Hole layouts that machine cleanly and why we always run the calculator first

If a hole pattern is off by half a degree, the best CAD model still becomes scrap. In our shop we treat hole layouts as a separate, deliberate step: pick the right pattern, lock the origin, generate coordinates, then hand clean files to CAM. The process is fast, boring—in a good way—and it removes the arguments between design and machining.

Use our Hole Layout Calculator while you read; the notes below map to its fields.

The shortest path from idea to coordinates

Most jobs fall into three buckets:

• Bolt circles (PCD/BCD): flanges, couplings, adapter rings.

• Rectangular arrays: vent patterns, pin jigs, electronics panels.

• Masked arrays: a grid where a few positions must disappear for cutouts or connectors.
  
  

Before typing numbers, decide where (0,0) lives. For concentric parts, keep the origin at the center. For sheet-metal panels measured from edges, use a corner origin and keep it on the drawing.

Open the Hole Layout Calculator and you’ll see the minimum set that never bites back:

• Pattern type (Circle / Grid / Custom mask)

• Count (holes, rows/columns)

• Size (PCD for circles; pitch or window size for grids)

• Base angle for the first hole (θ₀)

• Units and rounding

• Exports: DXF, CSV, and a 1:1 PDF with a scale bar
  
  

That’s 95% of real work—no manual trig, no spreadsheet gymnastics.

A routine we use daily (copy these steps)

Six-hole motor flange

• Pattern: Bolt Circle

• PCD: 120.00 mm → radius 60.00 mm

• Holes: 6 → 60° per step

• Base angle θ₀ = 90° (puts hole #1 straight up, +Y)

• Rounding: 0.01 mm, Units: mm
  
  

• Export DXF + CSV + 1:1 PDF, note on the print:
  ORIGIN = CENTER, HOLE Ø = 9.0 mm (clearance for M8), FINISH = …
  
  

If hole #1 sits on +X in the preview, only θ₀ is wrong—don’t touch anything else.

Panel vent array

• Pattern: Grid

• Rows/Columns: 5 × 8

• Pitch: 20 × 15 mm

• Alignment: Center within window 160 × 100 mm

• Optional: rotate 15°; mask the two positions that clash with a switch

• Origin = Top-Left of the window if your drawing dimensions from edges

• Export DXF + CSV + PDF (1:1)
  
  

If the grid looks “nearly centered,” you set pitch but forgot margins. Use the centered window option.

Notes that prevent rework later

• Clearance vs. fastener: on coated steel, M8 often prefers Ø8.8–9.0 mm to avoid “tap-through” on site.

• True position: call it from the same origin used in the calculator.

• Finish effects: anodizing/powder coat can tighten holes—flag the finish before programming.

• Unknown legacy mates: slot two opposing holes and keep the rest round; you’ll absorb accumulated error without losing location.

Hand-off package that keeps CAM moving

Send exactly three things—no screenshots as primary data:

1. DXF with only machining geometry (title blocks and dimensions removed).

2. CSV with ID, X, Y, HOLE_DIAMETER (add thread/countersink columns when relevant).

3. PDF at 1:1 with a scale bar and a bold line that states:
   UNITS = mm, ORIGIN = Center (or Top-Left), ROUNDING = 0.01 mm, FINISH = …
   
   

Run this checklist before you share files:

• Does the origin on the PDF match the origin used in the calculator?

• Is hole #1 where the drawing expects? (θ₀ sanity check)

• Are units consistent across PCD, hole Ø, and thickness?

• Do you actually have DXF + CSV + PDF?

What we machine at EKINSUN (so you can plan accordingly)

• Aluminum 6061/7075 for plates, adapters, heat-sinks

• Stainless 304/316 for flanges and brackets

• Carbon steel 1045/Q235 for bases and structural parts

• Plastics (Delrin/Acetal, ABS, PC) for jigs and enclosures
  
  

Typical hole-location ±0.05 mm with standard setups; tighter on request with fixturing and inspection planned from the start. Small batches are welcome; mixed-material kits ship together.

Turn a layout into parts on your bench

If you want us to cut the plate after you generate coordinates, send DXF + CSV + PDF, plus material, thickness, finish, and quantity. We confirm manufacturability, quote clearly, and ship worldwide with tracked express. You can start from the EKINSUN home page or jump straight into the Hole Layout Calculator and then contact us when your files are ready.

Micro-FAQ (reader questions we get the most)

• “My legacy print uses degrees clockwise from +X—how do I match it?”
  Set θ₀ to the legacy baseline and switch direction to CW in the calculator; the XY list will follow.
  
  

• “Can I give you only a PDF?”
  We can redraw if needed, but DXF + CSV removes interpretation and speeds CAM.
  
  

• “Will powder coat close the holes?”
  It can. Tell us the finish and we’ll compensate at programming time or open holes in finishing.