Workholding

Workholding is usually a combination of wasteboard / bed design and matching clamps. A further addition and nicety are Fixtures. (Forum example)

1 Securing the Workpiece
2 Orienting the Workpiece
3 Ensuring workpiece is plumb
4 Two-sided Cutting
- 4.1 Four-sided frame
5 Soft Jaws
6 Drilling Holes
7 Clamp Designs
- 7.1 Accessories
8 Usage
9 Accessories and Products
10 Table designs
11 Fixture designs
- 11.1 Boxes
- 11.2 Boards held vertically
12 Machining stock square
13 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.

Discussions:

https://old.reddit.com/r/hobbycnc/comments/blxmcs/what_is_you_preferred_holding_method_i_just_got_a/

De facto standard hole pattern for fixtures

Bootstrapping a fixture setup: https://community.carbide3d.com/t/notes-on-rapid-positions-and-wasteboard-leveling/8131/2

Threaded Inserts

See: https://community.carbide3d.com/t/threaded-wasteboards-for-xls-and-xxls/10357/2

SO3

http://docs.carbide3d.com/tutorials/project-wasteboard/
- 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[1]
- http://community.carbide3d.com/t/success-in-drilling-holes-for-threaded-inserts/1388 --- drilling an already mounted wasteboard
Cutrocket: Wasteboard V2 --- radial/centered layout

XL

XXL

http://community.carbide3d.com/t/xl-and-xxl-threaded-insert-table-grid-and-clamps/4014

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

http://community.carbide3d.com/t/nomad-waste-peg-board-compilation/9780

Cutrocket

Threaded tables

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

Thingiverse: Wasteboard for Nomad 883 Pro CNC [3]

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

Extension for front of machine: https://community.carbide3d.com/t/so3-removable-front-extension-table/3506

Mounted clamps

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

T-slot

https://shop.carbide3d.com/collections/tools/products/t-track-table
- http://community.carbide3d.com/t/t-track-extrusion/11473 --- dimensioned drawing of extrusion used
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[4]
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 [5]
Reddit: Finished new wasteboard with rails for clamping!
- http://www.busybeetools.com/products/utility-track-24in.html (Canada)
- http://www.busybeetools.com/products/hold-down-for-t-track.html
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 [6]
Fastenal: 10 Profile 1 Slot 1"W x 1/2"H x 145"L Grooved Extruded T-Slotted Bar [7]
http://community.carbide3d.com/t/wasteboard-that-deals-with-different-materials/10779/9
http://community.carbide3d.com/t/another-baseboard/10429

XXL

https://www.facebook.com/groups/unofficialshapeoko/permalink/535284736879490/

4 - Misumi HFSQN4-15250-1015 ALUMINUM FRAME incl. shipping: $263.99 https://us.misumi-ec.com/vona2/detail/110302261820/?ProductCode=HFSQN4-15250-1015
1 pack of 100 - Misumi PACK-HNTP6-6 NUTS FOR ALUMINUM FRAMES (spring nuts) incl. shipping: $55.01
16 - M6-1 flat head machine bolts (not very long - can't remember the exact length): $6
1/2" felt strip for steel bar: $3.50
1" steel bar from local steel company: $17

Also: Help from next door neighbor brazing tabs onto the steel bar for mounting: Priceless

Additionally: a tap-and-die set, a countersink bit, drill bits you're comfortable using on aluminum and steel, and plenty of time and patience.

Adhesives

Suggestions for when using adhesives[17]:

