An excavator flail mower turns your machine into a cutter for grass, brush and hedges, with the reach to get at banks, ditch sides and hedgerows from the cab. A direct drive motor spins a rotor fitted with Y-blades or hammer blades, and the head chops whatever it passes over. Here's how to choose the right size, check your hydraulics, set up, cut safely and stay within the hedge-cutting rules.
Choose the Right Size
Start with your excavator's operating weight, then check two things: the growth you'll be cutting, and your machine's auxiliary oil flow.
| Excavator size | Flail mower | Cutting width | Blades and max cut | Oil flow |
|---|---|---|---|---|
| 0.8–2 tonnes | 0.8–2 tonne flail mower | 600mm | Y-blades, up to 20mm | 15–24 l/min |
| 1.5–3 tonnes | 1.5–3 tonne flail mower | 800mm or 1000mm | Y-blades, up to 20mm | 22–30 l/min (800mm), 27–38 l/min (1000mm) |
| 3–7 tonnes | 3–7 tonne flail mower | 850mm or 1050mm | Hammer blades, up to 40mm | 30–50 l/min |
| 5–10 tonnes | 5–10 tonne flail mower | 1250mm or 1500mm | Hammer blades, up to 80mm | 60–80 l/min |
Y-blades suit grass, weeds and lighter growth. Hammer blades are heavier-duty and cut thicker brush, brambles and hedgerow wood. A wider head covers more ground with each pass, but it weighs more and, on the 1.5–3 tonne flail, needs more oil flow.
Check Your Hydraulics
A flail mower runs continuously, so oil flow matters more than it does with most attachments. Find your excavator's auxiliary flow and pressure in its manual or spec sheet and check them against the flail's range. If the flow is too low, the rotor won't reach full speed and you'll get a ragged cut.
The flails in our range come with two hoses for flow and return and don't need a case drain, and each has a pre-set flow control valve with anti-shock and anti-cavitation protection. If you're not sure what your machine has, send us your excavator details and we'll check.
Before You Cut
- Thrown debris. A flail can throw stones, wood and debris a long way. Keep people, vehicles and animals well clear, and stop if anyone comes near.
- Walk the ground. Look for wire, old fencing, stones, posts and anything else hidden in the growth. Hitting them damages the blades and can throw debris.
- Hedge-cutting rules. In England, you must not cut or trim hedgerows on or next to agricultural land from 1 March to 31 August, unless an exception applies. See the government guidance on hedgerow management.
- Nesting birds. It's an offence to damage or destroy an active bird's nest, so check hedges, scrub and long grass before you cut, even outside the hedge-cutting dates.
- Overhead lines. Keep the arm well away from power lines, especially when you're reaching up to cut hedge tops.
Rules differ in Scotland, Wales and Northern Ireland, so check the local requirements if you're working there.
Set Up the Flail
- Check the blades and their fixings before every job, and replace any that are damaged or missing.
- Set the roller height for the finish you want. The roller sets the cutting height, and the self-levelling head helps it follow the ground.
- Check the hoses are connected properly and routed so they won't rub, kink or snag as the arm moves.
- Make sure the cab has suitable protection against thrown debris.
How to Cut
- Start the rotor clear of the growth. Bring it up to working speed before the head touches anything.
- Lower the head onto the growth. Let the roller and self-levelling head follow the ground rather than forcing the head down.
- Work in steady, overlapping passes. Move at a pace that lets the rotor keep its speed. If it slows, slow down or take a lighter cut.
- Take tall growth in stages. Cut thick or tall growth from the top down rather than burying the head in it.
- Keep the open side of the head down. Never lift a running flail towards people, vehicles or the cab.
- Stop the rotor before you inspect. Shut it down and wait until it has stopped completely before you clear the head or check the blades.
Cutting Hedges
An excavator's reach makes hedge cutting quicker, especially across wide verges or ditches. Work along one side at a time at a steady pace, and cut the sides so the hedge is slightly wider at the base than at the top, which helps it stay thick at the bottom. Then cut the top. Keep to material within the flail's maximum cut: up to 20mm for the Y-blade heads, and up to 40mm or 80mm for the hammer heads.
Clearing Overgrown Ground
On land clearance jobs, a flail mower is a quick way to knock down grass, brambles and scrub before you start on the ground. Anything thicker than the flail can cut, such as trees and larger saplings, is a job for an excavator tree shear. Once the growth is down, a root rake pulls out the roots and brash. Our step-by-step guide to clearing overgrown land with an excavator covers the whole job.
Look After Your Flail
- Check the blades and fixings before each job, and replace worn or damaged blades promptly to keep the rotor balanced.
- With the rotor stopped, clear wrapped grass, wire and debris from the rotor and roller.
- Grease the roller and pivot points following the manufacturer's guidance.
- Inspect the hoses and couplings for wear or leaks.
Frequently Asked Questions
Can a mini digger run a flail mower?
Yes. Our 0.8–2 tonne flail mower needs only 15–24 l/min of oil flow, and the 1.5–3 tonne flail mower runs on 22–38 l/min, depending on the width.
How much oil flow does an excavator flail mower need?
It depends on the size. Our range runs from 15–24 l/min on the 0.8–2 tonne flail to 60–80 l/min on the 5–10 tonne flail. Check your machine's auxiliary flow before you choose.
Do I need a case drain?
Not for the flails in our range. They come with two hoses for flow and return and don't need a drain line.
What's the difference between Y-blades and hammer blades?
Y-blades suit grass, weeds and lighter growth, and cut material up to 20mm on our smaller flails. Hammer blades are heavier-duty and cut thicker brush and hedgerow wood, up to 40mm on the 3–7 tonne flail and 80mm on the 5–10 tonne flail.
When can I cut hedges?
In England, hedgerows on or next to agricultural land can't be cut or trimmed from 1 March to 31 August, apart from some exceptions. Whenever you cut, check for nesting birds first.
Ready to start? Browse our excavator flail mowers, or send us your machine details and we'll help you choose the right size.
