.5mm
- Nomad MDF wasteboard ~12.85mm
- Nomad alu. threaded table ~15.7mm