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[18] --- 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/
- https://shop.carbide3d.com/collections/tools/products/double-side-tape
- Ace hardware, light duty plastic carpet tape, 36mm wide, 12.8m long --- was included w/ the Nomad 883[19] but seems to be discontinued
- Duck Brand 240200 Double-Sided Duct Tape, 1.4-Inch by 12-Yards, Single Roll [20]
- Intertape
  - 591 Premium Double Sided Golf Grip Tape, 2" x 36 yd Amazon [21]
  - Intertape 591/BEIG136 591 Double Sided Flat Back Paper Tape: 1" x 36 yd, Beige ($11-$14) Amazon
- Scotch® Double Sided Tape 665, 1 Inch x 1296 Inches, Boxed
- Best Deal Depot Double Sided Foam Tape Adhesive [22]
- Nitto (Permacel) P-02 Double Coated Kraft Paper Tape: 1 in. x 36 yds. (White)[23] https://community.carbide3d.com/t/the-double-sided-tape-thread/24302/20
- https://www.amazon.com/gp/product/B07BBL4JXJ
Spray adhesive --- e.g., 3M Super 77[24]
- spray adhesive and contact paper: https://makezine.com/2017/07/19/keep-your-project-secure-cnc-workholding-techniques/
Rubber Cement
- rubber cement[25] --- see also State Outline Cut in Veneer
- Rubber Cement Hold-down Assist
CA glue
- for aluminum[26] 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[27]

Fasteners

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 [28] [29]

Clamping systems

Simple CNC Clamp Workholding System [30] --- Innovative system using a pair of inexpensive clamps to create a sliding side-clamping system.

Tooling Plates

Tooling Plate for Mini Mills [31]

Vacuum

SO3: Vacuum Table!
https://www.thingiverse.com/thing:2850918 [32]
Vacuum Table for Shapeoko 2
Large Format Fabric Cutter
Drawer Pulls (vacuum table used to cut) --- Google picture link
http://makezine.com/projects/shopbot-desktop-universal-vacuum-hold-down-system/ --- https://makezine.com/projects/make-41-tinkering-toys/shopbot-desktop-universal-vacuum-hold-down-system/
https://grabcad.com/library/mini-vacuum-cnc-table-1 --- photos ~100x130mm using vacuum cleaner for PCBs.[33]
Vacuum table[34]
- http://www.microsystemsgeorgia.com/Vacuum_Fixture_Part_1of2.pdf
- http://www.microsystemsgeorgia.com/Vacuum_Fixture_Part_2of2.pdf
CNC Cookbook on vacuum tables[35]
- http://www.cnccookbook.com/CCCNCDIYVacuumTable.html
- http://www.cnccookbook.com/CCCNCVacuumTable.html
Axiom Precision Vacuum Hold-Down Kit (5 Pods) (Amazon)
https://www.facebook.com/groups/unofficialshapeoko/permalink/838854086522552/ Simple box vacuum

Discussion of making one's own: http://community.carbide3d.com/t/rockler-vacuum-pods/5798/5

One ingenious idea was to use a layered system which had holes which could be filled with 6mm Airsoft pellets: https://www.facebook.com/groups/unofficialshapeoko/permalink/603645233376773/

Tabs

An interesting addition, tabs may be added either manually to a file, or as an automated/controlled feature in some CAM software. tab size/thickness is a consideration. Guideline(s):

Plywood --- tabs should be thick enough to include 2 plies. [36]

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.[37]

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[38]
Probe the workpiece/surface[39]
Mill a holding pocket in a suitable material
Shim the workpiece[40]

Two-sided Cutting

https://shop.carbide3d.com/products/nomad-flip-jig --- holds material up to 1.25" thick, 2.9" x 4.9" --- the circular and diamond locator pins are explained in the Carrlane Catalogue. Made to hold stock less than 3"x5" in size, and up to 1.2" thick. Machined to .002" tolerance. See: http://community.carbide3d.com/t/carbide-3d-flip-frame-for-2-sided-machining/563 and the video at: https://www.youtube.com/watch?v=rXChh__bJsw

Carbide 3D answer video: https://www.youtube.com/watch?v=o1LRC7QZoOs

http://www.shapeoko.com/forum/viewtopic.php?f=7&t=650
http://www.shapeoko.com/forum/viewtopic.php?f=6&t=3499
http://m.youtube.com/watch?v=BLD4dFoXC7o or http://vod.com.ng/en/video/BLD4dFoXC7o/Platform-CNC-Milling-a-Two-Sided-Soap-Dish [41]
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
http://community.carbide3d.com/t/made-a-spoon-with-my-so3/6766
https://community.carbide3d.com/t/a-simple-technique-for-two-sided-work/8117 --- flipping using the Probe
cutting gears using center holes for fixturing: https://www.reddit.com/r/hobbycnc/comments/eaens8/help_needed_for_cutting_cycloid_disk/
https://www.reddit.com/r/hobbycnc/comments/lw60ua/jig_for_registering_double_sided_projects/ --- ingenious fixture

