THE ACREAGE EQUIPMENT FIELD GUIDE

Chipper hopper size, throat size and branch diameter

A large hopper opening is not a promise to chip a log of that width. The outer mouth guides material toward a smaller cutting throat; the maker’s maximum branch diameter is a separate limit with its own power conditions. Compare all three measurements before paying for a larger chipper, especially if your brush is forked or your tractor is near the minimum PTO rating.

By Acreage Equipment · Reviewed November 7, 2026 · Specification research, not a field test

In this guide

THE DECISION IN NUMBERS

Three Woodland chipper sizes: throat, diameter and power

Manufacturer specifications, not Acreage Equipment performance testing. The full-feed column applies to full stated-diameter logs at full infeed speed; it is not the operating minimum. Engine horsepower cannot substitute for PTO horsepower. WC88’s 100+ wording is not a finite maximum and is not unlimited-power approval. Outer hopper mouths are intentionally excluded from this capacity table.

Scroll the table sideways on smaller screens.

Model	Cutting throat	Stated max. diameter	Operating PTO range	Full-size logs at full feed
WC46	4 × 6 in	4 in	15–30 PTO hp	Over 20 PTO hp
WC68	6 × 8 in	6 in	20–50 PTO hp	Over 40 PTO hp
WC88	8 × 8 in	8 in	35–100+ PTO hp; upper use needs confirmation	Over 60 PTO hp

Sources for this decision table (3)

Name the opening you are comparing

Woodland Mills gives WC46 a 19 × 18.5-inch outer hopper mouth and a 4 × 6-inch throat. WC68’s page gives a 23 × 27-inch mouth and a 6 × 8-inch throat. The broad mouth does not remove the smaller opening deeper inside the machine. For WC88, the page and retained manual disagree on outer mouth height, while both support the 8 × 8-inch cutting throat. Treat external clearance as an unresolved measurement on that model.

Read a rectangular throat without turning its long side into diameter

A 4 × 6-inch throat is not a six-inch round-log rating: WC46 is advertised for up to four-inch material. A straight 4.5-inch-diameter branch therefore exceeds that stated limit despite fitting easily inside its outer hopper. WC68’s six-inch maximum clears that diameter comparison only; wood condition, branch shape, available power and the operating manual remain separate checks. No opening measurement here establishes permission to force material through.

Forks create a different question from trunk diameter

A branch with a two-inch main stem can still have a fork or stiff side growth that does not follow the required feed path. Do not add stem diameters, compare hopper area, or use a drawing to declare it suitable. Photograph the typical material and ask the maker what preparation its manual requires. WC88’s operating manual specifically addresses side-branch preparation; a larger advertised throat is not evidence that all irregular brush will feed without preparation.

The full-size, full-feed condition is stricter than the minimum

Consider a hypothetical tractor with 28 PTO hp. It is within WC68’s 20–50 PTO-hp operating range but below the maker’s over-40-PTO-hp condition for full six-inch logs at full feed speed. That example does not predict a particular feed rate or productivity. WC88’s eight-inch label likewise has an over-60-PTO-hp full-feed condition, separate from its 35-PTO-hp minimum. Choose the capacity you need with an achievable operating expectation.

Use the brush pile to decide what to ask next

Record the diameter and shape of most material, plus the occasional largest pieces. Separate dry from fresh wood where the maker does: Farmry WCAP5’s page qualifies its five-inch claim for fresh/wet wood and limits dry material to four inches. Then ask about throat geometry, preparation and performance at your actual PTO output. The relevant upgrade may be feed control or preparation effort rather than the largest number on the product title.

Take these questions with you.

Which dimensions describe the outer hopper, the cutting throat and the maximum permitted branch diameter?
What preparation does the manual require for my typical forked, leafy or dry material?
At my tractor’s actual PTO output, what material size and feed expectations does the manufacturer specify?

Keep these questions with your exact tractor and attachment details.

Use these questions in my seller brief

FOLLOW THE NUMBERS