You can start a CNC project without CAD.

A useful CNC enquiry does not need specialist vocabulary or finished CAD. It needs enough information to understand the intended part, identify the main uncertainties and define what would be included in a quotation. A hand sketch with measurements can be more useful than a polished rendering that leaves function and scale unclear.

The short version: what to include

Prepare one page or message containing:

1. Purpose: what the part is and what it must do.
2. Overall size: approximate or confirmed length, width and thickness, with units.
3. Quantity: prototype, first order and likely repeat quantity as separate figures.
4. Material: MDF, MR MDF or structural plywood, or say that material needs discussion.
5. Important features: holes, slots, pockets, lettering, joints, hardware or visible faces.
6. Critical relationships: anything that must fit, align, clear or remain removable.
7. Finish and hand-off: what should happen after machining and who performs it.
8. Files and references: sketches, photographs, PDFs, vectors or physical samples available.
9. Unknowns: questions the review needs to resolve.

This is enough to begin a conversation. Production geometry, exact machining operations and any paid design-development work can be defined separately before production begins.

Start with function, not the outline

“A 400 mm plywood panel” gives a shape but little design intent. “A removable panel that locates over four existing studs, clears a handle and will be painted after machining” explains why the hole positions, clearance and finished face matter.

Write a short answer to each question:

• What does the part connect to, contain, support, locate or display?
• Who finishes or assembles it?
• Which outcome would make it unusable?
• Which details can change without harming its purpose?
• Is the work a one-off, prototype or smaller repeat run?

If the part carries load, guards machinery, is used by children or has another consequential purpose, state that early. CNC machining can create geometry, but an ordinary machining review does not certify the finished product for a regulated or safety-critical use.

Separate requirements, preferences and unknowns

These three labels prevent expensive misunderstandings:

Mark approximate measurements as approximate. Do not turn a preference into a tight numerical tolerance unless it controls function. Equally, do not hide a critical mating dimension among decorative measurements.

Measure from a clear reference

Choose a repeatable edge, face or centre as the datum. Locate important holes, slots and boundaries from that reference instead of building a long chain of measurements. Chained dimensions can accumulate small differences and make the final feature miss the real assembly datum.

A minimum useful drawing normally shows:

• overall length, width and intended material thickness;
• one unit system, normally millimetres for this service;
• hole diameters and centre positions from the datum;
• slot width, length, end shape and position;
• pocket boundary and depth from a named face;
• count and spacing of repeated features;
• front, back and visible face;
• dimensions that control fit marked as critical.

Use a ruler or tape for general sizes and a suitable calliper for sheet thickness, hardware and small mating features. Do not report more decimal places than the method can support. A measurement taken once from a worn or rounded edge should not be presented as exact.

Photographs and existing objects

Photographs are valuable for context, appearance and assembly. Take them square to the relevant face and include a ruler in the same plane where possible. Perspective and lens distortion mean a photograph should not be the sole authority for exact geometry.

When a new part must fit an existing object, identify the surfaces that touch or locate. Supply the actual hardware or a current manufacturer drawing when practical. A product name such as “M6 fixing” or “12 mm board” is not a complete dimensional definition.

If several existing objects must accept the same part, check whether they genuinely match. Measuring one example does not establish variation across all examples.

Describe every part and quantity

For an assembly, give each distinct component a stable ID such as SIDE-L, SIDE-R, BASE and BACK. List the quantity of each ID. Treat a mirrored part as distinct when its face operations, grain direction or hole pattern differs.

Separate four commercial quantities where relevant:

• one development coupon or prototype;
• the first test batch;
• the likely first normal order;
• a possible repeat quantity.

Quantities above 50 can be reviewed, but Wood to Spec is intended for prototypes and smaller production runs rather than high-volume manufacturing. Honest quantities help compare setup, sheet use and checking without implying a capacity or price that has not been reviewed.

Check whether CNC routing is a plausible process

CNC routing is most plausible when the geometry can be described as controlled outlines and depths in a supported sheet material. Repeated profiles, cut-outs, pockets, slots, suitable holes and engraving can suit the process.

Early questions include:

• Is the standard material scope suitable?
• Does the stock and finished part fit the usable machining area with room for workholding and cutter access?
• Can a round cutter reach the smallest detail and internal corners?
• Can the sheet and released parts remain safely controlled?
• Is the expected hand-off a machined component rather than an assumed finished retail product?

The standard maximum stock size is 1220 × 1220 mm. The usable finished-part area may be smaller because of workholding, cutter access, edge allowance and machining method. Final suitability is confirmed during review.

Metal, extremely fine laser-like detail, deep sculptural forms, on-site fitting and unsupported materials are not implied by the standard service. Sometimes a simple rectangular part is better suited to a conventional panel-cutting process. A suitability review may conclude “yes”, “yes with changes”, “test this first” or “another process is more appropriate”.

Define the expected production hand-off

“CNC cut” does not automatically mean separated, sanded, painted, assembled, retail packed or ready for installation. State the condition you need when responsibility changes hands.

Quotes define exactly what is included. Depending on the project, this may cover CNC machining only or additional agreed stages such as part separation, preparation or packing. Assembly, finishing and other post-machining work are included only when expressly stated in the quotation.

Also state the finish sequence where it affects dimensions. Paint on both faces of a tab or slot can change fit. Sanding a critical edge can remove material unevenly. The finishing and assembly guide helps expose those decisions.

Give enough information for a useful quotation

A quotation needs a defined scope. The initial submission should therefore identify:

• current drawing or file revision;
• material and nominal thickness, or the decision still required;
• stock and finished dimensions;
• quantities by part ID;
• intended profiles, pockets, holes and engraving;
• critical fits and actual mating objects;
• face, grain or orientation requirements;
• expected hand-off, finish and packing needs;
• delivery address context for UK-mainland dispatch;
• design work or technical preparation still needed.

The quotation will state whether material is supplied by Wood to Spec or by the customer. No production starts before scope, price and approval requirements are agreed. If substantial design development or production-file preparation is needed, any charge should be explained and agreed before that work begins.

A concise project brief example

For a wall-mounted display blank, a useful brief might say:

Flat panel for the seller to paint and package. Approximate overall size is shown on the sketch. It must accept the supplied fixing, remain within the target packed size and arrive as an agreed machined blank. Fixing position and packed width are requirements; the decorative edge is open to review. Material thickness and final corner radius are undecided.

This describes purpose and constraints without implying a price or guaranteed production answer.

Common gaps that delay review

• A rendering has no dimensions or material.
• Dimensions are present but critical fits are not identified.
• Several conflicting files are all labelled “final”.
• A nominal material label is used as an exact joint dimension.
• A pocket or recess has no depth or reference face.
• Quantity is a total piece count without a part breakdown.
• Sanding, assembly or packing is assumed but not included in the scope request.
• A photograph is expected to define exact geometry.
• Safety or regulatory requirements are mentioned only after quotation.

The strongest correction is often to write “unknown—please review” beside the unresolved point.

Before you submit

Check that the purpose, overall size, units, quantities and current revision are visible. Mark every part that mates with another object. Include the clearest drawing or image you have and explain what it proves. For commercially sensitive designs, submit an initial description without the sensitive file so that a suitable transfer method can be agreed during review.

Send the project information you have. If a vector already exists, continue with preparing a DXF or SVG.