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

Four-sided frame

http://community.carbide3d.com/t/4-sided-flip-frame-prototype/2882

Soft Jaws

http://community.carbide3d.com/t/workflow-for-machining-small-objects/1032/5

Drilling Holes

http://www.shapeoko.com/forum/viewtopic.php?f=7&t=7362&p=58151#p58151

Clamp Designs

http://carbide3d.com/docs/tutorials/shapeoko-clamps/
http://community.carbide3d.com/t/bamboo-work-clamps-made-with-carbide-create/2177
http://www.winstonmoy.com/2016/03/simple-workholding-clamps/ --- SVG files
Mill Clamps
Simple clamps may be fashioned from mending brackets, different lengths of bolts, nuts, and washers[42]
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
https://github.com/vlachoudis/bCNC/wiki/Simple%20Clamps
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
- http://community.carbide3d.com/t/carbide-3d-flip-frame-for-2-sided-machining/563
- 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)[43]
http://www.projectsinmetal.com/free-metalworking-project-plans-toolmakers-screwless-vise-mill/
Shapeoko 3 Joinery Vice
Lumberjocks: CNC cut cherry hold downs and knobs.
Woodsmithtips: Shop-Made Hold-Down
Thingiverse
- Thingiverse: Drilling Vice
- Customizable vise (vice)
- CNC Clamp [44]
- Thingiverse: CNC Clamping Stairs
- Shapeoko 2 Work Clamp
- http://www.deansphotographica.com/machining/projects/mill/vise/vise.html Precision Screwless Vise
- Thingiverse: Toolmaker's Vise
McMaster-Carr
- Cam: http://www.mcmaster.com/#cam-clamps/=104gwp5
- Edge holding: http://www.mcmaster.com/#standard-setup-accessories/=104gt63
- Toe clamps: http://www.mcmaster.com/#8958a11/=1071qs3 [45]
Grainger
- Side clamp: https://www.grainger.com/category/machining-machine-tool-accessories-straight-line-clamps/ecatalog/N-9nn/Ntt-toggle+clamp?nls=3&ssf=3&sst=subset&ts_optout=true
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 [46]

Discussions:

https://www.reddit.com/r/CNC/comments/48u6yn/low_profile_vise_optionsrecommendations/

Other options:

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

Accessories

thumbv3.stl [47] --- fits M6 SHCS

Usage

http://community.carbide3d.com/t/work-part-clamping-many-of-you-are-doing-it-wrong/3396

Use a bar across large flat stock: https://www.reddit.com/r/CNC/comments/5cvnck/best_way_to_hold_material_on_cnc_bed/d9zq4oa/

Accessories and Products

Threaded tables/wasteboards/Clamps

Shapeoko

Carbide 3D
- Shapeoko Threaded Table sp3001.pdf (reduced)[48] --- seems to not have holes suitable for direct use on the XL or XXL. Manufactured of 6061-T6 aluminum, 1/2" thick, (note that it is no longer anodized black), +/-0.003" in flatness. Note that it has fewer mounting holes than the MDF. Autodesk Fusion 360 model: http://a360.co/2w8yJnZ [49] c.f., https://community.carbide3d.com/t/carbide-create-wasteboard-files/20086
https://community.carbide3d.com/t/carbide3d-corner-square-digital-model/22954

Nomad

Bed layout: table.pdf[50]
- Nomad Threaded Table --- unofficial redrawing at: http://community.carbide3d.com/t/nomad-883-threaded-table-and-clamps/4691
- https://a360.co/2LoqgpC [51]
Low Profile Vise[52] 34 mm high [53]
- 3D model: http://a360.co/2glGNqw [54]
- https://www.youtube.com/watch?v=xNUvajslQqI
Tiger Claw Clamps: https://a360.co/3tsEMxz [55]
Custom corner finder: https://a360.co/3cJ9igI [56]
corners for holding sheets: https://community.carbide3d.com/t/nomad-jig-for-aluminium-plate-4x5/30248

