THE ACREAGE EQUIPMENT FIELD GUIDE
PTO input speed vs. rotor speed: which RPM matters?
A chipper can have a 540 RPM tractor input and a 1080 RPM cutter or discharge wheel. These are different parts of the drive system. Match the tractor PTO to the attachment’s specified input speed; do not set it from a prominent rotor-speed number in an advertisement.
By Acreage Equipment · Reviewed November 7, 2026 · Specification research, not a field test
- Tractor engineUse its manual to identify the engine setting for the required PTO output.
- Rear PTO shaftWCAP5 PRO specifies a maximum 540 RPM input here.
- Internal discThe PRO gearbox drives a disc rated up to 1080 RPM. This is not the tractor input.
WCAP5 PRO example only. Internal gearing differs by attachment. Never substitute a rotor-speed figure for the specified PTO input.
The PRO example: input and disc speed are separate rows
Farmry WCAP5 PRO specifies a 540 RPM maximum PTO input and a 1080 RPM maximum disc speed. Its gearbox raises internal speed. The disc number does not make it a 1000 RPM PTO attachment, and the PRO badge does not change the tractor’s required input setting.
The standard WCAP5 is a different speed specification
The current retained WCAP5 manual lists 540–1000 RPM input, while PRO lists a 540 maximum. Do not transfer one model’s range to the other. Ask Farmry which input speed, shaft and setup apply to the exact standard WCAP5 being supplied, then follow the applicable manuals.
A second flywheel does not change tractor PTO RPM
TFG55 uses a 540 RPM PTO/primary drive and a faster secondary flywheel for discharge. Its internal speed is a design characteristic, not an alternative tractor PTO setting. A feed-system choice and an RPM match are separate decisions.
Ask for the entire input specification
Before buying, confirm the attachment model/revision, permitted PTO input speed, connection and driveline specification, and required protection/setup. Use the tractor’s own manual for the engine setting that produces that PTO speed. This guide explains the labels; it does not authorize an adapter, improvised engine-speed workaround or shaft alteration.
Take these questions with you.
- Which number is the attachment’s PTO input speed, and which belongs to a cutter, rotor or discharge wheel?
- What input speed and supplied driveline apply to the exact model/revision in this quote?
- What tractor setting and setup does the serial-specific tractor manual require?
Keep these questions with your exact tractor and attachment details.
Use these questions in my seller briefFOLLOW THE NUMBERS
Sources & documentation
Research record reviewed November 7, 2026. Confirm the current manual and the exact revision supplied with your machine.
- Farmry official product specifications
- Farmry WCAP5 operator manual, Rev 1.5 — Printed pp19–20 specifications; pp30–34 driveline checks
- Farmry official product specifications
- Farmry WCAP5 PRO operator manual, Rev 1.4 — Printed p13 specifications; pp21–22 conflicting horsepower paragraphs
- Woodland Mills TFG55 PTO official U.S. product page
- Woodland Mills TFG55 PTO operator manual, Rev B, 15-Oct-2024 — Printed p9 weight/minimum HP; p11 hitch paragraph; p13 included parts
