Dipperfox SC400 stump grinder

The SC400 puts vertical stump drilling on a 1.5 to 5 tonne mini excavator: 190 kg, a 400 mm stump capacity and a 590 mm drilling depth on a carrier that fits through a side gate. Its commercial case is mobilisation as much as cutting, because the machine that removes the stump is the one already on site for the landscaping or the root work.

Where the SC400 sits in the range

The SC400 is the smallest of three Dipperfox models. The SC600 covers 6 to 12 tonne excavators with a 600 mm cut and 700 mm depth; the SC850 Pro is the 13 to 30 tonne production unit at 850 mm and 900 mm. The three do not overlap in carrier class, so the choice is made by the excavator you own and the stumps you meet rather than by fine comparison. The stump grinder buying guide explains the drilling principle and the three-way comparison sets the models side by side by buyer profile.

What the published figures mean on site

Four figures do the work. The 400 mm maximum stump diameter is the screw’s cutting envelope in one position; a stump just over that can be worked from two positions, but a routine diet of 500 mm stumps belongs on the SC600. The 590 mm drilling depth is what allows the stump and root crown to be processed to below finished grade rather than shaved at the surface, which is the difference between a lawn that can be re-turfed and one that needs a return visit. The 13,700 Nm first-gear torque, delivered through the two-speed planetary transmission, is why a mini excavator can drive a screw through hardwood at all: the gearbox drops into its low gear when resistance climbs so the screw keeps turning rather than stalling. The 190 kg weight is light enough that most 3 to 5 tonne machines carry it without stability concern, though a 1.5 tonne carrier at the bottom of the band will feel it at reach.

Carrier matching

Tonnage says the SC400 will bolt on. Hydraulics decide whether it will produce. The published envelope is 30 to 130 L/min at 110 to 250 bar on a 12 to 35 kW carrier, and Dipperfox is explicit that flow has to be available under load, not read off the pump’s nominal rating. A 1.7 tonne machine delivering 30 L/min will turn the screw slowly and stall it in dense stumps; a 5 tonne machine nearer 80 to 100 L/min at working pressure will drill the same stump in a fraction of the time. Illustratively, if the smaller carrier averages twelve minutes per hardwood stump and the larger one five, then on a 40 stump job the difference is more than four machine hours. Check your excavator’s auxiliary flow at working temperature, its relief pressure and return restriction with the hydraulic matching guide and the hydraulic power calculator. Weight matters less, but the lift chart guide is still worth a glance on the smallest carriers.

Typical work and production considerations

The SC400 lives in council parks and urban vegetation work, storm damage and dangerous tree clean-up and the orchard and fence-line end of farm clearing. A realistic urban program is mostly 150 to 350 mm stumps of mixed species, with a few larger ones near the top of the envelope, and the machine’s advantage over a wheeled grinder is that it arrives with the excavator, leaves no spread of chips and works between fences, paths and garden beds. Productivity depends on stump difficulty class more than diameter: a clean softwood stump in loam is quick, a dense eucalypt with a stony root crown is not. Dipperfox publishes European case studies of large gains from eliminating excavation and hauling, but those are manufacturer examples in European conditions, not Australian rates; a timed trial on your own stumps is the only basis for a per-stump price. Because the screw works below grade, underground services must be located before every stump, and a stump over power, water, gas or communications may need another method.

Limitations and when to step up or down a size

Step up to the SC600 when stumps above 400 mm are routine, when a 6 to 12 tonne excavator is already in the fleet, or when stump counts on civil sites make cycle time the whole business case. There is no step down; below the SC400 the alternative is a walk-behind wheel grinder or a hire machine. The SC400 is the wrong purchase for a contractor whose mini excavator sits at the bottom of the hydraulic envelope and whose stumps sit at the top of the diameter envelope.

Options and configuration to settle at quotation

Settle the bracket and hitch for your carrier, hose and coupler package, whether the mini excavator’s auxiliary circuit needs a flow or pressure adjustment, and whether installation and commissioning are included. Confirm the current technical sheet, since Dipperfox marketing pages show small differences in carrier descriptions.

Wear parts and support

The wear parts are the reversible double-sided blades and the replaceable centre screw, plus gearbox oil and seals. Price blades and a centre screw at quotation, confirm Australian stock, and carry a spare set for regional work; rock contact shortens blade life sharply. The wear parts guide has the list. Machinery Specialist is the Australian distributor.

Confirm before ordering

• Current SC400 technical sheet with the quotation
• Your carrier's auxiliary flow and pressure under load against the 30 to 130 L/min and 110 to 250 bar envelope
• Carrier engine power within the 12 to 35 kW range
• Bracket, hitch, hoses and coupler included and matched to the mini excavator
• Blade and centre screw pricing and Australian stock location
• Gearbox oil specification and service interval
• A timed trial on representative Australian stumps, classified by difficulty
• Service-location procedure for every stump on urban sites

Frequently asked questions