Clamps and clamp sets

Carbide 3D
Amazon: 24 Pcs Clamp Kit Set M6 (6 mm) For Rotary Tables, Milling Tables, Face Plates & Vertical Slide
https://www.a2zcorp.us/store/ProductDetailNP.asp?Cguid=%7B6F714609-E2EF-4AD1-A2A2-DC0488BFE2DD%7D&ProductID=5811&Category=WorkHolding%3AMillingClamps
Rockler
- http://www.rockler.com/auto-lock-t-track-clamp
- http://www.rockler.com/mini-deluxe-hold-down-clamp
Surface Toggle Clamp --- includes link to parts files (on Dropbox) and pdf diagram
Harbor Freight
- 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://www.harborfreight.com/42-piece-machinist-clamping-kit-90752.html [58]
Little Machine Shop
- 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).[59]
- M6 threaded rod version [60]
  - http://littlemachineshop.com/products/product_view.php?ProductID=1972&category=1130
  - http://littlemachineshop.com/products/product_view.php?view=classic&ProductID=203912
http://tradetools.co.nz/products/7000200 [61]
http://vacuumtables.co.uk/product/cast-aluminium-t-slot-plate-low-profile-6040/ [62]
Grizzly low-profile cam clamps [63]
Amazon Shop Fox D3347 Cam Clamp [64]
http://www.incra.com/jig_fixture-build-it_system-clamp.html [65]
http://www.widgetworksunlimited.com/CNC_Pressure_Foot_Clamping_Attachment_p/cnc-pressure.htm
Legacy Woodworking Low Pro clamps https://lwmcnc.com/cnc-accessories/ [66]
Carr Lane
- https://www.carrlane.com/en-us/product/clamps-accessories/edge-clamps/tiny-vise-edge-clamps/tiny-vise-edge-clamps-low-profile
- https://www.carrlane.com/en-us/product/clamps-accessories/edge-clamps/tiny-vise-edge-clamps/tiny-vise-edge-clamps
Mitee-Bite
- https://www.miteebite.com/products/pitbull-clamps/
- https://www.miteebite.com/products/fixture-clamps/

Machinist’s parallels

http://community.carbide3d.com/t/facing-a-brass-cube/1670/4

Vise

https://shop.carbide3d.com/collections/accessories/products/low-profile-vise https://community.carbide3d.com/t/vise-and-jig-in-fusion-360/3538/6 Holes on table are for 6mm pins: https://community.carbide3d.com/t/suggestion-include-6mm-pins-with-the-low-profile-vise/27226
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.[67]
https://www.amazon.com/Proxxon-24260-Precision-Machine-Vise/dp/B000S8HPLG [68]
Taig accessories including a low profile milling vise: http://www.leevalley.com/US/wood/page.aspx?p=50249&cat=1,330,50260
https://leadingedgeindustrial.com/product/leading-edge-industrial-low-profile-vise/ [69]

Vacuum

Vilmill --- substrate for working with a vacuum table system.
http://www.workholding.com/vAccssors.html --- vacuum gasket material
Gast vacuum pump[70]
vacuum pods
- http://www.rockler.com/rockler-vacuum-clamp-pod-kit [71]
- http://community.carbide3d.com/t/update-on-vacuum-table-stuff/6206

Fixturing Wax

Rigidax Tooling & Fixturing Wax [72] --- discussion of using it: http://www.shapeoko.com/forum/viewtopic.php?f=7&t=5870&p=46230 Source: https://www.paramelt.com/acquisition-of-casting-wax-producer-argueso.aspx MSDS: http://www.machinablewax.com/docs/MSDS_WI-Blue_23-8_Rigidax_Mar19-2009.pdf

DIY

Re: Workholding with Threaded Inserts --- interesting re-purposing of a wood thread box and thread cutting tap to make hold downs.

Threaded insert tools

T Wrench for 1/4"-20 Inserts

Carbide 3D wasteboard thicknesses

original SO3 two-part MDF wasteboard ~12.7mm --- current production (since Summer 2016?) are 0.75"
SO3 alu. threaded table ~13mm
XL MDF wasteboard ~19.5mm
Nomad MDF wasteboard ~12.85mm
Nomad alu. threaded table ~15.7mm[73]