How to increase sawmill yield: where volume leaks out (and what to fix first)

Yield rarely disappears in one place. It is usually a stack of small losses: a few millimeters wasted due to a bad multi-rip infeed, extra edge waste on wane, non-optimal rip patterns, kerf that is higher than it needs to be, and downtime that never shows up as “yield” but kills cost per m³.

This post is a practical map: where yield is typically lost, how to measure it, and what delivers the fastest improvement without replacing your line.

1) Define “yield” first (and measure it consistently)

Before you optimize anything, pick one consistent definition:

• log recovery: m³ lumber out / m³ logs in,
• multi-rip stage yield: m³ product out / m³ boards into the multi-rip,
• sales yield: sellable m³ (A/B) out / input m³.

If you need a clean measurement setup, start here: /blog/how-to-calculate-sawmill-yield/.

2) Where yield most commonly leaks out

Wane and variable board geometry

Unedged boards with wane are not symmetric. If the infeed reference is random, it is easy to “miss” the best placement and give away material on the wrong edge.

Random infeed offset and angle before the multi-rip

This is a classic: boards enter shifted and/or skewed. Even with perfect saw spacing, your rip pattern becomes inconsistent because the reference is inconsistent.

Kerf and blade condition

Kerf is a volume loss on every cut. On high-cut-count processes, 0.5–1.0 mm matters. How to calculate it: /blog/saw-kerf-vs-yield/.

Feed stability and guide wear

If boards “float” due to guide play, weak hold-down, or unstable feed, you get:

• lower width repeatability,
• higher allowances,
• more waste.

Changeovers and downtime (TCO)

Downtime doesn’t change yield % directly, but it increases cost per m³. Don’t ignore it when you compare investments.

3) “How much do I lose due to bad infeed?” – a 3-step quick estimate

You don’t need complex systems to start. Try a simple sample:

1. Take a sample, e.g. 200 boards from a normal shift.
2. Estimate average width loss caused by poor infeed (e.g. extra 1–3 mm edge waste or missed “closure” of the pattern).
3. Convert it to volume:

Loss m³/day = (avg width loss [m]) × (thickness [m]) × (length [m]) × (boards/day)

Example: 2 mm width loss, 25 mm thickness, 3 m length, 1500 boards/day:

0.002 × 0.025 × 3 × 1500 = 0.225 m³/day

That’s just one leak. Wane + skew often adds more.

4) How to reduce wane waste (without changing the multi-rip)

Practical moves that usually work:

• Run width sets per shift (primary + fallback), instead of ad-hoc decisions.
• Sort input into “easy” and “difficult” groups with different rules.
• Stabilize the infeed reference: apply the pattern consistently.

More detail here: /blog/reduce-wane-waste-unedged-boards/.

5) The fastest retrofit: board positioning before the multi-rip (this is where we fit)

If your multi-rip is mechanically sound but yield is leaking out, the problem is often before the saw:

• boards enter shifted,
• boards enter skewed,
• operators correct by feel.

xception.io provides an industrial board positioning retrofit module for multi-rip infeed:

• detects board position + angle,
• computes best placement for your target widths and saw spacing,
• centers and aligns the board in real time,
• integrates as a module on existing lines.

See the overview: /solution/
Read the technical article: /blog/board-centering-before-multi-rip-saw/
Contact us for a line review: /contact/

6) A 7-day checklist to recover yield

1. Pick a yield definition and measure it weekly.
2. Measure losses caused by random offset/angle at infeed.
3. Track wane waste stability (does it depend on the operator/shift?).
4. Convert kerf into m³ loss and compare it to geometry losses.
5. Fix one bottleneck before the multi-rip: stabilize the infeed reference.

Summary

Yield is not theory. It is the sum of decisions made in the meters before the saws. If you want more sellable volume from the same raw material, start with measurement and then stabilize board entry before the multi-rip. That is often the fastest path to real ROI.